Gen. Comp. Endocrinol. [JOURNAL]
Sun
200 papers
Fat mass and obesity associated gene and homeobox transcription factor iriquois-3 mRNA profiles in the metabolic tissues of zebrafish are modulated by feeding and food deprivation.
Karimzadeh K, Uju C, Zahmatkesh A … +1 more , Unniappan S
Gen Comp Endocrinol · 2025 Jan · PMID 39414090 · Publisher ↗
Fat mass and obesity associated gene (FTO) has been strongly associated with obesity, and it is functionally linked to the homeobox transcription factor iriquois-3 (IRX3). In mammals, FTO and IRX3 are involved in the reg...
Fat mass and obesity associated gene (FTO) has been strongly associated with obesity, and it is functionally linked to the homeobox transcription factor iriquois-3 (IRX3). In mammals, FTO and IRX3 are involved in the regulation of food intake and metabolism. This study aimed to determine whether FTO and IRX3are affected by feeding and food unavailability. FTO and IRX3 mRNA and protein were found widely distributed in all tissues examined, including the brain, muscle, gut, and liver. Postprandial increase in the abundance of FTO and IRX3 mRNAs was observed in metabolic tissues of both male and female zebrafish at 1 h post-feeding. Meanwhile, their expression in the brain and gut decreased at 3 h post-feeding, reaching preprandial levels. Additionally, FTO and IRX3 mRNA abundance in examined tissues increased after 7 days of food deprivation, but substantially decreased after refeeding for 24 h. In summary, we report that both FTO and IRX3 are meal-sensitive genes in zebrafish. The fasting-induced increase suggests a possible appetite regulatory role for FTO and IRX3 in zebrafish. These findings highlight the importance of FTO and IRX3 in appetite and metabolic regulation in zebrafish.
Identification, expression, and function analysis of Rbpms2 splicing variants in Japanese flounder gonad.
Liu C, Zhang L, Xia Y … +3 more , Li K, Wu J, Zhang J
Gen Comp Endocrinol · 2024 Dec · PMID 39414089 · Publisher ↗
Rbpms2, an RNA-binding protein with multiple splicing (Rbpms), can interact with RNAs to involve oocyte development, thereby influencing female sex differentiation in vertebrates. Here, two splicing variants of the Rbpms...
Rbpms2, an RNA-binding protein with multiple splicing (Rbpms), can interact with RNAs to involve oocyte development, thereby influencing female sex differentiation in vertebrates. Here, two splicing variants of the Rbpms2 gene from Japanese flounder (Paralichthys olivaceus) were identified, namely Rbpms2.1 and Rbpms2.2. The two variants exhibited 98.22 % amino acid homology, both featuring an RNA recognition motif (RRM) domain spanning positions 98-170 amino acids. They were relatively conserved throughout phylogenetic evolution. Differently, the C-terminal region of the Rbpms2.1 contains five additional sequential amino acids (-VRDQP-) compared to Rbpms2.2. The real-time qPCR results demonstrated that Rbpms2.1 and Rbpms2.2 had relatively abundant expression in the gonads of adult Japanese flounder, with higher expression levels in the ovary compared to the testis (P < 0.05). In situ hybridization results showed strong positive expression of Rbpms2 mRNA in oocytes at stages I-III during the V stage of ovarian development. In the testis atstage IV, the expression of Rbpms2 mRNA was mainly concentrated on primary spermatocytes. Importantly, Rbpms2 binding sites were found in the 3'UTR, 5'UTR, and ORF regions of the sex-related genes including dmrt1, sox9, amh, foxl2, and wnt4. siRNA interference and overexpression analysis of Rbpms2.1 and Rbpms2.2 in primary cells of the ovary and testis showed that Rbpms2 can repress the expression of male-related genes (dmrt1, sox9, and amh) and significantly promote the expression of female-related genes (foxl2 and wnt4). Our results revealed that Rbpms2 may play a critical role by targeting the sex-related genes in the gonad development of Japanese flounder.
Non-invasive monitoring of adrenocortical activity in the Gould's wattled bat (Chalinolobus gouldii).
Sandy LK, Fanson KV, Griffiths SR … +3 more , Robert KA, Palme R, Dimovski AM
Gen Comp Endocrinol · 2024 Dec · PMID 39368757 · Publisher ↗
Although bats are the second most species-rich mammalian order, very little is known about their endocrine physiology. Glucocorticoids (GCs) are commonly associated with the stress response, but also modulate vital physi...
Although bats are the second most species-rich mammalian order, very little is known about their endocrine physiology. Glucocorticoids (GCs) are commonly associated with the stress response, but also modulate vital physiological functions which help animals adapt to their environment. Understanding normal patterns of adrenocortical activity can provide valuable insights into a species' fitness. Non-invasive hormone monitoring via faecal samples provides an integrated measure of adrenocortical activity while minimising stress on the animal but must be properly validated to ensure reliable results. The goal of this study was to validate an enzyme immunoassay for monitoring faecal glucocorticoid metabolites (FGMs) in a common Australian insectivorous bat species, the Gould's wattled bat (Chalinolobus gouldii). We compared the performance of five assays for monitoring changes in FGMs following capture and transfer of C.gouldii from the wild to captivity. Four of the five assays detected a significant increase in FGMs following capture, but the magnitude of the increase and consistency across individuals differed considerably. We selected the UVM-69a assay as the best performing assay to then describe normative patterns of adrenocortical activity in the species. Males had higher FGM levels than females, and juveniles had higher FGM levels than adults. Individuals with poorer body condition had higher FGM levels. We also demonstrate seasonal patterns of FGMs with higher levels in March and April corresponding with reproductive up-regulation and lower levels in May and November. Our study is the first of its kind to examine adrenocortical activity in an Australian insectivorous bat and provides a valuable tool for studying this species. Understanding adrenal function in common species such as C.gouldii can shed light on the physiological mechanisms facilitating survival and success in changing environments.
Functional characterization of CCHamides and deorphanization of their receptors in the yellow fever mosquito, Aedes aegypti.
Tan J, Neupert S, Paluzzi JP
Gen Comp Endocrinol · 2024 Dec · PMID 39368756 · Publisher ↗
As a widely distributed anthropophilic mosquito species and vector of various arboviruses, Aedes aegypti poses a significant threat to human health on a global scale. Investigating mosquito neuropeptides allows us to bet...
As a widely distributed anthropophilic mosquito species and vector of various arboviruses, Aedes aegypti poses a significant threat to human health on a global scale. Investigating mosquito neuropeptides allows us to better understand their physiology. The neuropeptides CCHamide1 (CCHa1) and CCHamide2 (CCHa2) along with their associated G protein-coupled receptors (CCHa1R and CCHa2R) were recently identified and studied across insects. However, expression profiles and physiological roles of CCHamides and their receptors in many other insects, including A. aegypti, remain unclear. This research aimed to quantify and localize the expression of CCHamides along with their receptors and gain insight on their physiological function in the yellow fever mosquito. RT-qPCR analysis revealed transcript abundance of CCHamides and receptors changes over development. Differential expression was also observed in tissues/organs of adult mosquitoes indicating CCHa1 and CCHa2 transcripts are enriched in the midgut, while receptors are expressed across various tissues. CCHamide immunoreactivity was observed in neurons in the brain and ventral nerve cord along with enteroendocrine cells in the posterior midgut adjacent to the midgut-hindgut junction, corroborating their transcript expression profiles. Using different mass spectrometrical approaches, presence of CCHamides were confirmed in the brain of both sexes, including the pars intercerebralis of female mosquitoes, as well as in the gut of adult mosquitoes. For chemical identification of predicted CCHamides, we analyzed brain and gut extracts by ESI-Q Exactive Orbitrap MS and resulting fragmentations confirmed CCHa1 and CCHa2 in brain and midgut samples of both male and female mosquitoes. A heterologous functional assay was used to confirm the specificity and sensitivity of the two CCHamide receptors by assessing their activation in response to diverse mosquito peptides, which confirmed CCHa1 and CCHa2 as natural ligands. Finally, using a capillary feeder (CAFE) bioassay, our results suggest that CCHa2 modulates feeding behaviour in female mosquitoes.
Low-temperature-induced disruption of reproductive axis and sperm vitality via stress axis in Monopterus albus.
Gao X, Ke L, Wang L … +6 more , Zheng S, Liu X, Hu W, Tong G, Li Z, Hu G
Gen Comp Endocrinol · 2024 Dec · PMID 39368755 · Publisher ↗
The ricefield eel (Monopterus albus) is inherently timid and highly sensitive to stress. Our previous studies have shown that low-temperature weather could significantly affect the sperm vitality of ricefield eels. This...
The ricefield eel (Monopterus albus) is inherently timid and highly sensitive to stress. Our previous studies have shown that low-temperature weather could significantly affect the sperm vitality of ricefield eels. This study aims to investigate the regulatory mechanism of low-temperature effects on testicular function and sperm vitality in ricefield eels. The ricefield eels were initially reared at low (10 °C) and normal (25 °C) temperatures for 24 h. Low temperatures were found to induce the expression of pituitary pro-opiomelanocortin (POMC) and testes insulin-like growth factor-binding protein 1 (IGFBP1) mRNA expression, suggesting that the reduction in sperm vitality could be attributed to the activation of the stress axis. Moreover, the results indicated a significant decrease in sperm occupancy and count in the testes, along with a reduced percentage of motile sperm. Subsequent transcriptome analysis showed substantial inhibition of reproductive hormone genes (gnrh1, lh, and fsh) in the brain and pituitary, and downregulation of meiosis-related genes (dmc1, rec8, and sycp3) in the testes. These findings suggest that low temperatures might disrupt testicular development and spermatogenesis by inhibiting the reproductive axis. Metabolomics analysis then demonstrated a significant reduction in the levels of metabolites related to glycolysis, fatty acid metabolism, and the tricarboxylic acid (TCA) cycle in the testes after low-temperature treatment. Interestingly, the expression of zona pellucida sperm-binding proteins 3 and 4 (ZP3 and ZP4), which may affect sperm vitality and spermatogenesis, was significantly induced by low temperatures in the testes. In conclusion, these findings suggested that low temperatures might affect testicular function and sperm vitality by simultaneously activating the stress axis and inhibiting the reproductive axis and energy metabolism in the testes.
Molecular characterization and stage-dependent gene expression of gonadotropin receptors in Pacific bluefin tuna, Thunnus orientalis, ovarian follicles.
Higuchi K, Kazeto Y, Nyuji M … +5 more , Soma S, Takashi T, Okita K, Hayashida T, Gen K
Gen Comp Endocrinol · 2024 Dec · PMID 39368754 · Publisher ↗
To understand the physiological mechanisms by which pituitary-derived gonadotropins (Gths), follicle-stimulating hormone (Fsh) and luteinizing hormone (Lh) regulate asynchronous oocyte development, we investigated the fu...
To understand the physiological mechanisms by which pituitary-derived gonadotropins (Gths), follicle-stimulating hormone (Fsh) and luteinizing hormone (Lh) regulate asynchronous oocyte development, we investigated the function and expression of Fsh and Lh receptors (Fshr and Lhr, respectively) in Pacific bluefin tuna (PBT, Thunnus orientalis). As a first, we cloned the full-length cDNAs encoding PBT Fshr and Lhr. Recombinant PBT Fsh and Lh single-chain proteins were produced in abundance using stable CHO-DG44 cell lines and were subsequently purified from the culture medium, culminating in their yields being 87.0 and 88.2%, respectively. An in vitro reporter assay using homologous recombinant Gths revealed that PBT Fshr and Lhr responded strongly to their corresponding ligands in a dose-dependent manner, with no cross-activation over a wide range of concentrations. Moreover, quantitative expression analysis of Fshr and Lhr at the follicle level showed that fshr gene expression was highly upregulated in the ovarian follicles through vitellogenesis, while lhr expression was significantly upregulated and peaked in fully vitellogenic ovarian follicles. These findings suggest that asynchronous-type oocyte development is primarily attributed to the differential function and expression of Gthrs, rather than the ligand, in PBT.
Special issue of the seventh biennial meeting of the North American Society for comparative endocrinology (Sociedad Norteamericana de Endocrinología Comparada; Societé Nord-américaine de l'endocrinologie comparée).
Langlois VS, Orozco A, Zandawala M … +1 more , Sheridan MA
Gen Comp Endocrinol · 2024 Dec · PMID 39362610 · Publisher ↗
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Characterization of gonadotropins and their receptors in a chondrichthyan, Scyliorhinus canicula, fills a gap in the understanding of their coevolution.
Jeanne F, Pilet S, Klett D … +5 more , Combarnous Y, Bernay B, Dufour S, Favrel P, Sourdaine P
Gen Comp Endocrinol · 2024 Nov · PMID 39326529 · Publisher ↗
In Gnathostomes, reproduction is mainly controlled by the hypothalamic-pituitary-gonadal (HPG) axis, with the involvement of the pituitary gonadotropic hormones (GTH), follicle-stimulating hormone (FSH) and luteinizing h...
In Gnathostomes, reproduction is mainly controlled by the hypothalamic-pituitary-gonadal (HPG) axis, with the involvement of the pituitary gonadotropic hormones (GTH), follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which activate their cognate receptors, FSHR and LHR, expressed in gonads. Each GTH consists of a common α subunit and of a specific FSHβ or LHβ subunit. Chondrichthyes (holocephalans and elasmobranchs) is a sister group of bony vertebrates. This position is highly favorable for the understanding of the evolution of endocrine regulations of reproduction among gnathostomes. Surprisingly, the characterization of gonadotropins and their receptors is still limited in chondrichthyes. In the present study, GTH and GTHR sequences have been identified from several chondrichthyan genomes, and their primary structures were analyzed relative to human orthologs. 3D models of GTH/GTHR interaction were built, highlighting the importance of the receptor hinge region for ligand recognition. Functional hormone-receptor interactions have been studied in HEK cells using the small-spotted catshark (Scyliorhinus canicula) recombinant proteins and showed that LHR was specifically activated by LH whereas FSHR was activated by both FSH and LH. Expression profiles of GTHs and their receptors were explored by real-time PCR, in situ hybridization and immunohistochemistry during spermatogenesis, along the male genital tract and other tissues, as well as in some female tissues for comparison. Tissue-expression analyses showed that the highest levels were observed for fshr transcripts in testis and ovary and for lhr in specific extragonadal tissues. The two receptors were expressed at all stages of spermatogenesis by both germ cells and somatic cells, including undifferentiated spermatogonia, spermatocytes, spermatids, somatic precursors and Sertoli cells; differentiated Leydig cells being absent in the testis of S. canicula. Receptors were also expressed by the lymphomyeloid epigonal tissue and the testicular tubules. These results, suggest a wide range of gonadotropin-regulated functions in Elasmobranchs, as well as functional redundancy during spermatogenesis. These extended functions are discussed in an evolutionary context in which the specificity of gonadotropin signaling must have contributed to the evolution of gonadal cells' morphology and function.
Gene expression in the hypothalamic-pituitary-thyroid axis in Seriola rivoliana early larvae development at different temperatures.
Campos-Ramos R, Vázquez-Islas G, Calixto-Heredia LM … +1 more , Guerrero-Tortolero DA
Gen Comp Endocrinol · 2024 Nov · PMID 39321860 · Publisher ↗
We analyzed the expression of genes involved in the hypothalamic-pituitary-thyroid axis (HPT-axis) in the longfin yellowtail Seriola rivoliana early larva, including temperature effects (22, 26 and 28 °C) and days of dev...
We analyzed the expression of genes involved in the hypothalamic-pituitary-thyroid axis (HPT-axis) in the longfin yellowtail Seriola rivoliana early larva, including temperature effects (22, 26 and 28 °C) and days of development (day one, day two, and day six after hatching). We aimed to determine if egg and larval incubation at different temperatures could disrupt this critical endocrine axis, which, in an aquaculture context, it could provoke mortality during early metamorphosis. There was a significant interaction between temperature and developmental timing on the relative expression of thyrotropin releasing hormone (trh). Larvae at 22 °C was the longest and increased more trh expression than larvae at higher temperatures. Interestingly, thyrotropin stimulating hormone (tsh) was highly expressed after hatching. Subsequently, it was downregulated at any temperature at least until day four, suggesting a temporal inhibition of the HPT axis. Therefore, we suggest that tsh-binding (tshr) to follicles should have occurred from hatching, creating a further "cascade effect" of upregulation of larval thyroglobulin (tg) from day two in a temperature-dependent manner. Consequently, new thyroid hormones should have been produced after yolk sac absorption. The above may indicate a narrow window of larval survival, where the larval transition from endogenous to exogenous feeding would depend on the correct timing to synthesize tg. Temperature significantly affected the expressions of deiodinase 1 (dio1-downregulated) and deiodinase 2 (dio2-upregulated) after hatching. The expressions of thyroid receptors alpha (trα) and beta (trβ) remained constant after hatching without significant effects of temperature and days of development. Then, the differential expression on day six showed that all HPT-axis transcripts increased their expressions as larvae developed, which suggested a functional HPT. Finally, there was no evidence that any temperature would disrupt the endocrine's larval axis, which indicated that the longfin yellowtail has a wide temperature adaption. Nevertheless, based on tg upregulation, we suggest that larvae should be maintained around 25-26 °C after hatching for a better chance of survival and development.
Two phases of gonadal sex differentiation in zebrafish with ZZ/ZW sex determination system.
Hsu CW, Chung BC
Gen Comp Endocrinol · 2024 Nov · PMID 39303945 · Publisher ↗
Zebrafish sex chromosomes have been identified in the wild Nadia (NA) strain, and its sex determination belongs to the female-heterogametic ZZ/ZW system. Here, we investigate the correlation between ZZ/ZW sex chromosomes...
Zebrafish sex chromosomes have been identified in the wild Nadia (NA) strain, and its sex determination belongs to the female-heterogametic ZZ/ZW system. Here, we investigate the correlation between ZZ/ZW sex chromosomes in the NA strain with sex-related factors, and sort out the complicated process of sex determination in zebrafish. Two phases exist during zebrafish sex differentiation. In the first phase, ZW gonads differentiate into juvenile ovary while ZZ gonads remain indifferent. In the second phase, ZW gonads either continue ovary development or undergo female-to-male transition, while ZZ gonads undergo direct male development. The W chromosome may contribute to the first phase while the abundance of germ cells and other factors may be involved in the second phase of sex differentiation in zebrafish.
Chronic stress increases adaptive immune response over six weeks in the house sparrow, Passer domesticus.
Martinez V, Duran EMI, Kimmitt AA … +3 more , Russell KE, Jill Heatley J, Grace JK
Gen Comp Endocrinol · 2024 Nov · PMID 39293532 · Publisher ↗
The vertebrate stress response enables an organism to shift energy towards activities that promote immediate survival when facing a threat to homeostasis, but it can also have detrimental effects on organismal health. Ac...
The vertebrate stress response enables an organism to shift energy towards activities that promote immediate survival when facing a threat to homeostasis, but it can also have detrimental effects on organismal health. Acute and chronic stressors generally have contrasting effects on immune responses, but the timeline of this transition between acute and chronic stressors and their effects on immune responses remains unclear. In this study, we investigate changes in immune markers in captive house sparrows (Passer domesticus) after exposure to normal laboratory conditions, an acute stressor, and chronic stressors for 42 days. Specifically, we examined changes in baseline and stress-induced corticosterone concentrations, body condition, heterophil/lymphocyte (H:L) ratio, hemolysis-hemagglutination, and wound healing. We found that individuals exposed to a single acute stressor had significantly higher stress-induced corticosterone concentrations 24 h after stressor exposure, however this effect was reversed after 48 h. Chronic stressor exposure resulted in generally stronger adaptive immune responses, demonstrated by higher baseline and stress-induced lysis, higher baseline hemagglutination, and slower wound healing. Within-trait correlations also increased with chronic stressor exposure, suggesting limitations on phenotypic plasticity. Most of the effects of chronic stressor exposure on immune markers strengthened over the 42 days of the experiment and differences between captivity-only and treatment groups were not apparent until approximately 20 days of chronic stressor exposure. These results highlight the importance of stressor duration in understanding the effects of chronic stressor exposure on immune responses.
RhoprCAPA-2 acts as a gonadotropin regulating reproduction in adult female, Rhodnius prolixus.
Al-Dailami AN, Orchard I, Lange AB
Gen Comp Endocrinol · 2024 Nov · PMID 39260593 · Publisher ↗
CAPA peptides play diverse roles in insects, modulating muscle contraction, regulating fluid balance, and reproduction. In Rhodnius prolixus, a hematophagous insect and a vector for human Chagas disease, three CAPA pepti...
CAPA peptides play diverse roles in insects, modulating muscle contraction, regulating fluid balance, and reproduction. In Rhodnius prolixus, a hematophagous insect and a vector for human Chagas disease, three CAPA peptides are encoded by the capability gene, including RhoprCAPA-1, RhoprCAPA-2, and RhoprCAPA-PK-1. RhoprCAPA-2 is an anti-diuretic hormone in R. prolixus. Here, we explore the involvement of RhoprCAPA-2 in reproduction in adult female R. prolixus. Double-label immunohistochemistry reveals co-localization of RhoprCAPA-2-like and the glycoprotein hormone (GPA2/GPB5) subunit GPB5-like immunoreactivity in neurosecretory cells in the mesothoracic ganglionic mass and in their neurohemal sites, suggesting these peptides can be co-released to regulate physiological processes. qPCR analysis reveals changes in transcript expression levels of the RhoprCAPA receptor (CAPAR) in the fat body and reproductive tissues after feeding in adult female R. prolixus. RNA interference-mediated knockdown of CAPAR transcript decreases egg production and reduces hatching rate and survival rate in female R. prolixus. Downregulation of CAPAR decreases vitellogenin RhoprVg1 transcript expression in the fat body and deceases its receptor RhoprVgR transcript level in the ovaries; accompanied by a reduction in vitellogenin content in the fat body and hemolymph. Incubation of fat body and ovaries in vitro with RhoprCAPA-2 increases RhoprVg1 transcript expression in the fat body, vitellogenin content in the fat body culture medium, and increases RhoprVgR transcript in the ovaries. These findings implicate the CAPA signaling pathway in reproduction, with RhoprCAPA-2 acting as a gonadotropin in adult female R. prolixus.
The signalling association of glucagon-like peptide-1 and its receptors in the gastrointestinal tract and GPR40 and insulin receptor in the pancreas of sheep.
Krishnan G, Bagath M, Devaraj C … +1 more , Soren NM
Gen Comp Endocrinol · 2024 Nov · PMID 39226991 · Publisher ↗
The present study was aimed at gaining insight into the signalling relationship between glucagon-like peptide-1 (GLP-1) and its receptor (GLP-1R) in the regulation of glucose metabolism. Further, to assess the role of G-...
The present study was aimed at gaining insight into the signalling relationship between glucagon-like peptide-1 (GLP-1) and its receptor (GLP-1R) in the regulation of glucose metabolism. Further, to assess the role of G-protein-coupled receptor 40 (GPR40) and insulin receptor (INSR) in the pancreas of sheep that were supplemented with calcium salts of long-chain fatty acids (CSFAs). An experiment was carried out over a period of 60 days with eighteen sheep, and they were fed with a standard basal diet. The sheep were divided into three groups: CSFA0 (without CSFAs), while CSFA3 and CSFA5 were supplemented with 3 % and 5 % of CSFAs, respectively. Plasma concentrations of GLP-1, insulin, glucagon, and glucose were assessed every two weeks. At the end of the experiment, sheep were slaughtered, and samples of gastrointestinal tract (GIT) epithelial tissues and pancreas were collected to assess the relative expression of mRNA of GPR40, GLP-1R, and INSR. Postprandial GLP-1 and insulin were increased by 3.7-4.1 and 1.45-1.5 times, respectively, in the CSFAs-supplemented groups compared to CSFA0. Post-feeding, glucagon and glucose levels decreased in CSFA3 and CSFA5 compared to CSFA0. The results indicated that the supplementation of LCFAs increased the expression of GLP-1R in the GIT and pancreas, as well as the mRNA of GPR40 and INSR in the pancreas. Chemosensing of LCFAs by GPR40 in the pancreas triggers signalling transduction, and enhanced GLP-1 and GLP-1R resulted in moderately increased insulin secretion and reduced glucagon levels. These combined effects, along with the glucose-lowering effect of GLP-1, effectively lowered glucose levels in normoglycemic sheep.
Cloning and expression profiling of peptide YY in the brain of common carp, Cyprinus carpio.
Sudhakumari CC, Bhasker D, Kar S … +3 more , Pranoty A, Dutta-Gupta A, Senthilkumaran B
Gen Comp Endocrinol · 2024 Nov · PMID 39209004 · Publisher ↗
Peptide YY (PYY) is an anorectic brain-gut pancreatic peptide that helps in feeding regulation by reducing appetite and is well characterized in mammals. The role of PYY in relation to brain is least studied in mammals a...
Peptide YY (PYY) is an anorectic brain-gut pancreatic peptide that helps in feeding regulation by reducing appetite and is well characterized in mammals. The role of PYY in relation to brain is least studied in mammals as well as in lower vertebrates including fish, however high expression was evident in male reproductive tissue. In this regard, this study attempts to evaluate the significance of PYY in the brain of common carp, Cyprinus carpio. As a first step, the cDNA of PYY from brain of adult male carp was cloned. Following which expression analysis was performed using juvenile and adult fish. The differential distribution pattern in various regions of brain and ontogeny expression analysis indicated that PYY may involve in physiological processes related to brain-pituitary axis. In addition, a significant decrease in neuropeptide Y expression was observed upon PYY- endoribonuclease-prepared small interfering RNA transfection in brain cells, in vitro indicating plausible PYY-NPY interaction in brain-pituitary axis of common carp.
Revisiting the hormonal control of sexual dimorphism in chicken feathers.
You L, Nishio K, Kowata K … +5 more , Horikawa M, Fukuchi H, Ogoshi M, Aizawa S, Takeuchi S
Gen Comp Endocrinol · 2024 Oct · PMID 39179122 · Publisher ↗
Sexual dimorphism in plumage is widespread among avian species. In chickens, adult females exhibit countershading, characterized by dull-colored round feathers lacking fringe on the saddle, while adult males display vibr...
Sexual dimorphism in plumage is widespread among avian species. In chickens, adult females exhibit countershading, characterized by dull-colored round feathers lacking fringe on the saddle, while adult males display vibrant plumage with deeply fringed bright feathers. This dimorphism is estrogen-dependent, and administering estrogen to males transforms their showy plumage into cryptic female-like plumage. Extensive studies have shown that estrogen's role in female plumage formation requires thyroid hormone; however, the precise mechanisms of their interaction remain unclear. In this study, we investigated the roles of estrogen and thyroid hormone in creating sexual dimorphism in the structure and coloration of saddle feathers by administering each hormone to adult males and observing the resulting changes in regenerated feathers induced by plucking. RT-PCR analysis revealed that the expression of type 3 deiodinase (DIO3), responsible for thyroid hormone inactivation, correlates with fringing. Estrogen suppressed DIO3 and agouti signaling protein (ASIP) expression while stimulating BlSK1, a marker of barbule cells, resulting in female-like feathers with mottled patterns and lacking fringes. Administration of thyroxine (T4) stimulated BlSK1 and proopiomelanocortin (POMC) expression, with no effect on ASIP, leading to the formation of solid black feathers lacking fringes. Triiodothyronine (T3) significantly increased POMC expression in pulp cells in culture. Taken together, these findings suggest that estrogen promotes the formation of solid vanes by suppressing DIO3 expression, while also inducing the formation of mottled patterns through inhibition of ASIP expression and indirect stimulation of melanocortin expression via changes in local T3 concentration. This is the first report describing molecular mechanism underlying hormonal crosstalk in creating sexual dimorphism in feathers.
The annual ovarian cycle in Northern pit vipers (Bothrops atrox) using serum steroids and ultrasound of the female reproductive tract.
Emanuela Maria Vieira S, Fernandes Grego K, Henrique Blank M … +4 more , Augusto Novaes G, Perez Machado da Silveira G, Stefanini Sant'Anna S, José Garcia Pereira R
Gen Comp Endocrinol · 2024 Oct · PMID 39128814 · Publisher ↗
Knowledge on hormonal regulation of reproductive cycles in viperid snakes is still incipient, especially when it comes to females and tropical species. There is an urgent need to understand the reproduction of venomous s...
Knowledge on hormonal regulation of reproductive cycles in viperid snakes is still incipient, especially when it comes to females and tropical species. There is an urgent need to understand the reproduction of venomous snakes to improve assisted reproduction techniques and optimize the maintenance of these animals in captivity. With this in mind, we monitored Northern pit viper females year-round throughout different seasons via serum levels of progesterone (P) and estradiol (E) in conjunction with ultrasound examinations. Ovarian follicles were classified according to their size and stage of vitellogenesis in F-I and F-II (non-vitellogenic phase) or in F-III and F-IV (vitellogenic phase). During autumn and winter, five adult males were rotated among these females for reproductive pairing, which resulted in 17 copulations and 2 pregnancies in the first year and 12 copulations and 5 pregnancies in the second year. Then, we assessed changes in P4 and E2 levels according to seasons, predominant ovarian structures and the presence of embryos or eggs in the oviduct. Our findings showed high levels of E when a greater number of vitellogenic follicles were detected, indicating a possible influence of E on vitellogenesis and higher levels of P whenever eggs and embryos were visualized in the oviduct, implying its role in maintaining pregnancy. Descriptive analysis of the vipers' ovarian cycles revealed a greater number of vitellogenic follicles during winter, probably as a result of increases in E; whereas pregnancies occurred predominantly in spring, under the influence of P4. The use of ultrasound images, as a minimally invasive methodology, associated with serum steroid levels has proven to be an efficient approach in the reproductive monitoring of Northern pit vipers in vivo. In addition, these data suggest that female pit vipers under human care display a seasonal reproductive cycle, despite earlier studies involving captive males of the species indicating a lack of seasonality in sperm production and quality.
Temperature-driven changes in the neuroendocrine axis of the blue crab Callinectes sapidus during the molt cycle.
David DD, Zanetti G, Souto-Neto JA … +3 more , Sua-Cespedes CD, Lacerda JT, Castrucci AML
Gen Comp Endocrinol · 2024 Oct · PMID 39122124 · Publisher ↗
Environmental cues such as temperature induce macroscopic changes in the molting cycle of crustaceans, however, the physiological mechanisms behind these changes remain unclearWe aimed to investigate the regulatory mecha...
Environmental cues such as temperature induce macroscopic changes in the molting cycle of crustaceans, however, the physiological mechanisms behind these changes remain unclearWe aimed to investigate the regulatory mechanisms in the intermolt and premolt stages of the Callinectes sapidus molt cycle in response to thermal stimuli. The concentration of ecdysteroids and lipids in the hemolymph, and the expression of heat shock proteins (HSPs) and molt key genes were assessed at 19 °C, 24 °C and 29 °C. The premolt animals exhibited a much larger response to the colder temperature than intermolt animals. Ecdysteroids decreased drastically in premolt animals, whereas the expression of their hepatopancreas receptor (CasEcR) increased, possibly compensating for the low hemolymphatic levels at 19 °C. This decrease might be due to increased HSPs and inhibited ecdysteroidogenesis in the Y-organ. In addition, the molting-inhibiting hormone expression in the X-organ/sinus gland (XO/SG) remained constant between temperatures and stages, suggesting it is constitutive in this species. Lipid concentration in the hemolymph, and the expression of CasEcR and CasHSP90 in the XO/SG were influenced by the molting stage, not temperature. On the other hand, the expression of HSPs in the hepatopancreas is the result of the interaction between the two factors evaluated in the study. Our results demonstrated that temperature is an effective modulator of responses related to the molting cycle at the endocrine level and that temperature below the control condition caused a greater effect on the evaluated responses compared to the thermostable condition, especially when the animal was in the premolt stage.
Proteome-wide neuropeptide identification using NeuroPeptide-HMMer (NP-HMMer).
Zandawala M, Bilal Amir M, Shin J … +2 more , Yim WC, Alfonso Yañez Guerra L
Gen Comp Endocrinol · 2024 Oct · PMID 39084320 · Publisher ↗
Neuropeptides are essential neuronal signaling molecules that orchestrate animal behavior and physiology via actions within the nervous system and on peripheral tissues. Due to the small size of biologically active matur...
Neuropeptides are essential neuronal signaling molecules that orchestrate animal behavior and physiology via actions within the nervous system and on peripheral tissues. Due to the small size of biologically active mature peptides, their identification on a proteome-wide scale poses a significant challenge using existing bioinformatics tools like BLAST. To address this, we have developed NeuroPeptide-HMMer (NP-HMMer), a hidden Markov model (HMM)-based tool to facilitate neuropeptide discovery, especially in underexplored invertebrates. NP-HMMer utilizes manually curated HMMs for 46 neuropeptide families, enabling rapid and accurate identification of neuropeptides. Validation of NP-HMMer on Drosophila melanogaster, Daphnia pulex, Tribolium castaneum and Tenebrio molitor demonstrated its effectiveness in identifying known neuropeptides across diverse arthropods. Additionally, we showcase the utility of NP-HMMer by discovering novel neuropeptides in Priapulida and Rotifera, identifying 22 and 19 new peptides, respectively. This tool represents a significant advancement in neuropeptide research, offering a robust method for annotating neuropeptides across diverse proteomes and providing insights into the evolutionary conservation of neuropeptide signaling pathways.
Editorial for the special issue in GCE.
Mylonas CC, Schulz R, Bobe J … +1 more , Piferrer F
Gen Comp Endocrinol · 2024 Nov · PMID 39067713 · Publisher ↗
Abstract loading — click title to view on PubMed.
Early-life glucocorticoids accelerate lymphocyte count senescence in roe deer.
Lalande LD, Bourgoin G, Carbillet J … +12 more , Cheynel L, Debias F, Ferté H, Gaillard JM, Garcia R, Lemaître JF, Palme R, Pellerin M, Peroz C, Rey B, Vuarin P, Gilot-Fromont E
Gen Comp Endocrinol · 2024 Oct · PMID 39059616 · Publisher ↗
Immunosenescence corresponds to the progressive decline of immune functions with increasing age. Although it is critical to understand what modulates such a decline, the ecological and physiological drivers of immunosene...
Immunosenescence corresponds to the progressive decline of immune functions with increasing age. Although it is critical to understand what modulates such a decline, the ecological and physiological drivers of immunosenescence remain poorly understood in the wild. Among them, the level of glucocorticoids (GCs) during early life are good candidates to modulate immunosenescence patterns because these hormones can have long-term consequences on individual physiology. Indeed, GCs act as regulators of energy allocation to ensure allostasis, are part of the stress response triggered by unpredictable events and have immunosuppressive effects when chronically elevated. We used longitudinal data collected over two decades in two populations of roe deer (Capreolus capreolus) to test whether higher baseline GC levels measured within the first year of life were associated with a more pronounced immunosenescence and parasite susceptibility. We first assessed immunosenescence trajectories in these populations facing contrasting environmental conditions. Then, we found that juvenile GC levels can modulate lymphocyte trajectory. Lymphocyte depletion was accelerated late in life when GCs were elevated early in life. Although the exact mechanism remains to be elucidated, it could involve a role of GCs on thymic characteristics. In addition, elevated GC levels in juveniles were associated with a higher abundance of lung parasites during adulthood for individuals born during bad years, suggesting short-term negative effects of GCs on juvenile immunity, having in turn long-lasting consequences on adult parasite load, depending on juvenile environmental conditions. These findings offer promising research directions in assessing the carry-over consequences of GCs on life-history traits in the wild.
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