Comparative genomics of parasitic silkworm microsporidia reveal an association between genome expansion and host adaptation

Guoqing Pan, Jinshan Xu, Tian Li, Qingyou Xia, Shao-Lun Liu, Guojie Zhang, Songgang Li, Chunfeng Li, Handeng Liu, Liu Yang, Tie Liu, Xi Zhang, Zhengli Wu, Wei Fan, Xiaoqun Dang, Heng Xiang, Meilin Tao, Yanhong Li, Junhua Hu, Zhi Li, Lipeng Lin, Jie Luo, Lina Geng, LinLing Wang, Mengxian Long, Yongji Wan, Ningjia He, Ze Zhang, Cheng Lu, Patrick J Keeling, Jun Wang, Zhonghuai Xiang, Zeyang Zhou

Microsporidian Nosema bombycis has received much attention because the pébrine disease of domesticated silkworms results in great economic losses in the silkworm industry. So far, no effective treatment could be found for pébrine. Compared to other known Nosema parasites, N. bombycis can unusually parasitize a broad range of hosts. To gain some insights into the underlying genetic mechanism of pathological ability and host range expansion in this parasite, a comparative genomic approach is conducted. The genome of two Nosema parasites, N. bombycis and N. antheraeae (an obligatory parasite to undomesticated silkworms Antheraea pernyi), were sequenced and compared with their distantly related species, N. ceranae (an obligatory parasite to honey bees).