Gen. Comp. Endocrinol. [JOURNAL]
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200 papers
Development of a time-resolved fluoroimmunoassay for salmonid insulin-like growth factor-2.
Izutsu A, Suzuki S, Kitade H … +1 more , Shimizu M
Gen Comp Endocrinol · 2026 Jul · PMID 42401211 · Publisher ↗
In mammals, insulin-like growth factor (IGF)-1 and IGF-2 regulate postnatal growth and embryonic development, respectively. In fish, as in mammals, IGF-1 promotes somatic growth, whereas evidence suggests the possible in...
In mammals, insulin-like growth factor (IGF)-1 and IGF-2 regulate postnatal growth and embryonic development, respectively. In fish, as in mammals, IGF-1 promotes somatic growth, whereas evidence suggests the possible involvement of IGF-2 in the regulation of somatic growth. However, the measurement of circulating IGF-2 in fish has been hampered, possibly because of interference from IGF-binding proteins (IGFBPs). Extraction of IGFs from IGFBPs is essential before measuring them using immunoassays. We optimized acid-ethanol (AE) extraction method for salmonid IGF-2 and developed a time-resolved fluoroimmunoassay (TR-FIA) using recombinant IGF-2 as the assay component. In TR-FIA, the standard AE-extraction of IGF-1 was not validated for quantifying serum IGF-2 because of the presence of ethanol. Three treatments-vacuum drying, dialysis, and ultrafiltration-were compared after AE extraction, and ultrafiltration by centrifugation was found to be effective. With this extraction method, circulating IGF-2 levels were measured by TR-FIA in fed, fasted, and refed rainbow trout. Serum IGF-2 levels were similar or slightly lower in fed fish than in fasted fish, and refeeding had no positive effect. Serum IGF-2 levels were not correlated with individual growth rates. GH treatment tended to increase circulating IGF-2 levels albeit not statistically significant. Smolting masu salmon had similar but slightly lower serum IGF-2 levels than non-smolting fish, while exhibiting high serum IGF-1 levels. These results suggest that circulating IGF-2 levels were relatively stable. This newly developed assay should facilitate further exploration of the physiological responses and roles of circulating IGF-2 in salmonids.
Medaka as a model for seasonal adaptation: molecular insights across multiple biological systems.
Nakayama T, Yoshimura T
Gen Comp Endocrinol · 2026 Jul · PMID 42398547 · Publisher ↗
Animals in temperate zones have evolved sophisticated mechanisms to synchronize their physiology and behavior with the seasons. However, the molecular mechanisms underlying these seasonal adaptations have long remained p...
Animals in temperate zones have evolved sophisticated mechanisms to synchronize their physiology and behavior with the seasons. However, the molecular mechanisms underlying these seasonal adaptations have long remained poorly understood. Here, we highlight medaka (Oryzias latipes) as a powerful vertebrate model for studying seasonal adaptation, owing to its robust and experimentally tractable seasonal responses. Recent studies using medaka have uncovered the molecular mechanisms underlying several of these phenomena, such as seasonal reproduction, seasonal changes in feeding behavior, seasonal changes in color perception, stress-related defensive behavior, winter depression-like behavior, gut-length plasticity, and photoperiod-dependent metabolic reprogramming. Furthermore, medaka has enabled the first molecular-level investigation of the circannual clock, providing evidence for a tissue remodeling-based mechanism that drives endogenous annual rhythms. Together, these findings establish medaka as an invaluable model organism for deciphering the molecular architecture of seasonal adaptation in vertebrates.
Modulatory effect of probiotics and Spirulina platensis on the growth performance and immune response of Nile tilapia exposed to sumithion.
Ahmed S, Etti EZ, Amin MR … +4 more , Khanom H, Noor SA, Shahjahan M, Zahangir MM
Gen Comp Endocrinol · 2026 Jul · PMID 42392234 · Publisher ↗
Pesticide pollution in aquatic ecosystems has been increasing, especially organophosphates such as sumithion, which pose serious risks to non-target aquatic species including Nile tilapia (Oreochromis niloticus). In our...
Pesticide pollution in aquatic ecosystems has been increasing, especially organophosphates such as sumithion, which pose serious risks to non-target aquatic species including Nile tilapia (Oreochromis niloticus). In our study, we systematically assessed the therapeutic effects of probiotics and Spirulina platensis on sumithion-induced oxidative stress, immunosuppression, hematological alterations, and growth inhibition in O. niloticus. A total of 240 fingerlings (12.8 ± 0.09 g) were chosen randomly to receive four treatments for experimentation: control, sumithion (0.30 mg/L), sumithion and probiotics (0.30 mg/L and 1.0 ml/L), and sumithion and Spirulina (0.30 mg/L and 50 g/kg). Each treatment had three repetitions for a duration of six weeks. The exposure of fish to sumithion caused impaired growth performance, significant (p < 0.05) increase in metabolic and oxidative stress markers, as well as a decrease in hemoglobin (Hb) concentration, induced hyperglycemia, and downregulation of immune gene expression. Conversely, treatments with probiotics and Spirulina effectively ameliorated these toxic effects. Probiotics were effective in restoring immune gene expression (interferon-gamma, IFN-γ, interleukin-1 beta, IL-1β; and tumor necrosis factor-alpha, TNF-α), reducing glucose (Glu) levels, and improving growth performance, as evidenced by the highest weight gain, specific growth rate, and increased intestine-somatic index (ISI) and lowest feed conversion ratio. Furthermore, the probiotic-supplemented group showed an upregulation in hepatic igf-1, igf-2 (insulin-like growth factors) and pituitary gh (growth hormone) expression levels. In contrast, Spirulina had a greater impact on promoting antioxidant activity and boosting hematological parameters, particularly by improving Hb, SOD (superoxide dismutase), and CAT (catalase) levels, while also contributing to a significant increase in hepatosomatic index (HSI). These results emphasize the effectiveness of probiotics and Spirulina as eco-friendly complements to alleviate sumithion-prevailed toxicity, enhancing growth, immune response, and antioxidant capacity in O. niloticus, with probiotics being an effective approach in easing physiological impairments.
Nonapeptide modulation of looming-induced responses in male Betta splendens.
Fusani B, Cardoso SD, Ramos A … +1 more , Gonçalves D
Gen Comp Endocrinol · 2026 Jun · PMID 42361865 · Publisher ↗
The looming stimulus is a widely used paradigm for investigating defensive behaviours in prey-predator contexts, as it simulates an approaching threat through the rapid expansion of a dark disk. Such stimuli typically ev...
The looming stimulus is a widely used paradigm for investigating defensive behaviours in prey-predator contexts, as it simulates an approaching threat through the rapid expansion of a dark disk. Such stimuli typically evoke fight, flight, or freeze responses. In the present study, the role of the nonapeptides oxytocin and vasotocin, both known for their roles in social behaviour and stress regulation, in the behavioural and endocrine response to a looming stimulus in the Siamese fighting fish Betta splendens was assessed. Fish displayed pronounced freezing behaviour and the expression of conspicuous body stripes in response to a 10-min looming stimulus. Despite the marked behavioural reaction, no concomitant changes in plasma cortisol levels were recorded. The oxytocin receptor antagonist (L-368,899) did not affect the behavioural response, whereas treatment with the vasotocin receptor antagonist Manning compound enhanced fight and reduced flight responses. None of the nonapeptides modulated post-looming plasma cortisol levels. These findings provide new insights into the expression and regulation of stripe patterns in B. splendens, a phenomenon previously noted in aquaculture and behavioural studies but not quantitatively described, and highlight the involvement of the vasotocin system in the modulation of defensive strategies.
Phytochemicals as eco-friendly modulators of ovarian vitellogenesis and reproductive efficiency in aquaculture.
Elumalai M, Sampath S
Gen Comp Endocrinol · 2026 Jun · PMID 42309196 · Publisher ↗
The search for natural alternatives to chemical additives and artificial hormones to enhance reproductive function in aquatic animals is driven by demand for eco-friendly aquaculture. This review explores how bioactive p...
The search for natural alternatives to chemical additives and artificial hormones to enhance reproductive function in aquatic animals is driven by demand for eco-friendly aquaculture. This review explores how bioactive plant compounds can enhance ovarian vitellogenesis and reproductive efficiency in crustaceans and finfish. Vitellogenesis is regulated by the hypothalamic-pituitary-gonadal axis, controlling yolk protein deposition and embryogenesis. While synthetic hormones have significant effects, their environmental and health impacts have sparked interest in phytochemicals such as carotenoids, flavonoids, alkaloids, and phytoestrogens. These compounds can stimulate vitellogenin production, boost reproductive performance, and improve egg quality through immunomodulatory, hormone-mimetic, and antioxidant activities that reduce oxidative stress. Plant extracts like Moringa oleifera, Eurycoma longifolia, and Cyperus spp. boost reproductive maturity and larval survival. The review highlights their cost-effectiveness, biodegradability, and cultural acceptance aligned with sustainable aquaculture demands. Challenges include variation in bioactivity, lack of standardized protocols, and species-specific responses. Future research should explore nanotechnology, omics, and precision extraction to enhance the applications of phytochemicals. Combining traditional knowledge with modern science can improve aquaculture productivity for environmental and food security.
Roles of the FAM237-derived small proteins in energy homeostasis: a comparative perspective of neurosecretory protein GL and GM across vertebrates.
Narimatsu Y, Iwakoshi-Ukena E, Ukena K
Gen Comp Endocrinol · 2026 Jun · PMID 42288123 · Publisher ↗
Hypothalamic neuropeptides and neural circuits integrate peripheral signals, nutrient demand, and environmental cues to orchestrate energy homeostasis in vertebrates. Neurosecretory protein GL (NPGL) and neurosecretory p...
Hypothalamic neuropeptides and neural circuits integrate peripheral signals, nutrient demand, and environmental cues to orchestrate energy homeostasis in vertebrates. Neurosecretory protein GL (NPGL) and neurosecretory protein GM (NPGM) are hypothalamic small secretory proteins encoded by paralogous genes of the FAM237 family. These genes were initially identified in birds, but database search showed evolutionary conservation across vertebrates, suggesting conserved physiological roles for NPGL and NPGM. Previous studies on NPGL have demonstrated that NPGL stimulates overeating and fat accumulation in a diet- and strain-dependent manner in both mammals and birds. Accumulating evidence suggests that NPGM may also be involved in hyperphagia and adiposity. Notably, recent progress in transcriptomics and histological analyses has revealed expression of Npgl and Npgm in specific hypothalamic neuronal subpopulations involved in energy homeostasis. Here, we summarize recent progress in understanding the metabolic actions of NPGL and NPGM. We then focus on the cellular identity of Npgl- and Npgm-expressing neurons. Finally, we discuss future directions and potential molecular mechanisms of metabolic regulation by NPGL and NPGM. Investigating the NPGL/NPGM system, which regulates energy metabolism, will contribute to understanding both conserved and species-specific mechanisms of energy homeostasis across vertebrates.
Nucleobindin-derived peptides and stress regulation in vertebrates.
Sethi P, Nasri A, Unniappan S
Gen Comp Endocrinol · 2026 Jun · PMID 42285421 · Publisher ↗
Stress response entails a complex array of interactions between the neuroendocrine and nervous systems. When a sensory stimulus is perceived as stressful, the brain triggers a response controlled by two key neuroendocrin...
Stress response entails a complex array of interactions between the neuroendocrine and nervous systems. When a sensory stimulus is perceived as stressful, the brain triggers a response controlled by two key neuroendocrine systems: the sympathetic pathways for the "fight or flight" response, and the hypothalamus-pituitary-adrenal (HPA) axis, for a long-term stress response. Growing evidence suggests that nucleobindin (Nucb)-derived peptides nesfatin-1 and nesfatin-1-like peptide (NLP), two anorexigens and metabolic regulators, are also involved in stress regulation. Nesfatin-1 stimulates corticotropin-releasing hormone (CRH) in the hypothalamus to induce stress and satiety. Nesfatin-1 and NLP activate the stress axis, by stimulating adrenocorticotropic hormone (ACTH) synthesis and through the modulation of cortisol synthesis. Nesfatin-1 elicits stress behavior, such as anxiety and depression. Nesfatin-1 and NLP regulate both stress and metabolism, suggesting their role in interlinking these processes. This review discusses the involvement of nesfatin-1 and NLP in stress-related pathways in vertebrates, their mechanism of action, as well as existing knowledge gaps that warrant further research.
Circulating testosterone is not associated with social challenge or aggression in female northern house wrens (Troglodytes aedon).
Krieg CA, Prior NH, Ball GF … +1 more , Odom KJ
Gen Comp Endocrinol · 2026 Jun · PMID 42276384 · Publisher ↗
Mechanisms that coordinate appropriate behavioral responses to social competition are important for both sexes. Males in many species show a seasonal peak in baseline circulating testosterone (T) concentrations at times...
Mechanisms that coordinate appropriate behavioral responses to social competition are important for both sexes. Males in many species show a seasonal peak in baseline circulating testosterone (T) concentrations at times when social challenges are more frequent with additional acute elevation in T following competitive interactions. Females in some species show the same patterns, while others do not, making females interesting test cases to evaluate these mechanisms. Here we used three approaches to investigate the interrelationship among circulating T, social challenge, and aggression in female northern house wrens (Troglodytes aedon), a species where female aggression confers a variety of fitness benefits. First, we compared circulating T concentration after a simulated territorial intrusion to T in unchallenged females to determine if T responds to social challenge. Second, we compared T concentrations between females that responded to simulated female intrusions with different levels of aggressive intensity to determine if aggressive behavior relates to T concentrations. Third, we compared natural T concentrations across breeding stages to determine if T is elevated during stages when competition is most common. Overall, female circulating T concentrations were quite low. Neither social challenge nor breeding stage had any impact on T concentrations. Likewise, the intensity of a female's aggressive response to simulated female intruders was unrelated to T. Our results indicate that house wrens may be one of a growing number of species where females mediate competitive behavior through alternative circulating signals or local mechanisms at target tissues.
Characterizing the annual cycle of steroid hormones in males from an invasive vertebrate (Python bivittatus) of management concern.
Logo G, Sandfoss MR, Claunch NM … +5 more , Currylow AF, Bartoszek IA, Easterling I, Yackel Adams AA, Romagosa CM
Gen Comp Endocrinol · 2026 Jun · PMID 42270012 · Publisher ↗
South Florida's subtropical climate has facilitated the establishment of numerous invasive species, including the Burmese python (Python bivittatus). Despite decades of efforts to manage the invasive python population ac...
South Florida's subtropical climate has facilitated the establishment of numerous invasive species, including the Burmese python (Python bivittatus). Despite decades of efforts to manage the invasive python population across South Florida, we lack a comprehensive understanding of their reproductive physiology, limiting the development of targeted control strategies. Here, we characterized seasonal patterns of testosterone (T) and corticosterone (CORT) in free-ranging adult male pythons and evaluated environmental correlates of hormone variation. Results indicate that T peaks before the onset of the breeding season and declines through the season to baseline levels in the non-breeding season. CORT did not show a clear seasonal trend but showed greater variability during the breeding season. These findings reveal that photoperiod and ambient temperature are key environmental correlates of male hormone cycles, contributing to our understanding of the endocrine phenology of a tropical ectotherm in a novel environment.
Conserved function of WNT4 in reptilian granulosa cell proliferation: insights from the Chinese soft-shelled turtle.
Zhang Y, Wang J, Tang J … +4 more , Han X, Xiao L, Ge C, Guo Y
Gen Comp Endocrinol · 2026 Jun · PMID 42264274 · Publisher ↗
The continuous process of folliculogenesis involves precise coordination between the oocyte and surrounding somatic cells, especially the granulosa cells. However, the roles of granulosa cells and associated gene express...
The continuous process of folliculogenesis involves precise coordination between the oocyte and surrounding somatic cells, especially the granulosa cells. However, the roles of granulosa cells and associated gene expression changes during vitellogenesis remain poorly understood. In the Chinese soft-shelled turtle, our study found that granulosa cells undergo a morphological change from flattened to dense cuboidal during the white-to-yellow follicle transition, accompanied by increased relative expression of WNT4, as a WNT ligand, as confirmed through RNA-seq analysis and RT-qPCR. Notably, in situ hybridization revealed that WNT4 was expressed in granulosa cells, as further demonstrated by its co-localization with FOXL2 immunofluorescence signaling, a granulosa cell-specific transcription factor. Furthermore, we successfully established a functional primary culture of granulosa cell, characterized by the expression of key markers FOXL2 and CYP19A1 (aromatase). Treatment with IWP-2, a specific inhibitor of WNT4, significantly reduced both EdU signal and the phosphorylation level of JNK in cultured granulosa cells. Together, these results shed light on the regulation of granulosa cell proliferation, and highlight a conserved role for WNT4 in this process.
Corticosteroids modulate bovine oocyte maturation through mineralocorticoid receptor.
Kunori R, Kashima A, Sakuma C … +2 more , Tani N, Tetsuka M
Gen Comp Endocrinol · 2026 Jun · PMID 42252061 · Publisher ↗
The ovary is continuously exposed to circulating corticosteroids, yet their physiological roles in oocyte physiology remain unclear. This study investigated how mineralocorticoids and glucocorticoids regulate nuclear mat...
The ovary is continuously exposed to circulating corticosteroids, yet their physiological roles in oocyte physiology remain unclear. This study investigated how mineralocorticoids and glucocorticoids regulate nuclear maturation in bovine cumulus-oocyte complexes (COCs). COCs collected from 2 to 5 mm small antral follicles were subjected to 21 h of in vitro maturation (IVM). Immunohistochemistry and RT-PCR showed that the mineralocorticoid receptor (MR) and 11β-hydroxysteroid dehydrogenase type 2 (HSD11B2) were predominantly expressed in oocytes, whereas the glucocorticoid receptor (GR) was restricted to cumulus cells, specialized granulosa cells that surround and nourish the oocyte. Aldosterone increased the metaphase II (MII) rate at 50 nM but reduced it at 500 nM, with both effects abolished by the MR antagonist eplerenone. Cortisol at pharmacological levels (10 μM) similarly decreased MII%, and this inhibition was also reversed by eplerenone. To assess the protective role of HSD11B2, COCs were exposed to the HSD11B2 inhibitor 11-ketoprogesterone (11-kp) with or without cortisol (1 μM). Neither treatment alone altered MII%, whereas the combination significantly reduced MII%. These findings demonstrate that bovine oocytes are direct targets of mineralocorticoids and that both aldosterone and cortisol modulate nuclear maturation through MR. Moreover, HSD11B2 functions as a key protective mechanism preventing nonspecific MR activation by cortisol under physiological conditions.
Ectoparasite presence is associated with alterations in immune function after an acute stressor in cane toads (Rhinella marina).
Floreste FR, Titon B, Gomes FR … +3 more , Ward CK, Mendonça MT, Assis VR
Gen Comp Endocrinol · 2026 Jun · PMID 42242399 · Publisher ↗
Parasites can alter host fitness and physiology in multiple ways, including chronic activation of the hypothalamus-pituitary-adrenal/interrenal (HPA/I) axis, resulting in prolonged glucocorticoid release. Such chronic ef...
Parasites can alter host fitness and physiology in multiple ways, including chronic activation of the hypothalamus-pituitary-adrenal/interrenal (HPA/I) axis, resulting in prolonged glucocorticoid release. Such chronic effects may also disrupt the acute stress response mediated by the HPA/I axis, with consequences for immune function. In this study, we investigated if ectoparasites (ticks) are associated with alterations in stress biomarkers and immune function in Florida invasive cane toads (Rhinella marina). We measured corticosterone (CORT) plasma levels and neutrophil to lymphocyte ratio (NLR), two common stress indicators, as well as the bacterial killing ability (BKA), a protein-mediated innate immunity trait, at baseline and after a short-term stressor (24 h restraint). Parasitized toads had higher baseline CORT levels than non-parasitized individuals, although restraint increased CORT and NLR similarly in both groups. Interestingly, only toads with ticks had increased BKA post-restraint. In addition, baseline CORT was negatively correlated with body index (BI) in parasitized toads, suggesting a possible association between tick presence and increased energetic demands. Together, these results indicate that ectoparasites modulate the interplay between stress physiology and immunity in invasive cane toads. Future work should experimentally manipulate tick infection and broaden immune measures to clarify mechanisms underlying parasite-host stress-immune interactions.
Profiles in comparative endocrinology: Louis J. Guillette, Jr.
Heindel JJ, Sheridan MA
Gen Comp Endocrinol · 2026 May · PMID 42176995 · Publisher ↗
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Functional divergence of NPR1 paralog in the Japanese eel: Identification and neuroanatomical characterization.
Okinishi R, Watanabe T, Ida T … +4 more , Wong MK, Izumi T, Tsuneoka Y, Tsukada T
Gen Comp Endocrinol · 2026 Apr · PMID 42140325 · Publisher ↗
Natriuretic peptides (NPs) play critical roles in cardiovascular and osmoregulatory homeostasis via guanylyl cyclase-coupled natriuretic peptide receptors (NPRs). Although teleost fishes possess a diverse NP repertoire,...
Natriuretic peptides (NPs) play critical roles in cardiovascular and osmoregulatory homeostasis via guanylyl cyclase-coupled natriuretic peptide receptors (NPRs). Although teleost fishes possess a diverse NP repertoire, their receptor systems remain incompletely understood. In the present study, we identified and characterized a novel npr1 paralog (npr1a) in the Japanese eel (Anguilla japonica), a representative of early-diverging lineages. Phylogenetic and synteny analyses revealed that eel npr1a and the previously reported npr1b (also known as npra) are teleost-specific paralogs generated by the third round of whole-genome duplication (3R). Functional analysis using COS-7 cells demonstrated distinct ligand responsiveness: Npr1a exhibited preferential responsiveness to VNP with lower signaling efficacy than Npr1b, whereas Npr1b responded broadly to cardiac NPs (eel ANP-NH > VNP > BNP). In situ hybridization chain reaction revealed marked spatial divergence of these receptors in the eel brain: npr1a was predominantly localized in the parvocellular preoptic nucleus (Pp) and anterior tuberal nucleus (NAT), whereas npr1b was specifically expressed in the area postrema (AP). These regions are located at or near blood-brain barrier-deficient areas. Notably, RT-qPCR data showed that npr1b expression was significantly upregulated in seawater-acclimated eels, while npr1a levels remained stable, indicating distinct transcriptional regulation. Collectively, our findings demonstrate 3R-driven subfunctionalization of Npr1 in the Japanese eel and suggest that the retention of vnp in early-diverging lineages may have facilitated lineage-specific functional diversification of NP receptors during teleost evolution.
Development of specific ELISAs for luteinizing hormone and follicle-stimulating hormone in the commercially important cyprinid fish.
Chen J, Ouyang Y, Zeng X … +9 more , Cao H, Shi X, Shu T, Han C, Ke L, Hu W, Liu X, Yang J, Hu G
Gen Comp Endocrinol · 2026 Apr · PMID 42128310 · Publisher ↗
Grass carp (Ctenopharyngodon idella) is an important aquaculture species, yet no specific immunoassay is available for quantifying its pituitary gonadotropins-luteinizing hormone (LH) and follicle-stimulating hormone (FS...
Grass carp (Ctenopharyngodon idella) is an important aquaculture species, yet no specific immunoassay is available for quantifying its pituitary gonadotropins-luteinizing hormone (LH) and follicle-stimulating hormone (FSH)-which are key regulators of reproduction in vertebrates. Here, we developed and validated competitive enzyme-linked immunosorbent assays (ELISAs) for grass carp LH and FSH using recombinant proteins and specific polyclonal antibodies. The recombinant proteins were expressed in E. coli based on the native hormone sequences, and polyclonal antibodies were generated in rabbits. Antibody specificity was validated by immunohistochemistry and western blotting, which confirmed that LH and FSH are produced by distinct cell populations in the grass carp pituitary, consistent with the organizational pattern observed in other teleosts. The standard curves showed excellent correlation (mean R = 0.994). Assay sensitivities were 1.27 ng/mL for LH and 1.18 ng/mL for FSH, with IC values of 9.19 ng/mL and 9.29 ng/mL, respectively. Intra-assay CVs ranged from 0.68% to 4.10% (LH) and 0.44% to 4.27% (FSH), while inter-assay CVs averaged 5.43% and 1.92%, demonstrating good reproducibility. Using this assay, we quantified LH and FSH levels in grass carp across different developmental stages, revealing distinct age- and sex-specific secretion patterns that provide insights into the differential regulation of gonadotropins during sexual maturation in cyprinids. The assay also successfully detected hormone responses to salmon gonadotropin-releasing hormone (sGnRH) stimulation both in vivo and in vitro. This ELISA system provides a reliable tool for investigating gonadotropin dynamics in grass carp and offers a methodological foundation for comparative studies on the endocrine regulation of reproduction in teleost fishes.
Genetic analyses show frog metamorphosis requires thyroid hormone signaling increased by glucocorticoid receptor signaling.
Culbert BM, Chen MS, Uluwaduge CH … +3 more , Heininger LE, Nguyen HA, Buchholz DR
Gen Comp Endocrinol · 2026 Apr · PMID 42070639 · Publisher ↗
Virtually all vertebrates experience a post-embryonic developmental transition dependent on thyroid and corticosteroid hormones. Molecular and developmental actions of these hormones are highly conserved among vertebrate...
Virtually all vertebrates experience a post-embryonic developmental transition dependent on thyroid and corticosteroid hormones. Molecular and developmental actions of these hormones are highly conserved among vertebrates, but the significance and nature of hormone interaction regulating the process has not been well understood. Frog metamorphosis is an excellent model for hormones in development due to the dramatic, sensitive, and readily manipulable changes occurring during the 2-week transition. In frogs, thyroid hormone initiates metamorphosis, and corticosteroid hormones accelerate thyroid hormone-induced changes. Sorting out precise roles of corticosteroid hormones and receptors has been challenging due to lack of genetic models. Here, we review results from four genetic frog models affecting corticosteroid signaling. Tadpoles with adrenocorticotropic hormone and glucocorticoid receptor mutations have low to no corticosteroid signaling and die during metamorphosis, but exogenous thyroid hormone allows them to complete metamorphosis. Tadpoles with 21-hydroxylase mutations survive through metamorphosis, despite lack of 21-hydroxyated corticosteroids, via corticosteroid signaling from high levels of low affinity steroid biosynthesis intermediates. Tadpoles with mineralocorticoid receptor mutations have no apparent metamorphic phenotype. These results indicate that survival through metamorphosis requires activation of the glucocorticoid receptor with no requirement for mineralocorticoid receptor activation. Further, these results show that the only vital role of corticosterone signaling through the glucocorticoid receptor is increasing tissue sensitivity to thyroid hormone thereby enabling endogenous thyroid hormone levels to accomplish metamorphic completion. These hormone interactions observed in frogs will inform similar examinations in other groups where developmental transitions may be highly influenced by such interactions but remain uncharacterized.
Measuring diurnal and lifespan variations of Brain-derived neurotrophic factor in titi monkeys (Plecturocebus cupreus).
Meckler LA, Sosnowski MJ, Bales KL
Gen Comp Endocrinol · 2026 Apr · PMID 42069264 · Publisher ↗
Pair bonding requires substantial neural flexibility to form and maintain complex social relationships in dynamic environments over time. Due to its involvement in synaptic plasticity, Brain-derived neurotrophic factor (...
Pair bonding requires substantial neural flexibility to form and maintain complex social relationships in dynamic environments over time. Due to its involvement in synaptic plasticity, Brain-derived neurotrophic factor (BDNF) is a promising candidate for modulating this flexibility, although it has never been studied within the context of pair bonding. The present study sought analytically and biologically validate an enzyme-linked immunosorbent assay (ELISA) to measure BDNF in coppery titi monkeys (Plecturocebus cupreus), a pair bonding non-human primate model. We first validated a commercially available ELISA to detect and measure BDNF in titi monkey serum, and then subsequently characterized the natural decline of BDNF in titi monkeys throughout the day (morning to evening) and across the lifespan (into old age). Titi monkeys showed significantly lower serum levels of BDNF at the end of the day, suggesting a consistent diurnal cycle, and in older age, suggesting age-related decline. This work establishes the foundation for examining BDNF's role within the behavioral endocrinology of pair bonding.
Endocrine cells of the gastroenteropancreatic system in Testudines A brief review.
Sousa DF, Guerra LS, Branco É … +2 more , Ferreira PG, Lima AR
Gen Comp Endocrinol · 2026 Apr · PMID 42049129 · Publisher ↗
Enteroendocrine cells (EECs) are present throughout the digestive tract and synthesize various types of hormones that play important roles in gastrointestinal and systemic physiological regulation. These cells have been...
Enteroendocrine cells (EECs) are present throughout the digestive tract and synthesize various types of hormones that play important roles in gastrointestinal and systemic physiological regulation. These cells have been described in the gastrointestinal tract of several animals and can be classified according to their ability to retain silver salts, their communication with an animal's lumen and their immunoreactivity to specific molecules. Because the search for these cells has been important for understanding phylogenetic relationships, the objective was to perform a brief review of the existing literature on studies involving EECs in animals of the Testudines Order in order to help understand the digestive physiology of this group. Although there are a large number of species in this order, relatively few have their EECs details known, elucidated and well described. An improved understanding of these cells has enormous potential for functional and molecular studies, as well as having important implications for the conservation and comparative biology of species. We therefore believe that further research involving immunohistochemical assays as well also microscopic analysis (light and electron), is necessary in order to fill existing gaps.
Elucidating the regulatory mechanism of differentially expressed miRNA in the proliferation and differentiation of bovine intramuscular fat preadipocytes.
Jilo DD, Abebe BK, Guo J … +7 more , Wang J, Ma H, Yang Z, Liu H, Cheng G, Li A, Zan L
Gen Comp Endocrinol · 2026 Apr · PMID 42049128 · Publisher ↗
Meat quality characteristics such as juiciness, tenderness, and flavor are greatly enhanced by intramuscular fat (IMF). Improving intramuscular adipose tissue accumulation while maintaining stable lipid levels in fat dep...
Meat quality characteristics such as juiciness, tenderness, and flavor are greatly enhanced by intramuscular fat (IMF). Improving intramuscular adipose tissue accumulation while maintaining stable lipid levels in fat depots has become a critical priority in the beef sector. Understanding the molecular mechanisms driving intramuscular fat deposition is critical because it can enable the utilization of genetic selection to produce high-quality beef. Emerging research suggests that miRNAs play essential roles in regulating IMF deposition, particularly through regulating preadipocyte dynamics such as proliferation and differentiation. Our study aimed to screen and explore the function of potential miRNA in bovine intramuscular preadipocytes and to delineate the underlying molecular mechanisms governing cell proliferation and differentiation. Through time series cluster analysis following by experimental validation by qPCR and Agarose gel PCR identified that bta-miR-380-3p was potential miRNA that highly related with intramuscular preadipocyes differentiation in beef cattle. Bta-miR-380-3p enhanced the proliferation of intramuscular pre-adipocytes by increasing the cell cycle progression and show dynamic time dependent regulation during proliferation and differentiation. It also boosted the formation of lipid droplets in intramuscular pre-adipocytes. The qPCR results revealed that bta-miR-380-3p mimic boosted the expression of PPARγ, FASN, FABP4, SREBP1, and DGAT2 differentiation marker genes. These results provide new insight on the regulatory processes of intramuscular adipogenesis and identify bta-miR-380-3p as a potential target for increasing beef quality through directional selection and molecular breeding. This finding provides a theoretical framework and molecular targets for increasing IMF content.
Purification and charcterization of a neuropeptide (AN peptide) from starfish, Asterias amurensis.
Jo MJ, Go HJ, Park NG … +1 more , Kim GD
Gen Comp Endocrinol · 2026 Apr · PMID 42002085 · Publisher ↗
Although neuropeptides have been extensively studied in marine invertebrates, their diversity and physiological roles remain incompletely understood. Starfish is marine echinoderm with a unique water structure, and lives...
Although neuropeptides have been extensively studied in marine invertebrates, their diversity and physiological roles remain incompletely understood. Starfish is marine echinoderm with a unique water structure, and lives in seas around the world. In this study, neuropeptide was purified from starfish Asterias amurensis and their properties were analyzed. ANP is a muscle-contracting peptide composed of 18 amino acids purified from starfish tube feet. As a result of full-length cDNA analysis, a total of 5 isotypes were identified through post-translational conversion by dibasic cleavage site (KR) and monobasic cleavage site (K). To investigate the potential physiological role of ANP, tissue-specific expression profiles of ANP transcript were checked and it was found to be highly expressed in the nerve cord. In vitro pharmacological assay confirmed that ANP caused contraction in the apical muscle of A. amurensis. Additionally, the effect of in vivo injection on starfish motility revealed that starfish motility was significantly reduced by ANP. These findings suggest that ANP is a neuropeptide involved in the regulation of muscle contraction and locomotor behavior in starfish, providing new insights into the physiological roles of neuropeptides in echinoderms.
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