AIMTo perform screening, related to A-kinase anchoring proteins 4 (AKAP4) and tubulin proteins, in spermatozoa with absent or severely reduced motility in order to detect the status of the fibrous sheath and the axonemal structure.

METHODSAn immunocytochemical study of tubulin, used as a positive control, and AKAP4 was carried out to detect the presence and the distribution of these proteins in different sperm samples. The morphological characteristics of sperm were studied by transmission electron microscope (TEM) and the results were elaborated using a formula reported in previous studies. PCR was carried out on DNA extracted from peripheral blood lymphocytes to analyse partial sequences of the Akap4 and Akap3 genes.

RESULTSImmunolabelling of tubulin and AKAP4 showed different patterns, which led us to divide the patients into groups. In group I, the absence of AKAP4 and tubulin was revealed, although these patients did not show alterations in the Akap4/Akap3 binding site. TEM evaluation highlighted that a high presence of necrosis was associated with total sperm immotility. In group II, a regular AKAP4 and tubulin signal was present, although motility was reduced and TEM analysis revealed the presence of immaturity. In group III, in which a weak AKAP4 label associated with normal tubulin staining and reduced motility was observed, a severe disorganization of the fibrous sheath was highlighted by TEM.

CONCLUSIONWhile the role of AKAP4 in sperm motility is unclear, absent or weak AKAP4-labelling seems to be associated with absent or weak sperm motility.

A Kinase Anchor Proteins ; Humans ; Infertility, Male ; genetics ; physiopathology ; Male ; Microscopy, Electron ; Polymerase Chain Reaction ; Protein Precursors ; genetics ; metabolism ; Semen ; physiology ; Sperm Motility ; Spermatozoa ; physiology ; ultrastructure ; Tubulin ; genetics ; metabolism

We analysed ejaculated spermatozoa from five infertile men with different balanced reciprocal translocations to contribute to the study of meiotic segregation of chromosomes 18, X and Y and also to evaluate sperm morphology by transmission electron microscopy (TEM) analysis. Conventional lymphocyte karyotype analyses highlighted different reciprocal balanced translocations: t(12;13), t(4;9), t(X;8), t(8;10) and t(3;16). Semen analysis was performed by light and TEM. Fluorescence in situ hybridization was performed directly on sperm nuclei using centromeric probes for chromosomes 18, X and Y. The carriers of the balanced reciprocal translocations considered in the present study showed a very similar pattern of sperm pathologies: diffused presence of apoptosis and immaturity. All patients showed meiotic segregation derangements, highlighted by the presence of sperm diploidies and sex chromosome disomies particularly related to the failure of the first meiotic division. However, an increased incidence of chromosome 18 aneuploidy was detected in spermatozoa from t(X;8) and t(8;10) carriers. We have also reported values from sex chromosomes such as t(X;8), although the X chromosome was involved in translocation. Since patients with reciprocal translocations and spermatogenetic impairment are candidates for intracytoplasmic sperm injection cycles, the study of sperm parameters, and particularly of the level of aneuploidy rates, would provide better information for couples at risk and would contribute to the data in the literature for a better understanding of the effects of chromosomal rearrangement on the whole meiotic process and, in particular, on chromosomes not involved in translocation.
Adult ; Aneuploidy ; Apoptosis ; Chromosome Banding ; Chromosomes, Human, X ; Chromosomes, Human, Y ; Humans ; In Situ Hybridization, Fluorescence ; Infertility, Male ; genetics ; pathology ; Lymphocytes ; physiology ; Male ; Microscopy, Electron, Transmission ; Spermatozoa ; pathology ; ultrastructure ; Translocation, Genetic