Pub Date : 2026-01-01DOI: 10.1016/j.ygcen.2025.114868
Mark A. Sheridan, Andrea M. Hanson
{"title":"Corrigendum to “Effects of endocrine disrupting compounds on growth and the growth hormone/insulin-like growth factor system of fish” [Gen. Comp. Endocrinol. 375C (2026) 114837]","authors":"Mark A. Sheridan, Andrea M. Hanson","doi":"10.1016/j.ygcen.2025.114868","DOIUrl":"10.1016/j.ygcen.2025.114868","url":null,"abstract":"","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"376 ","pages":"Article 114868"},"PeriodicalIF":1.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939371","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 : 2025-12-28DOI: 10.1016/j.ygcen.2025.114873
Lisa K. Lauderdale , Douglas A. Granger , Michael T. Walsh , Lance J. Miller
Cortisol, an end product of hypothalamic–pituitary–adrenal (HPA) axis activation, plays a critical role in responding to arousal and restoring homeostasis. Chronic or repeated activation of the HPA axis may lead to physiological dysregulation that has potential negative health consequences. Quantifying stable, trait-like components of fecal glucocorticoid metabolite concentrations in animals could have a marked effect on investigating physiological stress responses and establishing higher resolution baselines for intra-individual clinical management, yet no studies have examined latent state-trait (LST) models for any non-human animals. Using an LST model, trait and state sources of fecal glucocorticoid metabolite variation were decomposed. Fecal samples were collected from 179 common bottlenose dolphins (Tursiops truncatus) in 41 habitats in late afternoon. The fit indices were excellent suggesting that LST models can be applied to bottlenose dolphin glucocorticoid metabolite measures. Trait factors (i.e., individual specific) accounted for an estimated 49 % of the variance in glucocorticoid metabolite concentrations and state factors (i.e., day-to-day factors) accounted for an estimated 41 % of the variance. This work suggests that LST models provide valuable evidence of a trait-like component in glucocorticoid metabolites in bottlenose dolphins that can be widely used in clinical management and research settings.
{"title":"Latent trait-like component identified for bottlenose dolphin fecal glucocorticoid metabolite concentrations","authors":"Lisa K. Lauderdale , Douglas A. Granger , Michael T. Walsh , Lance J. Miller","doi":"10.1016/j.ygcen.2025.114873","DOIUrl":"10.1016/j.ygcen.2025.114873","url":null,"abstract":"<div><div>Cortisol, an end product of hypothalamic–pituitary–adrenal (HPA) axis activation, plays a critical role in responding to arousal and restoring homeostasis. Chronic or repeated activation of the HPA axis may lead to physiological dysregulation that has potential negative health consequences. Quantifying stable, trait-like components of fecal glucocorticoid metabolite concentrations in animals could have a marked effect on investigating physiological stress responses and establishing higher resolution baselines for intra-individual clinical management, yet no studies have examined latent state-trait (LST) models for any non-human animals. Using an LST model, trait and state sources of fecal glucocorticoid metabolite variation were decomposed. Fecal samples were collected from 179 common bottlenose dolphins (<em>Tursiops truncatus</em>) in 41 habitats in late afternoon. The fit indices were excellent suggesting that LST models can be applied to bottlenose dolphin glucocorticoid metabolite measures. Trait factors (i.e., individual specific) accounted for an estimated 49 % of the variance in glucocorticoid metabolite concentrations and state factors (i.e., day-to-day factors) accounted for an estimated 41 % of the variance. This work suggests that LST models provide valuable evidence of a trait-like component in glucocorticoid metabolites in bottlenose dolphins that can be widely used in clinical management and research settings.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"377 ","pages":"Article 114873"},"PeriodicalIF":1.7,"publicationDate":"2025-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145862771","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 : 2025-12-16DOI: 10.1016/j.ygcen.2025.114872
Donald A. Larsen , Mollie A. Middleton , Deborah L. Harstad , Dina K. Spangenberg , Abby E. Fuhrman
Spring Chinook salmon, Oncorhynchus tshawytscha, are typically semelparous, dying after a single lifetime spawning event. However, observations of survival following maturation in males that mature at age-1 (common names: precocious parr or microjacks) have been documented, but little is known regarding their post-maturation physiology. In this investigation, mature microjacks were fed either a high or low winter ration to examine potential effects of feeding regime on mortality, smoltification and rematuration the following year. We measured a series of physiological factors including survival, size, percent whole body solid (an index of whole body lipid), and gill Na+/K+-ATPase activity (an index of smoltification). We also analyzed a series of maturation indices including plasma 11-ketotestosterone (11-KT), gonadosomatic index (GSI), pituitary follicle stimulating hormone (fshb) and luteinizing hormone (lhb) beta-subunit mRNA, and testicular histology in male fish following maturation as microjacks. In both treatments, the proportion of males that survived (High Ration: 0.91, Low Ration: 0.87) and rematured (High Ration: 1.0, Low Ration: 1.0) was very high, more indicative of iteroparity than semelparity. The low winter ration may have caused a slight delay in rematuration as evidenced by delayed fshb expression and 11-KT secretion in the spring. However, there was no evidence microjacks smolted in the spring after maturation at age-1. From a fisheries conservation perspective, the potential for iteroparity in microjacks (survival to remature at age-2) means it is possible they contribute genetically more than once when breeding in the natural environment.
{"title":"Life after precocious male maturation in a semelparous salmonid: A physiological perspective in Chinook salmon, Oncorhynchus tshawytscha","authors":"Donald A. Larsen , Mollie A. Middleton , Deborah L. Harstad , Dina K. Spangenberg , Abby E. Fuhrman","doi":"10.1016/j.ygcen.2025.114872","DOIUrl":"10.1016/j.ygcen.2025.114872","url":null,"abstract":"<div><div>Spring Chinook salmon, <em>Oncorhynchus tshawytscha</em>, are typically semelparous, dying after a single lifetime spawning event. However, observations of survival following maturation in males that mature at age-1 (common names: precocious parr or microjacks) have been documented, but little is known regarding their post-maturation physiology. In this investigation, mature microjacks were fed either a high or low winter ration to examine potential effects of feeding regime on mortality, smoltification and rematuration the following year. We measured a series of physiological factors including survival, size, percent whole body solid (an index of whole body lipid), and gill Na+/K+-ATPase activity (an index of smoltification). We also analyzed a series of maturation indices including plasma 11-ketotestosterone (11-KT), gonadosomatic index (GSI), pituitary follicle stimulating hormone (<em>fshb)</em> and luteinizing hormone (<em>lhb</em>) beta-subunit mRNA, and testicular histology in male fish following maturation as microjacks. In both treatments, the proportion of males that survived (High Ration: 0.91, Low Ration: 0.87) and rematured (High Ration: 1.0, Low Ration: 1.0) was very high, more indicative of iteroparity than semelparity. The low winter ration may have caused a slight delay in rematuration as evidenced by delayed <em>fshb</em> expression and 11-KT secretion in the spring. However, there was no evidence microjacks smolted in the spring after maturation at age-1. From a fisheries conservation perspective, the potential for iteroparity in microjacks (survival to remature at age-2) means it is possible they contribute genetically more than once when breeding in the natural environment.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"376 ","pages":"Article 114872"},"PeriodicalIF":1.7,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145780967","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}
Thyroid hormones (THs) are indispensable regulators of vertebrate embryogenesis, orchestrating signaling networks that direct cardiac morphogenesis. To investigate how disruption of this pathway impacts early development, fertilized Gallus domesticus eggs were exposed to amiodarone, a potent TH receptor (THR) antagonist and deiodinase inhibitor. Treated embryos displayed pronounced defects, including impaired heart looping, edema, increased apoptotic regions and sustained bradycardia during Hamburger-Hamilton stages 12 to 18. By day 10, histology revealed significant thinning of ventricular and atrial walls, with the compact ventricular layer reduced by ∼22 % while trabeculae were relatively preserved. These changes were accompanied by reduced acetylcholinesterase activity, indicating impaired neurocardiac regulation. Molecular analyses showed broad downregulation of WNT11, GATA4/5, TBX20, HAND2, BMP4, SHH, FGF8, MYOD, and MYOSIN, together with decreased PCNA and compensatory upregulation of GATA6. Interestingly, discrepancies between transcript and protein levels suggested post-transcriptional control under hypothyroid conditions. In silico promoter scanning identified thyroid hormone response elements within HAND2, GATA6, TBX5, PITX2, and BMP4, linking maternal TH signaling directly to lateral plate mesoderm gene networks. Flow cytometry and whole-mount immunolocalization confirmed reduced expression and altered localization of MYOD and MYOSIN, including loss of the normal heart-tube–restricted MYOD signal. Collectively, these findings establish that TH signaling networks coordinate structural, functional, and molecular programs essential for early cardiogenesis. Amiodarone-induced THR blockade recapitulates developmental hypothyroidism, providing mechanistic insight into how maternal TH deficiency or endocrine-disrupting exposures may contribute to congenital heart defects.
{"title":"Amiodarone disrupts thyroid hormone signaling networks governing early heart development in the chick embryo","authors":"Juhi Vaishnav , Aashi Maurya , Varun Varadarajan , Suresh Balakrishnan","doi":"10.1016/j.ygcen.2025.114871","DOIUrl":"10.1016/j.ygcen.2025.114871","url":null,"abstract":"<div><div>Thyroid hormones (THs) are indispensable regulators of vertebrate embryogenesis, orchestrating signaling networks that direct cardiac morphogenesis. To investigate how disruption of this pathway impacts early development, fertilized <em>Gallus domesticus</em> eggs were exposed to amiodarone, a potent TH receptor (THR) antagonist and deiodinase inhibitor. Treated embryos displayed pronounced defects, including impaired heart looping, edema, increased apoptotic regions and sustained bradycardia during Hamburger-Hamilton stages 12 to 18. By day 10, histology revealed significant thinning of ventricular and atrial walls, with the compact ventricular layer reduced by ∼22 % while trabeculae were relatively preserved. These changes were accompanied by reduced acetylcholinesterase activity, indicating impaired neurocardiac regulation. Molecular analyses showed broad downregulation of WNT11, GATA4/5, TBX20, HAND2, BMP4, SHH, FGF8, MYOD, and MYOSIN, together with decreased PCNA and compensatory upregulation of GATA6. Interestingly, discrepancies between transcript and protein levels suggested post-transcriptional control under hypothyroid conditions. In silico promoter scanning identified thyroid hormone response elements within HAND2, GATA6, TBX5, PITX2, and BMP4, linking maternal TH signaling directly to lateral plate mesoderm gene networks. Flow cytometry and whole-mount immunolocalization confirmed reduced expression and altered localization of MYOD and MYOSIN, including loss of the normal heart-tube–restricted MYOD signal. Collectively, these findings establish that TH signaling networks coordinate structural, functional, and molecular programs essential for early cardiogenesis. Amiodarone-induced THR blockade recapitulates developmental hypothyroidism, providing mechanistic insight into how maternal TH deficiency or endocrine-disrupting exposures may contribute to congenital heart defects.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"376 ","pages":"Article 114871"},"PeriodicalIF":1.7,"publicationDate":"2025-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145767806","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}
We previously demonstrated that two major hormonal phases, testosterone (T)-phase and progesterone (P4)-phase, which are marked by high plasma T and P4, respectively, appeared in each egg-laying cycle of cloudy catshark. In the present study, the mechanisms underlying the cyclical fluctuations of sex steroids were investigated by follicular steroid measurement and gene expression analyses in vivo and in vitro. In the ovary of catshark, a hierarchical pattern of follicles of increasing sizes is present. Estradiol (E2) was produced by early vitellogenic follicles, while T was produced by mid- to late-vitellogenic follicles. The production of T was downregulated in the follicles at P4-phase, concomitant with the significant decreases in expression of cyp17a1 gene encoding P450c17, an enzyme converting P4 to androgen. Meanwhile, P4 was exclusively produced by preovulatory F1 follicles only at P4-phase, which was related in time to a marked upregulation of steroidogenic acute regulatory protein 2 (star2), suggesting that star2 is a key regulatory factor for inducing the P4 surge. Our newly established in vitro follicle culture system confirmed the secretion of E2, T and P4 from follicles at the different hierarchical stages. These findings provide clear evidence that follicular hierarchy is an important driver of the cyclical secretion of steroid hormones by follicles, and of circulating steroids in plasma, in the cloudy catshark.
{"title":"Hierarchical regulation of steroid synthesis in ovarian follicles drives progesterone surge in cloudy catshark","authors":"Ryotaro Inoue , Mai Kawano , Koya Shimoyama , Momoko Saito , Shogo Arimura , Kotaro Tokunaga , Wataru Takagi , Marty Kwok Shing Wong , Susumu Hyodo","doi":"10.1016/j.ygcen.2025.114870","DOIUrl":"10.1016/j.ygcen.2025.114870","url":null,"abstract":"<div><div>We previously demonstrated that two major hormonal phases, testosterone (T)-phase and progesterone (P4)-phase, which are marked by high plasma T and P4, respectively, appeared in each egg-laying cycle of cloudy catshark. In the present study, the mechanisms underlying the cyclical fluctuations of sex steroids were investigated by follicular steroid measurement and gene expression analyses <em>in vivo</em> and <em>in vitro</em>. In the ovary of catshark, a hierarchical pattern of follicles of increasing sizes is present. Estradiol (E2) was produced by early vitellogenic follicles, while T was produced by mid- to late-vitellogenic follicles. The production of T was downregulated in the follicles at P4-phase, concomitant with the significant decreases in expression of <em>cyp17a1</em> gene encoding P450c17, an enzyme converting P4 to androgen. Meanwhile, P4 was exclusively produced by preovulatory F1 follicles only at P4-phase, which was related in time to a marked upregulation of steroidogenic acute regulatory protein 2 (<em>star2</em>), suggesting that <em>star2</em> is a key regulatory factor for inducing the P4 surge. Our newly established <em>in vitro</em> follicle culture system confirmed the secretion of E2, T and P4 from follicles at the different hierarchical stages. These findings provide clear evidence that follicular hierarchy is an important driver of the cyclical secretion of steroid hormones by follicles, and of circulating steroids in plasma, in the cloudy catshark.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"376 ","pages":"Article 114870"},"PeriodicalIF":1.7,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145761586","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 : 2025-12-06DOI: 10.1016/j.ygcen.2025.114869
Foroozan Torki, William G. Bendena, Ian D. Chin-Sang
Neuropeptides in Caenorhabditis elegans regulate physiological and behavioural responses to environmental cues, influencing locomotion, feeding, and fat storage via interactions with G-protein coupled receptors (GPCRs). C. elegans expresses a diverse repertoire of neuropeptides, including FMRFamide-related peptides, neuropeptide-like peptides (NLPs), and insulin-like peptides (INSs). Among these, the galanin/allatostatin-like GPCR, NPR-9, localized in the AIB interneurons, regulates locomotory behaviours (roaming and dwelling) and fat accumulation by inhibiting AIB activity. Recent studies identified NLP-1 as a ligand for NPR-9, modulating behaviour through direct receptor interaction. However, our research explored whether other neuropeptides, specifically NLP-5 and NLP-6 (allatostatin A-type/galanin-like neuropeptides), could also function as NPR-9 ligands, despite evidence suggesting NLP-1 as the primary ligand. In this study, we characterized phenotypes associated with NPR-9 receptor function, including Omega turns, roaming, and fat accumulation. Loss-of-function mutations in nlp-5, nlp-6, and nlp-1 exhibited behavioural phenotypes similar to npr-9 mutants, suggesting that NLP-5 and NLP-6 may act as additional ligands for NPR-9 or affect NPR-9 signalling. Furthermore, double-mutant analyses with candidate ligand genes suppressed phenotypes associated with NPR-9 overexpression, reinforcing the hypothesis that these neuropeptides may regulate NPR-9-mediated signalling.
{"title":"IDENTIFICATION of NLP-5 and NLP-6 as potential ligands for the NPR-9 receptor in Caenorhabditis elegans","authors":"Foroozan Torki, William G. Bendena, Ian D. Chin-Sang","doi":"10.1016/j.ygcen.2025.114869","DOIUrl":"10.1016/j.ygcen.2025.114869","url":null,"abstract":"<div><div>Neuropeptides in <em>Caenorhabditis elegans</em> regulate physiological and behavioural responses to environmental cues, influencing locomotion, feeding, and fat storage via interactions with G-protein coupled receptors (GPCRs). <em>C. elegans</em> expresses a diverse repertoire of neuropeptides, including FMRFamide-related peptides, neuropeptide-like peptides (NLPs), and insulin-like peptides (INSs). Among these, the galanin/allatostatin-like GPCR, NPR-9, localized in the AIB interneurons, regulates locomotory behaviours (roaming and dwelling) and fat accumulation by inhibiting AIB activity. Recent studies identified NLP-1 as a ligand for NPR-9, modulating behaviour through direct receptor interaction. However, our research explored whether other neuropeptides, specifically NLP-5 and NLP-6 (allatostatin A-type/galanin-like neuropeptides), could also function as NPR-9 ligands, despite evidence suggesting NLP-1 as the primary ligand. In this study, we characterized phenotypes associated with NPR-9 receptor function, including Omega turns, roaming, and fat accumulation. Loss-of-function mutations in <em>nlp-5</em>, <em>nlp-6</em>, and <em>nlp-1</em> exhibited behavioural phenotypes similar to <em>npr-9</em> mutants, suggesting that NLP-5 and NLP-6 may act as additional ligands for NPR-9 or affect NPR-9 signalling. Furthermore, double-mutant analyses with candidate ligand genes suppressed phenotypes associated with NPR-9 overexpression, reinforcing the hypothesis that these neuropeptides may regulate NPR-9-mediated signalling.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"376 ","pages":"Article 114869"},"PeriodicalIF":1.7,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145707770","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}
Major yolk protein (MYP) serves as a critical nutrient reservoir for gonadal development in sea urchins, but the transcriptional regulation of its encoding gene remains largely uncharacterized. Here, we cloned and analyzed the MYP promoter from Mesocentrotus nudus and found two conserved elements with putative binding sites for the orphan nuclear receptor COUP-TF (chicken ovalbumin upstream promoter-transcription factor). We cloned the full-length cDNA encoding COUP-TF from M. nudus (MnCOUP-TF). The cDNA encoded a 472-amino acid protein highly homologous to other COUP-TF/SVP subfamily members. RT-PCR and qPCR analyses revealed that transcripts of both MnCOUP-TF and MYP were present in several tissues, including gonads, and their levels exhibited a significant positive correlation during gonadal maturation (R2 = 0.6764, p < 0.01). Electrophoretic mobility shift assays demonstrated specific binding of MnCOUP-TF to the MYP promoter, and transactivation assays showed that MnCOUP-TF activates transcription through these sites. Furthermore, total lipids extracted from gonadal tissue enhanced MnCOUP-TF–dependent reporter activity in a dose-dependent manner. This enhancement was comparable to the effect of 9-cis-retinoic acid, a compound known to activate COUP-TF at high concentrations, although it is not considered to be a physiological COUP-TF ligand. These results suggest that MnCOUP-TF regulates MYP expression in a ligand-dependent manner and that endogenous activators may be present in gonadal lipids. To our knowledge, this is the first molecular evidence implicating COUP-TF in yolk protein gene regulation in sea urchins, providing new insights into nuclear receptor-mediated control of reproduction in marine invertebrates.
主要卵黄蛋白(Major蛋黄蛋白,MYP)是海胆性腺发育的重要营养储备,但其编码基因的转录调控在很大程度上尚不清楚。在这里,我们克隆并分析了裸鸡中心虾的MYP启动子,发现了两个保守的元件,它们与孤儿核受体COUP-TF(鸡卵白蛋白上游启动子转录因子)有可能的结合位点。我们从裸鼠中克隆了编码COUP-TF的全长cDNA (MnCOUP-TF)。该cDNA编码了一个472个氨基酸的蛋白,与其他COUP-TF/SVP亚家族成员高度同源。RT-PCR和qPCR分析显示,MnCOUP-TF和MYP转录本均存在于包括性腺在内的多种组织中,其水平在性腺成熟过程中呈显著正相关(R2 = 0.6764, p < 0.01)。电泳迁移率转移实验表明MnCOUP-TF与MYP启动子特异性结合,反式激活实验表明MnCOUP-TF通过这些位点激活转录。此外,从性腺组织中提取的总脂质以剂量依赖的方式增强了mncoup - tf依赖的报告细胞活性。这种增强与9-顺式维甲酸的作用相当,9-顺式维甲酸是一种已知在高浓度下激活COUP-TF的化合物,尽管它不被认为是一种生理上的COUP-TF配体。这些结果表明,MnCOUP-TF以配体依赖的方式调节MYP的表达,内源性激活剂可能存在于性腺脂质中。据我们所知,这是暗示COUP-TF参与海胆卵黄蛋白基因调控的第一个分子证据,为核受体介导的海洋无脊椎动物生殖控制提供了新的见解。
{"title":"Potential role of COUP-TF in regulating major yolk protein gene expression in sea urchin","authors":"Ichiro Higuchi , Shiori Tsue , Yudai Kitano , Osamu Nishimiya , Masashi Hosokawa , Fumiaki Beppu , Kazuhiro Ura , Yasuaki Takagi","doi":"10.1016/j.ygcen.2025.114867","DOIUrl":"10.1016/j.ygcen.2025.114867","url":null,"abstract":"<div><div>Major yolk protein (MYP) serves as a critical nutrient reservoir for gonadal development in sea urchins, but the transcriptional regulation of its encoding gene remains largely uncharacterized. Here, we cloned and analyzed the <em>MYP</em> promoter from <em>Mesocentrotus nudus</em> and found two conserved elements with putative binding sites for the orphan nuclear receptor COUP-TF (chicken ovalbumin upstream promoter-transcription factor). We cloned the full-length cDNA encoding COUP-TF from <em>M. nudus</em> (MnCOUP-TF). The cDNA encoded a 472-amino acid protein highly homologous to other COUP-TF/SVP subfamily members. RT-PCR and qPCR analyses revealed that transcripts of both <em>MnCOUP-TF</em> and <em>MYP</em> were present in several tissues, including gonads, and their levels exhibited a significant positive correlation during gonadal maturation (R<sup>2</sup> = 0.6764, <em>p</em> < 0.01). Electrophoretic mobility shift assays demonstrated specific binding of MnCOUP-TF to the <em>MYP</em> promoter, and transactivation assays showed that MnCOUP-TF activates transcription through these sites. Furthermore, total lipids extracted from gonadal tissue enhanced MnCOUP-TF–dependent reporter activity in a dose-dependent manner. This enhancement was comparable to the effect of 9-<em>cis</em>-retinoic acid, a compound known to activate COUP-TF at high concentrations, although it is not considered to be a physiological COUP-TF ligand. These results suggest that MnCOUP-TF regulates <em>MYP</em> expression in a ligand-dependent manner and that endogenous activators may be present in gonadal lipids. To our knowledge, this is the first molecular evidence implicating COUP-TF in yolk protein gene regulation in sea urchins, providing new insights into nuclear receptor-mediated control of reproduction in marine invertebrates.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"376 ","pages":"Article 114867"},"PeriodicalIF":1.7,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145705435","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 : 2025-11-26DOI: 10.1016/j.ygcen.2025.114866
Bérénice Bichon , Gladys Alfama , Anne-Laure Gaillard , Feng B. Quan , Pascal Sourdaine , Hervé Tostivint
The caudal neurosecretory system (CNSS) is a neuroendocrine complex unique to fish. In teleosts, the neuroendocrine neurons of the CNSS, called Dahlgren cells, are located in the terminal part of the spinal cord and project to a neurohemal organ, the urophysis, from which several hormones are released. The two major hormones secreted by Dahlgren cells are two neuropeptides called urotensin 1 (UI), related to the corticotropin-releasing hormone and urotensin 2 (UII), related to somatostatin. In cartilaginous fishes, the CNSS organization is simpler than in teleosts due to the absence of urophysis. As a consequence, Dahlgren cells project into a diffuse neurohemal region located at the ventral base of the spinal cord. Such an organization of the CNSS is considered as primitive. An important feature of Dahlgren cells in cartilaginous fishes is also their huge size. The goal of the present study was to provide more insight into the CNSS in cartilaginous fish, which has been poorly studied so far. For this purpose, we used the small-spotted catshark Scyliorhinus canicula, as a model. We first cloned the cDNAs encoding for both catshark UI (uts1) and UII (uts2). This search revealed the existence of two copies of the uts1 gene, uts1a and uts1b, that are tandemly arranged. We then determined by RT-qPCR the expression pattern of the uts1a, uts1b, and uts2 genes in various catshark tissues. Our results revealed that uts1a and uts2 genes are primarily expressed in giant cells of the caudal spinal cord, that likely correspond to Dahlgren cells. The uts1a transcript was also detected in the epididymis head of the testis but at a much lower level. In contrast, the uts1b transcript was detected at very low levels in all tissues examined. Further study by double fluorescence in situ hybridization showed that in the caudal spinal cord, all uts1a mRNA-containing cells expressed uts2 while only about half of the uts2-expressing cells also expressed uts1a. Taken together these results suggest the existence of two populations of Dahlgren cells: one of which expressing solely uts2 and the other expressing both uts1a and uts2. In conclusion, our work showed that, as in teleosts, uts1 and uts2 are two potentially useful markers for studying the CNSS in cartilaginous fish.
{"title":"Characterization and expression of urotensin1 and urotensin2 genes in the caudal neurosecretory system of the small-spotted catshark Scyliorhinus canicula","authors":"Bérénice Bichon , Gladys Alfama , Anne-Laure Gaillard , Feng B. Quan , Pascal Sourdaine , Hervé Tostivint","doi":"10.1016/j.ygcen.2025.114866","DOIUrl":"10.1016/j.ygcen.2025.114866","url":null,"abstract":"<div><div>The caudal neurosecretory system (CNSS) is a neuroendocrine complex unique to fish. In teleosts, the neuroendocrine neurons of the CNSS, called Dahlgren cells, are located in the terminal part of the spinal cord and project to a neurohemal organ, the urophysis, from which several hormones are released. The two major hormones secreted by Dahlgren cells are two neuropeptides called urotensin 1 (UI), related to the corticotropin-releasing hormone and urotensin 2 (UII), related to somatostatin. In cartilaginous fishes, the CNSS organization is simpler than in teleosts due to the absence of urophysis. As a consequence, Dahlgren cells project into a diffuse neurohemal region located at the ventral base of the spinal cord. Such an organization of the CNSS is considered as primitive. An important feature of Dahlgren cells in cartilaginous fishes is also their huge size. The goal of the present study was to provide more insight into the CNSS in cartilaginous fish, which has been poorly studied so far. For this purpose, we used the small-spotted catshark <em>Scyliorhinus canicula</em>, as a model. We first cloned the cDNAs encoding for both catshark UI (<em>uts1</em>) and UII (<em>uts2</em>). This search revealed the existence of two copies of the <em>uts1</em> gene, <em>uts1a</em> and <em>uts1b</em>, that are tandemly arranged. We then determined by RT-qPCR the expression pattern of the <em>uts1a</em>, <em>uts1b</em>, and <em>uts2</em> genes in various catshark tissues. Our results revealed that <em>uts1a</em> and <em>uts2</em> genes are primarily expressed in giant cells of the caudal spinal cord, that likely correspond to Dahlgren cells. The <em>uts1a</em> transcript was also detected in the epididymis head of the testis but at a much lower level. In contrast, the <em>uts1b</em> transcript was detected at very low levels in all tissues examined. Further study by double fluorescence in situ hybridization showed that in the caudal spinal cord, all <em>uts1a</em> mRNA-containing cells expressed <em>uts2</em> while only about half of the <em>uts2</em>-expressing cells also expressed <em>uts1a.</em> Taken together these results suggest the existence of two populations of Dahlgren cells: one of which expressing solely <em>uts2</em> and the other expressing both <em>uts1a</em> and <em>uts2</em>. In conclusion, our work showed that, as in teleosts, <em>uts1</em> and <em>uts2</em> are two potentially useful markers for studying the CNSS in cartilaginous fish.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"376 ","pages":"Article 114866"},"PeriodicalIF":1.7,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145632230","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 : 2025-11-21DOI: 10.1016/j.ygcen.2025.114856
Rudy Boonstra , Joanne Castillo , Tim J. Karels , F.Stephen Dobson , Rupert Palme , Curtis O. Bosson
A lack of agreement between the diet an animal needs for reproduction and survival and the food available in its environment has major impact on its fitness. The complexity of their digestive system is critical and may affect stress axis function. The squirrel family (sciurids) have a very simple gut and do not have the microbiome to digest high fiber foods well. Thus, they forage preferentially on forbs, seeds, and fungi, and avoid hard-to-digest grasses. We compared two measures of their stress axis − plasma free cortisol, a glucocorticoid (GC), and fecal cortisol metabolites (FCMs) − in Columbian ground squirrels (Urocitellus columbianus) from two meadows as they were building up body reserves in July for their pending hibernation. One meadow was natural with an abundance of forbs and the other unnatural with an abundance of grasses that had been seeded as a horse pasture. Our two measures went in the opposite direction: GC levels were lower on the natural meadow but FCMs were higher, whereas GC levels were higher on the grass meadow but FCMs lower. The fecal fiber content was lower on the natural meadow. Thus, when interpreting FCM levels, it is critical to understand both the digestive system of the study mammal and its diet to interpret stress axis function.
{"title":"Assessing stress in a mammal from plasma and feces: A nutritional mismatch between the diet needed and the food -available","authors":"Rudy Boonstra , Joanne Castillo , Tim J. Karels , F.Stephen Dobson , Rupert Palme , Curtis O. Bosson","doi":"10.1016/j.ygcen.2025.114856","DOIUrl":"10.1016/j.ygcen.2025.114856","url":null,"abstract":"<div><div>A lack of agreement between the diet an animal needs for reproduction and survival and the food available in its environment has major impact on its fitness. The complexity of their digestive system is critical and may affect stress axis function. The squirrel family (sciurids) have a very simple gut and do not have the microbiome to digest high fiber foods well. Thus, they forage preferentially on forbs, seeds, and fungi, and avoid hard-to-digest grasses. We compared two measures of their stress axis − plasma free cortisol, a glucocorticoid (GC), and fecal cortisol metabolites (FCMs) − in Columbian ground squirrels <em>(Urocitellus columbianus)</em> from two meadows as they were building up body reserves in July for their pending hibernation. One meadow was natural with an abundance of forbs and the other unnatural with an abundance of grasses that had been seeded as a horse pasture. Our two measures went in the opposite direction: GC levels were lower on the natural meadow but FCMs were higher, whereas GC levels were higher on the grass meadow but FCMs lower. The fecal fiber content was lower on the natural meadow. Thus, when interpreting FCM levels, it is critical to understand both the digestive system of the study mammal and its diet to interpret stress axis function.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"375 ","pages":"Article 114856"},"PeriodicalIF":1.7,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145586996","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 : 2025-11-19DOI: 10.1016/j.ygcen.2025.114855
Thomas M. Banks , Susan Glendinning , Courtney Lewis , Avani Bhojwani , Quinn P. Fitzgibbon , Gregory G. Smith , Tomer Ventura
The slipper lobster, Thenus australiensis has gained attention as a candidate species for aquaculture production. Recent studies have investigated various aspects of rearing T. australiensis in an aquaculture setting, however genetic resources are limited. Here, we generated the first multiple tissue transcriptome library for T. australiensis for immature male and female lobster tissues including the eyestalk, brain, testis, ovary, 3rd and 5th walking leg regions, hepatopancreas, stomach and muscle, with a total of 38 samples sequenced. From this transcriptome, we describe the neuropeptidome of T. australiensis and provide neuropeptide precursor expression patterns across tissues. The eyestalk and brain expressed the most neuropeptide precursor genes as expected, although surprisingly several others were enriched in the testis and ovary. Members of the allatostatin, crustacean hyperglycaemic hormone, and insulin like peptide family were among those highly expressed in gonad tissue, alongside peptides previously linked to reproduction such as corazonin and crustacean female sex hormone, and other neuropeptides without any established roles in reproduction. This repertoire of neuropeptides possibly related to reproductive processes provides a basis for future functional characterisation and may offer an avenue for enhancing production with aquaculture biotechnology.
{"title":"In silico analysis of the slipper lobster (Thenus australiensis) neuropeptidome reveals unique enrichment of peptide hormones in reproductive tissues using multi-tissue transcriptomics","authors":"Thomas M. Banks , Susan Glendinning , Courtney Lewis , Avani Bhojwani , Quinn P. Fitzgibbon , Gregory G. Smith , Tomer Ventura","doi":"10.1016/j.ygcen.2025.114855","DOIUrl":"10.1016/j.ygcen.2025.114855","url":null,"abstract":"<div><div>The slipper lobster, <em>Thenus australiensis</em> has gained attention as a candidate species for aquaculture production. Recent studies have investigated various aspects of rearing <em>T. australiensis</em> in an aquaculture setting, however genetic resources are limited. Here, we generated the first multiple tissue transcriptome library for <em>T. australiensis</em> for immature male and female lobster tissues including the eyestalk, brain, testis, ovary, 3rd and 5th walking leg regions, hepatopancreas, stomach and muscle, with a total of 38 samples sequenced. From this transcriptome, we describe the neuropeptidome of <em>T. australiensis</em> and provide neuropeptide precursor expression patterns across tissues. The eyestalk and brain expressed the most neuropeptide precursor genes as expected, although surprisingly several others were enriched in the testis and ovary. Members of the allatostatin, crustacean hyperglycaemic hormone, and insulin like peptide family were among those highly expressed in gonad tissue, alongside peptides previously linked to reproduction such as corazonin and crustacean female sex hormone, and other neuropeptides without any established roles in reproduction. This repertoire of neuropeptides possibly related to reproductive processes provides a basis for future functional characterisation and may offer an avenue for enhancing production with aquaculture biotechnology.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"375 ","pages":"Article 114855"},"PeriodicalIF":1.7,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145573393","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}