A. Oustry
Institut national de la recherche agronomique
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Featured researches published by A. Oustry.
Mammalian Genome | 1996
D. Vaiman; O. Koutita; A. Oustry; J. M. Elsen; E. Manfredi; Marc Fellous; E. P. Cribiu
Contrary to other genetic disorders, the genetic study of sex determination anomalies in humans stumbles over the difficulty in observing large pedigrees. In goats, abnormalities in sex determination are intimately linked to a dominant Mendelian gene coding for the “polled” (hornless) character, which could render this species an interesting animal model for the rare human cases of SRY-negative XX males. In this report, we describe genetic linkage between the polled/intersex synchome (PIS) and four microsatellite markers of the distal region of goat Chromosome 1 (CHI1), quite distinct from the bovine “polled” region. According to comparative mapping data, no sex-determining gene has been described so far in homologous regions in the human. This genetic localization constitutes a first step towards identifying a new autosomal sex-determining gene in mammals.
Mammalian Genome | 1998
Sophie Godard; Laurent Schibler; A. Oustry; Edmond Cribiu; Gérard Guérin
Abstract. A horse BAC library was constructed with about 40, 000 clones and mean insert size of 110 kb representing a 1.5 genome equivalent coverage and a probability of finding a single sequence of 0.75. It was characterized by PCR screening of about 130 sequences of horse microsatellites and exonic gene sequences retrieved from databases. BACs containing 8 microsatellites and 12 genes were subsequently localized by fluorescent in situ hybridization (FISH) on chromosomes. Two linkage groups were newly assigned to chromosomes: LG2 to ECA3 and LG5 to ECA24, and five linkage groups were also oriented—LG3, LG4, LG5, LG8, and LG12—leaving only three groups unassigned. This work showed how this library makes an integrated map a realistic objective for the near future and how it can make comparative mapping more efficient in a search for candidate genes of interest.
Mammalian Genome | 1998
Laurent Schibler; D. Vaiman; A. Oustry; Nathalie Guinec; Anne-Laure Dangy-Caye; Alain Billault; Edmond Cribiu
A goat Bacterial Artificial Chromosome (BAC) library of 61,440 independent clones was constructed and characterized. The average size of the inserts was estimated at 153 kilobases by analyzing almost 500 clones using Not1 digestion followed by FIGE (Field Inverted Gel Electrophoresis) analysis. The library represents about three genome equivalents, which yields a theoretical probability of 0.95 of isolating a particular DNA sequence. After individual growth, the clones were arrayed in 40 superpools, which were organized in three dimension pools. A rapid technique for pool DNA preparation by microwave treatment was set up. This technique was compatible with PCR analysis. Primer pairs from 166 sequences (microsatellites, coding sequences from goat, and conserved Expressed Sequence Tags (ESTs) from humans) enabled the library to be successfully searched in 165 cases, with an average of 3.52 positive superpools. Only one sequence could not be found. The degree of chimerism was evaluated by FISH analysis with DNA from over 110 clones and was estimated at 4%. This BAC library will constitute an invaluable tool for positional cloning in ruminants, as well as for more general comparative mapping studies in mammals.
Mammalian Genome | 1997
Sophie Godard; D. Vaiman; A. Oustry; M. Nocart; Maud Bertaud; S. Guzylack; J.C. Mériaux; E. P. Cribiu; Gérard Guérin
Abstract. Thirty-six new horse microsatellites (11 from plasmid libraries and 25 from a cosmid library) were isolated and characterized on a panel of four horse breeds. Thirty were found to be polymorphic with heterozygosity levels ranging between 0.20 and 0.87. Twenty-two of the cosmids were physically mapped to R-banded single horse Chromosomes (Chrs) 1, 3, 4, 9, 11, 12, 13, 15, 18, 19, 21, 22, 23 and three to pericentromeric regions. Furthermore, linkage analysis between a selection of 42 DNA markers, including those presented in this study, and 16 conventional markers of the horse hemotype was performed on six paternal half-sib horse families. Five linkage groups were detected, of which four were assigned to Chr 10, 11, 15, and 18. This work increased by one-third the number of published polymorphic DNA markers suitable for horse mapping and approximately doubled the number of known linkage groups. Our cosmids labeled 14 out of the 31 horse autosomes. Moreover, the physical anchoring of part of these markers will orient linkage and synteny groups on the chromosomes and will contribute to their assignment.
Cytogenetic and Genome Research | 1998
François Piumi; Laurent Schibler; D. Vaiman; A. Oustry; E. P. Cribiu
Cytogenetic localization of 24 BACs containing type I (genes and ESTs) and type II (microsatellites) markers were used to construct cytogenetic maps of caprine (CHI) and bovine (BTA) X chromosomes. Comparison of these two maps revealed that the distal region of the goat X long arm (CHI Xq38→q42) was located inside the bovine X chromosome, between PGK1 (BTA Xq25) and DVEPC137 (BTA Xq12). The marker order was globally conserved without any pericentric inversion, as previously postulated in the literature. The caprine centromere was found between DVEPC053 and DVEPC102 (belonging to the same band in the bovine X: BTA Xq41), whereas the bovine centromere was between DVEPC076 and DVEPC132, belonging to the same region of the caprine X chromosome (CHI Xq31→q33). The pseudoautosomal region was situated at the tip of the bovine X long arm and on the tiny short arm of the caprine X chromosome. In the non-pseudoautosomal (NPA) region, the synteny of coding sequences was well conserved between the human species and the two ruminant species, but the gene order was dramatically divergent. It is suggested that the 24 BACs of this study could constitute a new tool to measure phylogenetic distances between different mammalian species by comparing chromosome rearrangements inside the NPA region of the X.
Theriogenology | 1997
D. Vaiman; Eric Pailhoux; Laurent Schibler; A. Oustry; S. Chaffaux; Corinne Cotinot; Marc Fellous; E. P. Cribiu
Abstract Sex determination in mammals is due to a complex cascade of gene regulations involving SRY and autosomal and X genes. Study of intersex cases in domestic mammals could enlighten some parts of this basic developmental pathway and therefore clarify the mechanisms of sexual differentiation in humans, especially for autosomal mutations affecting non Y-downstream sex-determining genes. Intersex condition is well documented in dairy goats. It is due to a recessive gene which is associated with the dominant autosomal gene for hornlessness, P. In the homozygous state, the P gene causes masculinization of all polled genetic females PP. The study of 13 polled intersex goats permitted to describe in detail the external morphology, anatomy of the reproductive tract, gonadal histology and chromosomal constitution. All animals exhibited two inguinally located udders. Seven of them appeared to be closer to the female phenotype on the basis of general conformation, external and internal genitalia while the other six had the general appearance and internal reproductive tract resembling males. The gonads of all animals contained seminiferous tubules lined by Sertoli cells. No germ cells were observed. The chromosome analyses of the blood and gonadal cultures prepared from each animal showed a normal female karyotype (2n = 60,XX). No Y chromosome was observed in any of the metaphase spreads. Futhermore, using PCR amplification and Southern blot, no DNA specific sequence of the Y chromosome (SRY and ZFY) was detected. A linkage analysis within 12 pedigrees segregating for the polled trait allowed the localization of the polled/intersex locus in the distal region of goat chromosome 1. According to comparative mapping data, no sex-determining gene has been described so far in the human homologous region. This genetic localization constitutes the first step towards the identification of a new autosomal sex determining gene in mammals.
Mammalian Genome | 1995
A. Schmitz; A. Oustry; B. Chaput; I. Bahri-Darwich; M. Yerle; D. Millan; G. Frelat; E. P. Cribiu
A bovine bivariate flow karyotype has been established from a primary fibroblast cell culture carrying a 4;10 Robertsonian translocation. From 27 to 36 populations could be resolved by flow cytometry although the anticipated number was 31. Separation of chromosomal pairs into two populations explains this high resolution and confirms the high level of heteromorphism previously observed. We used a PARM-PCR (Priming Autorizing Random Mismatches) procedure for the production of paint probes from flow-sorted chromosome fractions. These probes were used for chromosome identification by fluorescence in situ hybridization (FISH) on R-banded metaphase spreads. We present the localization of all the bovine chromosome types on the flow karyotype. Twenty-two chromosome types including the translocated chromosome were sorted as pure fractions.
Cytogenetic and Genome Research | 1997
D. Vaiman; Laurent Schibler; A. Oustry; A. Schmitz; Jean-Pierre Furet; W. Barendse; E. P. Cribiu
A genomic library was constructed from a peak of flow-sorted bovine chromosomes 1 + X after PCR amplification. Forty-three bovine chromosome 1 microsatellites were isolated, genetically mapped and integrated in the international genetic map. In addition, BAC clones from a goat BAC library were identified for five markers (DVEPC119, INRA011, BM4307, KAP8 and MAF64). These goat BACs could be mapped by FISH onto bovine chromosome 1 to bands 1q44-->q45, 1q25, 1q21, 1q12 and 1q14-->q21, respectively. This map reduces the average interval between consecutive markers on the international bovine genetic map from 5.5 cM to 2.5 cM, and provides a good starting point for positional cloning projects in cattle, sheep or goats.
Genome Research | 1998
Laurent Schibler; Daniel Vaiman; A. Oustry; Corinne Giraud-Delville; Edmond Cribiu
Genetics | 1996
D. Vaiman; Laurent Schibler; Florence Bourgeois; A. Oustry; Yves Amigues; Edmond Cribiu