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C Cotinot

Publications and source records attributed to C Cotinot.

34 records · Page 2Linked to original sources
PubMed1997

Mapping in pig of genes involved in sexual differentiation: AMH, WT1, FTZF1, SOX2, SOX9, AHC, and placental and embryonic CYP19.

Intersexuality has been reported in pigs and investigations are in progress to identify and physically map the genes involved in sex-reversal. In this study we have mapped on porcine chromosomes seven genes which might be implicated in this developmental pathway. Four genes were mapped by radioactive in situ hybridization: AMH (Anti-Müllerian Hormone) and WT1 (Wilms' Tumor gene 1) were both mapped to pig chromosome 2 (SSC2) in the q14-->q21 and p14-->q11 regions, placental CYP19 (cytochrome P450, subfamily XIX) and FTZF1 (fushi tarazu factor [Drosophila] homolog 1, alias SF1 [steroidogenic factor 1]) to pig chromosome 1 (SSC1) in the q14-->q17 and q210-->q211 regions respectively. Four other genes were regionally located by PCR analysis on a cytogenetically characterized porcine somatic cell hybrid panel: a second CYP19 gene (expressed in embryo) was mapped to porcine 1q12-->q17, AHC (alias DAX1, adrenal hypoplasia congenital) to porcine Xp24, SOX2 and SOX9 (SRY sex determining region Y-box 2 and 9) to 13q23-->q41 and 12p13-->p11 respectively. These results are in global agreement with mapping data available in other mammalian species.

Animals↗
PubMed1996

Transcription of Y- and X-linked genes in preimplantation ovine embryos.

Because male ovine embryos develop faster than female embryos, the transcription of SRY and ZFY, two genes located on the Y chromosome, was examined in preimplantation stages using the reverse transcriptase polymerase chain reaction (RT-PCR). RNA was extracted from pools of ovine embryos matured and fertilized in vitro then cultured in synthetic oviduct fluid medium and recovered from 24 to 207 hr post-insemination (two-cell up to hatched blastocyst stage). Since primers used to amplify ZFY also amplify the homologue ZFX, located on the X chromosome, transcripts were differentiated by digestion with restriction enzymes. ZFY and ZFX transcripts were present in all stages examined following RT-PCR, whereas transcripts for SRY were undetectable in all investigated stages following either RT nested PCR or Southern analysis. The presence of ZFY transcripts suggests that Y chromosome is transcriptionally active during early ovine preimplantation development. The possible relationship between a faster growth of male embryos and the transcription of Y-linked genes at early stages of development is discussed.

Animals↗
PubMed1996

Characterization of ovine SRY transcript and developmental expression of genes involved in sexual differentiation.

In mammals, the presence of SRY, the sex-determining gene located on the Y chromosome is required to induce the gonadal anlage to differentiate as a testis, whereas its absence leads to the development of an ovary. We report here the characterization by 5' and 3' RACE analysis of several SRY transcripts which are expressed in the ovine male developing gonads. These transcripts were not detected in any other fetal tissues and were expressed only in the genital portion of the urogenital ridge. The temporal profile of SRY expression analyzed by RT-PCR suggests that in the sheep fetus the role of SRY is not limited to initiating Sertoli cell differentiation as in mice. Indeed, SRY transcripts persist after the full differentiation of the testis. In addition to SRY, other genes are known to be involved in mammalian sex determination: Wilms' tumor gene WT-1, steroidogenic factor gene Ftz-F1 (SF-1) and anti-Müllerian hormone (AMH). We investigated the expression patterns of these genes by RT-PCR during fetal development in sheep gonads. Concerning WT-1 and SF-1, our results are consistent with those described in mice where the earliest expression was detected before the sexual differentiation in both sexes. In male, the ontogenesis of AMH transcription corresponds to the seminiferous cords formation (30 dpc). In female, we have observed the presence of SF-1 transcripts from the undifferentiated stage until birth. In addition, P450 aromatase expression is detected from 30 dpc and is correlated with the presence of 17-beta estradiol in sheep ovary. These data reveal significant differences between rodent and ruminant models concerning the sex-determining pathway.

Aging↗
PubMed1995

Sheep gene mapping: assignment of ALDOB, CYP19, WT and SOX2 by somatic cell hybrid analysis.

Twenty-four hamster-sheep hybrid cell lines representing eleven ovine synteny groups were used to make syntenic assignments for seven loci ALDOB (aldolase B, fructose biophosphate); AMH (anti-Müllerian hormone); CYP19 [cytochrome P450 aromatase, subfamily XIX (aromatization of androgens)]; WT (Wilms' tumour gene); SOX2 (SRY-related HMG-box gene 2); FSHB (follicle-stimulating hormone, beta polypeptide); and SRY (sex region of Y chromosome). These loci were assigned to synteny groups U11(chr2) (ALDOB); U19 (AMH); U3(chr7) (CYP19); and to chromosome 15 (WT) and 1 (SOX2). SRY defines the hybrids containing the Y chromosome.

Animals↗
PubMed1995

Molecular analysis of an XY mare with gonadal dysgenesis.

In this study, cytogenetic analysis of an infertile mare revealed a 64, XY karyotype. The XY sex-reversed animal had a female phenotype with gonadal dysgenesis. Using Southern blot analysis, we tested for the presence of two Y-specific genes SRY and ZFY by using DNA isolated from peripheral blood leukocytes. The results showed that at least the DNA-binding domain of the SRY gene was deleted from the Y chromosome of the XY mare but that the ZFY gene was present on this chromosome.

Animals↗
PubMed1995

Evolutionary conservation of a microsatellite in the Wilms tumour (WT) gene: mapping in sheep and cattle.

A microsatellite in the WT (Wilms tumour) gene is shown to be evolutionarily conserved in a range of mammals. The microsatellite was monomorphic in pig and two alleles have been found in goat. In cattle, a one-base size polymorphism has been discovered outside the microsatellite. WT was genetically mapped to bovine chromosome 15 and to sheep chromosome 15 by synteny mapping. Conservation of chromosome segments of HSA11 and BTA15 is discussed.

Animals↗
PubMed1994

Cloning and characterization of a full-length cDNA coding for ovine aldolase B from fetal mesonephros.

An ovine aldolase B cDNA was isolated from mesonephros (29 d pc). The sequence covers 1649 nucleotides. Comparison with human liver aldolase B cDNA shows a homology of about 86%. The deduced amino acid sequence is composed of 364 residues and exhibits 92% homology to the human protein. Northern blot analysis and in situ hybridization data show that during the first third of gestation in sheep, aldolase B expression is restricted to the mesonephros.

Amino Acid Sequence↗
PubMed1994

Genetic analysis of 38XX males with genital ambiguities and true hermaphrodites in pigs.

In pig, the frequency of intersexuality ranges from 0.1 to 0.6%, depending on the breed. In a closed pig herd at INRA an intersex condition was observed in 0.75% of 'females'. The present study describes 11 animals with a 38XX karyotype and the presence of testicular tissue. Phenotypically, all presented with abnormal external or/and internal genitalia. Southern blot analysis with Y-specific probes (SRY and ZFY) revealed the absence of Y material in all animals tested. By polymerase chain reaction (PCR) amplification, 10 of 11 intersex pigs lacked the SRY gene in gonad DNA. These data are compatible with an autosomally (or pseudoautosomally) determined mechanism. Moreover, analysis of familial cases seemed to indicate that 38XX male pseudohermaphrodites and 38XX true hermaphrodites may represent alternative manifestations of the same genetic defect.

Animals↗
PubMed1994

Molecular analysis of 60,XX pseudohermaphrodite polled goats for the presence of SRY and ZFY genes.

The polled mutation is characterized by a recessive, incompletely penetrant, hermaphroditic effect associated with the dominant genetic factor responsible for polledness in breeds of goat. The present study describes the external morphology, anatomy of the reproductive tract, histology, chromosomal constitution and Y chromosome screening of three intersex polled goats. The animals were tested for different Y-specific sequences, including SRY and ZFY. Using Southern blot and PCR amplification, no Y-derived sequences were detected in DNA from three 60,XX pseudohermaphrodite goats. This, therefore, excludes Y chromosome translocation and XX/XY chimaerism and mosaicism. This recessive mutation leading to sex reversal might be used to map and ultimately clone the autosomal genes implicated in the sex-determining pathway.

Animals↗
PubMed1991

Improvement of flow cytometry analysis and sorting of bull spermatozoa by optical monitoring of cell orientation as evaluated by DNA specific probing.

Flow cytometry is a potential method for the separation of X and Y bearing spermatozoa, on the basis of their relative DNA content evaluated by the fluorescence emission intensity due to specific fluorochrome DNA staining. However, spermatozoa DNA is highly condensed and nuclei exhibit flat non spherical shape, which can produce artefacts impeding accurate analysis. In order to avoid these limitations, decondensation of DNA performed by enzymatic treatment and a modification of the flow cytometer that orients the spermatozoa relative to the laser beam are generally used. In this work, we describe alternative methods and materials for selection of 1) decondensed and thus dead spermatozoa without orientation, sorted on the basis of only the 10% spermatozoa containing the least DNA (expected Y) and the 10% spermatozoa containing the more DNA (expected X), or 2) native spermatozoa homogeneously oriented using a simultaneous measurement of Axial light loss (extinction) and Forward angle light scatter. For testing enrichment of each selected fraction we have worked out a molecular hybridization procedure using X and Y specific DNA probes. We analyse and sort bull spermatozoa on these basis: the purity obtained for these fractions is 80% without orientation after enzymatic treatment, and 70% on live spermatozoa "optically" oriented.

Animals↗
PubMed1991

Isolation of bovine Y-derived sequence: potential use in embryo sexing.

To obtain bovine Y-derived probes, we have constructed a bovine plasmid library enriched for Y-specific DNA sequences by the deletion enrichment method. The resulting clones were analyzed by hybridization to Southern blots of male and female genomic DNA. From 200 clones tested, two (BC1.2 and BC1.34) were entirely male specific, six gave a male-female differential hybridization pattern, and the remaining reacted similarly with male and female DNA. Interspecies somatic cell hybrid studies and chromosomal in situ hybridization confirmed that the BC1.2 sequence was derived from the Y chromosome. This 54-bp fragment is present at about 2000-2500 copies in the bovine male genome. No polymorphism was revealed with any of the restriction enzymes used, suggesting enzyme site conservation within blocks of repeats. Evolutionary study has shown that the BC1.2 sequence is conserved within Bos and Bison genera and remains male specific. The male specificity and repeated nature of the BC1.2 sequence have enabled us to use it as a molecular probe for sex determination on small numbers of cells by in situ hybridization.

Animals↗
PubMed1990

[Diagnosis of the sex of bovine embryos using molecular biology].

Thanks to a bovine genomic library enriched with Y chromosome-specific sequences, a probe specific to this chromosome of genera Bos and Bison and repeated on about 2,000 copies in the male genome was isolated. To be compatible with embryo transfer and/or freezing, sex determination has to be done on a 10-20 cell embryo biopsy from a day-7 bovine blastocyst. The in situ hybridization with biotinylated BC 1.2 probe and immunocytochemical revelation permitted the visualization of the hybridization signal on the nucleus of each cell. Because of the numerous steps required, this technique was difficult to apply routinely. For that reason we worked out the polymerase chain reaction technique. From the BC 1.2 sequence, we determined several oligonucleotide primers and probes with the aim of amplifying the Y chromosome-specific sequences. This technique, which is easy to perform and to automate, enabled us to obtain a strong male-specific hybridization signal on genomic DNA and embryo cells.

Animal Husbandry↗
PubMed1988

Chromosomal localization of a bovine male specific probe.

The B.C.1.2. probe, a fairly repeated sequence of the bovine male genome, was located by in situ hybridization on cattle karyotype. Of a total of 711 silver grains, 139 (19.5%) clustered on chromosome Y and about 71% of the grains were located on the short arm. This Y specific bovine male probe could be useful for routine embryo sexing in connection with embryo transfer.

Animals↗
PubMed1985

A method of purifying sheep sIg+ lymphocytes as a tool for class II MHC antigen analysis.

A method is described for the purification of sheep lymphocytes carrying class II MHC antigens. After incubation of purified blood lymphocytes on anti-IgM-coated petri dishes, the adherent fraction contained 95% sIg-positive cells determined by immunofluorescence. When tested with cross-reacting anti-class II (bovine and human) monoclonal antibodies, more than 95% of these cells were positive either by immunofluorescence or cytotoxicity. This technique will permit studies of the polymorphism of sheep class II antigens.

Animals↗