Male-killing symbiont damages host’s dosage-compensated sex chromosome to induce embryonic apoptosis

• DOI: 10.1038/ncomms12781
• Publication Date: 2016-09-21T10:22:59Z
• Authors: Toshiyuki Harumoto; Hisashi Anbutsu; Bruno Lemaitre; Takema Fukatsu
• Keywords: Male; 0303 health sciences; Embryo, Nonmammalian; Science; Spiroplasma; Q; Apoptosis; Article; 03 medical and health sciences; Drosophila melanogaster; Host-Pathogen Interactions; Animals; Female

AbstractSome symbiotic bacteria are capable of interfering with host reproduction in selfish ways. How such bacteria can manipulate host’s sex-related mechanisms is of fundamental interest encompassing cell, developmental and evolutionary biology. Here, we uncover the molecular and cellular mechanisms underlyingSpiroplasma-induced embryonic male lethality inDrosophila melanogaster. Transcriptomic analysis reveals that many genes related to DNA damage and apoptosis are up-regulated specifically in infected male embryos. Detailed genetic and cytological analyses demonstrate that male-killingSpiroplasmacauses DNA damage on the male X chromosome interacting with the male-specific lethal (MSL) complex. The damaged male X chromosome exhibits a chromatin bridge during mitosis, and bridge breakage triggers sex-specific abnormal apoptosis via p53-dependent pathways. Notably, the MSL complex is not only necessary but also sufficient for this cytotoxic process. These results highlight symbiont’s sophisticated strategy to target host’s sex chromosome and recruit host’s molecular cascades toward massive apoptosis in a sex-specific manner.