Infectious bursal disease virus (IBDV) can cause immuno-suppression and morbidity in chickens and mainly replicate in the bursa of Fabricius, spleen, thymus and other lymphoid tissues. Rab1 gene is one of Rab GTPases and mainly deal with intracellular protein transport between endoplasmic reticulum (ER) and Golgi. In the present study, SPF layer chickens were artificially challenged with IBDV and the relationship between Rab1 protein gene expression and virus replication was explored by real-time PCR. The aim of the current study was to initially understand dynamic expression of Rab1 during the IBDV infection and offer basic data for further study of IBDV pathogenesis. The data showed that the content of Rab1 peaked on day 3 P.I. in infected group and the Rab1 gene levels were about 2.7 times those of the mocked-infected group. Likewise, the contents of VP2 of chickens in the infected group peaked on day 4 post-infection. After that, the VP2 gene levels slowly dropped until chickens were sacrificed. Moreover, there were two amino acid mutation sites were found on sites 61 and 159 in the infected groups and Lysine (K) and threonine (T) were mutated into glutamate (E) and alanine (A), respectively. The change of mRNA expression level of Rab1 gene from chick bursa post IBDV infection suggested that Rab1 might play a vital role during IBDV replication.

Key words: Gene expression, Infectious bursal disease virus, Rab1, VP2