Overexpression of induces testicular differentiation in a temperature-dependent sex determination system.

In reptiles, such as the red-eared slider turtle ( ), gonadal sex determination is highly dependent on the environmental temperature during embryonic stages. This complex process, which leads to differentiation into either testes or ovaries, is governed by the finely tuned expression of upstream genes, notably the testis-promoting gene and the ovary-promoting gene . Recent studies have identified epigenetic regulation as a crucial factor in testis development, with the H3K27me3 demethylase KDM6B being essential for expression in However, whether KDM6B alone can induce testicular differentiation remains unclear.

pSTAT3 activation of initiates the female pathway underlying temperature-dependent sex determination.

Ovarian development was traditionally recognized as a "default" sexual outcome and therefore received much less scientific attention than testis development. In turtles with temperature-dependent sex determination (TSD), how the female pathway is initiated to induce ovary development remains unknown. In this study, we have found that phosphorylation of the signal transducer and activator of transcription 3 (pSTAT3) and exhibit temperature-dependent sexually dimorphic patterns and tempo-spatial coexpression in early embryos of the red-eared slider turtle ().

[Estrogen receptor Esr1 induces early ovarian differentiation in ].

This study aims to explore the roles of three estrogen receptors (Esr1, Esr2, and Gper1) in early differentiation of embryonic gonads of . The expression characteristics of the receptor genes were studied first. The Esr1, Esr2, and Gper1 agonists PPT, WAY 200070, and G-1 were respectively injected into the embryos at the male-producing temperature (MPT) before initiation of gonadal differentiation.

Insights into sequence characteristics and evolutionary history of DGATs in arthropods.

Triacylglycerol (TAG) is crucial in animal energy storage and membrane biogenesis. The conversion of diacylglycerol (DAG) to triacylglycerol (TAG) is catalyzed by diacylglycerol acyltransferase enzymes (DGATs), which are encoded by genes belonging to two distinct gene families. Although arthropods are known to possess DGATs activities and utilize the glycerol-3-phosphate pathway and MAG pathway for TAG biosynthesis, the sequence characterization and evolutionary history of DGATs in arthropods remains unclear.

MicroRNA transcriptome analysis for elucidating the immune mechanism of the redclaw crayfish Cherax quadricarinatus under Decapod iridescent virus 1 infection.

Redclaw crayfish (Cherax quadricarinatus) is a large, tropical freshwater crustacean species with considerable potential of commercial production. In recent years, infection with DIV1 in redclaw crayfish is being reported in aquaculture industries, causing high mortality and huge economic losses. However, many characteristics of this virus, including pathogenesis, transmission mechanism, and host immunity, remain largely unknown.

Evidence for RA-dependent meiosis onset in a turtle embryo.

Meiotic entry is one of the earliest sex determination events of the germ cell in higher vertebrates. Although advances in meiosis onset have been achieved in mammals, birds and fish, how this process functions in reptiles is largely unknown. In this study, we present the molecular analysis of meiosis onset and the role of retinoic acid (RA) in this process in the red-eared slider turtle.

Loss- and gain-of-function analyses reveal the essential role of Cyp19a1 in ovarian determination of the red-eared slider turtle.

Estrogen signaling exerts a decisive role in female sex determination and differentiation in chicken and fish. Aromatase encoded by Cyp19a1 is the key enzyme that catalyzes the conversion of androgen to estrogen. Correlative analyses implicate the potential involvement of aromatase in reptilian sexual development, however, the direct genetic evidence is lacking.

SOX8 is essential for male sexual differentiation in the Chinese soft-shelled turtle Pelodiscus sinensis‡.

SOX8, which belongs to SOXE transcription factor subfamily together with SOX9, participates in sex differentiation and testicular development by enhancing the function of SOX9 in mammals. However, the functional role of SOX8 in sex differentiation has not yet been identified in any non-mammalian vertebrates. Here, we found in the Chinese soft-shelled turtle Pelodiscus sinensis that SOX8 exhibited male-specific higher expression from stage 14 to 18, the critical period of sex determination, prior to the onset of gonadal differentiation.

The forkhead factor Foxl2 participates in the ovarian differentiation of Chinese soft-shelled turtle Pelodiscus sinensis.

The forkhead transcription factor Foxl2 plays a major role in ovarian development and function in mice and fish, and acts as a female sex-determining gene in goat. Its functional role in the sex determination and gonadal differentiation has not yet been investigated in reptiles. Here, we characterized Foxl2 gene in Chinese soft-shelled turtle Pelodiscus sinensis, exhibiting ZZ/ZW sex chromosomes.

Foxl2 is required for the initiation of the female pathway in a temperature-dependent sex determination system in Trachemys scripta.

KDM6B-mediated epigenetic modification of the testicular regulator Dmrt1 has previously been identified as the primary switch of the male pathway in a temperature-dependent sex-determination (TSD) system; however, the molecular network of the female pathway has not yet been established. Here, we have functionally characterized for the first time an upstream regulator of the female pathway, the forkhead transcription factor FOXL2, in Trachemys scripta, a turtle species with a TSD system. FOXL2 exhibited temperature-dependent female-specific expression patterns before the onset of gonadal differentiation and was preferentially localized in ovarian somatic cells.

Sex determination mechanisms and sex control approaches in aquaculture animals.

Aquaculture is one of the most efficient modes of animal protein production and plays an important role in global food security. Aquaculture animals exhibit extraordinarily diverse sexual phenotypes and underlying mechanisms, providing an ideal system to perform sex determination research, one of the important areas in life science. Moreover, sex is also one of the most valuable traits because sexual dimorphism in growth, size, and other economic characteristics commonly exist in aquaculture animals.

ESR1 mediates estrogen-induced feminization of genetic male Chinese soft-shelled turtle†.

Exogenous estrogen have shown their feminization abilities during the specific sex differentiation period in several reptiles. However, the specific regulatory mechanism and downstream regulatory genes of estrogen remain elusive. In the present study, 17β-estradiol (E2), as well as drugs of specific antagonists and/or agonists of estrogen receptors, were employed to figure out the molecular pathway involved in the E2-induced feminization in Chinese soft-shelled turtles, an important aquaculture species in China.

Knockdown of R-spondin1 leads to partial sex reversal in genetic female Chinese soft-shelled turtle Pelodiscus sinensis.

Chinese soft-shelled turtle Pelodiscus sinensis is an important aquaculture species in China, the male individual being more valuable in aquaculture because of its larger body size, higher growth rate and less fat compared with females. Understanding the mechanism of ovarian differentiation and development is crucial for the production of mono-sex male offspring. However, little is known about the molecular mechanism underlying turtle ovarian differentiation.

Temperature-dependent sex determination is mediated by pSTAT3 repression of .

In many reptiles, including the red-eared slider turtle (), sex is determined by ambient temperature during embryogenesis. We previously showed that the epigenetic regulator is elevated at the male-producing temperature and essential to activate the male pathway. In this work, we established a causal link between temperature and transcriptional regulation of We show that signal transducer and activator of transcription 3 (STAT3) is phosphorylated at the warmer, female-producing temperature, binds the locus, and represses transcription, blocking the male pathway.

The Role of Anti-Müllerian Hormone in Testis Differentiation Reveals the Significance of the TGF-β Pathway in Reptilian Sex Determination.

Anti-Müllerian hormone (, or Müllerian-inhibiting substance, ), a member of TGF-β superfamily, has been well documented in some vertebrates as initiator or key regulator in sexual development, and particularly in fish. However, its functional role has not yet been identified in reptiles. Here, we characterized the gene in the Chinese soft-shelled turtle , a typical reptilian species exhibiting ZZ/ZW sex chromosomes.

The histone demethylase KDM6B regulates temperature-dependent sex determination in a turtle species.

Temperature-dependent sex determination is a notable model of phenotypic plasticity. In many reptiles, including the red-eared slider turtle (), the individual's sex is determined by the ambient temperature during egg incubation. In this study, we show that the histone H3 lysine 27 (H3K27) demethylase KDM6B exhibits temperature-dependent sexually dimorphic expression in early embryos before the gonad is distinct.

Author Correction: Dmrt1 is required for primary male sexual differentiation in Chinese soft-shelled turtle Pelodiscus sinensis.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Dmrt1 is required for primary male sexual differentiation in Chinese soft-shelled turtle Pelodiscus sinensis.

In vertebrates, the primary sex-determining signals that initiate sexual development are remarkably diverse, ranging from complete genetic to environmental cues. However, no sex determination-related genes have been functionally identified in reptiles. Here, we characterized a conserved DM domain gene, Dmrt1, in Chinese soft-shelled turtle Pelodiscus sinensis (P.

induces the male pathway in a turtle species with temperature-dependent sex determination.

The molecular mechanism underlying temperature-dependent sex determination (TSD) has been a long-standing mystery; in particular, the thermosensitive genetic triggers for gonadal sex differentiation are largely unknown. Here, we have characterized a conserved DM domain gene, , in the red-eared slider turtle (), which exhibits TSD. We found that has a temperature-dependent, sexually dimorphic expression pattern, preceding gonadal sex differentiation, and is capable of responding rapidly to temperature shifts and aromatase inhibitor treatment.

RALDH2, the enzyme for retinoic acid synthesis, mediates meiosis initiation in germ cells of the female embryonic chickens.

Meiosis is a process unique to the differentiation of germ cells and exhibits sex-specific in timing. Previous studies showed that retinoic acid (RA) as the vitamin A metabolite is crucial for controlling Stra8 (Stimulated by retinoic acid gene 8) expression in the gonad and to initiate meiosis; however, the mechanism by which retinoid-signaling acts has remained unclear. In the present study, we investigated the role of the enzyme retinaldehyde dehydrogenase 2 (RALDH2) which catalyzes RA synthesizes by initiating meiosis in chicken ovarian germ cells.

G protein-coupled receptor 30 mediates estrogen-induced proliferation of primordial germ cells via EGFR/Akt/β-catenin signaling pathway.

In vertebrates, estrogens are required for the normal development and function of postnatal gonads. However, it remains unclear whether estrogens are able to modulate development of the fetal germ cells. Here, we show that, unexpectedly, chicken primordial germ cells (PGC) lacking estrogen receptor α/β still proliferate in response to 17β-estradiol (E(2)).

Retinoic acid promotes proliferation of chicken primordial germ cells via activation of PI3K/Akt-mediated NF-κB signalling cascade.

As embryonic progenitors for the gametes, PGCs (primordial germ cells) proliferate and develop under strict regulation of numerous intrinsic and external factors. As the most active natural metabolite of vitamin A, all-trans RA (retinoic acid) plays pivotal roles in regulating development of various cells. The proliferating action of RA on PGCs was investigated along with the intracellular PI3K (phosphoinositide 3-kinase)/Akt (protein kinase B; also known as Akt)-mediated NF-κB (nuclear factor κB) signalling cascade.

Polycyclic aromatic hydrocarbons suppress meiosis in primordial germ cells via the AHR signaling pathway.

Numerous studies have demonstrated that polycyclic aromatic hydrocarbon (PAH) exposure during pregnancy is associated with negative reproductive consequences in adulthood, such as reduced sperm production and oocyte destruction in human and laboratory animals. However, the mechanism(s) underlying these epidemiological findings is still unclear, largely due to the lack of an in vitro model of gametogenesis. Here we established an in vitro model of gametogenesis through retinoic acid (RA)-induced differentiation of chicken primordial germ cells (PGCs) that progressed through meiosis to generate 55% of haploid cells.