The cloning and sequencing of the virion protein genes from a British isolate of porcine respiratory coronavirus: comparison with transmissible gastroenteritis virus genes

Abstract

Previous analysis of porcine respiratory coronavirus (PRCV) mRNA species showed that mRNAs 2 and 3 were smaller than the corresponding transmissible gastroenteritis virus (TGEV) mRNA species (Page et al. (1991) J. Gen. Virol. 72, 579-587). Sequence analysis showed that mRNA 3 was smaller due to the presence of a new putative RNA-leader binding site upstream of the PRCV ORF-3 gene. However, this observation did not explain the deletion observed in PRCV mRNA 2. Polymerase chain reaction (PCR) was used to generate cDNA from the 3' coding region of the putative polymerase gene to the poly (A) tail of PRCV for comparison to the equivalent region from TGEV. The PRCV S protein was found to consist of 1225 amino acids, which had 98% similarity to the TGEV S protein. However, the PRCV S gene contained a 672 nucleotide deletion, corresponding to 224 amino acids (residues 21 to 245 in TGEV S protein), 59 nucleotides downstream of the S gene initiation codon. The PRCV genome from the ORF-3 gene to the poly (A) tail was sequenced for comparison to TGEV in order to identify other potential differences between the two viruses. Four ORFs were identified that showed 98% similarity to the TGEV ORF-4, M, N and ORF-7 genes. No other deletions or any PRCV specific sequences were identified.

Sequence determination of the nucleocapsid protein gene of the porcine epidemic diarrhoea virus confirms that this virus is a coronavirus related to human coronavirus 229E and porcine transmissible gastroenteritis virus

“…More than 10 coronavirus N genes have now been sequenced, including those of HCV 229E, TGEV, PRCV, FIPV, CCV, murine hepatitis virus (MHV), HCV OC43, bovine coronavirus (BCV) and infectious bronchitis virus (IBV) (Schreiber et al, 1989;Kapke & Brian, 1986;Britton et al, 1991 ;Vennema et al, 1991 ;Horsburgh et al, 1992;Parker & Masters, 1990;Kamahora et al, 1989;Lapps et al, 1987;Boursnell et al, 1985). Many of these viruses have been sequenced by more than one group; the references quoted here were those used in the sequence analyses shown in Fig.…”

“…Bridgen and others At present the only reported examples of PCR amplification of coronaviral cDNA of unknown sequence have involved amplification with primers derived from closely related coronaviruses. For example, porcine respiratory coronavirus (PRCV), the sequence of which shows a 96 to 98 % amino acid identity to that of TGEV (Britton et al, 1991;Rasschaert et al, 1990), was amplified using TGEV primers (Britton et al, 1991), and feline enteric coronavirus (FECV) was amplified using FIPV primers (Vennema et al, 1992). The approach used in the experiments described in this paper should, however, be applicable to the cloning of any coronaviral genome.…”

Field Isolates of Transmissible Gastroenteritis Virus Differ at the Molecular Level from the Miller and Purdue Virulent and Attenuated Strains and from Porcine Respiratory Coronaviruses.

“…Sequence data revealed that PRCV has a large deletion in the 5' region of the S glycoprotein gene. It has been proposed that the deletion may be related to the differences observed in tissue tropism or pathogenicity between PRCV and TGEV strains [3,30,49]. Researchers have reported that PRCV strains replicate almost exclusively in the respiratory tract [15,48] and usually cause subclinical infections or only mild signs of respiratory disease.…”

Sporadic re-emergence of enzootic porcine transmissible gastroenteritis in Hungary

“…Acta Veterinaria Hungarica 62, 2014 terised mainly by deletions in the spike (S) protein (Rasschaert et al, 1990;Britton et al, 1991) emerged. PRCoV is pneumotropic, replicating mainly in alveolar cells, but it can also replicate in the gastrointestinal tract in cells located underneath the villi, and the infections are usually inapparent (Cox et al, 1990).…”