Nucleotide sequences of glycoprotein I and E genes of equine herpesvirus type 4.

The research involved gaining better understanding of the nucleotide sequences for two specific genes (glycoprotein I and E) found in strain TH20 of equine herpesvirus type 4 (EHV-4). The findings offer significant insights which may help in devising a vaccine against EHV-1 and 4 infections.

Understanding the Nucleotide Sequence Determination

• The process of nucleotide sequencing reveals the precise order of nucleotides within a DNA molecule.
• In the context of this research paper, detailed nucleotide sequencing of glycoprotein I (gI) and E (gE) genes were carried out on EHV-4 TH20 strain.
• The purpose of this sequencing was to determine the size and structure of the encoded genes, which in turn aids in understanding the protein structures.

Sequences of gI and gE Genes

• The predicted region encoding the EHV-4 gI gene was found to contain 1,263 nucleotides. These nucleotides, when translated into protein, would result in a polypeptide chain comprising 420 amino acids.
• For the gE gene of EHV-4, the encodes region was larger with 1,647 nucleotides. This gene encodes a longer polypeptide, made up of 548 amino acids.

Comparison With Equine Herpesvirus Type 1

• The researchers compared the determined gI and gE sequence data of EHV-4 with those of equine herpesvirus type 1 (EHV-1).
• They found that the EHV-4 gI and gE genes showed a considerable level of identity at the amino acid level with those of EHV-1, being 74% and 85% identical respectively. This suggests some level of homology and therefore similarities in functionality between the strains.
• A further discovery revealed an open reading frame in EHV-4 that was similar to the EHV-1 gene 75, indicating another point of similarity between the two viruses.

Relevance for Vaccine Development

• The researchers concluded that their gathered genetic sequence data could prove valuable in the development of a modified live vaccine to address infections caused by both EHV type 1 and 4.
• A live vaccine uses a weakened form of the virus to stimulate the body’s immune response without causing the disease. Therefore, a deeper understanding of the viruses’ genetic structures can help in designing a safe and effective vaccine.