-deficient fish delay grass carp reovirus (GCRV) replication and attenuate GCRV-triggered apoptosis.

Bid, BH3-interacting domain death agonist, is a pro-apoptotic BH3-only member of Bcl-2 family, playing an important role in apoptosis. In the study, genes from grass carp () and rare minnow (), named and , were cloned and analyzed. was constitutively expressed in all examined tissues of grass carp, but the expression level varied in different tissues. Following grass carp reovirus (GCRV) stimulation , and apoptosis related genes and was up-regulated significantly at the late stage of infection. Moreover, we generated a -deficient rare minnow () to investigate the possible role of in GCRV-triggered apoptosis. We found that the survival time of rare minnow after GCRV infection was extended when compared with wild-type fish, the relative copy number of GCRV in rare minnow was lower than that in wild-type fish, and the expression level of and in rare minnow were significantly lower than that in the wild-type fish. Collectively, the current data revealed the important role of during virus-induced apoptosis in teleost fish. Our study would provide new insight into understanding the GCRV induced apoptosis and may provide a target gene for virus-resistant breeding in grass carp.