Study On The Construction Of E3 Region Vector And Analysis Of The DNA Terminal Sequences Of Canine Adenovirus Type 1 Vaccine Strain

Adenoviruses first isolated and studied by Rowe et al in 1953, During past 40 years, great achievements have been made in the studies on its pathogenicity, Biochemistry and molecular biology. Recently, the studies on the using of adenoviruses as vectors have become hotter topics. It is reported that vectors of human adenovirus type 5, type 4 and type 7 and bovine adenovirus type 3 have been constructed, and more than 30 kinds of foreign genes including the antigen genes from virus and genetics disease related genes were expressed in adenovirus vectors successfully. Adenovirus vectors have several advantages, which included:1) Detailed study reports on its gene molecular biology2) Easy to propagate in many kinds of cells to produce high titer of virus3) High and stable expression of foreign genes4) Safe for human or animals5) Large capacity for foreign genesCanine adenovirus type 1 is the same as human adenovirus in the characterizations of biochemistry and molecular biology, It is assummed that vectors made of Canine adenovirus type 1, which can infect many kinds of domestic and wild animals naturally, can be more useful in control or elimination of zoonosis than human adenovirus vectors.In this paper, the DNA terminal sequence of canine adenovirus type 1 vaccine strain werestudied and the E3 region vectors of it were also constructed. The results were reported asfollows:1. DNA Terminal Sequences and Structure1) Non-symmetrical Inverted Terminal Repeats (ITR):There is two 40 bp short repeats in the ITR of the E1A region, and three ones in the ITR of E4 region, so the ITR of E1A region has 198 bp, and the ITR of E4 region, 238 bp, which made the two ITRs non-symmetrical.