The role of Drosophila hyperplastic discs gene in spermatogenesis

Abstract

In Drosophila, the ubiquitin ligase Hyd (hyperplastic disc) is required for regulation of cell proliferation during development [Martin et al. (1977) Dev Biol 55, 213-232; Mansfield et al. (1994) Dev Biol 165, 507-526]. Earlier, we demonstrated that the Drosophila tumour suppressor Merlin participates not only in imaginal discs proliferation control, but also performs a separate Nebenkern structural function in Drosophila spermatogenesis [Dorogova et al. (2008) BMC Cell Biol 9, 1. Here, we show that the hyd mutants also have spermatogenesis defects: chromosome condensation and attachment to the spindle, centrosome behaviour and cytokinesis in meiosis. The process of spermatid elongation was also greatly affected: nuclei were scattered along the cyst and had an abnormal shape, Nebenkern-axoneme angular relation and attachment was distorted, axonemes themselves lost correct structure. Since Hyd and pAbp protein families share a common PABC [poly(A)-binding protein C-terminal] protein domain, we also studied spermatogenesis in pAbp homozygotes and found defects in cytokinesis and spermatid elongation. However, our study of hyd and pAbp genetic interaction revealed only the phenotype of defective nuclei shape at the final stage of spermatid differentiation. So, the PABC domain is unlikely to be responsible for meiotic defects. Thus, our data document that, in addition to the tumour suppressor Merlin, another tumour suppressor, Hyd, also has a function in spermatogenesis.

Identification of novel Drosophila centromere‐associated proteins

“…An additional indication for a possible involvement in centromere functions is the frequent overexpression of its human homolog EDD in breast, ovarian, and other cancers . In line with previously published data , we observe an increase in mitotic defects after RNAi‐mediated depletion of Hyd (Fig. A).…”

“…We also detected Hyd in our screen, which is a putative E3 ubiquitin ligase required for the regulation of cell proliferation during development. In addition, it acts as a tumor suppressor in Drosophila and its depletion causes defects on chromosome condensation, attachment to the spindle, centrosome behavior, and cytokinesis in spermatogenesis . An additional indication for a possible involvement in centromere functions is the frequent overexpression of its human homolog EDD in breast, ovarian, and other cancers .…”

Poly(A)-binding proteins are required for diverse biological processes in metazoans

“…In addition to affecting oogenesis and body pattern, dPABP is also required for spermatogenesis [30,32] as several compound heterozygous pAbp mutant flies are male sterile and display aberrant meiosis (only undergoing one meiotic division), spermatid elongation and/or cytokinesis [30,32]. Although the molecular events leading to these defects are unknown, the pAbp meiotic phenotype partially overlaps with that of Larp (La-related protein), a factor thought to regulate mRNA stability in Caenorhabditis elegans and translation of certain mRNAs in mammalian cells [40–42], which interacts biochemically and genetically with dPABP [30].…”

GAGA protein is required for multiple aspects of Drosophila oogenesis and female fertility

“…Experimental procedures for electron and fluorescence microscopy were performed as described previously (Pertceva et al, 2010;Xue & Cooley, 1993). TRITC-labeled phalloidin (Sigma-Aldrich #P1951) was used at 1:100 dilution to visualize F-actin as described previously (Guild, Connelly, Shaw, & Tilney, 1997).…”