LUMP Is a Putative Double-Stranded RNA Binding Protein Required for Male Fertility in Drosophila melanogaster

Abstract

In animals, male fertility requires the successful development of motile sperm. During Drosophila melanogaster spermatogenesis, 64 interconnected spermatids descended from a single germline stem cell are resolved into motile sperm in a process termed individualization. Here we identify a putative double-stranded RNA binding protein LUMP that is required for male fertility. lump1 mutants are male-sterile and lack motile sperm due to defects in sperm individualization. We show that one dsRNA binding domains (dsRBD) is essential for LUMP function in male fertility. These findings reveal LUMP is a novel factor required for late stages of male germline differentiation.

Separating from the pack: Molecular mechanisms ofDrosophilaspermatid individualization

“…80 Recently, it was found that genetic perturbation of the RNAi pathway causes individualization phenotypes. [81][82][83] RNAi pathway mutations also perturb cytoskeletal reorganization of the oocyte in a checkpointmediated process. 84 This seems to be a way for the oocyte to abort development when chromosomal integrity is disturbed by unregulated transposon activity.…”

Gudu, an Armadillo repeat-containing protein, is required for spermatogenesis in Drosophila

“…Individualization has been extensively studied in Drosophila , and many genes are involved in this process, including lump , myosinVI , auxilin and npc1 (Hicks et al, 1999; Zhou et al, 2007; Sanders and Smith, 2011; Wang et al, 2011). From these studies, actin assembly, apoptosis, and membrane trafficking become the three best understood processes shown to affect different aspects of sperm maturation.…”

“…Spermatogenesis involves a series of tightly regulated stages including mitotic proliferation, meiotic division, and cellular remodeling (Sanders and Smith, 2011). The adult Drosophila testis is a bipolar tube-like structure.…”

“…Individualization initiates when the F-actin based individualization complex (IC), composed of 64 actin cones, assembles around each spermatid nucleus and moves synchronously down the length of the cyst toward the tails, expelling the excess cytosol and simultaneously wrapping each spermatid into its own plasma membrane (Fabrizio et al, 1998). Defects in IC formation and movement can lead to failure of individualization, resulting in sperm reduction and male sterility (Fabrizio et al, 1998; Sanders and Smith, 2011). Previous studies have identified many genes involved in individualization such as those coding for Auxilin, Myosin VI, Clathrin, Rab11 and Lump (Zhou et al, 2007; Sanders and Smith, 2011).…”

“…Defects in IC formation and movement can lead to failure of individualization, resulting in sperm reduction and male sterility (Fabrizio et al, 1998; Sanders and Smith, 2011). Previous studies have identified many genes involved in individualization such as those coding for Auxilin, Myosin VI, Clathrin, Rab11 and Lump (Zhou et al, 2007; Sanders and Smith, 2011). These proteins either are part of the IC or regulate the integrity and membrane trafficking of the IC.…”