wolbachia-mediated male killing is associated with defective chromatin remodelingwolbachia-mediated男性杀死与有缺陷的染色质重塑.pdfVIP

Wolbachia-Mediated Male Killing Is Associated with Defective Chromatin Remodeling 1 2 3 1 Maria Giovanna Riparbelli , Rosanna Giordano , Morio Ueyama , Giuliano Callaini * 1 Department of Evolutionary Biology, University of Siena, Siena, Italy, 2 Illinois Natural History Survey, Institute of Natural Resource Sustainability, University of Illinois at Urbana-Champaign, Champaign, Illinois, United States of America, 3 Laboratory of Cell Biology, Department of Bioinformatics, Soka University, Hachioji, Tokyo, Japan Abstract Male killing, induced by different bacterial taxa of maternally inherited microorganisms, resulting in highly distorted female- biased sex-ratios, is a common phenomenon among arthropods. Some strains of the endosymbiont bacteria Wolbachia have been shown to induce this phenotype in particular insect hosts. High altitude populations of Drosophila bifasciata infected with Wolbachia show selective male killing during embryonic development. However, since this was first reported, circa 60 years ago, the interaction between Wolbachia and its host has remained unclear. Herein we show that D. bifasciata male embryos display defective chromatin remodeling, improper chromatid segregation and chromosome bridging, as well as abnormal mitotic spindles and gradual loss of their centrosomes. These defects occur at different times in the early development of male embryos leading to death during early nuclear division cycles or large defective areas of the cellular blastoderm, culminating in abnormal embryos that die before eclosion. We propose that Wolbachia affects the development of male embryos by specifically targeting male chromatin remodeling and thus disturbing m