Effect of Fromestane on Gonadal Sex Differentiation and Sex Ratio in the Frog,Euphlyctis cyanophlyctis, with Undifferentiated Type of Gonadal Differentiation

2018 ◽  
Vol 52 (2) ◽  
pp. 171-175 ◽  
Author(s):  
Samadhan K. Phuge
Keyword(s):  
Sex Ratio ◽  
Sex Differentiation ◽  
Gonadal Differentiation ◽  
Euphlyctis Cyanophlyctis ◽  
Undifferentiated Type

scholarly journals Impact of butyl benzyl phthalate on development of the reproductive system of European pikeperch, Sander lucioperca (L.)

2014 ◽  
Vol 62 (3) ◽  
pp. 397-407 ◽  
Author(s):  
Sylwia Jarmołowicz ◽  
Krystyna Demska-Zakęś ◽  
Zdzisław Zakęś
Keyword(s):  
Sex Ratio ◽  
Sex Differentiation ◽  
Testicular Development ◽  
Gonadal Differentiation ◽  
Differentiation Process ◽  
Sander Lucioperca ◽  
Butyl Benzyl Phthalate ◽  
Gonad Differentiation ◽  
Survival And Growth ◽  
Differentiation Period

The effect of butyl benzyl phthalate (BBP) on the sex differentiation process of fish is practically unknown. The experimental material of this study was juvenile European pikeperch [Sander lucioperca (L.)], which is gonochoristic, undergoes immediate sex differentiation, and has a fixed gonad differentiation period. The fish were fed a diet supplemented with BBP (during the sex differentiation phase: age 61–96 days post hatch) in the following quantities: 1.0; 2.0; 4.0; 8.0; 16.0 g BBP kg−1 feed. The control feed was a xenobiotic-free base feed. In the present experiment lasting 10 weeks, the survival and growth of fish, the histopathological changes of the fish gonads and the sex ratio were evaluated. After administration of the two highest doses of BBP, growth inhibition of the fish was observed. BBP also seriously disturbed the gonadal differentiation process of pikeperch. All analysed concentrations of BBP delayed testicular development and, at concentrations of 4.0, 8.0 and 16.0 g BBP kg−1, induction of the feminisation process was observed. The sex ratio was distinctly disrupted in groups receiving 8.0 and 16.0 g BBP kg−1.

scholarly journals Müllerian Inhibiting Substance Is Required for Germ Cell Proliferation during Early Gonadal Differentiation in Medaka (Oryzias latipes)

Endocrinology ◽  
2007 ◽  
Vol 149 (4) ◽  
pp. 1813-1819 ◽  
Author(s):  
Eri Shiraishi ◽  
Norifumi Yoshinaga ◽  
Takeshi Miura ◽  
Hayato Yokoi ◽  
Yuko Wakamatsu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Germ Cell ◽  
Germ Cells ◽  
Sex Differentiation ◽  
Somatic Cells ◽  
Oryzias Latipes ◽  
Cell Number ◽  
Gonadal Differentiation ◽  
Loss Of Function ◽  
Germ Cell Proliferation

Müllerian inhibiting substance (MIS) is a glycoprotein belonging to the TGF-β superfamily. In mammals, MIS is responsible for the regression of Müllerian ducts in the male fetus. However, the role of MIS in gonadal sex differentiation of teleost fish, which have no Müllerian ducts, has yet to be clarified. In the present study, we examined the expression pattern of mis and mis type 2 receptor (misr2) mRNAs and the function of MIS signaling in early gonadal differentiation in medaka (teleost, Oryzias latipes). In situ hybridization showed that both mis and misr2 mRNAs were expressed in the somatic cells surrounding the germ cells of both sexes during early sex differentiation. Loss-of-function of either MIS or MIS type II receptor (MISRII) in medaka resulted in suppression of germ cell proliferation during sex differentiation. These results were supported by cell proliferation assay using 5-bromo-2′-deoxyuridine labeling analysis. Treatment of tissue fragments containing germ cells with recombinant eel MIS significantly induced germ cell proliferation in both sexes compared with the untreated control. On the other hand, culture of tissue fragments from the MIS- or MISRII-defective embryos inhibited proliferation of germ cells in both sexes. Moreover, treatment with recombinant eel MIS in the MIS-defective embryos dose-dependently increased germ cell number in both sexes, whereas in the MISRII-defective embryos, it did not permit proliferation of germ cells. These results suggest that in medaka, MIS indirectly stimulates germ cell proliferation through MISRII, expressed in the somatic cells immediately after they reach the gonadal primordium.

Gonadal sex differentiation in the neonatal marsupial, Monodelphis domestica

Development ◽  
1990 ◽  
Vol 109 (3) ◽  
pp. 699-703
Author(s):  
P.J. Baker ◽  
H.D. Moore ◽  
L.M. Penfold ◽  
A.M. Burgess ◽  
U. Mittwoch
Keyword(s):  
Sex Chromosomes ◽  
Tunica Albuginea ◽  
Histological Study ◽  
Sex Differentiation ◽  
In Utero ◽  
Monodelphis Domestica ◽  
Gonadal Differentiation ◽  
Marsupial Species

A quantitative and histological study of the gonads of newborn grey short-tailed opossums, Monodelphis domestica, is described. The pups were karyotyped, and comparisons were made within litters segregating for XX and XY sex chromosomes. A total of four litters including 25 pups were available. On the day of birth, developing testes were significantly larger than the ovaries of litter mates, and testes could be histologically distinguished by the formation of sex cords and a tunica albuginea. The data suggest that in this marsupial species gonadal differentiation may be initiated in utero.

scholarly journals Cerebral and gonadal aromatase expressions are differently affected during sex differentiation of Pleurodeles waltl

2004 ◽  
Vol 33 (3) ◽  
pp. 717-727 ◽  
Author(s):  
Sandra Kuntz ◽  
Amand Chesnel ◽  
Stéphane Flament ◽  
Dominique Chardard
Keyword(s):  
Sex Differentiation ◽  
Temperature Sensitive ◽  
Aromatase Activity ◽  
Gonadal Differentiation ◽  
Aromatase Expression ◽  
Larval Stages ◽  
Exon 1 ◽  
The Individual ◽  
Pleurodeles Waltl ◽  
The Brain

In vertebrates, sex is determined essentially by two means, genetic factors located on sex chromosomes and epigenetic factors such as temperature experienced by the individual during development. Steroids, especially estrogens, are clearly involved in gonadal differentiation in non-mammalian vertebrates. In this regard, the expression of the estrogen-producing enzyme, aromatase, has been shown to be temperature-sensitive in species where temperature can reverse sex differentiation, especially in our model, the amphibian Pleurodeles waltl. We investigated here the regulation of aromatase expression in the brain during sex differentiation in Pleurodeles. We first isolated a brain isoform of aromatase mRNA which differs in its 5′ untranslated region from the isoform previously isolated from adult gonads. In adult Pleurodeles, the brain isoform is mainly expressed in brain tissue while the other isoform is gonad specific. Thus, regulation of aromatase expression in P. waltl could occur by alternative splicing of non-coding exon 1 as previously described in mammals. We then investigated aromatase expression in the brain of male and female larvae and found no differences with regard to sex. Measures of aromatase activity in the brain also showed no differences between sexes at larval stages whereas activity markedly increases in the ovary concomitant with the start of gonadal differentiation. These results support the hypothesis that aromatase could be a target of a temperature-sensitive sex-reversing effect in the gonads but not in the brain.

Genetic basis for the determination of sex

1970 ◽  
Vol 259 (828) ◽  
pp. 3-14 ◽  
Keyword(s):  
Sex Ratio ◽  
Genetic Basis ◽  
Sex Differentiation ◽  
Genetic Material ◽  
Selective Advantage ◽  
Mature Spermatozoon ◽  
General Question ◽  
Parental Expenditure ◽  
General Aspects

An introductory review is given of some general aspects of the genetic basis for the determination of sex, with particular reference to vertebrates. The Weismann-Fisher view is that sex arose because it was of selective advantage. The bisexuality of vertebrates is not necessarily ‘best’ for the group in terms of selective advantage; however, the very simplicity of the bisexual system may have been advantageous. The common near-equality in the numbers of the sexes is explained by the Darwin-Fisher ‘ automatic 1:1 tendency’, and Fisher’s concept of parental expenditure can explain deviations from equality and also changes in the ratio during embryogenesis. A direct selective advantage can be argued for the 1:1 ratio—or, more generally, for that ratio which maximizes the chance of a successful encounter of the sexes. Possible modes of gene action affecting sex ratio are discussed. A new assessment is made of the identity of the heterogametic and homogametic sexes in vertebrates, the conclusions for Amphibia deviating from those in some of the literature. It is maintained for vertebrates in general that the ‘ odd ’ sex chromosomes (Y or W) of a species determine strongly in the direction of one gonadal sex. Responsibility for determining the opposite sex must lie between the autosomes and the ‘ even ’ chromosomes (X or Z), but there is little evidence that the ‘even’ chromosomes are specifically implicated. Sex differentiation may not be controlled by a limited number of sex-determining genes, and the ultimate units may be aggregates of the genetic material larger than genes. The possibility of controlling sex ratio at conception by altering the proportion in which X- and Y-bearing spermatozoa fertilize eggs is discussed in relation to the more general question of whether the phenotype of a developing or mature spermatozoon can be affected by its own haploid genetic content.

Environmental regulation of sex determination in reptiles

1988 ◽  
Vol 322 (1208) ◽  
pp. 19-39 ◽  
Keyword(s):  
Sex Ratio ◽  
Sex Determination ◽  
Growth And Development ◽  
Incubation Temperature ◽  
Sex Differentiation ◽  
Developmental Time ◽  
Alligator Mississippiensis ◽  
Phylogenetic Implications ◽  
History Of ◽  
Determining Factor

The various patterns of environmental sex determination in squamates, chelonians and crocodilians are described. High temperatures produce males in lizards and crocodiles but females in chelonians. Original experiments on the effects of incubation at 30 °C (100% females) or 33 °C (100% males) on development in Alligator mississippiensis are described. These include an investigation of the effect of exposing embryos briefly to a different incubation temperature on the sex ratio at hatching, and a study of the effects of 30 °C and 33 °C on growth and development of alligator embryos and gonads. A 7-day pulse of one temperature on the background of another was insufficient to alter the sex ratio dramatically. Incubation at 33 °C increased the rate of growth and development of alligator embryos. In particular, differentiation of the gonad at 33 °C was enhanced compared with 30 °C. A hypothesis is developed to explain the mechanism of temperature-dependent sex determination (TSD) in crocodilians. The processes of primary sex differentiation are considered to involve exposure to a dose of some male-determining factor during a specific quantum of developmental time during early incubation. The gene that encodes for the male- determining factor is considered to have an optimum temperature (33 °C). Any change in the temperature affects the expression o f this gene and affects the dose or quantum embryos are exposed to. In these cases there is production of females by default. The phylogenetic implications of TSD for crocodilians, and reptiles in particular, are related to the life history of the animal from conception to sexual maturity. Those animals that develop under optimal conditions grow fastest and largest and become male. A general association between the size of an animal and its sex is proposed for several types of vertebrate.

Effect of exogenous hormones on R-spondin 1 (RSPO1) gene expression and embryo development in Pelodiscus sinensis

2019 ◽  
Vol 31 (9) ◽  
pp. 1425
Author(s):  
Hongwei Liang ◽  
Yan Meng ◽  
Lihuan Cao ◽  
Xiang Li ◽  
Guiwei Zou
Keyword(s):  
Sex Ratio ◽  
Aromatase Inhibitor ◽  
Embryo Development ◽  
Molecular Mechanisms ◽  
Sex Differentiation ◽  
Adult Brain ◽  
Embryo Morphology ◽  
Pelodiscus Sinensis ◽  
Growth Status ◽  
Important Regulator

Little is known about sex determination and differentiation in the Chinese soft-shelled turtle Pelodiscus sinensis. R-Spondin 1 (RSPO1), a candidate sex-determining gene, is an important regulator of ovarian differentiation in animals. Exogenous drugs can affect sex differentiation. In this study we cloned the RSPO1 gene from P. sinensis (psRSPO1) and analysed its expression profile. The psRSPO1 gene exhibited sequence identity with RSPO1 genes from other species. RSPO1 protein-based phylogenetic analysis showed that psRSPO1 in P. sinensis is closely related to RSPO1 proteins from other turtles. psRSPO1 showed abundant expression in adult brain and gonads, with higher levels in females than males. We also evaluated the effects of three finaconcentration of 2.5, 5.0 and 10mgmL−1 exogenous oestradiol (E2) and aromatase inhibitor (letrozole) on the expression of psRSPO1, external embryo morphology, growth status of embryos and the sex ratio when the drugs were injected to eggs during incubation. The expression of psRSPO1 was upregulated and downregulated by exogenous oestradiol and letrozole respectively, despite inconsistent expression trends at different embryo development times. External embryo morphology, growth status and sex ratio were affected by both exogenous oestradiol and the aromatase inhibitor. Feminisation was induced by oestradiol, but inhibited by letrozole. These results will contribute to studies of the potential molecular mechanisms underlying sex differentiation and sex control in the Chinese soft-shelled turtle.

scholarly journals The unusual rainbow trout sex determination gene hijacked the canonical vertebrate gonadal differentiation pathway

2018 ◽  
Vol 115 (50) ◽  
pp. 12781-12786 ◽  
Author(s):  
Sylvain Bertho ◽  
Amaury Herpin ◽  
Adèle Branthonne ◽  
Elodie Jouanno ◽  
Ayaka Yano ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Differentiation ◽  
Genetic Network ◽  
Transcriptional Networks ◽  
Classical Pathway ◽  
Gonadal Differentiation ◽  
Forkhead Box ◽  
Immune Related Gene ◽  
Single Exception ◽  
New Gene

Evolutionary novelties require rewiring of transcriptional networks and/or the evolution of new gene functions. Sex determination (SD), one of the most plastic evolutionary processes, requires such novelties. Studies on the evolution of vertebrate SD revealed that new master SD genes are generally recruited from genes involved in the downstream SD regulatory genetic network. Only a single exception to this rule is currently known in vertebrates: the intriguing case of the salmonid master SD gene (sdY), which arose from duplication of an immune-related gene. This exception immediately posed the question of how a gene outside from the classical sex differentiation cascade could acquire its function as a male SD gene. Here we show that SdY became integrated in the classical vertebrate sex differentiation cascade by interacting with the Forkhead box domain of the female-determining transcription factor, Foxl2. In the presence of Foxl2, SdY is translocated to the nucleus where the SdY:Foxl2 complex prevents activation of the aromatase (cyp19a1a) promoter in cooperation with Nr5a1 (Sf1). Hence, by blocking a positive loop of regulation needed for the synthesis of estrogens in the early differentiating gonad, SdY disrupts a preset female differentiation pathway, consequently allowing testicular differentiation to proceed. These results also suggest that the evolution of unusual vertebrate master sex determination genes recruited from outside the classical pathway likesdYis strongly constrained by their ability to interact with the canonical gonadal differentiation pathway.

Temperature-Sensitive Period of Sex Determination in the Atlantic Silverside, Menidia menidia

1986 ◽  
Vol 43 (3) ◽  
pp. 514-520 ◽  
Author(s):  
David O. Conover ◽  
Mark H. Fleisher
Keyword(s):  
Sex Ratio ◽  
Sex Determination ◽  
Sex Differentiation ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Measurable Effect ◽  
Menidia Menidia ◽  
Atlantic Silverside ◽  
Gonad Differentiation ◽  
Hormone Sensitive

We investigated the timing and duration of the temperature-sensitive period of development in the Atlantic silverside, Menidia menidia, by measuring the sex ratio in groups of larvae shifted reciprocally among low and high temperatures as development progressed. The sensitive period of sex determination was dependent on body size, rather than age, and occurred during the middle to later stages of larval development when fish were between 8 and 21 mm in total length. Sex determination was irreversibly fixed earlier in development (i.e. at 15 mm in length) at higher than at lower temperatures. Higher, male-producing temperatures therefore appear to more strongly effect sex determination than do lower, female-producing temperatures. Temperature prior to, or after, the sensitive period had no measurable effect on sex ratio. From histological examination we suggest that gonad differentiation coincided with the end of the temperature-sensitive period. The timing and duration of the temperature-sensitive period in M. menidia is generally similar to the hormone-sensitive period identified in other fishes. Both phenomena reveal a specific developmental period during which the course of primary sex differentiation in fishes is labile.

Primordial Germ Cell Migration and Histological and Molecular Characterization of Gonadal Differentiation in Pachón Cavefish Astyanax mexicanus

2021 ◽  
pp. 1-18
Author(s):  
Boudjema Imarazene ◽  
Séverine Beille ◽  
Elodie Jouanno ◽  
Adéle Branthonne ◽  
Violette Thermes ◽  
...  
Keyword(s):  
Germ Cell ◽  
Regulatory Network ◽  
Sex Differentiation ◽  
Expression Patterns ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Gonadal Development ◽  
Individual Variability ◽  
Gonadal Differentiation ◽  
Astyanax Mexicanus

The genetic regulatory network governing vertebrate gonadal differentiation appears less conserved than previously thought. Here, we investigated the gonadal development of Astyanax mexicanus Pachón cavefish by looking at primordial germ cells (PGCs) migration and proliferation, gonad histology, and gene expression patterns. We showed that PGCs are first detected at the 80% epiboly stage and then reach the gonadal primordium at 1 day post-fertilization (dpf). However, in contrast to the generally described absence of PGCs proliferation during their migration phase, PGCs number in cavefish doubles between early neurula and 8–9 somites stages. Combining both gonadal histology and vasa (germ cell marker) expression patterns, we observed that ovarian and testicular differentiation occurs around 65 dpf in females and 90 dpf in males, respectively, with an important inter-individual variability. The expression patterns of dmrt1, gsdf, and amh revealed a conserved predominant male expression during cavefish gonadal development, but none of the ovarian differentiation genes, i. e., foxl2a, cyp19a1a, and wnt4b displayed an early sexually dimorphic expression, and surprisingly all these genes exhibited predominant expression in adult testes. Altogether, our results lay the foundation for further research on sex determination and differentiation in A. mexicanus and contribute to the emerging picture that the vertebrate sex differentiation downstream regulatory network is less conserved than previously thought, at least in teleost fishes.

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