cloning & expression of f protein gene (hr1 region) of newcastle disease virus nr43 isolate from iran in e.coli

background and aims: ndv (newcastle disease virus) is one of the viruses that cause disease in avian with severe economic losses in the poultry industry in many countries. fusion protein (f) which plays a major role in the virus pathogenicity contains several regions that have a role in the fusion process. mutation in the sequence of hr1 & hr2 regions of this protein prevents fusion of the virus to host cell. in addition, the proteins of hr1 and hr2 regions have antitumor properties that are related to their pathogenicity. methods: in this investigation we used newcastle disease virus nr43 isolate, from poultry diseases diagnostic department of razi vaccine and serum research institute. rna was extracted using sds and proteinase k procedure. in the next step, rt-pcr was carried out and then cdna cloned in ptz57rt vector. after sequencing and alignmenting of the cdna, a pair of proper primers for cloning hr1 in expression vector pet32a(+) was designed. the hr1 expression was carried out by sds–page western- blotting in which the peptides were blotted onto nitrocellulose membrane using ni-nta anti his tag (1:1500 dilutions) coupled to hrp enzyme. results: a peptide with 23.76 kd/a molecular weight s peptide was obtained. conclusion: by cloning and expression of hr1 region of protein f, it will be possible to express the whole gene that could be introduced as a novel vaccine against ndv.