CLONING AND SEQUENCING OF A 8.4-KB REGION FROM THE 3'-END OF A TAIWANESE VIRULENT ISOLATE OF THE CORONAVIRUS TRANSMISSIBLE GASTROENTERITIS VIRUS

The nucleotide sequence (8396 nucleotides) was determined, from the 3' -end of the putative polymerase gene to the poly(A) tail, for a Taiwan ese virulent isolate, TFI, of transmissible gastroenteritis virus (TGE V). The TFI nucleotide sequence had very high identity to the British virulent field isolate FS772/70 (98.3%), the attenuated Purdue 115 (96 .7%) and from the S gene to ORF-4 gene region, to the low passaged vir ulent Miller (98.3%) strains of TGEV. Comparison of the TFI S protein sequence with those determined from other TGEV strains and those of th e TGEV variant, porcine respiratory coronavirus, isolated from Europe and North America showed that they had changed very little over a peri od of 4 decades. The two extra amino acids found to be present in the spike proteins of the virulent FS772/70 and Miller strains when compar ed to the avirulent Purdue strain were found to be present in the TFI strain. The genomic organisation of the TFI strain was the same as tha t of the other TGEV viruses.