Molecular analysis of the genome of Chuzan virus, a member of the Palyam serogroup viruses, and its phylogenetic relationships to other orbiviruses.

The nucleotide sequence of the entire genome of Chuzan virus, which belongs to the Palyam serogroup orbiviruses and causes congenital abnormalities of cattle, has been completed by analysis of the genes encoding minor core proteins (VP1, VP4 and VP6) and non-structural proteins (NS1, NS2 and NS3). The genome of Chuzan virus is 18,915 bp in length and the coding capacity of its open reading frames is 6071 aa. Comparative sequence analysis with other serogroups of the genus Orbivirus indicated that the outer capsid protein VP2, which is the neutralizing antigen, appears to be the most variable and the major core protein VP3 is the most conserved. Overall, the structural proteins, with the exception of VP2, are more conserved than the non-structural proteins among orbiviruses. Chuzan virus is phylogenetically most related to African horsesickness virus.