Chromosomally-induced meiotic drive in Drosophila males: checkpoint or fallout?
In male Drosophila melanogaster, anomalies in sex chromosome pairing at meiosis often lead to complete or partial sperm dysfunction. This observation has led to the suggestion that defects in either the efficiency or configuration of chromosome pairing at metaphase trigger a checkpoint mechanism that leads to the elimination of meiotic products. Here, we discuss this model in consideration of recent observations on the conservation of metaphase checkpoint components in male meiosis, and on the phenotype of new alleles of the male-specific meiotic mutant teflon. Based on these observations, we propose an alternative hypothesis for the cause of sperm dysfunction in cases of chromosomal sterility and drive. We suggest that disruption of the prophase compartmentalization of sex chromatin, rather than abnormal pairing at metaphase, may be the causative defect. Such disruption may occur as a result of perturbations in sex chromosome pairing, or by translocations involving autosomal and sex chromatin. We discuss how this hypothesis may account for previously described examples chromosomal causes of meiotic drive and sterility in Drosophila.
Tomkiel
J E
JE
Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI 48202, USA. jtomkiel@cmb.biosci.wayne.edu
D000818:Animals; D004331:Drosophila melanogaster / Q000235:genetics*; D008297:Male; D008540:Meiosis / Q000235:genetics*; D014960:X Chromosome; D014998:Y Chromosome