Infertility concerns a minimum of 70 million couples worldwide. An important proportion of cases is believed to have a genetic component, yet few causal genes have been identified so far. In a previous study, we demonstrated that a homozygous mutation (c.
View Article and Find Full Text PDFA local study carried out in the Medical School of Grenoble shows that teaching in the first year in medicine studies satisfies neither the students, nor the teachers. The Faculty of Medicine of Grenoble decided to set up a reform in order to offer a high quality education. This reform leads to a complete reorganization of the curriculum and to the intensive use of new information and communication technologies of information, in particular, the use of multimedia documents.
View Article and Find Full Text PDFThe World Health Organization conservatively estimates that 80 million people suffer from infertility worldwide. Male factors are believed to be responsible for 20-50% of all infertility cases, but microdeletions of the Y chromosome are the only genetic defects altering human spermatogenesis that have been reported repeatedly. We focused our work on infertile men with a normal somatic karyotype but typical spermatozoa mainly characterized by large heads, a variable number of tails and an increased chromosomal content (OMIM 243060).
View Article and Find Full Text PDFIn addition to genetic information, the spermatozoon carries another type of information, named epigenetic, which is not associated with variations of the DNA sequence. In somatic cells, it is now generally admitted that epigenetic information is not only regulated by DNA methylation but also involves modifications of the genome structure, or epigenome. During male germ cell maturation, the epigenome is globally re-organized, since most histones, which are associated to DNA in somatic cells, are removed and replaced by sperm specific nuclear proteins, the protamines, responsible for the tight compaction of the sperm DNA.
View Article and Find Full Text PDFJ Gynecol Obstet Biol Reprod (Paris)
February 2005
Purpose: Lymphomas and testicular cancers are the most frequent malignancies among young men. With recent improvement of survival rates, for many patients, the question is raised of the consequences of the anticancer treatments on their fertility and more specifically of a potential genetic risk for the offspring. This article presents the study of sperm aneuploidy rates in the largest population of cancer-treated patients studied thus far.
View Article and Find Full Text PDFThanks to the success of new assisted reproductive technology, including sperm microinjection (i.c.s.
View Article and Find Full Text PDFIn many species, including humans, chromatin remodelling during spermiogenesis is initiated with a marked increase in histone acetylation in elongating spermatids. We have investigated whether this process is disturbed when spermatogenesis is defective or in human testicular tumours. For this purpose, the presence of highly acetylated histone H4 was detected on testicular sections from men with a severe impairment of spermatogenesis of several origins, as well as in different types of testicular tumours.
View Article and Find Full Text PDFBackground: Macrocephalic or large headed sperm with multiflagella is a rare abnormality often associated with infertility. Sperm chromosomal abnormalities could be associated with this specific morphological abnormality.
Methods: The cytogenetic content of large-headed sperm was assessed by dual and three-colour fluorescence in-situ hybridization in three patients carrying this specific morphological abnormality.
Here we report a detailed analysis of waves of histone acetylation that occurs throughout spermatogenesis in mouse. Our data showed that spermatogonia and preleptotene spermatocytes contained acetylated core histones H2A, H2B and H4, whereas no acetylated histones were observed throughout meiosis in leptotene or pachytene spermatocytes. Histones remained unacetylated in most round spermatids.
View Article and Find Full Text PDFThe sperm nucleus has a unique chromatin structure where the DNA is highly condensed and associated with specific proteins, the protamines. It is a nondividing cell which is also transcriptionally inactive. After fusion with an oocyte, the sperm nucleus undergoes decondensation and, in the same time, starts replication and transcription.
View Article and Find Full Text PDFIn order to further investigate the paternal-age effect on meiotic non-disjunction rates for the chromosomes 14 and 21, we examined spermatozoa from three men aged > 60, using multicolour fluorescent in-situ hybridization (FISH). More than 10,000 sperm cells were analysed for each of the three subjects (A, B and C), by simultaneously hybridizing two YAC probes specific for chromosomes 14 and 21 respectively using two-colour FISH. The results show that the disomy 21 rates observed in the spermatozoa of two out of the three men aged > 60 years were higher (1.
View Article and Find Full Text PDFMeiotic segregation of sex chromosomes from two fertile 47,XYY men was analysed by a three-colour fluorescence in situ hybridisation procedure. This method allows the identification of hyperhaploidies (spermatozoa with 24 chromosomes) and diploidies (spermatozoa with 46 chromosomes), and their meiotic origin (meiosis I or II). Alpha-satellite probes specific for chromosomes X, Y and 1 were observed simultaneously in 35,142 sperm nuclei.
View Article and Find Full Text PDFThe 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).
View Article and Find Full Text PDFSperm 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.
View Article and Find Full Text PDFMeiotic 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.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFJ Assist Reprod Genet
July 1995
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.
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.
View Article and Find Full Text PDFThe 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.
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