Publications by authors named "Eozenou C"

The Y-linked SRY gene initiates mammalian testis-determination. However, how the expression of SRY is regulated remains elusive. Here, we demonstrate that a conserved steroidogenic factor-1 (SF-1)/NR5A1 binding enhancer is required for appropriate SRY expression to initiate testis-determination in humans.

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During embryonic development, mutually antagonistic signaling cascades determine gonadal fate toward a testicular or ovarian identity. Errors in this process result in disorders of sex development (DSDs), characterized by discordance between chromosomal, gonadal, and anatomical sex. The absence of an appropriate, accessible in vitro system is a major obstacle in understanding mechanisms of sex-determination/DSDs.

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Study Question: Do human granulosa cells (GCs) ingest and destroy apoptotic oocytes?

Summary Answer: Somatic GCs ingest and destroy apoptotic oocytes and other apoptotic substrates through unconventional autophagy-assisted phagocytosis.

What Is Known Already: Most (99%) ovarian germ cells undergo apoptosis through follicular atresia. The mode of cleaning of atretic follicles from the ovary is unclear.

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Sex determination in mammals is governed by antagonistic interactions of two genetic pathways, imbalance in which may lead to disorders/differences of sex development (DSD) in human. Among 46,XX individuals with testicular DSD (TDSD) or ovotesticular DSD (OTDSD), testicular tissue is present in the gonad. Although the testis-determining gene is present in many cases, the etiology is unknown in most -negative patients.

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Forkhead Box L2 (FOXL2) is a member of the FOXL class of transcription factors, which are essential for ovarian differentiation and function. In the endometrium, FOXL2 is also thought to be important in cattle; however, it is not clear how its expression is regulated. The maternal recognition of pregnancy signal in cattle, interferon-Tau, does not regulate expression.

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Article Synopsis
  • The study investigates genetic causes of 46,XY disorders/differences of sex development (DSD), particularly gonadal dysgenesis and testis regression syndrome (TRS), which often have unknown origins.
  • Researchers used exome and Sanger sequencing on 145 individuals, discovering pathogenic variants in the DHX37 gene that are linked to these conditions.
  • The findings suggest that DHX37 variants contribute to an autosomal dominant form of 46,XY DSD, indicating a potential connection between these conditions and ribosomopathies.
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Human sex-determination is a poorly understood genetic process, where gonad development depends on a cell fate decision that occurs in a somatic cell to commit to Sertoli (male) or granulosa (female) cells. A lack of testis-determination in the human results in 46,XY gonadal dysgenesis. A minority of these cases is explained by mutations in genes known to be involved in sex-determination.

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In mammals, tight regulation of maternal endometrial function is critical for pregnancy success. In bovine species, endometrial expression of members of the scavenger receptor class A (SR-A) has been listed in high-throughput analyses, but very little is known about the involvement of these immune factors during implantation in mammals. To provide first insights into the contribution of SR-A to endometrial physiology, we analysed the expression and regulation of all members of SR-A (SR-A1, SR-A3-SR-A6) during the oestrous cycle and early pregnancy in cattle.

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Mammalian sex determination is controlled by the antagonistic interactions of two genetic pathways: The SRY-SOX9-FGF9 network promotes testis determination partly by opposing proovarian pathways, while RSPO1/WNT-β-catenin/FOXL2 signals control ovary development by inhibiting SRY-SOX9-FGF9. The molecular basis of this mutual antagonism is unclear. Here we show that ZNRF3, a WNT signaling antagonist and direct target of RSPO1-mediated inhibition, is required for sex determination in mice.

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Article Synopsis
  • Recent research on mice suggests that sex determination in mammals results from competing male and female regulatory systems, but the pathways for ovary development are less understood.
  • A study sequenced genetic data from 79 individuals with unexplained virilization or disorders of sex development and found mutations in the NR2F2 gene in three children, which were linked to several congenital conditions.
  • The study highlights COUP-TF2 as a key "pro-ovary" factor in human ovaries, contrasting with its role in mice, suggesting differing roles for nuclear receptors in human and mouse sex determination.
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  • SOX8 is a transcription factor involved in sex determination, and while its role in humans isn't fully understood, it is expressed in early gonadal development.
  • Research identified SOX8 mutations and chromosomal rearrangements in individuals with 46, XY disorders of sex development (DSD) and male infertility, suggesting a link to reproductive issues.
  • SOX8 mutations were found more frequently in infertile men and women with primary ovarian insufficiency, indicating that alterations in SOX8's function could contribute to various reproductive conditions.
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  • Intensive milk production in dairy cattle negatively affects reproductive efficiency, particularly during the critical phase of embryo implantation.
  • The study examined the effects of maternal metabolism on the endometrial response to the embryo and found that reproductive hormones showed similar expression levels in both high-producing and non-producing cows.
  • Results indicated that variations in maternal metabolism influenced gene expression significantly, especially in areas of the endometrium, suggesting that understanding these changes could improve conceptus development post-implantation.
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Maternal recognition of pregnancy (MRP) and implantation involve appropriate interactions between the elongating conceptus and the receptive endometrium that will condition development of the feto-placental unit to term. Molecular mechanisms that take place at the conceptus-endometrium interface during early pregnancy have been extensively investigated in domestic ungulates but they are still poorly understood in camelids including the dromedary camel (Camelus dromedarius), a domestic species with important economic and social roles in arid and semi-arid areas. In order to better understand how MRP and implantation take place in the left horn of this species, we investigated expression levels of genes encoding steroid hormones (PGR, ESR1), transcription factors (STAT1, FOXL2), interferon stimulated genes (MX1, MX2, OAS1, RSAD2) including SOCS genes (SOCS1, SOCS2, SOCS3 and CISH), previously identified as conceptus regulated genes in the endometrium of other domestic animals.

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Human sex determination (SD) involves complex mutually antagonistic genetic interactions of testis- and ovary-determining pathways. For many years, both male and female SD were considered to be regulated by a linear cascade of pro-male and pro-female genes, respectively; however, it has become clear that male and female development is achieved through the repression of the alternative state. A gene determining the formation of a testis may function by repressing the female state and vice versa.

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We investigated the diagnostic reliability of pregnancy detection using changes in interferon stimulated gene (ISG) messenger RNA (mRNA) levels in circulating immune cells in ewes. Two different groups of ewes (an experimental group, experiment 1 and a farm group, experiment 2) were oestrus-synchronized and blood sampled on day 14 (D0=day of insemination in control animals, experiment 1) and day 15 (experiment 2). Real-time PCR were performed to evaluate the abundance of different ISG mRNAs.

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Cell lineages of the early human gonad commit to one of the two mutually antagonistic organogenetic fates, the testis or the ovary. Some individuals with a 46,XX karyotype develop testes or ovotestes (testicular or ovotesticular disorder of sex development; TDSD/OTDSD), due to the presence of the testis-determining gene, SRY Other rare complex syndromic forms of TDSD/OTDSD are associated with mutations in pro-ovarian genes that repress testis development (e.g.

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In terms of contribution to pregnancy, the mother not only produces gametes, but also hosts gestation, whose progression in the uterus is conditioned by early events during implantation. In ruminants, this period is associated with elongation of the extra-embryonic tissues, gastrulation of the embryonic disk and cross-talk with the endometrium. Recent data have prompted the need for accurate staging of the bovine conceptus and shown that asynchrony between elongation and gastrulation processes may account for pregnancy failure.

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In mammals, suppressor of cytokine signalling (CISH, SOCS1 to SOCS7) factors control signalling pathways involved in the regulation of numerous physiological processes including pregnancy. In order to gain new insights into the biological functions of SOCS in the endometrium, a comprehensive analysis of SOCS gene expression was carried out in bovine caruncular (CAR) and intercaruncular (ICAR) tissues collected i) during the oestrous cycle, ii) at the time of maternal recognition of pregnancy and at implantation in inseminated females, iii) following uterine interferon-tau (IFNT) infusion at day 14 post-oestrus, iv) following a period of controlled intravaginal progesterone release and v) following transfer of embryos by somatic-cell nuclear transfer (SCNT). The regulatory effects of IFNT on in vitro cultured epithelial and stromal cells were also examined.

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Signal transducer and activator of transcription (STAT) proteins are critical for the regulation of numerous biological processes. In cattle, microarray analyses identified STAT1 as a differentially expressed gene in the endometrium during the peri-implantation period. To gain new insights about STAT1 during the oestrous cycle and early pregnancy, we investigated STAT1 transcript and protein expression, as well as its biological activity in bovine tissue and cells of endometrial origin.

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FOXL2, a winged-helix/forkhead domain transcription factor, is a key gene involved in the differentiation and biological functions of the ovary. In a recent transcriptomic analysis, we found that FOXL2 expression in bovine caruncular endometrium was different from that in intercaruncular endometrium. In order to gain new insights into FOXL2 in this tissue, we determined the expression of this transcription factor during the estrous cycle and the establishment of pregnancy in cattle.

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