ИСТИНА

The morphological changes that occur in the germ cells during spermatid maturation were studied at ultrastructural level. However, the effect of various ultrastructural centriole abnormalities in the mature sperm on male fertility actually is not enough studied. Previously, by using EM analysis of sperm of patients with idiopathic infertility we found various defects in a structure of proximal centriole cylinders. Such defects could be the reason that in these patients normal fertilization and embryo development did not occur even when ICSI is performed. For the detailed analysis of sperm abnormalities, we reconstructed the proximal centriole structure. During maturation the proximal centriole elongates and form the centriolar adjunct, specific structure at the distal end of the proximal centriole, which later disappears. Thus, in mature sperm the proximal centriole has a length of about 0,4 μm. We found that unlike the sperm of healthy donors, the mature sperm of unfertile patients where embryo development stopped in the early stages of cleavage had not fully resorbed centriolar adjunct. The length of the proximal centriole together with centriolar adjunct in the sperm of idiopathic patients was more than 0,7 μm. Besides that, we found significant heterogeneity in the length and the structure of microtubules of various triplets at the distal end of the proximal centriole, expressed in varying degrees in different patients. Since human sperm proximal centriole plays an important role in sperm-aster formation and sperm spindle organization during the first cleavage, we suggested that the absence of centriolar ajunct disruption along with the other ultrastructural disorders might be one of the causes of idiopathic infertility. Thus, the presence of centriolar adjunct in mature sperm of patients can serve as a diagnostic feature of this type of male infertility.