Knockdown of Dynamitin in testes significantly decreased male fertility in Drosophila melanogaster

Abstract

Dynamitin (Dmn) is a major component of dynactin, a multiprotein complex playing important roles in a variety of intracellular motile events. We previously found that Wolbachia bacterial infection resulted in a reduction of Dmn protein. As Wolbachia may modify sperm in male hosts, we speculate that Dmn may have a function in male fertility. Here we used nosGal4 to drive Dmn knock down in testes of Drosophila melanogaster to investigate the functions of Dmn in spermatogenesis. We found that knockdown of Dmn in testes dramatically decreased male fertility, overexpression of Dmn in Wolbachia-infected males significantly rescued male fertility, indicating an important role of Dmn in inducing male fertility defects following Wolbachia infection. Some scattered immature sperm with late canoe-shaped head distributed in the end of Dmn knockdown testis and only about half mature sperm were observed in the Dmn knockdown testis relative to those in the control. Transmission electron microscopy (TEM) exhibited fused spermatids in cysts and abnormal mitochondrial derivatives. Immunofluorescence staining showed significantly less abundance of tubulin around the nucleus of spermatid and scattered F-actin cones to different extents in the individualization complex (IC) during spermiogenesis in Dmn knockdown testes, which may disrupt the nuclear condensation and sperm individualization. Since dynein-dynactin complex has been shown to mediate transport of many cellular components, including mRNAs and organelles, these results suggest that Dmn may play an important role in Drosophila spermiogenesis by affecting transport of many important cytoplasmic materials.

Ocnus is essential for male germ cell development in Drosophila melanogaster

“…Ubiquitous reduction in p24‐2 levels in adults did not affect female fecundity but decreased male fertility in Drosophila (Saleem et al ., ); however, the underlying mechanism remains unclear. Wolbachia affects many transport‐associated molecules in male hosts (Zheng et al ., ; Yuan et al ., ; Wu et al ., ) and thus affects spermatogenesis. Therefore, Wolbachia infection may result in a reduction of ocn expression, thereby reducing p24‐2 expression, and affecting spermatogenesis by reducing vesicular transport activity.…”

“…Many studies have demonstrated that Wolbachia significantly modify host sperm and affect fertility (Serbus et al ., ; Yuan et al ., ; Wu et al ., ). However, the potential molecular mechanisms remain unclear.…”

The effect of the endosymbiont Wolbachia on the behavior of insect hosts

“…Wolbachia have been estimated to be the most ubiquitous endosymbiont, and can be used as an ideal model for studying the interactions between microbials and their hosts (Werren, 1997;Wu et al, 2016;Bhattacharya et al, 2017;Pan et al, 2018). So far, most studies on Wolbachia focus on the regulatory mechanisms by which Wolbachia mediate host reproduction (Zheng et al, 2011a(Zheng et al, , 2011bLiu et al, 2014;Beckmann et al, 2017;LePage et al, 2017;Bonneau et al, 2018;Shropshire et al, 2018).…”

A new function of immunity‐related gene Zn72D in male fertility of Drosophila melanogaster

“…Evidences have demonstrated that vesicle trafficking plays an important role during spermiogenesis. A number of vesicle trafficking factors are required for the deposition of actin and new membrane during individualization and elongation (Kracklauer et al, ; Wu et al, ). Therefore we explored the expressions of three cytoskeleton‐associated genes: Arp53D (coding for actin‐related protein), CG9313 (related to microtubule‐based movement), and βTub85D (coding for β‐Tubulin at 85D, also called β2‐tubulin).…”