Ultrastructural features of spermatozoa and their phylogenetic application in Zaprionus (Diptera, Drosophilidae)

Abstract

The genus Zaprionus consists of approximately 60 species of drosophilids that are native to the Afrotropical region. The phylogenetic position of Zaprionus within the Drosophilidae family is still unresolved. In the present study, ultrastructural features of spermatozoa of 6 species of Zaprionus as well as the species Drosophila willistoni and Scaptodrosophila latifasciaeformis were analyzed. The ultrastructure revealed that the species have the same flagellar ultrastructure. Two mitochondrial derivatives, one larger than the other, close to the axoneme were present, primarily in D. willistoni (subgenus Sophophora). Except for Z. davidi and Z. tuberculatus, the analyzed species had paracrystalline material in both mitochondrial derivatives. Moreover, the testes showed 64 spermatozoa per bundle in all of the species. In the cluster analysis, 6 Zaprionus species were grouped closely, but there were some incongruent positions in the cladogram. The results indicated that sperm ultrastructure is an important tool for elucidating the phylogeny and taxonomy of insects.

Structural and functional characterization of a putative de novo gene in Drosophila

“…First, Gdrd might have quickly evolved an essential function in late-stage spermatogenesis but became dispensable in the D. willistoni lineage because of lineage-specific changes to this process in the ancestor of this species. Less is known about spermatogenesis in this species, though ultrastructural studies of the process indicate that it is broadly similar to D. melanogaster 69 . Further mechanistic investigation of spermatogenesis in D. willistoni may help generate hypotheses about why Gdrd was lost specifically in this lineage, while it was retained in other divergent Drosophila species.…”

Mitochondrial DNA Identification and Ultrastructure of Spermatozoa of the Forensically Important Blowfly, Lucilia cuprina (Diptera: Calliphoridae) in Sharkia Governorate, Egypt.

“…The mitochondrial derivatives in L. cuprina were equal in diameter, but unequal in length; meanwhile in Musca domestica, such organelles are asymmetric and show variance in length, and such derivatives are entirely filled with paracrystalline material in both species (Gassner 1970, Gassner andKlemetson 1981). In two mitochondrial derivatives, one bigger than the other, near the axoneme was present primarily in Drosophila willistoni (Rego et al, 2016).…”

The importance of insect sperm: Sperm ultrastructure of Hermetia illucens (black soldier fly)

“…We investigated sperm structure and ultrastructure from sperm recovered from female storage organs, the spermathecae (capsule and capsular duct), and describes the structure of post-testicular, mature sperm that will take part in fertilization. Contrary, majority of studies reporting on sperm structure and ultrastructure, in particularly brachyceran subspecies, report on sperm recovered from the male reproductive system, such as the testes and deferent ducts (Name et al, 2010;Name et al, 2012;Rego et al, 2016). Although sperm maturation in Diptera is likely to be completed in the male reproductive system before eclosion or shortly thereafter (Spiegel et al, 2013), there are further structural changes that sperm can undergo within the spermathecae in preparation for successful fertilization (Degrugillier, 1985).…”