CODON USAGE IN THE PROTOTYPE BACULOVIRUS - AUTOGRAPHA-CALIFORNICA NUCLEAR POLYHEDROSIS-VIRUS

The overall codon usage profile of Autographa californica nuclear poly hedrosis virus (AcNPV) was analyzed, using UWGCG sequence analysis sof tware package from the known protein coding gene sequences available i n GenBank Release 72. The analysis revealed that although only 45% of the codon used by AcNPV have G/C at wobble' base position, 15 out of 2 0 AcNPV codons over-utilized for their given amino acids has G/C at th e wobble position indicating a possible selection of these codons. The differences in codon usage profile were studied using a parameter cal led D squared value, calculated with the aid of CORRESPOND program of UWGCG software package. While most of the codon usage profile of the i ndividual genes was very similar to the overall AcNPV codon usage prof ile (D squared value less than 1.5), there were notable differences (D -squared value greater than 1.5). These genes were polh, p10, ub, sod, gp41, core, 25k, 39k, ie-n, etm, ets most of which, interestingly, be longed to late or very late class and were expressed relatively more e fficiently. The two highly expressed genes of AcNPV, polh and the p10, differ from the overall AcNPV codon usage profile with respect to at least nine amino acids (Val, Ala, Ser, Lys, lie, Thr; Leu, Phe, Arg). Our findings that the two highly expressed late genes polh and p10 uti lize a codon usage profile different from the early genes have importa nt implications.