Biomedical subjects

S Rousseaux

Publications and source records attributed to S Rousseaux.

32 records · Page 2Linked to original sources

PubMed1997

Increased aneuploid frequency in spermatozoa from a Hodgkin's disease patient after chemotherapy and radiotherapy.

The frequency of sperm aneuploidy was investigated by fluorescence in situ hybridization (FISH) in a Hodgkin's disease patient shortly after he had received chemotherapy and radiotherapy. Sperm karyotyping of the same patient had previously shown multiple structural abnormalities in most spermatozoa immediately after radiotherapy (day 0), whereas most spermatozoa collected 5 wk later (day 38) exhibited normal metaphase divisions (Rousseaux et al., 1993). Variations in the frequency of aneuploidy could not be detected by sperm karyotyping. Multicolor FISH on interphase spermatozoa revealed an increase in the rate of disomy for chromosomes 1, 6, 11, X, and Y at day 0 as well as at day 38. The high frequency of 24,XY (nondisjunction at meiosis I) and 24,XX (nondisjunction at meiosis II) spermatozoa (8.46% and 1.64% at day 0, respectively) from the Hodgkin's disease patient suggests that both meiosis I and II are affected and that the X chromosome is frequently involved in such malsegregation events. The rate of 46,XY diploidy was also increased in the patient's sperm, up to 0.62% at day 0. While radiotherapy probably affected the postmeiotic cells (spermatids), the patient's cancer and/or chemotherapy are the two major factors that could have affected the dividing spermatogonia and/or spermatocytes, resulting in high aneuploidy rates.

Aneuploidy↗

PubMed1996

Increased incidence of hyperhaploid 24,XY spermatozoa detected by three-colour FISH in a 46,XY/47,XXY male.

Meiotic segregation of gonosomes from a 46,XY/47,XXY male was analysed by a three-colour fluorescence in situ hybridisation (FISH) procedure. This method allows the identification of hyperhaploid spermatozoa (with 24 chromosomes), diploid spermatozoa (with 46 chromosomes) and their meiotic origin (meiosis I or II). Alpha satellite DNA probes specific for chromosomes X, Y and 1 were observed on 27,097 sperm nuclei. The proportions of X- and Y-bearing sperm were estimated to 52.78% and 43.88%, respectively. Disomy (24,XX, 24,YY, 24,X or Y,+1) and diploidy (46,XX, 46,YY, 46,XY) frequencies were close to those obtained from control sperm, whereas the frequency of hyperhaploid 24,XY spermatozoa (2.09%) was significantly increased compared with controls (0.36%). These results support the hypothesis that a few 47,XXY germ cells would be able to complete meiosis and to produce mature spermatozoa.

Adult↗

PubMed1996

Identification of exons in a region of human chromosome 6q known to contain tumour suppressor genes.

An important objective in human genomic mapping is the isolation of expressed sequences from defined chromosomal regions. The 6q27 region of the long arm of chromosome 6 is an important target in this endeavour because a number of tumour suppressor genes have been mapped to this region. We have used exon trapping and amplification in conjunction with a chromosome specific genomic library to generate ESTs in 6q27. Nine novel expressed sequences have been identified and these provide additional markers and potential candidate genes for the tumour suppressor genes known to be in 6q27.

Animals↗

PubMed1995

Sperm nuclei analysis of a Robertsonian t(14q21q) carrier, by FISH, using three plasmids and two YAC probes.

The meiotic segregation of chromosomes 14 and 21 was analysed in 1116 spermatozoa from an oligoasthenospermic carrier of a Robertsonian translocation t(14q21q), and in 16,392 spermatozoa from a control donor, using two-colour fluorescence in situ hybridisation (FISH). Two YAC probes (cloned in yeast artificial chromosomes) specific for regions on the long arms of these chromosomes were co-hybridised. Of the spermatozoa, 12% were unbalanced, resulting from adjacent segregations. Chromosomes X, Y and 1 were also simultaneously detected in 1335 spermatozoa from the same carrier. Whereas gonosomal disomy rates were not significantly different from those of the control donors, disomy 1 were slightly but significantly increased to 0.7%. The diploidy rate was also slightly increased to approximately 1% in the translocation carrier.

Adult↗

PubMed1995

Human sperm chromosome analysis after microinjection into hamster oocytes.

PURPOSE: Subzonal sperm insemination (SUZI) into hamster oocytes was performed to establish the karyotypes of the fertilizing spermatozoa. METHODS: Spermatozoa from two males with normal semen parameters were microinjected. Of 72 (52 + 20) analyzed sperm chromosome metaphases, only 1 (1.4%) was considered abnormal, showing a structural abnormality. RESULTS: No hyperhaploidy was observed. Rates of sperm chromosomal abnormalities after microinjection were not higher than those reported previously using zona-free egg insemination, suggesting that the SUZI procedure per se does not increase sperm chromosomal abnormalities. CONCLUSIONS: The use of subzonal insemination into hamster oocytes for the study of human sperm chromosomes in males with low sperm counts is discussed.

Animals↗

PubMed1995

Meiotic segregation of the X and Y chromosomes and chromosome 1 analyzed by three-color FISH in human interphase spermatozoa.

Meiotic segregation of the X and Y chromosomes and chromosome 1 was analyzed by three-color fluorescence in situ hybridization (FISH) in 94,575 human interphase spermatozoa from four control subjects. More than 99% of the sperm cells were labeled. The proportions of X- and Y-bearing sperm were estimated to be 49.83% and 48.30%, respectively. The disomy rates were 0.04%, 0.009%, and 0.20% for the X and Y chromosomes and chromosome 1, respectively. Hyperhaploidy with an extra gonosome was found in 0.34% of spermatozoa, due to nondisjunction during meiosis I. The frequency of diploidy was 0.11% at meiosis I and 0.036% at meiosis II. Cohybridization of one autosomal and two gonosomal probes, in three-color FISH in interphase spermatozoa, seems to accurately discriminate diploidies from disomies, as well as the meiotic origin of gonosomal aneuploidies in sperm cells.

DNA Probes↗

PubMed1995

Meiotic segregation in males heterozygote for reciprocal translocations: analysis of sperm nuclei by two and three colour fluorescence in situ hybridization.

The meiotic segregation of chromosomes was analysed in three reciprocal translocation carriers, using FISH on interphase spermatozoa. The segregation pattern was first studied in 27,844 spermatozoa from two siblings carrying the reciprocal translocation t(6;11)(q14;p14). Three centromeric probes, specific for chromosomes 6, 11 and 1, were simultaneously hybridized so that all centric fragments as well as the ploidy of each cell could be determined by three colour FISH. For both subjects, the respective frequencies of alternate/adjacent 1, adjacent 2, 3:1 and 4:0 segregation modes were 88%, 9%, 3+ and < 1%. In another reciprocal translocation t(2;14)(p23.1;q31), a two colour FISH analysis was performed on 4,610 spermatozoa, using a chromosome 2 centromeric probe and a YAC probe located on the centric fragment of chromosome 14. Frequencies of alternate/adjacent 1, adjacent 2, and 3:1 segregations were 89%, 5.2%, and 5.8% respectively. The segregation of chromosomes X, Y and 1 were also analyzed with three colour FISH on the spermatozoa from all three translocation carriers, in order to detect an interchromosomal effect. Aneuploidy rates for the X and Y chromosomes were found to be in the same range in the three translocation carriers and control donors, but disomy 1 rates were slightly increased in the translocation carriers.

Cell Nucleus↗

PubMed1995

In-vitro decondensation of human spermatozoa for fluorescence in-situ hybridization.

In order to enhance the efficiency of fluorescence in-situ hybridization (FISH) on human interphase spermatozoa, a simple method for partial decondensation of human spermatozoa chromatin is described. The spermatozoa were washed once in 0.01 M Tris and decondensed using 10 mM dithiothreitol in 0.05 M Tris for 10-50 min, before being spread onto clean slides. Sperm samples were observed every 10 min under a phase-contrast microscope in order to modify the duration of the decondensation process. Using several centromeric or YAC probes in multicolour FISH, high hybridization rates were obtained.

Adult↗

PubMed1994

Male meiotic segregation of gonosomes analysed by two colour FISH in human interphase spermatozoa.

Human meiotic segregation of X and Y chromosomes was simultaneously analysed by dual fluorescence in situ hybridization (FISH) on 10,638 interphase spermatozoa from the same donor. A modified method for sperm decondensation ensured access of both X and Y probes to the sperm chromatin and a 99% hybridization efficiency. Expected sex ratios were obtained (49.30% haploidy X and 49.22% haploidy Y). The frequencies of meiotic II non-disjunctions for X and Y chromosomes (0.05%) were similar to those observed in sperm karyotypes after heterospecific fertilization of hamster eggs. In contrast, the frequency of XY bearing cells was significantly higher (0.42%). However, XY cells detected by FISH could either be diploid somatic cells, diploid germinal cells or hyperhaploid XY spermatozoa, the latter resulting from meiotic I non-disjunctions.

Chromosome Aberrations↗

PubMed1994

Achievement of meiosis in XXY germ cells: study of 543 sperm karyotypes from an XY/XXY mosaic patient.

Human sperm chromosomes from a 46,XY/47,XXY male were obtained using the technique of in vitro penetration of zona-free hamster eggs. The analysis of 543 sperm complements shows a significantly increased incidence (0.9%) of hyperhaploid gonosomal 24,XY sets, with a lack of the expected corresponding gonosomal hypohaploidies, and a normal rate of autosomal non-disjunctions. These results support the suggestion that 47,XXY cells are able to go through meiosis and to form spermatozoa. Only 24,XY sperm chromosomal constitutions were observed suggesting a preferential pairing of homologous sex chromosomes in 47,XXY spermatocytes.

Adult↗

PubMed1993

Immediate rearrangements of human sperm chromosomes following in-vivo irradiation.

The short-term effects of radiotherapy on sperm chromosomes was evaluated in two Hodgkin patients. Sperm cytogenetics were analysed by using human-hamster cross-fertilization. Immediately after irradiation, most sperm metaphases from the first patient exhibited multiple rearrangements, whereas in the second one, the incidence of such abnormalities was only slightly increased. Multi-fragmented chromosomes and structural aberrations of the chromatid-type were observed, suggesting a specific immediate response.

Animals↗

PubMed1990

[Chromosome abnormalities of human gametes].

Human newborns carrying chromosomal abnormalities are the survivors of a considerably larger cohort of affected conceptions. A direct cytogenetic study of these conceptuses would imply their destruction. Moreover, the ability to determine the parental origin of an additional or missing chromosome is limited from a methodological point of view. The cytogenetic study of human gametes provides information on these mechanisms. Several large-scale studies on sperm complements of normal men give an estimated abnormality rate of 10%. Our results concerning four carriers of reciprocal translocations show no evidence for a selection against abnormal sperm. Since about 30% of the recovered eggs fail to become fertilized in IVF programs, human oocytes have become available for large cytogenetic studies. Analysis of oocytes II provides information on the first meiotic non-disjunction rate. In our sample of 405 karyotypes, the rate of aneuploidy was 27%. No relationship was established between this frequency and the mode of stimulation of ovulation. No increase was observed with maternal aging.

Adult↗

PubMedDate not supplied

[Intracytoplasmic sperm injection and Klinefelter syndrome].

Sperm cytogenetic study in two patients with Klinefelter's syndrome have demonstrated that there existed a risk low but highly significant, to transmit a sex chromosome abnormality to the offsprings. This result argues for a systematic karyotype before ICSI, and if such mosaïcs can be treated by ICSI, they must be firstly associated to a genetic counselling.

Fertilization in Vitro↗

PubMedDate not supplied

Integrated radiation hybrid and yeast artificial chromosome map of chromosome 9p.

A panel of 93 radiation-reduced hybrids have been screened using PCR amplification and oligonucleotide primers for sequence-tagged sites (STSs) specific for 114 single-copy loci mapping to the short arm of chromosome 9. An x-ray dose of 6,000 rads gave an average retention frequency of approximately 23%. We have constructed a framework map containing 31 markers ordered by analyzing coretention patterns, with support for the order greater than 1,000:1. In addition, we have placed the remaining markers which could not be mapped to a single interval with this support to a range of intervals on the framework map. The STS oligonucleotide primers used in the construction of the radiation hybrid (RH) map have been used to isolate and order yeast artificial chromosomes (YACs) assigned to 9p identified from the CEPH megaYAC library. Eighty-nine STS markers have screened positive with at least one YAC. A total of 88 individual YACs (with an average size of 0.9 MB) have been placed on the map in a series of contigs and in some cases mapped cytogenetically by fluorescence in situ hybridization. Additionally, the YAC information has been used in conjunction with the RH framework placements to generate an integrated map containing 65 loci including 51 uniquely positioned markers, with an average resolution of 0.79 Mb.

Animals↗