Pub Date : 2024-09-15DOI: 10.1101/2024.09.13.612986
Kazuya Suzuki, Fumi Wagai, Mototsugu Eiraku
During the development of the olfactory epithelium (OE), olfactory sensory neurons (OSNs) express only one member of the odorant receptor (OR) gene family, and OSNs expressing the same OR converge their axons to the same set of glomeruli on the olfactory bulb (OB). The resulting odor maps allow mice to discriminate more than 100,000 different odorants using about 1,000 ORs. It remains elusive how odor maps are formed. Here, we show a means of forming OE organoids with pseudostratified structure from mouse embryonic OE stem cells. Single-cell RNA sequencing revealed that the OE organoids give rise to all the OE cellular lineages and undergo active neurogenesis. We also found that most OSNs in OE organoids exclusively express only one type of ORs and exhibit a unique molecular code of axon guidance-related genes that can discriminate between OR classes. Thus, OE organoids could be a useful model for studying olfactory nervous system development.
{"title":"Reconstruction of functional olfactory sensory tissue from embryonic nasal stem cells","authors":"Kazuya Suzuki, Fumi Wagai, Mototsugu Eiraku","doi":"10.1101/2024.09.13.612986","DOIUrl":"https://doi.org/10.1101/2024.09.13.612986","url":null,"abstract":"During the development of the olfactory epithelium (OE), olfactory sensory neurons (OSNs) express only one member of the odorant receptor (OR) gene family, and OSNs expressing the same OR converge their axons to the same set of glomeruli on the olfactory bulb (OB). The resulting odor maps allow mice to discriminate more than 100,000 different odorants using about 1,000 ORs. It remains elusive how odor maps are formed. Here, we show a means of forming OE organoids with pseudostratified structure from mouse embryonic OE stem cells. Single-cell RNA sequencing revealed that the OE organoids give rise to all the OE cellular lineages and undergo active neurogenesis. We also found that most OSNs in OE organoids exclusively express only one type of ORs and exhibit a unique molecular code of axon guidance-related genes that can discriminate between OR classes. Thus, OE organoids could be a useful model for studying olfactory nervous system development.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hypoglycemia is the process of reducing blood glucose concentration to below 2.5-2.8 mmol/L in men and less than 1.9-2.2 mmol/L in women. Prolonged hyperglycemia can lead to a range of serious chronic complications such as diabetic nephropathy, diabetic retinopathy, cardiovascular diseases in diabetes, and so forth, threatening human life, health, and safety. Scutellaria baicalensis is one of the most commonly used remedies in traditional Chinese medicine. This plant contains a number of biologically active compounds that contribute to improving kidney function, insulin resistance, and retinopathy in patients with type 2 diabetes, but few researchers study the toxic effects of medicinal plant components. Therefore, the aim of this study was to evaluate the hypoglycemic activity of trans-cinnamic acid isolated from the extract of hairy rots of Scutellaria baicalensis in in vivo experiments. This study involved intraperitoneal administration of alloxan at a dose of 150.0 mg/kg and oral administration of trans-cinnamic acid at doses of 50.0 and 100.0 mg/kg. During the experiment, it was found that trans-cinnamic acid at the presented doses does not affect the body weight dynamics of experimental animals with diabetes. Thus, this study demonstrates that trans-cinnamic acid at the presented dosage can be safely used as an ingredient in the creation of dietary supplements for the prevention of diabetes, thereby contributing to healthy aging.
{"title":"Assessment of the hypoglycemic activity of trans-cinnamic acid isolated from the extract of hairy rots Scutellaria baicalensis in in vivo experiments","authors":"Anastasia Mikhailovna Fedorova, Irina Sergeevna Milentyeva, Lyudmila Konstantinovna Asyakina, Alexander Yuryevich Prosekov","doi":"10.1101/2024.09.12.612583","DOIUrl":"https://doi.org/10.1101/2024.09.12.612583","url":null,"abstract":"Hypoglycemia is the process of reducing blood glucose concentration to below 2.5-2.8 mmol/L in men and less than 1.9-2.2 mmol/L in women. Prolonged hyperglycemia can lead to a range of serious chronic complications such as diabetic nephropathy, diabetic retinopathy, cardiovascular diseases in diabetes, and so forth, threatening human life, health, and safety. Scutellaria baicalensis is one of the most commonly used remedies in traditional Chinese medicine. This plant contains a number of biologically active compounds that contribute to improving kidney function, insulin resistance, and retinopathy in patients with type 2 diabetes, but few researchers study the toxic effects of medicinal plant components. Therefore, the aim of this study was to evaluate the hypoglycemic activity of trans-cinnamic acid isolated from the extract of hairy rots of Scutellaria baicalensis in in vivo experiments. This study involved intraperitoneal administration of alloxan at a dose of 150.0 mg/kg and oral administration of trans-cinnamic acid at doses of 50.0 and 100.0 mg/kg. During the experiment, it was found that trans-cinnamic acid at the presented doses does not affect the body weight dynamics of experimental animals with diabetes. Thus, this study demonstrates that trans-cinnamic acid at the presented dosage can be safely used as an ingredient in the creation of dietary supplements for the prevention of diabetes, thereby contributing to healthy aging.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1101/2024.09.13.612912
Alexa Di Pede, Bokang Ko, Abdelrahman AlOkda, Aura A. Tamez Gonzalez, Jeremy M. Van Raamsdonk
The mitochondrial unfolded protein response (mitoUPR) is a stress response pathway that responds to mitochondrial insults by altering gene expression to recover mitochondrial homeostasis. The mitoUPR is mediated by the stress-activated transcription factor ATFS-1. Constitutive activation of ATFS-1 increases resistance to exogenous stressors but paradoxically decreases lifespan. In this work, we determined the optimal levels of expression of activated ATFS-1 with respect to lifespan and resistance to stress by treating constitutively-active atfs-1(et17) worms with different concentrations of RNA interference (RNAi) bacteria targeting atfs-1. We observed the maximum lifespan of atfs-1(et17) worms at full-strength atfs-1 RNAi, which was significantly longer than wild-type lifespan. Under the conditions of maximum lifespan, atfs-1(et17) worms did not show enhanced resistance to stress, suggesting a trade-off between stress resistance and longevity. The maximum resistance to stress in atfs-1(et17) worms occurred on empty vector (0% atfs-1 knockdown). Under these conditions, atfs-1(et17) worms are short-lived. This indicates that constitutive activation of ATFS-1 can increase lifespan or enhance resistance to stress but not both, at the same time. Finally, we determined the timing requirements for ATFS-1 to affect lifespan. We found that knocking down atfs-1 expression only during development is sufficient to extend atfs-1(et17) lifespan, while adult-only knockdown has no effect. Overall, these results demonstrate that constitutively active ATFS-1 can extend lifespan when expressed at low levels and that this lifespan extension is not dependent on the ability of ATFS-1 to enhance resistance to stress.
{"title":"Mild activation of the mitochondrial unfolded protein response increases lifespan without increasing resistance to stress","authors":"Alexa Di Pede, Bokang Ko, Abdelrahman AlOkda, Aura A. Tamez Gonzalez, Jeremy M. Van Raamsdonk","doi":"10.1101/2024.09.13.612912","DOIUrl":"https://doi.org/10.1101/2024.09.13.612912","url":null,"abstract":"The mitochondrial unfolded protein response (mitoUPR) is a stress response pathway that responds to mitochondrial insults by altering gene expression to recover mitochondrial homeostasis. The mitoUPR is mediated by the stress-activated transcription factor ATFS-1. Constitutive activation of ATFS-1 increases resistance to exogenous stressors but paradoxically decreases lifespan. In this work, we determined the optimal levels of expression of activated ATFS-1 with respect to lifespan and resistance to stress by treating constitutively-active atfs-1(et17) worms with different concentrations of RNA interference (RNAi) bacteria targeting atfs-1. We observed the maximum lifespan of atfs-1(et17) worms at full-strength atfs-1 RNAi, which was significantly longer than wild-type lifespan. Under the conditions of maximum lifespan, atfs-1(et17) worms did not show enhanced resistance to stress, suggesting a trade-off between stress resistance and longevity. The maximum resistance to stress in atfs-1(et17) worms occurred on empty vector (0% atfs-1 knockdown). Under these conditions, atfs-1(et17) worms are short-lived. This indicates that constitutive activation of ATFS-1 can increase lifespan or enhance resistance to stress but not both, at the same time. Finally, we determined the timing requirements for ATFS-1 to affect lifespan. We found that knocking down atfs-1 expression only during development is sufficient to extend atfs-1(et17) lifespan, while adult-only knockdown has no effect. Overall, these results demonstrate that constitutively active ATFS-1 can extend lifespan when expressed at low levels and that this lifespan extension is not dependent on the ability of ATFS-1 to enhance resistance to stress.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1101/2024.09.13.612902
Wojciech Derkowski, Alicja Kedzia, Krzysztof Dudek, Michal Glonek
The research presents findings from a study on the development of the skull and brain in human fetuses, specifically focusing on the anterior cranial fossa. This area provides protection for the frontal lobes, which are crucial for human personality development later in life. The study describes the anatomical structure of the anterior cranial fossa during the prenatal period and examines disorders that may lead to congenital defects. The aim was to assess the anterior cranial fossa during prenatal development using innovative computer image processing techniques not previously applied in this anatomical area. A metrological analysis of the human anterior cranial fossa was conducted at various developmental stages, and the study explored the relationship between selected dimensions and developmental age. It compared the development of the anterior cranial fossa to that of the other two cranial fossae, investigating symmetry during development and sexual dimorphism of the anterior fossa and skull base before birth. The study also considered clinical aspects, including a mechanical model of developing skull based on obtained results, enabling the approximation of the pathomechanism of congenital skull and brain defects and potential treatment options. The study included a collection of 77 human fetuses aged between 10 and 27 weeks of gestation. Computer image processing techniques were employed, representing a novelty in neuroanatomical research. The study also discussed the advantages of computerized image acquisition and measurement methods over traditional anatomical preparation methods, particularly due to the possibility of non-contact measurements, crucial for delicate neural tissue of fetal brains. Detailed results obtained were presented along with their statistical analysis. The study found that during the development of the human cranial base, the angle of the anterior cranial fossa decreased, compensated by an increase in the angle of the middle cranial fossa. It was also noted that the development of the cranial base within the studied age range occurred symmetrically relative to the midline plane of the body. Sexual dimorphism of the anterior fossa was evident in the prenatal period, with male fetuses exhibiting a larger angle compared to female fetuses, while female fetuses exhibited greater height of the crista galli of the ethmoid bone. The study also discussed the findings regarding the skull's structure in relation to function, describing it as resembling an elevated drop-shaped tank associated with the containment of cerebrospinal fluid and highly hydrated brain tissue. Additionally, the study observed the formation of the so-called Felizter's supporting arches, a ribbed system formed at the lower part of the skull tank, stiffening the shell structure. In our discussion, we compared our results with existing research in this field. We looked at earlier studies on fetal skull anatomy and reviewed findings from prenatal and neonata
{"title":"Morphometric evaluation of the anterior cranial fossa during the prenatal stage in humans and its clinical implications.","authors":"Wojciech Derkowski, Alicja Kedzia, Krzysztof Dudek, Michal Glonek","doi":"10.1101/2024.09.13.612902","DOIUrl":"https://doi.org/10.1101/2024.09.13.612902","url":null,"abstract":"The research presents findings from a study on the development of the skull and brain in human fetuses, specifically focusing on the anterior cranial fossa. This area provides protection for the frontal lobes, which are crucial for human personality development later in life. The study describes the anatomical structure of the anterior cranial fossa during the prenatal period and examines disorders that may lead to congenital defects. The aim was to assess the anterior cranial fossa during prenatal development using innovative computer image processing techniques not previously applied in this anatomical area. A metrological analysis of the human anterior cranial fossa was conducted at various developmental stages, and the study explored the relationship between selected dimensions and developmental age. It compared the development of the anterior cranial fossa to that of the other two cranial fossae, investigating symmetry during development and sexual dimorphism of the anterior fossa and skull base before birth. The study also considered clinical aspects, including a mechanical model of developing skull based on obtained results, enabling the approximation of the pathomechanism of congenital skull and brain defects and potential treatment options. The study included a collection of 77 human fetuses aged between 10 and 27 weeks of gestation. Computer image processing techniques were employed, representing a novelty in neuroanatomical research. The study also discussed the advantages of computerized image acquisition and measurement methods over traditional anatomical preparation methods, particularly due to the possibility of non-contact measurements, crucial for delicate neural tissue of fetal brains. Detailed results obtained were presented along with their statistical analysis. The study found that during the development of the human cranial base, the angle of the anterior cranial fossa decreased, compensated by an increase in the angle of the middle cranial fossa. It was also noted that the development of the cranial base within the studied age range occurred symmetrically relative to the midline plane of the body. Sexual dimorphism of the anterior fossa was evident in the prenatal period, with male fetuses exhibiting a larger angle compared to female fetuses, while female fetuses exhibited greater height of the crista galli of the ethmoid bone. The study also discussed the findings regarding the skull's structure in relation to function, describing it as resembling an elevated drop-shaped tank associated with the containment of cerebrospinal fluid and highly hydrated brain tissue. Additionally, the study observed the formation of the so-called Felizter's supporting arches, a ribbed system formed at the lower part of the skull tank, stiffening the shell structure. In our discussion, we compared our results with existing research in this field. We looked at earlier studies on fetal skull anatomy and reviewed findings from prenatal and neonata","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1101/2024.09.13.612906
Juliane Glaser, Giulia Cova, Beatrix Fauler, Cesar Prada-Medina, Virginie Stanislas, Mai H.Q. Phan, Robert Schopflin, Yasmin Aktas, Martin Franke, Guillaume Andrey, Christina Paliou, Verena Laupert, Wing-Lee Chan, Lars Wittler, Thorsten Mielke, Stefan Mundlos
Mammalian genomes are scattered with transposable elements (TEs). TEs are epigenetically silenced to prevent harmful effects caused by either global activation leading to genome instability or insertional mutation disturbing gene transcription. However, whether the activation of a single element can contribute to pathological phenotypes without directly affecting gene expression is largely unknown. Here, we show that tissue-specific expression of a TE in the embryo leads to the production of viral-like particles (VLPs) which can affect organ formation. Failure to silence an LTR retrotransposon inserted upstream of the Fgf8 gene results in its coexpression with Fgf8 in the developing embryo. While local gene regulation is unaffected, the LTR retrotransposon participates in chromatin folding at the locus and adopts the expression of the regulatory domain it is located in. This drives the production of VLPs in the Fgf8-expressing cells of the developing limb, triggering apoptotic cell death at the time of digit outgrowth and resulting in a limb malformation resembling human ectrodactyly. This phenotype can be rescued by knock-out or knock-in of the retrotransposon causing mutations preventing its full retroviral cycle. Insertion of the same element at other developmental loci faithfully recapitulates expression according to the neighboring regulatory activity. Our findings provide a mechanism by which TE insertion is incorporated into the local genomic regulatory landscape and show how VLP production in post-implantation embryos can interfere with organ formation.
{"title":"Enhancer adoption by an LTR retrotransposon generates viral-like particles causing developmental limb phenotypes","authors":"Juliane Glaser, Giulia Cova, Beatrix Fauler, Cesar Prada-Medina, Virginie Stanislas, Mai H.Q. Phan, Robert Schopflin, Yasmin Aktas, Martin Franke, Guillaume Andrey, Christina Paliou, Verena Laupert, Wing-Lee Chan, Lars Wittler, Thorsten Mielke, Stefan Mundlos","doi":"10.1101/2024.09.13.612906","DOIUrl":"https://doi.org/10.1101/2024.09.13.612906","url":null,"abstract":"Mammalian genomes are scattered with transposable elements (TEs). TEs are epigenetically silenced to prevent harmful effects caused by either global activation leading to genome instability or insertional mutation disturbing gene transcription. However, whether the activation of a single element can contribute to pathological phenotypes without directly affecting gene expression is largely unknown. Here, we show that tissue-specific expression of a TE in the embryo leads to the production of viral-like particles (VLPs) which can affect organ formation. Failure to silence an LTR retrotransposon inserted upstream of the Fgf8 gene results in its coexpression with Fgf8 in the developing embryo. While local gene regulation is unaffected, the LTR retrotransposon participates in chromatin folding at the locus and adopts the expression of the regulatory domain it is located in. This drives the production of VLPs in the Fgf8-expressing cells of the developing limb, triggering apoptotic cell death at the time of digit outgrowth and resulting in a limb malformation resembling human ectrodactyly. This phenotype can be rescued by knock-out or knock-in of the retrotransposon causing mutations preventing its full retroviral cycle. Insertion of the same element at other developmental loci faithfully recapitulates expression according to the neighboring regulatory activity. Our findings provide a mechanism by which TE insertion is incorporated into the local genomic regulatory landscape and show how VLP production in post-implantation embryos can interfere with organ formation.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1101/2024.09.13.612925
Tess D. Fasteen, Melody R. Hernandez, Robert A. Policastro, Maria C. Sterrett, Gabriel E. Zentner, Jason M. Tennessen
The Estrogen-Related Receptor (ERR) family of nuclear receptors (NRs) serve key roles in coordinating triglyceride (TG) accumulation with juvenile growth and development. In both insects and mammals, ERR activity promotes TG storage during the post-embryonic growth phase, with loss-of-function mutations in mouse Esrra and Drosophila melanogaster dERR inducing a lean phenotype. However, the role of insect ERRs in controlling TG accumulation within adipose tissue remains poorly understood, as previous transcriptomic and metabolomic studies relied on whole animal analyses. Here we address this shortcoming by using tissue-specific approaches to examine the role of dERR in regulating lipid metabolism within the Drosophila larval fat body. We find that dERR autonomously promotes TG accumulation within fat body cells and regulates expression of genes involved in glycolysis, β-oxidation, and mevalonate metabolism. As an extension of these results, we not only discovered that dERR mutant fat bodies exhibit decreased expression of known dHNF4 target genes but also found that dHNF4 activity is decreased in dERR mutants. Overall, our findings indicate that dERR plays a multifaceted role in the larval fat body to coordinate lipid storage with developmental growth and hint at a conserved mechanism by which ERR and HNF4 homologs coordinately regulate metabolic gene expression.
{"title":"The Drosophila Estrogen-Related Receptor promotes triglyceride storage within the larval fat body","authors":"Tess D. Fasteen, Melody R. Hernandez, Robert A. Policastro, Maria C. Sterrett, Gabriel E. Zentner, Jason M. Tennessen","doi":"10.1101/2024.09.13.612925","DOIUrl":"https://doi.org/10.1101/2024.09.13.612925","url":null,"abstract":"The Estrogen-Related Receptor (ERR) family of nuclear receptors (NRs) serve key roles in coordinating triglyceride (TG) accumulation with juvenile growth and development. In both insects and mammals, ERR activity promotes TG storage during the post-embryonic growth phase, with loss-of-function mutations in mouse <em>Esrra</em> and <em>Drosophila melanogaster dERR</em> inducing a lean phenotype. However, the role of insect ERRs in controlling TG accumulation within adipose tissue remains poorly understood, as previous transcriptomic and metabolomic studies relied on whole animal analyses. Here we address this shortcoming by using tissue-specific approaches to examine the role of dERR in regulating lipid metabolism within the <em>Drosophila</em> larval fat body. We find that dERR autonomously promotes TG accumulation within fat body cells and regulates expression of genes involved in glycolysis, β-oxidation, and mevalonate metabolism. As an extension of these results, we not only discovered that <em>dERR</em> mutant fat bodies exhibit decreased expression of known dHNF4 target genes but also found that dHNF4 activity is decreased in <em>dERR</em> mutants. Overall, our findings indicate that dERR plays a multifaceted role in the larval fat body to coordinate lipid storage with developmental growth and hint at a conserved mechanism by which ERR and HNF4 homologs coordinately regulate metabolic gene expression.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electric eels (Electrophorus) are renowned for their ability to generate electric discharge, which is used for prey capture and defense. Their electric organs (EOs) are located along the lateral-ventral region of the tail and contain electrocytes, which are multinucleated syncytium cells. Two major hypotheses for the electrocyte origin are proposed: (1) muscle fibers or their precursors, and (2) mesodermal cells not via muscle lineage. In this study, we demonstrate the likely molecular mechanisms and processes involved in this differentiation, supporting the second hypothesis. We report the regional differences in cell morphology within the main EO (mEO) of Electrophorus. The cell morphology and distribution from the ventral terminal to the dorsal region of the mEO suggest the segregation of progenitors from the ventral cluster and their gradual transformation into mature multinucleated electrocytes via the layering and proliferation stages along the dorsal axis. Myosin-positive muscle cells were not included in the mEO differentiation process. Immunohistochemistry revealed strong expression of sodium-potassium adenosine triphosphatase (Na+/K+-ATPase), a key component in generating electric discharge in the mEO, across most mEO regions, except in the ventral cluster cells. Based on these observations, we propose that electrocyte progenitors develop from ventral cluster cells in the mEO and differentiate into mature multinucleated cells as they migrate dorsally. This is the first report to approach the developmental process of Electrophorus electrocytes from cell morphology and genetic profiles. Our findings represent a breakthrough in understanding the differentiation of electrocytes during the growth stages of Electrophorus.
{"title":"Ventral-to-dorsal electrocyte development in electric organs of electric eel (Electrophorus).","authors":"Sinlapachai Senarat, Ayako Matsumoto, Shintaro Sakaki, Daichi Tsuzuki, Kazuko Uchida, Makoto Kuwahara, Eiichi Hondo, Atsuo Iida","doi":"10.1101/2024.08.21.606117","DOIUrl":"https://doi.org/10.1101/2024.08.21.606117","url":null,"abstract":"Electric eels (Electrophorus) are renowned for their ability to generate electric discharge, which is used for prey capture and defense. Their electric organs (EOs) are located along the lateral-ventral region of the tail and contain electrocytes, which are multinucleated syncytium cells. Two major hypotheses for the electrocyte origin are proposed: (1) muscle fibers or their precursors, and (2) mesodermal cells not via muscle lineage. In this study, we demonstrate the likely molecular mechanisms and processes involved in this differentiation, supporting the second hypothesis. We report the regional differences in cell morphology within the main EO (mEO) of Electrophorus. The cell morphology and distribution from the ventral terminal to the dorsal region of the mEO suggest the segregation of progenitors from the ventral cluster and their gradual transformation into mature multinucleated electrocytes via the layering and proliferation stages along the dorsal axis. Myosin-positive muscle cells were not included in the mEO differentiation process. Immunohistochemistry revealed strong expression of sodium-potassium adenosine triphosphatase (Na+/K+-ATPase), a key component in generating electric discharge in the mEO, across most mEO regions, except in the ventral cluster cells. Based on these observations, we propose that electrocyte progenitors develop from ventral cluster cells in the mEO and differentiate into mature multinucleated cells as they migrate dorsally. This is the first report to approach the developmental process of Electrophorus electrocytes from cell morphology and genetic profiles. Our findings represent a breakthrough in understanding the differentiation of electrocytes during the growth stages of Electrophorus.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-13DOI: 10.1101/2024.09.13.612840
Gauthier Toulouse, William Jarassier, Valerie Morin, Fabien Le Grand, Christophe Marcelle
Myogenesis in amniotes unfolds through two consecutive waves. The primary myotube lineage is characterized by the expression of slow myosin, sometimes in combination with fast myosin, and may serve as a scaffold for the secondary lineage, which expresses exclusively fast myosin. The embryonic origin of these two lineages, their relationship, and their connection to adult muscle stem cells are unknown. Here, we employed innovative strategies, combining novel TCF-LEF/β-catenin signaling reporters with the precise spatiotemporal control of in vivo electroporation in avian embryos, to track limb muscle progenitors from early migration to late fetal stages. Strikingly, we uncovered two distinct progenitor populations co-existing from the earliest stages of limb myogenesis, with specific developmental fates: reporter-positive progenitors exclusively form primary myotubes, while reporter-negative progenitors generate secondary myotubes and adult muscle stem cells. Furthermore, we uncovered a novel function of TCF-LEF/β-catenin signaling in regulating the spatial organization of the primary myotube lineage via CXCR4-mediated control of myoblast migration, likely contributing to its proposed organizing function. By redefining the embryonic origins of these myogenic populations, our findings not only resolve a longstanding question in muscle biology but also provide a crucial molecular entry point for understanding the cellular and molecular underpinnings of muscle fiber type diversity and function.
{"title":"Early lineage segregation of primary myotubes from secondary myotubes and adult muscle stem cells.","authors":"Gauthier Toulouse, William Jarassier, Valerie Morin, Fabien Le Grand, Christophe Marcelle","doi":"10.1101/2024.09.13.612840","DOIUrl":"https://doi.org/10.1101/2024.09.13.612840","url":null,"abstract":"Myogenesis in amniotes unfolds through two consecutive waves. The primary myotube lineage is characterized by the expression of slow myosin, sometimes in combination with fast myosin, and may serve as a scaffold for the secondary lineage, which expresses exclusively fast myosin. The embryonic origin of these two lineages, their relationship, and their connection to adult muscle stem cells are unknown. Here, we employed innovative strategies, combining novel TCF-LEF/β-catenin signaling reporters with the precise spatiotemporal control of in vivo electroporation in avian embryos, to track limb muscle progenitors from early migration to late fetal stages. Strikingly, we uncovered two distinct progenitor populations co-existing from the earliest stages of limb myogenesis, with specific developmental fates: reporter-positive progenitors exclusively form primary myotubes, while reporter-negative progenitors generate secondary myotubes and adult muscle stem cells. Furthermore, we uncovered a novel function of TCF-LEF/β-catenin signaling in regulating the spatial organization of the primary myotube lineage via CXCR4-mediated control of myoblast migration, likely contributing to its proposed organizing function. By redefining the embryonic origins of these myogenic populations, our findings not only resolve a longstanding question in muscle biology but also provide a crucial molecular entry point for understanding the cellular and molecular underpinnings of muscle fiber type diversity and function.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1101/2024.09.11.612533
Bowen Shen, Fei Zhou, Peter Nemes
Detection of trace-sensitive signals is a current challenge is single-cell mass spectrometry (MS) proteomics. Separation prior to detection improves the fidelity and depth of proteome identification and quantification. We recently recognized capillary electrophoresis (CE) electrospray ionization (ESI) for ordering peptides into mass-to-charge (m/z)-dependent series, introducing electrophoresis-correlative (Eco) data-independent acquisition. Here, we demonstrate that these correlations based on electrophoretic mobility in the liquid phase are transferred into the gas phase, essentially temporally ordering the peptide ions into charge-dependent ion mobility (IM, 1/K0) trends (> 0.97). Rather than sampling the entire IM region broadly, we pursued these predictable correlations to schedule narrower frames. Compared to classical ddaPASEF, Eco-framing significantly enhanced the resolution of IM on a trapped ion mobility mass spectrometer (timsTOF PRO). This approach returned ~50% more proteins from HeLa proteome digests approximating to one-to-two cells, identifying ~962 proteins from ~200 pg in <20 min of effective electrophoresis, without match-between-runs. As a proof of principle, we deployed Eco-ddaPASEF on 1,157 proteins by analyzing <4% of the total proteome in single, yolk-laden embryonic stem cells (~80-micron) that were isolated from the animal cap of the South African clawed frog (Xenopus laevis). Quantitative profiling of 9 different blastomeres revealed detectable differences among these cells, which are normally fated to form the ectoderm but retain pluripotentiality. Eco-framing effectively deepens the proteome sensitivity in IMS using ddaPASEF, raising the possibility of a proteome-driven classification of embryonic cell differentiation.
{"title":"Electrophoresis-Correlative Ion Mobility Deepens Single-cell Proteomics in Capillary Electrophoresis Mass Spectrometry","authors":"Bowen Shen, Fei Zhou, Peter Nemes","doi":"10.1101/2024.09.11.612533","DOIUrl":"https://doi.org/10.1101/2024.09.11.612533","url":null,"abstract":"Detection of trace-sensitive signals is a current challenge is single-cell mass spectrometry (MS) proteomics. Separation prior to detection improves the fidelity and depth of proteome identification and quantification. We recently recognized capillary electrophoresis (CE) electrospray ionization (ESI) for ordering peptides into mass-to-charge (m/z)-dependent series, introducing electrophoresis-correlative (Eco) data-independent acquisition. Here, we demonstrate that these correlations based on electrophoretic mobility in the liquid phase are transferred into the gas phase, essentially temporally ordering the peptide ions into charge-dependent ion mobility (IM, 1/K0) trends (> 0.97). Rather than sampling the entire IM region broadly, we pursued these predictable correlations to schedule narrower frames. Compared to classical ddaPASEF, Eco-framing significantly enhanced the resolution of IM on a trapped ion mobility mass spectrometer (timsTOF PRO). This approach returned ~50% more proteins from HeLa proteome digests approximating to one-to-two cells, identifying ~962 proteins from ~200 pg in <20 min of effective electrophoresis, without match-between-runs. As a proof of principle, we deployed Eco-ddaPASEF on 1,157 proteins by analyzing <4% of the total proteome in single, yolk-laden embryonic stem cells (~80-micron) that were isolated from the animal cap of the South African clawed frog (Xenopus laevis). Quantitative profiling of 9 different blastomeres revealed detectable differences among these cells, which are normally fated to form the ectoderm but retain pluripotentiality. Eco-framing effectively deepens the proteome sensitivity in IMS using ddaPASEF, raising the possibility of a proteome-driven classification of embryonic cell differentiation.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1101/2024.09.11.612529
Çağrı Çevrim, Béryl Laplace-Builhé, Ko Sugawara, Maria Lorenza Rusciano, Nicolas Labert, Jacques Brocard, Alba Almazán, Michalis Averof
High resolution live imaging of regeneration presents unique challenges, due to the nature of the specimens (large mobile animals), the duration of the process (spanning days or weeks), and the fact that cellular resolution must be achieved without damage caused by lengthy exposures to light. Here, we develop a method for live imaging that captures the entire process of leg regeneration, spanning up to 10 days, at cellular resolution, in the crustacean Parhyale hawaiensis. Our method allows (1) mounting and long-term live imaging of regenerating legs under conditions that yield high spatial and temporal resolution but minimise photodamage, (2) fixing and in situ staining of the regenerated legs that were imaged, to identify cell fates, and (3) computer-assisted cell tracking to determine the cell lineages and progenitors of identified cells. The method is optimised to limit light exposure while maximising tracking efficiency. Combined with appropriate cell-type-specific markers, this method may allow the description of cell lineages for every regenerated cell type in the limb.
{"title":"Long-term live imaging, cell identification and cell tracking in regenerating crustacean legs","authors":"Çağrı Çevrim, Béryl Laplace-Builhé, Ko Sugawara, Maria Lorenza Rusciano, Nicolas Labert, Jacques Brocard, Alba Almazán, Michalis Averof","doi":"10.1101/2024.09.11.612529","DOIUrl":"https://doi.org/10.1101/2024.09.11.612529","url":null,"abstract":"High resolution live imaging of regeneration presents unique challenges, due to the nature of the specimens (large mobile animals), the duration of the process (spanning days or weeks), and the fact that cellular resolution must be achieved without damage caused by lengthy exposures to light. Here, we develop a method for live imaging that captures the entire process of leg regeneration, spanning up to 10 days, at cellular resolution, in the crustacean Parhyale hawaiensis. Our method allows (1) mounting and long-term live imaging of regenerating legs under conditions that yield high spatial and temporal resolution but minimise photodamage, (2) fixing and in situ staining of the regenerated legs that were imaged, to identify cell fates, and (3) computer-assisted cell tracking to determine the cell lineages and progenitors of identified cells. The method is optimised to limit light exposure while maximising tracking efficiency. Combined with appropriate cell-type-specific markers, this method may allow the description of cell lineages for every regenerated cell type in the limb.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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