title: [An electron microscopic study of the structure of the spermatozoa from sterile males from a crossing of Drosophila virilis x Drosophila lummei].
abstract: Using electron microscope, we have studied structure of the tail region of developing spermatozoa in sterile hybrid males FB1 and F2 resulting from D. virilis x D. lummei crosses, as well as in fertile males of D. virilis. Multiple disturbances in the structure of spermatid plasma membrane have been found in sterile males. The membrane is interrupted in many points; this is particularly apparent in the outer thicker layer. The adjacent nucleus (AN) of spermatids of hybrids also differs from that in D. virilis spermatid. The crystalline ultrastructure in this case has a lower volume as compared with D. virilis, it is located asymmetrically within the AN and is displaced to the edge of that part of the AN, which is located closely to the bundle of contractile fibrils. At the stage of elongation, nonuniform inclusions of irregular shape, several times larger than globules of the crystalline structure, are located nonuniformly within this crystal-like structure. The membrane of the AN is interrupted in many points or is fully absent. Matrix consisting of a large number of small globules is distributed nonuniformly within the AN. It is concluded that the presence of multiple disturbances of spermatid ultra-structure is the main factor leading to lack of sperm mobility and, correspondingly, sterility of virilis-lummei hybrid males.
authors.forename: L I
authors.initials: LI
authors.lastname: Falileeva
authors.forename: V G
authors.initials: VG
authors.lastname: Mitrofanov
mesh_terms: D000818:Animals; D003433:Crosses, Genetic; D004330:Drosophila; D007248:Infertility, Male / Q000473:pathology / Q000662:veterinary*; D008297:Male; D008854:Microscopy, Electron; D013081:Sperm Motility; D013082:Sperm Tail / Q000648:ultrastructure; D013094:Spermatozoa / Q000648:ultrastructure*