Cysteine proteinase genes in Indian strain of Haemonchus contortus

- Common vulval morphotypes of Indian female H. contortus cysteine proteinase genes were characterized.
- Cysteine proteinase genes of Indian strain of H. contortus showed polymorphism with USA and UK strains.
- Indian strains are expressing hmcp1, hmcp6 and gcp7 genes, as hmcp1 and hmcp6 are specific to UK and gcp7 to USA strains.
- Role of geographical variations is an important factor for vaccine development based on cysteine proteinases.

The genes of microvillar cysteine proteinases such as hmcp1, hmcp6 and gcp7 of phenotypically distinct morphotypes of female H. contortus having knobbed and linguiform vulvar flaps were cloned and characterized. Complementary DNA (cDNA) was synthesized from total RNA of both the morphotypes. The hmcp1, hmcp6 and gcp7 genes were amplified from cDNA. The amplicons were cloned in pDRIVE T/A cloning vector and sequenced by Sanger's dideoxy method. The nucleotide and deduced amino acid sequences were compared with the USA/UK strain H. contortus cysteine proteinase sequences. The cysteine proteinase genes of Indian strain show considerable variations with USA/UK strains. Our results revealed that Indian strain of H. contortus expresses both UK strain (hmcp1 and 6) and USA strain (gcp7) cysteine proteinases.

Phylogenetic tree of cysteine proteinase (hmcp1, hmcp6 and gcp7) genes of H. contortus.72