scholarly journals Inheritance of T-associated sex reversal in mice

1990 ◽  
Vol 56 (2-3) ◽  
pp. 185-191 ◽  
Author(s):  
Linda L. Washburn ◽  
Barbara K. Lee ◽  
Eva M. Eicher

SummaryWe previously identified a primary sex-determining locus,Tas, on mouse Chr 17 that causes ovarian tissue development in C57BL/6JThp/ + andTorl/ + individuals if the AKR/J Y chromosome is present. We hypothesized thatTasis located within the region of Chr 17 deleted byThpandTorland that C57BL/6J carries a diagnosticTasallele, based on the observation that ovarian tissue develops in XY mice whenThpis on a C57BL/6J inbred strain background, whereas normal testicular development occurs whenThpis on a C3H/HeSnJ inbred strain background. To test this hypothesis, we mated (C57BL/6J × C3H/HeSnJ)F1 females to C57BL/6JThp/ + hermaphrodites. As expected, half of the XYThp/+ offspring developed ovarian and testicular tissue while half developed exclusively testicular tissue. Unexpectedly, the inheritance of selected Chr 17 molecular loci was independent of gonadal development, as half of the male and hermaphroditic offspring inherited C3H/HeSnJ-derived Chr 17 loci and half inherited C57BL/6J-derived Chr 17 loci. We conclude that for ovarian tissue to develop in an XYThp/ + or XYTort/ + individual (1)Tasmust be present in a hemizygous state, which is accomplished by heterozygosity for theThporTortdeletions; (2) the AKR/J-derived Y chromosome must be present; and (3) an additional locus involved in primary sex determination must be present in a homozygous C57BL/6J state. This newly identified gene may be one of the previously defined loci,tda-1ortda-2.

1995 ◽  
Vol 350 (1333) ◽  
pp. 263-269 ◽  

C57BL/6J mice carrying a Mus domesticus poschiavinus Y chromosome (Y POS ) develop as females with ovarian tissue or as hermaphrodites with ovarian and testicular tissue. We tested the hypothesis that the Y-linked component of this inherited sex reversal is caused by the M. d. poschiavinus Y-linked testis determining gene (symbolized Tdy or Sry ) by examining gonadal development in C57BL/6J XY POS mice carrying a M. musculus allele of Sry as a transgene. We found that in the presence of the transgene, XY POS mice developed exclusively testicular tissue. This result indicates that the Sry allele carried on the Y PDS chromosome is responsible for development of ovarian tissue in the G57BL/6J inbred strain background. We discuss this finding in light of DNA polymorphisms present in Sry alleles carried by various M. domesticus and M.musculus Y chromosomes. In addition, we present a hypothesis concerning the timing of expression of the testicular and ovarian determining genes in the developing fetal gonad based on the organization of ovarian and testicular tissue in ovotestes.


Genetics ◽  
1989 ◽  
Vol 123 (1) ◽  
pp. 173-179 ◽  
Author(s):  
L L Washburn ◽  
E M Eicher

Abstract We previously described a locus on chromosome (Chr) 17 of the mouse that is critical for normal testis development. This locus was designated "T-associated sex reversal" (Tas) because it segregated with the dominant brachyury allele hairpin tail (Thp) and caused gonads of C57BL/6J XY, Thp/+ individuals to develop as ovaries or ovotestes rather than as testes. To clarify the inheritance of Tas, we investigated the effects of T-Orleans (TOrl), another brachyury mutation, on gonad development. We found that gonads of C57BL/6J XY, Thp/+ and TOrl/+ mice develop ovarian tissue if the Y chromosome is derived from the AKR/J inbred strain, whereas normal testicular development occurs in the presence of a Y chromosome derived from the C57BL/6J inbred strain. From these observations we conclude that: (1) Tas is located in a region on Chr 17 common to the deletions associated with Thp, and TOrl, and (2) the Y-linked testis determining gene, Tdy, carried by the AKR/J inbred strain differs from that of the C57BL/6J inbred strain. We suggest that in mammals Tdy is not the sole testis determinant because autosomal loci must be genetically compatible with Tdy for normal testicular development.


It has long been assumed that the mammalian Y chromosome either encodes, or controls the production of, a diffusible testis-determining molecule, exposure of the embryonic gonad to this molecule being all that is required to divert it along the testicular pathway. My recent finding that Sertoli cells in XX ↔ XY chimeric mouse testes are exclusively XY has led me to propose a new model in which the Y acts cell-autonomously to bring about Sertoli-cell differentiation. I have suggested that all other aspects of foetal testicular development are triggered by the Sertoli cells without further Y-chromosome involvement. This model thus equates mammalian sex determination with Sertoli-cell determination. Examples of natural and experimentally induced sex reversal are discussed in the context of this model.


Genetics ◽  
2021 ◽  
Author(s):  
Xingyong Liu ◽  
Shengfei Dai ◽  
Jiahong Wu ◽  
Xueyan Wei ◽  
Xin Zhou ◽  
...  

Abstract Duplicates of amh are crucial for fish sex determination and differentiation. In Nile tilapia, unlike in other teleosts, amh is located on X chromosome. The Y chromosome amh (amh△-y) is mutated with 5 bp insertion and 233 bp deletion in the coding sequence, and tandem duplicate of amh on Y chromosome (amhy) has been identified as the sex determiner. However, the expression of amh, amh△-y and amhy, their roles in germ cell proliferation and the molecular mechanism of how amhy determines sex is still unclear. In this study, expression and functions of each duplicate were analyzed. Sex reversal occurred only when amhy was mutated as revealed by single, double and triple mutation of the three duplicates in XY fish. Homozygous mutation of amhy in YY fish also resulted in sex reversal. Earlier and higher expression of amhy/Amhy was observed in XY gonads compared with amh/Amh during sex determination. Amhy could inhibit the transcription of cyp19a1a through Amhr2/Smads signaling. Loss of cyp19a1a rescued the sex reversal phenotype in XY fish with amhy mutation. Interestingly, mutation of both amh and amhy in XY fish or homozygous mutation of amhy in YY fish resulted in infertile females with significantly increased germ cell proliferation. Taken together, these results indicated that up-regulation of amhy during the critical period of sex determination makes it the sex-determining gene, and it functions through repressing cyp19a1a expression via Amhr2/Smads signaling pathway. Amh retained its function in controlling germ cell proliferation as reported in other teleosts, while amh△-y was nonfunctionalized.


1995 ◽  
Vol 46 (4) ◽  
pp. 723 ◽  
Author(s):  
GJ Gooley ◽  
TA Anderson ◽  
P Appleford

The gonadal development of Murray cod, Maccullochella peelii peelii, in Lake Charlegrark, Victoria, and adjacent farm ponds was evaluated. Gonadosomatic index, macroscopic classification and histological analysis were used to determine the age at first maturity and the gonadal development in this introduced population. There is a marked difference between the sexes in the size at first maturity, with females maturing at approximately 6 years of age and 2000 g in weight and males maturing at 3-4 years and 700 g. Gonadosomatic index data indicate that spawning occurs around November. Ovarian development in this species follows a pattern similar to that in a number of other teleosts. Testes have a lobular structure. Macroscopic evaluation of ovaries provided a good indication of the stage of the development of the gonad. However, the presence of spermatozoa throughout the year in the gonads of mature male fish makes the macroscopic evaluation of testicular development less reliable. Three cod, approximately 1% of the population, contained gonads with both ovarian and testicular tissue.


2004 ◽  
Vol 2 (1) ◽  
pp. 19-30 ◽  
Author(s):  
Simone Ferreira Teixeira ◽  
Beatrice Padovani Ferreira ◽  
Isaíras Pereira Padovan

The reproductive biology of the black grouper Mycteroperca bonaci, caught by artisanal fishermen using hook and line or compressor - assisted spear fishing, from the Northeastern shelf and oceanic banks of Brazil, was studied between August 1996 and April 1998. The sexual pattern, gonadal development, the spawning mode and seasonality were investigated. The gonadal stages indicated that this species is a protogynous hermaphrodite and that transition from female to male occurs through simultaneous re-absorption of ovarian tissue and proliferation of testicular tissue in the gonads. The specie is a multiple spawner and frequency analysis of gonadal stages and gonadosomatic index suggest that the spawning season occurs between April and September. Considerations about the fisheries, related to size structure of fishes caught, were based on length frequency distribution. The phenomenon of "correção" was described based on ethnobiology studies and informations from the Northeast Fisheries Statistics Bulletin of the Brazilian Environmental Institute (IBAMA). The phenomenon of the "correção" undergone by Mycteroperca bonaci seems to be a Southward chain reaction (of the State of Ceará to Bahia) and is a feeding aggregation.


Genome ◽  
1988 ◽  
Vol 30 (6) ◽  
pp. 870-878 ◽  
Author(s):  
Fred G. Biddle ◽  
Yutaka Nishioka

The Y chromosome of Mus musculus poschiavinus interacts with the autosomal recessive gene tda-1b of the C57BL/6J laboratory strain of the house mouse to cause complete or partial sex reversal. Ovaries or ovotestes develop in a substantial proportion of the XY fetuses. Several different Y-specific DNA probes distinguish two major types of Y chromosome in the house mouse and they are represented by M. m. domesticus and M. m. musculus. The poschiavinus Y chromosome appears identical to the domesticus Y. The developmental distribution of the gonad types was examined in the first backcross or N2 generation of fetuses in C57BL/6J with six different domesticus-type Y chromosomes and, as controls, three different musculus-type Y chromosomes. Gonadal hermaphrodites were found with three of the six domesticus-type Y chromosomes. Both overall frequency and phenotypic distribution of types of gonadal hermaphrodites identify three classes of domesticus-type Y chromosome by their differential interaction with the C57BL/6J genetic background.Key words: mouse, Y chromosomes, gonadal hermaphrodites, primary sex determination.


Genetics ◽  
2019 ◽  
Vol 213 (4) ◽  
pp. 1317-1327 ◽  
Author(s):  
Yingjie Zhou ◽  
Wei Sun ◽  
Han Cai ◽  
Haisheng Bao ◽  
Yu Zhang ◽  
...  

Anti-Müllerian hormone (Amh, or Müllerian-inhibiting substance, Mis), 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 Amh gene in the Chinese soft-shelled turtle Pelodiscus sinensis, a typical reptilian species exhibiting ZZ/ZW sex chromosomes. The messenger RNA of Amh was initially expressed in male embryonic gonads by stage 15, preceding gonadal sex differentiation, and exhibited a male-specific expression pattern throughout embryogenesis. Moreover, Amh was rapidly upregulated during female-to-male sex reversal induced by aromatase inhibitor letrozole. Most importantly, Amh loss of function by RNA interference led to complete feminization of genetic male (ZZ) gonads, suppression of the testicular marker Sox9, and upregulation of the ovarian regulator Cyp19a1. Conversely, overexpression of Amh in ZW embryos resulted in female-to-male sex reversal, characterized by the formation of a testis structure, ectopic activation of Sox9, and a remarkable decline in Cyp19a1. Collectively, these findings provide the first solid evidence that Amh is both necessary and sufficient to drive testicular development in a reptilian species, P. sinensis, highlighting the significance of the TGF-β pathway in reptilian sex determination.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Naoki Okashita ◽  
Shunsuke Kuroki ◽  
Ryo Maeda ◽  
Makoto Tachibana

Abstract SRY is the master regulator of male sex determination in eutherian mammals. In mice, Sry expression is transcriptionally and epigenetically controlled in a developmental stage-specific manner. The Sry promoter undergoes demethylation in embryonic gonadal somatic cells at the sex-determining period. However, its molecular mechanism and in vivo significance remain unclear. Here, we report that the Sry promoter is actively demethylated during gonadal development, and TET2 plays a fundamental role in Sry demethylation. Tet2-deficient mice showed absence of 5-hydroxymethylcytosine in the Sry promoter. Furthermore, Tet2 deficiency diminished Sry expression, indicating that TET2-mediated DNA demethylation regulates Sry expression positively. We previously showed that the deficiency of the H3K9 demethylase Jmjd1a compromises Sry expression and induces male-to-female sex reversal. Tet2 deficiency enhanced the sex reversal phenotype of Jmjd1a-deficient mice. Thus, TET2-mediated active DNA demethylation and JMJD1A-mediated H3K9 demethylation contribute synergistically to sex determination.


2007 ◽  
Vol 19 (6) ◽  
pp. 771 ◽  
Author(s):  
Monique C. J. Paris ◽  
Stefan Schlatt

In the present paper we aim to review the development of both ovarian and testicular xenografting with specific emphasis on its usage for companion animals, non-domestic and endangered species. Ovarian and testicular tissue xenografting has been used successfully across a variety of species for the harvesting of mature gametes and subsequent fertilisation. It has become a novel and promising tool to explore various aspects of testicular development and function and was useful for determination of gonadotoxic treatments on xenografted gonads. In rodent animal models live births have been reported using gametes from xenografted gonadal tissue. Live births were also reported after grafting of human ovarian tissue. We envisage that it will not be long before the first live births across other species, including companion animals, non-domestic and endangered species, will be achieved.


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