The purpose of this study was to analyse the frequency of disomy for chromosomes 1, 13, 14, 18, 21, 22, X and Y in sperm nuclei of 50 infertile men and 10 healthy probands of proven fertility. Semen parameters (sperm count, global motility and morphology), urological clinical examination, genital ultrasound and lymphocyte karyotyping were performed for each patient. Disomy frequency was established by fluorescence in situ hybridization by using whole chromosome paint probes. The mean rate of disomy for the various autosomes studied was higher in infertile males than in subjects of proven fertility. Interchromosomal and interindividual differences in the disomy frequency were observed between the 50 patients. The mean frequency of homodisomy YY and heterodisomy XY was increased in spermatozoa of patients with low semen quality parameters (0.24% and 0.54%, respectively). The disomy frequency in infertile males was directly correlated with the severity of oligospermia. However, no relationship was established between aneuploidy rate, sperm motility, morphology or clinical phenotype. These results support the hypothesis that, during spermatogenesis of males with sperm parameter alterations, a decreased frequency of meiotic chromosome pairing and crossing over may lead to spermatogenesis arrest at the meiosis stage and/or to an increase of meiotic nondisjunctions. Meiotic arrest in some germ cells may be responsible for oligospermia and nondisjunctions in other cells for aneuploidy in mature male gametes.

Semen cryopreservation is possible for most adolescents and, regardless of disease type, may be a means of preserving fertility prior to gonadotoxic treatment that might impair the spermatogenesis process.

Disomy and diploidy frequencies for autosomes 1-22 and the gonosomes were assessed in 299,442 sperm nuclei from four normal fertile men by chromosome painting. This novel approach allowed us to perform a specific and sensitive detection of each chromosome. A minimum of 5000 sperm nuclei per subject were evaluated for each chromosome by dual colour fluorescence in situ hybridization. The disomy rate proved to be similar for all the autosomes (0.24%) and the diploidy rate varied from 0.12% to 0.15%. No interchromosomal or interindividual differences in the frequency of disomic and diploid sperm nuclei were observed between the four subjects. The mean frequency of XX-, YY- and XY-bearing spermatozoa was estimated to 0.17%, 0.17% and 0.32%, respectively. This strategy constitutes a new approach for detecting aneuploidy in human sperm nuclei and suggests an equal repartition of non-disjunction among chromosomes in male gametes.

No abstract

RESUMELes spermatozo'ides testiculaires ont une mobilit~ souvent diminude voire nulle qui est consid(~rable-ment altdr6e par le processus de congdlationd6cong(Hation. La difficult6, face & des spermatozo'ides immobiles, est de faire la distinction entre un spermatozo'ide vivant et un spermatozo'ide mort. La plupart des test de vitalitd spermatique explore I'int6gritd fonctionnelle et structurale de la membrane plasmique, comme les tests d'exclusion des colorants vitaux ou le test de gonflement hypo-osmotique.La mobilite spermatique est le seul param~tre qui permet d'avoir la certitude de la vitalitd spermatique. Nous avons dvalu(~ les effets de la Pentoxifylline (PTX), inhibiteur de la phosphodiestdrase de I'AMPc, sur les spermatozo'ides testiculaires decongeles (n=14), afin de ddmontrer que ce stimulant chimique est capable d'induire ou d'augmenter leur mobilite. La PTX augmente significativement le nombre de spermatozo'ides testiculaires mobiles apr~s ddcongelation dans les pr61~ve-ments de patients pr(~sentant une azoospermie s(~cretoire (n=8) ou excrdtoire (n-6). L'action maximale est atteinte entre 60 et 120 minutes. L'effet de la PTX sur la mobilitd est supdrieure Iorsque les spermatozdides sont issus de sujets prdsentant une azoospermie excrdtoire. L'association PTX-gradient de migration amplifie cet effet sur la mobilitd dans les prelevements d'origine excr~toire. Cet effet cumulatif n'est pas observd sur les spermatozo'ides des azoospermies s6cr6toires.Sur les 100 cycles d'ICSI realises ~ I'aide de spermatozo'/des testiculaires ou epididymaires decongelds et traitds par la PTX & 3,5mM, aucune diff(~-rence significative n'a 6t~ observde entre les taux de fecondation, le nombre d'embryons obtenus, transfer6s ou congel~s ainsi que les taux de grossesse entre les cycles d'ICSI utilisant des spermatozo'ides testiculaires des azoospermies s~cretoi-res et ceux des azoospermies excr~toires.Le Pentoxifylline, en induisant et augmentant la mobilit~ des spermatozo'ides testiculaires d6conge-16s, facilite la s61ection des spermatozdides vivants en vue de leur utilisation ult6rieure.