Pub Date : 2024-05-24DOI: 10.1016/j.ygcen.2024.114557
He Zou , Peimin Wang , Jinglin Zhang
The gonadotrope cells within the pituitary control vital processes of reproduction by producing follicle stimulating hormone (FSH) and luteinizing hormone (LH). Both external stimuli and internal regulatory factors contribute to the regulation of gonadotrope development and function. In recent years, growing evidences indicate that microRNAs (miRNAs), which regulate gene expression post-transcriptionally, play critical roles in multiple processes of gonadotrope development and function, including the syntheses of α or β subunits of FSH and LH, the secretion of LH, the regulation of GnRH signaling, and the maintenance of gonadotrope cell kinetics. Here, we review recent advances of miRNAs’ expression, functions and mechanisms approached by using miRNA knockout mouse models, in silico analysis and the in vitro cultures of primary pituitary cells and gonadotrope-derived cell lines. By summarizing and discussing different roles of miRNAs in gonadotropes, this minireview helps to gain insights into the complex molecular network in gonadotropes and reproduction.
{"title":"Role of microRNAs in pituitary gonadotrope cells","authors":"He Zou , Peimin Wang , Jinglin Zhang","doi":"10.1016/j.ygcen.2024.114557","DOIUrl":"10.1016/j.ygcen.2024.114557","url":null,"abstract":"<div><p>The gonadotrope cells within the pituitary control vital processes of reproduction by producing follicle stimulating hormone (FSH) and luteinizing hormone (LH). Both external stimuli and internal regulatory factors contribute to the regulation of gonadotrope development and function. In recent years, growing evidences indicate that microRNAs (miRNAs), which regulate gene expression post-transcriptionally, play critical roles in multiple processes of gonadotrope development and function, including the syntheses of α or β subunits of FSH and LH, the secretion of LH, the regulation of GnRH signaling, and the maintenance of gonadotrope cell kinetics. Here, we review recent advances of miRNAs’ expression, functions and mechanisms approached by using miRNA knockout mouse models, <em>in silico</em> analysis and the <em>in vitro</em> cultures of primary pituitary cells and gonadotrope-derived cell lines. By summarizing and discussing different roles of miRNAs in gonadotropes, this minireview helps to gain insights into the complex molecular network in gonadotropes and reproduction.</p></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141131736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-19DOI: 10.1016/j.ygcen.2024.114547
Brian F. Case , Jordy Groffen , Thomas M. Galligan , Catherine M. Bodinof Jachowski , John J. Hallagan , Sherry B. Hildreth , Valentina Alaasam , W. Keith Ray , Richard F. Helm , William A. Hopkins
The behavioral endocrinology associated with reproduction and uniparental male care has been studied in teleosts, but little is known about hormonal correlates of uniparental male care in other ectotherms. To address this gap, we are the first to document the seasonal steroid endocrinology of uniparental male hellbender salamanders during the transition from pre-breeding to nest initiation, and through the subsequent eight months of paternal care. In doing so, we investigated the correlates of nest fate and clutch size, exploring hellbenders’ alignment with several endocrinological patterns observed in uniparental male fish. Understanding the endocrinology of hellbender paternal care is also vital from a conservation perspective because high rates of nest failure were recently identified as a factor causing population declines in this imperiled species. We corroborated previous findings demonstrating testosterone and dihydrotestosterone (DHT) to be the primary androgens in hellbender reproduction, and that cortisol circulates as the most abundant glucocorticoid. However, we were unable to identify a prolactin or a “prolactin-like” peptide in circulation prior to or during parental care. We observed ∼ 80 % declines in both primary androgens during the transition from pre-breeding to nest initiation, and again as paternal care progressed past its first month. In the days immediately following nest initiation, testosterone and DHT trended higher in successful individuals, but did not differ with males’ clutch size. We did not observe meaningful seasonality in baseline glucocorticoids associated with breeding or nesting. In contrast, stress-induced glucocorticoids were highest at pre-breeding and through the first two months of care, before declining during the latter-most periods of care as larvae approach emergence from the nest. Neither baseline nor stress-induced glucocorticoids varied significantly with either nest fate or clutch size. Both stress-induced cortisol and corticosterone were positively correlated with total length, a proxy for age in adult hellbenders. This is consistent with age-related patterns in some vertebrates, but the first such pattern observed in a wild amphibian population. Generally, we found that nesting hellbenders adhere to some but not all of the endocrinological patterns observed in uniparental male teleosts prior to and during parental care.
{"title":"Androgen and glucocorticoid profiles throughout extended uniparental paternal care in the eastern hellbender salamander (Cryptobranchus a. alleganiensis)","authors":"Brian F. Case , Jordy Groffen , Thomas M. Galligan , Catherine M. Bodinof Jachowski , John J. Hallagan , Sherry B. Hildreth , Valentina Alaasam , W. Keith Ray , Richard F. Helm , William A. Hopkins","doi":"10.1016/j.ygcen.2024.114547","DOIUrl":"10.1016/j.ygcen.2024.114547","url":null,"abstract":"<div><p>The behavioral endocrinology associated with reproduction and uniparental male care has been studied in teleosts, but little is known about hormonal correlates of uniparental male care in other ectotherms. To address this gap, we are the first to document the seasonal steroid endocrinology of uniparental male hellbender salamanders during the transition from pre-breeding to nest initiation, and through the subsequent eight months of paternal care. In doing so, we investigated the correlates of nest fate and clutch size, exploring hellbenders’ alignment with several endocrinological patterns observed in uniparental male fish. Understanding the endocrinology of hellbender paternal care is also vital from a conservation perspective because high rates of nest failure were recently identified as a factor causing population declines in this imperiled species. We corroborated previous findings demonstrating testosterone and dihydrotestosterone (DHT) to be the primary androgens in hellbender reproduction, and that cortisol circulates as the most abundant glucocorticoid. However, we were unable to identify a prolactin or a “prolactin-like” peptide in circulation prior to or during parental care. We observed ∼ 80 % declines in both primary androgens during the transition from pre-breeding to nest initiation, and again as paternal care progressed past its first month. In the days immediately following nest initiation, testosterone and DHT trended higher in successful individuals, but did not differ with males’ clutch size. We did not observe meaningful seasonality in baseline glucocorticoids associated with breeding or nesting. In contrast, stress-induced glucocorticoids were highest at pre-breeding and through the first two months of care, before declining during the latter-most periods of care as larvae approach emergence from the nest. Neither baseline nor stress-induced glucocorticoids varied significantly with either nest fate or clutch size. Both stress-induced cortisol and corticosterone were positively correlated with total length, a proxy for age in adult hellbenders. This is consistent with age-related patterns in some vertebrates, but the first such pattern observed in a wild amphibian population. Generally, we found that nesting hellbenders adhere to some but not all of the endocrinological patterns observed in uniparental male teleosts prior to and during parental care.</p></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141075401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-18DOI: 10.1016/j.ygcen.2024.114550
Liu Zhaoyu , Ye Xiaomeng , Li Na, Shang Jiamin, Du Guanhua, Yang Xiuying
Skeletal muscles serve both in movement and as endocrine organs. Myokines secreted by skeletal muscles activate biological functions within muscles and throughout the body via autocrine, paracrine, and/or endocrine pathways. Skeletal muscle atrophy can influence myokine expression and secretion, while myokines can impact the structure and function of skeletal muscles. Regulating the expression and secretion of myokines through the pharmacological approach is a strategy for alleviating skeletal muscle atrophy. Natural products possess complex structures and chemical properties. Previous studies have demonstrated that various natural products exert beneficial effects on skeletal muscle atrophy. This article reviewed the regulatory effects of natural products on myokines and summarized the research progress on skeletal muscle atrophy associated with myokine regulation. The focus is on how small-molecule natural products affect the regulation of interleukin 6 (IL-6), irisin, myostatin, IGF-1, and FGF-21 expression. We contend that the development of small-molecule natural products targeting the regulation of myokines holds promise in combating skeletal muscle atrophy.
{"title":"Roles of natural products on myokine expression and secretion in skeletal muscle atrophy","authors":"Liu Zhaoyu , Ye Xiaomeng , Li Na, Shang Jiamin, Du Guanhua, Yang Xiuying","doi":"10.1016/j.ygcen.2024.114550","DOIUrl":"10.1016/j.ygcen.2024.114550","url":null,"abstract":"<div><p>Skeletal muscles serve both in movement and as endocrine organs. Myokines secreted by skeletal muscles activate biological functions within muscles and throughout the body via autocrine, paracrine, and/or endocrine pathways. Skeletal muscle atrophy can influence myokine expression and secretion, while myokines can impact the structure and function of skeletal muscles. Regulating the expression and secretion of myokines through the pharmacological approach is a strategy for alleviating skeletal muscle atrophy. Natural products possess complex structures and chemical properties. Previous studies have demonstrated that various natural products exert beneficial effects on skeletal muscle atrophy. This article reviewed the regulatory effects of natural products on myokines and summarized the research progress on skeletal muscle atrophy associated with myokine regulation. The focus is on how small-molecule natural products affect the regulation of interleukin 6 (IL-6), irisin, myostatin, IGF-1, and FGF-21 expression. We contend that the development of small-molecule natural products targeting the regulation of myokines holds promise in combating skeletal muscle atrophy.</p></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141070812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-16DOI: 10.1016/j.ygcen.2024.114548
Samiha A.M. Benrabaa , Sharon A. Chang , Ernest S. Chang , Donald L. Mykles
Ecdysteroid molting hormones coordinate arthropod growth and development. Binding of 20-hydroxyecdysone (20E) to ecdysteroid receptor EcR/RXR activates a cascade of nuclear receptor transcription factors that mediate tissue responses to hormone. Insect ecdysteroid responsive and Forkhead box class O (FOXO) transcription factor gene sequences were used to extract orthologs from blackback land crab (Gecarcinus lateralis) Y-organ (YO) transcriptome: Gl-Ecdysone Receptor (EcR), Gl-Broad Complex (Br-C), Gl-E74, Gl-Hormone Receptor 3 (HR3), Gl-Hormone Receptor 4 (HR4), Gl-FOXO, and Gl-Fushi tarazu factor-1 (Ftz-f1). Quantitative polymerase chain reaction quantified mRNA levels in tissues from intermolt animals and in YO of animals induced to molt by multiple limb autotomy (MLA) or eyestalk ablation (ESA). Gl-EcR, Gl-Retinoid X Receptor (RXR), Gl-Br-C, Gl-HR3, Gl-HR4, Gl-E74, Gl-E75, Gl-Ftz-f1, and Gl-FOXO were expressed in all 10 tissues, with Gl-Br-C, Gl-E74, Gl-E75, and Gl-HR4 mRNA levels in the YO lower than those in most of the other tissues. In MLA animals, molting had no effect on Gl-Br-C, Gl-E74, and Gl-Ftz-f1 mRNA levels and little effect on Gl-EcR, Gl-E75, and Gl-HR4 mRNA levels. Gl-HR3 and Gl-FOXO mRNA levels were increased during premolt stages, while Gl-RXR mRNA level was highest during intermolt and premolt stages and lowest at postmolt stage. In ESA animals, YO mRNA levels were not correlated with hemolymph ecdysteroid titers. ESA had no effect on Gl-EcR, Gl-E74, Gl-HR3, Gl-HR4, Gl-Ftz-f1, and Gl-FOXO mRNA levels, while Gl-RXR, Gl-Br-C, and Gl-E75 mRNA levels were decreased at 3 days post-ESA. These data suggest that transcriptional up-regulation of Gl-FOXO and Gl-HR3 contributes to increased YO ecdysteroidogenesis during premolt. By contrast, transcriptional regulation of ecdysteroid responsive genes and ecdysteroidogenesis were uncoupled in the YO of ESA animals.
{"title":"Effects of molting on the expression of ecdysteroid responsive genes in the crustacean molting gland (Y-organ)","authors":"Samiha A.M. Benrabaa , Sharon A. Chang , Ernest S. Chang , Donald L. Mykles","doi":"10.1016/j.ygcen.2024.114548","DOIUrl":"10.1016/j.ygcen.2024.114548","url":null,"abstract":"<div><p>Ecdysteroid molting hormones coordinate arthropod growth and development. Binding of 20-hydroxyecdysone (20E) to ecdysteroid receptor EcR/RXR activates a cascade of nuclear receptor transcription factors that mediate tissue responses to hormone. Insect ecdysteroid responsive and <em>Forkhead box class O</em> (<em>FOXO</em>) transcription factor gene sequences were used to extract orthologs from blackback land crab (<em>Gecarcinus lateralis</em>) Y-organ (YO) transcriptome: <em>Gl-Ecdysone Receptor</em> (<em>EcR</em>), <em>Gl-Broad Complex</em> (<em>Br-C</em>), <em>Gl-E74, Gl-Hormone Receptor 3</em> (<em>HR3</em>), <em>Gl-Hormone Receptor 4</em> (<em>HR4</em>), <em>Gl-FOXO</em>, and <em>Gl-Fushi tarazu factor-1</em> (<em>Ftz-f1</em>). Quantitative polymerase chain reaction quantified mRNA levels in tissues from intermolt animals and in YO of animals induced to molt by multiple limb autotomy (MLA) or eyestalk ablation (ESA). <em>Gl-EcR</em>, <em>Gl-Retinoid X Receptor</em> (<em>RXR</em>), <em>Gl-Br-</em>C, <em>Gl-HR3</em>, <em>Gl-HR4</em>, <em>Gl-E74</em>, <em>Gl-E75</em>, <em>Gl-Ftz-f1</em>, and <em>Gl-FOXO</em> were expressed in all 10 tissues, with <em>Gl-Br-C</em>, <em>Gl-E74</em>, <em>Gl-E75</em>, and <em>Gl-HR4</em> mRNA levels in the YO lower than those in most of the other tissues. In MLA animals, molting had no effect on <em>Gl-Br-C, Gl-E74</em>, and <em>Gl-Ftz-f1</em> mRNA levels and little effect on <em>Gl-EcR</em>, <em>Gl-E75</em>, and <em>Gl-HR4</em> mRNA levels. <em>Gl-HR3</em> and <em>Gl-FOXO</em> mRNA levels were increased during premolt stages, while <em>Gl-RXR</em> mRNA level was highest during intermolt and premolt stages and lowest at postmolt stage. In ESA animals, YO mRNA levels were not correlated with hemolymph ecdysteroid titers. ESA had no effect on <em>Gl-EcR</em>, <em>Gl-E74</em>, <em>Gl-HR3</em>, <em>Gl-HR4</em>, <em>Gl-Ftz-f1</em>, and <em>Gl-FOXO</em> mRNA levels, while <em>Gl-RXR</em>, <em>Gl-Br-C</em>, and <em>Gl-E75</em> mRNA levels were decreased at 3 days post-ESA. These data suggest that transcriptional up-regulation of <em>Gl-FOXO</em> and <em>Gl-HR3</em> contributes to increased YO ecdysteroidogenesis during premolt. By contrast, transcriptional regulation of ecdysteroid responsive genes and ecdysteroidogenesis were uncoupled in the YO of ESA animals.</p></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140957069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.1016/j.ygcen.2024.114546
Wendy Ángela González-López, Sandra Ramos-Júdez, Neil J. Duncan
The reproductive failure of Senegalese sole (Solea senegalensis) cultured males (reared entirely in captivity from egg through to adult) that do not participate in reproductive behaviours to fertilise spawns, results in a problem to achieve reproductive control in captivity. However, cohabitation with wild males has led to an increase in the involvement of cultured males in reproductive behaviour, although their contribution to fertilised spawning is still lower than that of wild breeders. This study aimed to examine the effect of different social conditions, on the reproductive behaviour and spawning success of cultured breeders over three reproductive seasons. Before starting this study, different social learning opportunities were provided to the breeders from the juvenile to the pubertal stages of the individuals. Behaviour and spawning were evaluated in four experimental groups of cultured breeders: two groups (W1 and W2) that prior to this study were reared during the juvenile stage with wild breeders that fertilized spawns, a Culture breeder group (CB) that was previously reared with cultured breeders that spawned unfertile eggs, and a negative control group (CN) that was reared in isolation from adult fish.
During the three reproductive seasons, spawning was obtained from all groups. Generally, the first year had the highest egg production and the third year the lowest. However, fertilised eggs were only obtained from W1 in the first year. A total of eight fertilised spawns were collected with a fertilisation rate of 28.02 ± 13.80 % and a hatching rate of 15.04 ± 10.40 %. The mean number of larvae obtained per spawn was 7,683 ± 5,947 and the total number of larvae from all eight spawns was 61,468. The paternity analysis assigned 64.3 % of larvae to a single couple of breeders, while 34.3 % of larvae were not assigned to any single family, but inconclusively to more than three parents. The highest locomotor activity was observed in W1, while no significant differences were observed in the number of movements within W2, CB and CN. In all groups, during the peak of locomotor activity (19h00-20h00), the main reproductive behaviours observed were Rest the Head and Follow, while the Guardian behaviour was low and Coupled behaviour was only observed in W1. Over time, the reproductive behaviours decreased, except for Follow. The social learning opportunities provided by cohabitation with wild fish during juvenile stages prior to spawning in W1, increased activity and fertilised spawning. However, the number of successful spawns was low and over time stopped in association with a decrease in reproductive behaviour. This suggests that other mechanisms of behavioural learning could be involved in reproductive success, such as reproductive dominance, environmental conditions or hormonal interactions that could affect physiological processes in the reproduction of ca
{"title":"Reproductive behaviour and fertilized spawns in cultured Solea senegalensis broodstock co-housed with wild breeders during their juvenile stages","authors":"Wendy Ángela González-López, Sandra Ramos-Júdez, Neil J. Duncan","doi":"10.1016/j.ygcen.2024.114546","DOIUrl":"10.1016/j.ygcen.2024.114546","url":null,"abstract":"<div><p>The reproductive failure of Senegalese sole (<em>Solea senegalensis</em>) cultured males (reared entirely in captivity from egg through to adult) that do not participate in reproductive behaviours to fertilise spawns, results in a problem to achieve reproductive control in captivity. However, cohabitation with wild males has led to an increase in the involvement of cultured males in reproductive behaviour, although their contribution to fertilised spawning is still lower than that of wild breeders. This study aimed to examine the effect of different social conditions, on the reproductive behaviour and spawning success of cultured breeders over three reproductive seasons. Before starting this study, different social learning opportunities were provided to the breeders from the juvenile to the pubertal stages of the individuals. Behaviour and spawning were evaluated in four experimental groups of cultured breeders: two groups (W1 and W2) that prior to this study were reared during the juvenile stage with wild breeders that fertilized spawns, a Culture breeder group (CB) that was previously reared with cultured breeders that spawned unfertile eggs, and a negative control group (CN) that was reared in isolation from adult fish.</p><p>During the three reproductive seasons, spawning was obtained from all groups. Generally, the first year had the highest egg production and the third year the lowest. However, fertilised eggs were only obtained from W1 in the first year. A total of eight fertilised spawns were collected with a fertilisation rate of 28.02 ± 13.80 % and a hatching rate of 15.04 ± 10.40 %. The mean number of larvae obtained per spawn was 7,683 ± 5,947 and the total number of larvae from all eight spawns was 61,468. The paternity analysis assigned 64.3 % of larvae to a single couple of breeders, while 34.3 % of larvae were not assigned to any single family, but inconclusively to more than three parents. The highest locomotor activity was observed in W1, while no significant differences were observed in the number of movements within W2, CB and CN. In all groups, during the peak of locomotor activity (19<em>h</em>00-20<em>h</em>00), the main reproductive behaviours observed were <em>Rest the Head</em> and <em>Follow</em>, while the <em>Guardian</em> behaviour was low and <em>Coupled</em> behaviour was only observed in W1. Over time, the reproductive behaviours decreased, except for <em>Follow</em>. The social learning opportunities provided by cohabitation with wild fish during juvenile stages prior to spawning in W1, increased activity and fertilised spawning. However, the number of successful spawns was low and over time stopped in association with a decrease in reproductive behaviour. This suggests that other mechanisms of behavioural learning could be involved in reproductive success, such as reproductive dominance, environmental conditions or hormonal interactions that could affect physiological processes in the reproduction of ca","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140891772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-03DOI: 10.1016/j.ygcen.2024.114544
V. Melica, S.J. Thornton
Fecal samples are a non-invasive and relatively accessible matrix for investigating physiological processes in resident killer whale (Orcinus orca) populations. The high lipid content of the diet (primarily salmonids) leads to lower density fecal material and slower dispersion, facilitating sample collection. As fecal discharge is relatively infrequent and the volume of sample is variable, maximizing analytical options is an important consideration. Here we present an extraction methodology to measure hormones and lipid content from the same fecal aliquot. Lipid extractions are commonly conducted using chloroform and methanol from Folch or Bligh and Dyer (B&D), while alcohol is the primary solvent for hormone extraction. We evaluated the possibility of using the methanol layer from lipid extractions to assess fecal steroid hormone levels. Folch and B&D methanol residues were assayed form metabolites of progesterone (PMs) and corticosterone (GCs), and results were compared to aliquots extracted in 70 % ethanol. Hormone concentrations measured in the methanol layer from Folch and B&D extractions were 55 % to 79 % lower than concentrations in 70 % ethanol. We developed mathematical corrections, using linear regression models fitted to Folch or B&D methanol vs 70 % ethanol hormone concentrations (p < 0.01). Fecal concentrations of PMs and GCs from methanol extractions were biologically validated and are significantly higher in confirmed pregnant females compared to non-pregnant individuals (p < 0.05). This study demonstrates that lipid extraction protocols may be used for the analysis of multiple biomarkers, maximizing the use of small-volume samples.
{"title":"Killer whale fecal samples: How to get the most out of a single extraction","authors":"V. Melica, S.J. Thornton","doi":"10.1016/j.ygcen.2024.114544","DOIUrl":"10.1016/j.ygcen.2024.114544","url":null,"abstract":"<div><p>Fecal samples are a non-invasive and relatively accessible matrix for investigating physiological processes in resident killer whale <em>(Orcinus orca)</em> populations. The high lipid content of the diet (primarily salmonids) leads to lower density fecal material and slower dispersion, facilitating sample collection. As fecal discharge is relatively infrequent and the volume of sample is variable, maximizing analytical options is an important consideration. Here we present an extraction methodology to measure hormones and lipid content from the same fecal aliquot. Lipid extractions are commonly conducted using chloroform and methanol from Folch or Bligh and Dyer (B&D), while alcohol is the primary solvent for hormone extraction. We evaluated the possibility of using the methanol layer from lipid extractions to assess fecal steroid hormone levels. Folch and B&D methanol residues were assayed form metabolites of progesterone (PMs) and corticosterone (GCs), and results were compared to aliquots extracted in 70 % ethanol. Hormone concentrations measured in the methanol layer from Folch and B&D extractions were 55 % to 79 % lower than concentrations in 70 % ethanol. We developed mathematical corrections, using linear regression models fitted to Folch or B&D methanol <em>vs</em> 70 % ethanol hormone concentrations (p < 0.01). Fecal concentrations of PMs and GCs from methanol extractions were biologically validated and are significantly higher in confirmed pregnant females compared to non-pregnant individuals (p < 0.05). This study demonstrates that lipid extraction protocols may be used for the analysis of multiple biomarkers, maximizing the use of small-volume samples.</p></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0016648024001059/pdfft?md5=c231a35aabedf78f59c04b81c73195ae&pid=1-s2.0-S0016648024001059-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140848662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1016/j.ygcen.2024.114545
Z.M. Benowitz-Fredericks , A.P. Will , S.N. Pete , S. Whelan , A.S Kitaysky
In birds, patterns of development of the adrenocortical response to stressors vary among individuals, types of stressors, and species. Since there are benefits and costs of exposure to elevated glucocorticoids, this variation is presumably a product of selection such that animals modulate glucocorticoid secretion in contexts where doing so increases their fitness. In this study, we evaluated hypothalamo–pituitary–adrenal (HPA) activity in first-hatched free-living seabird nestlings that engage in intense sibling competition and facultative siblicide (black-legged kittiwakes, Rissa tridactyla). We sampled 5 day old chicks (of the ∼45 day nestling period), a critical early age when food availability drives establishment of important parent-offspring and intra-brood dynamics. We experimentally supplemented parents with food (“supplemented”) and measured chick baseline corticosterone secretion and capacity to rapidly increase corticosterone in response to an acute challenge (handling and 15 min of restraint in a bag). We also used topical administration of corticosterone to evaluate the ability of chicks to downregulate physiologically relevant corticosterone levels on a short time scale (minutes). We found that 5 day old chicks are not hypo-responsive but release corticosterone in proportion to the magnitude of the challenge, showing differences in baseline between parental feeding treatments (supplemented vs non-supplemented), moderate increases in response to handling, and a larger response to restraint (comparable to adults) that also differed between chicks from supplemented and control nests. Topical application of exogenous corticosterone increased circulating levels nearly to restraint-induced levels and induced downregulation of HPA responsiveness to the acute challenge of handling. Parental supplemental feeding did not affect absorbance/clearance or negative feedback. Thus, while endogenous secretion of corticosterone in young chicks is sensitive to environmental context, other aspects of the HPA function, such as rapid negative feedback and/or the ability to clear acute elevations in corticosterone, are not. We conclude that 5 day old kittiwake chicks are capable of robust adrenocortical responses to novel challenges, and are sensitive to parental food availability, which may be transduced behaviorally, nutritionally, or via maternal effects. Questions remain about the function of such rapid, large acute stress-induced increases in corticosterone in very young chicks.
{"title":"Corticosterone release in very young siblicidal seabird chicks (Rissa tridactyla) is sensitive to environmental variability and responds rapidly and robustly to external challenges","authors":"Z.M. Benowitz-Fredericks , A.P. Will , S.N. Pete , S. Whelan , A.S Kitaysky","doi":"10.1016/j.ygcen.2024.114545","DOIUrl":"10.1016/j.ygcen.2024.114545","url":null,"abstract":"<div><p>In birds, patterns of development of the adrenocortical response to stressors vary among individuals, types of stressors, and species. Since there are benefits and costs of exposure to elevated glucocorticoids, this variation is presumably a product of selection such that animals modulate glucocorticoid secretion in contexts where doing so increases their fitness. In this study, we evaluated hypothalamo–pituitary–adrenal (HPA) activity in first-hatched free-living seabird nestlings that engage in intense sibling competition and facultative siblicide (black-legged kittiwakes, <em>Rissa tridactyla</em>). We sampled 5 day old chicks (of the ∼45 day nestling period), a critical early age when food availability drives establishment of important parent-offspring and intra-brood dynamics. We experimentally supplemented parents with food (“supplemented”) and measured chick baseline corticosterone secretion and capacity to rapidly increase corticosterone in response to an acute challenge (handling and 15 min of restraint in a bag). We also used topical administration of corticosterone to evaluate the ability of chicks to downregulate physiologically relevant corticosterone levels on a short time scale (minutes). We found that 5 day old chicks are not hypo-responsive but release corticosterone in proportion to the magnitude of the challenge, showing differences in baseline between parental feeding treatments (supplemented vs non-supplemented), moderate increases in response to handling, and a larger response to restraint (comparable to adults) that also differed between chicks from supplemented and control nests. Topical application of exogenous corticosterone increased circulating levels nearly to restraint-induced levels and induced downregulation of HPA responsiveness to the acute challenge of handling. Parental supplemental feeding did not affect absorbance/clearance or negative feedback. Thus, while endogenous secretion of corticosterone in young chicks is sensitive to environmental context, other aspects of the HPA function, such as rapid negative feedback and/or the ability to clear acute elevations in corticosterone, are not. We conclude that 5 day old kittiwake chicks are capable of robust adrenocortical responses to novel challenges, and are sensitive to parental food availability, which may be transduced behaviorally, nutritionally, or via maternal effects. Questions remain about the function of such rapid, large acute stress-induced increases in corticosterone in very young chicks.</p></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140853783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-29DOI: 10.1016/j.ygcen.2024.114543
Tengfei Wu , You Wu , Yanlong Li , Yiyun Du , Saining Feng , Deshou Wang , Linyan Zhou
Relaxin3 (rln3) has been associated with various emotional and cognitive processes, including stress, anxiety, learning, memory, motivational behavior, and circadian rhythm. Notably, previous report revealed that Rln3a played an indispensable role in testicular development and male fertility in Nile tilapia (Oreochromis niloticus). However, the underlying molecular mechanisms remain largely unknown. We found that Rln3a is expressed exclusively in the diencephalon* (Di*) of the brain. Deficiency of Rln3a resulted in a significant increase in serum dopamine level and an upregulation of gene expression of gnrh1 and kisspeptin2. To further elucidate the role of Rln3a in fish fertility, we collected two different regions of Di* and hypothalamus (Hyp) tissues for subsequent RNA-seq analysis of both wild-type (rln3a+/+) and rln3a-/- male tilapia. Upon the transcriptomic data, 1136 and 755 differentially expressed genes (DEGs) were identified in the Di* and Hyp tissues, respectively. In Di*, the up-regulated genes were enriched in circadian rhythm, chemical carcinogenesis, while the down-regulated genes were enriched in type II diabetes mellitus, dopaminergic synapse, and other pathways. In Hyp, the up-regulated genes were enriched in circadian rhythm, pyrimidine metabolism, while the down-regulated genes were enriched in type I diabetes mellitus, autoimmune thyroid disease, and other pathways. Subsequently, the results of both qRT-PCR and FISH assays highlighted a pronounced up-regulation of core circadian rhythm genes, cry1b and per3, whereas genes such as clocka, clockb, and arntl exhibited down-regulation. Furthermore, the genes associated with dopamine biosynthesis were significantly increased in the Hyp. In summary, the mutation of rln3a in male tilapia resulted in notable changes in circadian rhythm and disease-linked signaling pathways in the Di* and Hyp. These changes might account for the fertility defects observed in rln3a-/- male mutants in tilapia.
{"title":"Genome-wide analysis of two different regions of brain reveals the molecular changes of fertility related genes in rln3a-/- mutants in male Nile tilapia (Oreochromis niloticus)","authors":"Tengfei Wu , You Wu , Yanlong Li , Yiyun Du , Saining Feng , Deshou Wang , Linyan Zhou","doi":"10.1016/j.ygcen.2024.114543","DOIUrl":"10.1016/j.ygcen.2024.114543","url":null,"abstract":"<div><p>Relaxin3 (<em>rln3</em>) has been associated with various emotional and cognitive processes, including stress, anxiety, learning, memory, motivational behavior, and circadian rhythm. Notably, previous report revealed that Rln3a played an indispensable role in testicular development and male fertility in Nile tilapia (<em>Oreochromis niloticus</em>). However, the underlying molecular mechanisms remain largely unknown. We found that Rln3a is expressed exclusively in the diencephalon* (Di*) of the brain. Deficiency of Rln3a resulted in a significant increase in serum dopamine level and an upregulation of gene expression of <em>gnrh1</em> and <em>kisspeptin2</em>. To further elucidate the role of Rln3a in fish fertility, we collected two different regions of Di* and hypothalamus (Hyp) tissues for subsequent RNA-seq analysis of both wild-type (<em>rln3a</em><sup>+/+</sup>) and <em>rln3a</em><sup>-/-</sup> male tilapia. Upon the transcriptomic data, 1136 and 755 differentially expressed genes (DEGs) were identified in the Di* and Hyp tissues, respectively. In Di*, the up-regulated genes were enriched in circadian rhythm, chemical carcinogenesis, while the down-regulated genes were enriched in type II diabetes mellitus, dopaminergic synapse, and other pathways. In Hyp, the up-regulated genes were enriched in circadian rhythm, pyrimidine metabolism, while the down-regulated genes were enriched in type I diabetes mellitus, autoimmune thyroid disease, and other pathways. Subsequently, the results of both qRT-PCR and FISH assays highlighted a pronounced up-regulation of core circadian rhythm genes, <em>cry1b</em> and <em>per3</em>, whereas genes such as <em>clocka</em>, <em>clockb</em>, and <em>arntl</em> exhibited down-regulation. Furthermore, the genes associated with dopamine biosynthesis were significantly increased in the Hyp. In summary, the mutation of <em>rln3a</em> in male tilapia resulted in notable changes in circadian rhythm and disease-linked signaling pathways in the Di* and Hyp. These changes might account for the fertility defects observed in <em>rln3a</em><sup>-/-</sup> male mutants in tilapia.</p></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140863443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in cloudy catshark were cloned, and recombinant FSHR and LHR were expressed for characterization. Ventral lobe extract (VLE) from the pituitary contains homologous FSH and LH, and it stimulated the cAMP signaling of FSHR and LHR dose-dependently. Two transcript variants of LHR (LHR-L with exon 10 and LHR-S without) were identified, and LHR-S was the dominant form with higher basal cAMP activity without VLE stimulation. Among various developmental stages of follicles, FSHR expression was mainly associated with the pre-vitellogenic and early white follicles. When follicles were recruited into vitellogenesis, the expression of FSHR decreased while of LHR was upregulated reciprocally, suggesting that LHR may also be responsible for the control of vitellogenesis in chondrichthyans. The expression of LHR-L was upregulated among maturing follicles before ovulation, indicating LHR-L could have a specific role in receiving the LH surge signal for final maturation. Plasma LH-like activity was transiently increased prior to the progesterone (P4)-surge and testosterone-drop at the beginning of P4-phase, supporting a pituitary control of follicle-maturation via LH signaling in chondrichthyans. The expression of follicular LHR was downregulated during the P4-phase when LH-like activity was high, indicating that the LH-dependent downregulation of LHR is conserved in chondrichthyans as it is in other vertebrate lineages. (213 words)
{"title":"Functional characterization of follicle-stimulating hormone and luteinizing hormone receptors in cloudy catshark, Scyliorhinus torazame","authors":"Shogo Arimura , Marty Kwok Shing Wong , Ryotaro Inoue , Mai Kawano , Koya Shimoyama , Chika Fujimori , Kotaro Tokunaga , Wataru Takagi , Susumu Hyodo","doi":"10.1016/j.ygcen.2024.114542","DOIUrl":"10.1016/j.ygcen.2024.114542","url":null,"abstract":"<div><p>The follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in cloudy catshark were cloned, and recombinant FSHR and LHR were expressed for characterization. Ventral lobe extract (VLE) from the pituitary contains homologous FSH and LH, and it stimulated the cAMP signaling of FSHR and LHR dose-dependently. Two transcript variants of LHR (LHR-L with exon 10 and LHR-S without) were identified, and LHR-S was the dominant form with higher basal cAMP activity without VLE stimulation. Among various developmental stages of follicles, FSHR expression was mainly associated with the pre-vitellogenic and early white follicles. When follicles were recruited into vitellogenesis, the expression of FSHR decreased while of LHR was upregulated reciprocally, suggesting that LHR may also be responsible for the control of vitellogenesis in chondrichthyans. The expression of LHR-L was upregulated among maturing follicles before ovulation, indicating LHR-L could have a specific role in receiving the LH surge signal for final maturation. Plasma LH-like activity was transiently increased prior to the progesterone (P4)-surge and testosterone-drop at the beginning of P4-phase, supporting a pituitary control of follicle-maturation via LH signaling in chondrichthyans. The expression of follicular LHR was downregulated during the P4-phase when LH-like activity was high, indicating that the LH-dependent downregulation of LHR is conserved in chondrichthyans as it is in other vertebrate lineages. (213 words)</p></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0016648024001035/pdfft?md5=aac52ad87174812c90c0f8a8d2479963&pid=1-s2.0-S0016648024001035-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140860534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-27DOI: 10.1016/j.ygcen.2024.114541
Vincent A. Viblanc , Sylvia Pardonnet , Anouch Tamian , Laura K. McCaw , F. Stephen Dobson , Rudy Boonstra
The measurement of glucocorticoid (GC) hormones provides us with a window into the stress physiology of vertebrates and the adaptative responses they use to cope with predictable and unpredictable changes in the environment. Baseline GCs inform us about the metabolic demands they are subject to at that point in their yearly life-history stage, whereas GC changes (often increases) in response to acute challenges inform us on their capacity to cope with more immediate environmental challenges. However, baseline GC levels and the kinetics of GC responses to acute stressors can vary substantially among and within species, depending on individual characteristics (age, sex, condition, life-history stage). In addition, a thorough understanding of the stress status of an animal requires moving beyond the measurement of GCs alone by focusing on downstream measures of metabolic activation, such as oxidative stress. Here, we evaluated the changes in blood cortisol and oxidative stress markers in wild adult Columbian ground squirrels (Urocitellus columbianus), following a 30-min capture-handling stress performed in mid-late June. Measurements were taken when males were post-reproductive and preparing for hibernation and adult females were weaning litters. We found three key results. First, the time-course of GC increase was markedly slower (by an order of magnitude) than what is currently reported in the literature for most species of mammals, birds and reptiles. Second, there were marked differences in the male and female response, linked to differences in life-history stage: females close to weaning had abolished GC responses, whereas post-reproductive males did not. Third, there were mild to moderate increases in oxidative damage and decreases in oxidative defenses in response to our short-term challenge, consistent with the idea that short-term acute metabolic activation may carry physiological costs. However, these changes were not correlated to the changes in GCs, a novel result suggesting a disconnect between the hormonal stress response and oxidative damage.
{"title":"Down-regulating the stress axis: Living in the present while preparing for the future","authors":"Vincent A. Viblanc , Sylvia Pardonnet , Anouch Tamian , Laura K. McCaw , F. Stephen Dobson , Rudy Boonstra","doi":"10.1016/j.ygcen.2024.114541","DOIUrl":"https://doi.org/10.1016/j.ygcen.2024.114541","url":null,"abstract":"<div><p>The measurement of glucocorticoid (GC) hormones provides us with a window into the stress physiology of vertebrates and the adaptative responses they use to cope with predictable and unpredictable changes in the environment. Baseline GCs inform us about the metabolic demands they are subject to at that point in their yearly life-history stage, whereas GC changes (often increases) in response to acute challenges inform us on their capacity to cope with more immediate environmental challenges. However, baseline GC levels and the kinetics of GC responses to acute stressors can vary substantially among and within species, depending on individual characteristics (age, sex, condition, life-history stage). In addition, a thorough understanding of the stress status of an animal requires moving beyond the measurement of GCs alone by focusing on downstream measures of metabolic activation, such as oxidative stress. Here, we evaluated the changes in blood cortisol and oxidative stress markers in wild adult Columbian ground squirrels (<em>Urocitellus columbianus</em>), following a 30-min capture-handling stress performed in mid-late June. Measurements were taken when males were post-reproductive and preparing for hibernation and adult females were weaning litters. We found three key results. First, the time-course of GC increase was markedly slower (by an order of magnitude) than what is currently reported in the literature for most species of mammals, birds and reptiles. Second, there were marked differences in the male and female response, linked to differences in life-history stage: females close to weaning had abolished GC responses, whereas post-reproductive males did not. Third, there were mild to moderate increases in oxidative damage and decreases in oxidative defenses in response to our short-term challenge, consistent with the idea that short-term acute metabolic activation may carry physiological costs. However, these changes were not correlated to the changes in GCs, a novel result suggesting a disconnect between the hormonal stress response and oxidative damage.</p></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140825163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}