Genetic background impacts the timing of synaptonemal complex breakdown in Drosophila melanogaster

Abstract

Experiments performed in different genetic backgrounds occasionally exhibit failure in experimental reproducibility. This is a serious issue in Drosophila where there are no standard control stocks. Here, we illustrate the importance of controlling genetic background by showing that the timing of a major meiotic event, the breakdown of the synaptonemal complex (SC), varies in different genetic backgrounds. We assessed SC breakdown in three different control stocks and found that in one control stock, y w; svspa-pol, the SC broke down earlier than in Oregon-R and w1118 stocks. We further examined SC breakdown in these three control backgrounds with flies heterozygous for a null mutation in c(3)G, which encodes a key structural component of the SC. Flies heterozygous for c(3)G displayed differences in the timing of SC breakdown in different control backgrounds, providing evidence of a sensitizing effect of this mutation. These observations suggest that SC maintenance is associated with the dosage of c(3)G in some backgrounds. Lastly, chromosome segregation was not affected by premature SC breakdown in mid-prophase, consistent with previous findings that chromosome segregation is not dependent on full-length SC in mid-prophase. Thus, genetic background is an important variable to consider with respect to SC behavior during Drosophila meiosis.

Attenuation of Seizures, Cognitive Deficits, and Brain Histopathology by Phytochemicals of Imperata cylindrica (L.) P. Beauv (Poaceae) in Acute and Chronic Mutant Drosophila melanogaster Epilepsy Models

“…15,16 The Drosophila models of the bang sensitive (BS) family used in the study were the bang senseless or bss1 mutants of the paralytic gene (para bss1 ), 48,49 and the wild-type strains used as controls were Oregon-R or OrR and Canton-Special (CS). [49][50][51] Male flies were used as a previous laboratory study has shown differences between female and male bss Drosophila because the para bss is located on the X chromosome, and heterozygous para bss/+ female Drosophila have significantly decreased recovery times. 52 Only animals that underwent seizures were included in the study during behavioral (convulsion and learning/memory tests) and histological assessments.…”

Chromatin-associated cohesin turns over extensively and forms new cohesive linkages during meiotic prophase

“…Therefore, SC defects serve as a proxy for premature loss of meiotic cohesion. In wild-type Drosophila oocytes, the SC fully assembles in germarial region 2A and usually remains intact until stages 5-6, although the timing of disassembly can be affected by genetic background [30,31]. To express lower levels of RNAi insensitive HA-tagged Smc3* specifically during prophase, we utilized a previously described weak mata-Gal4-VP16 driver chromosome [23].…”