GAGA protein is essential for male germ cell development in Drosophila

Abstract

The Drosophila Trithorax-like (Trl) gene encodes a GAGA factor which regulates a number of developmentally important genes. In this study, we identify a new function for Drosophila GAGA factor in male germ cell development. Trl mutants carrying strong hypomorphic alleles display loss of primordial germ cells during their migration in embryogenesis and severe disruption in mitochondria structure during early spermatogenesis. The mutation resulted in small testes formation, a deficit of germ cells, abnormal mitochondrial morphogenesis, spermatocyte death through autophagy, and partial or complete male sterility. Pleiotropic mutation effects can be explained by the misexpression of GAGA factor target genes, the products of which are required for germ cell progression into mature sperm.

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

“…As shown in Figure , all three mutations studied in this study disrupt the structure of the 5′ region of the Trl gene, where five transcriptional start sites were identified in Drosophila S2 cells (Kosoy et al, ) and several starts mapped in embryos (Hoskins et al, ) and in adult females (Ahsan et al, ; Batut et al, ). The Trl (ex)15 mutation remove several transcription start sites and the largest part of the upstream region among the mutants (Dorogova et al, ). The Trl 362 mutation contains a P‐element insertion and an adjacent deletion that also remove some transcription initiation sites (Figure ).…”

“…The mutant allele Trl R85 was kindly provided by Dr. F. Karch (University of Geneva, Switzerland) and described previously (Farkas et al, ). Trl 362 (Ogienko et al, ), Trl en82 (Ogienko et al, ) and Trl (ex)15 (Dorogova et al, ) are the hypomorphic alleles that interrupts the 5′ region of the Trl gene (Figure a). Line #76363 ( w * ; P{GAL4‐slbo.2.6}16, P{10XUAS‐IVS‐mCD8::GFP}attP40) was received from the BDSC (Bloomington, http://flystocks.bio.indiana.edu) (Ogienko et al, ); line #109171 VasaGFP ( w*;P{vas.EGFP.HA} ) ‐ from the Kyoto DGGR Stock Center (http://www.dgrc.kit.ac.jp).…”

“…The mutant allele Trl R85 was kindly provided by Dr. F. Karch (University of Geneva, Switzerland) and described previously (Farkas et al, 1994). Trl 362 (Ogienko et al, 2006), Trl en82 (Ogienko et al, 2008) and Trl (ex)15 (Dorogova et al, 2014) are the hypomorphic alleles that interrupts the 5 0 region of the Trl gene (Figure 2a). Line #76363 (w * ;…”

“…It has been shown that GAF is necessary for embryogenesis, oogenesis, spermatogenesis, and eye and wing development (Bayarmagnai, Nicolay, Islam, Lopez‐Bigas, & Frolov, ; Bhat et al, ; Dos‐Santos et al, ; Ogienko et al, ; Ogienko et al, ; Omelina, Pavlova, Ogienko, & Baricheva, ). GAF is also involved in processes responsible for cellular memory, migration, and programmed cell death (Cavalli & Paro, ; Dorogova, Fedorova, Bolobolova, Ogienko, & Baricheva, ; Dorogova, Khrushcheva, Fedorova, Ogienko, & Baricheva, ; Mishra, Chopra, Srinivasan, & Mishra, ; Ogienko et al, ; Poux, Horard, Sigrist, & Pirrotta, ).…”

Cellular aspects of gonadal atrophy in P-M hybrid dysgenesis

“…Embryos were then fixed in 3.7% formaldehyde and heptane, devitellinised with methanol/heptane and stained with antibodies using standard protocols (Patel, 1994). Lysosome staining was carried out in 1 μ M LysoTracker red DND-99 (Invitrogen, Molecular Probes, Basel, Switzerland) according to a previously described procedure (Dorogova et al, 2014). Embryonic germ cell development was analyzed in nearly 500 embryos, and later developmental stages were analyzed in no less than 100 flies per experiment.…”