Genetic variation of Haemonchus contortus (Trichostrongylidae) in sheep and goats from Malaysia and Yemen

Sympatric species distribution, genetic diversity and population structure of Haemonchus isolates from domestic ruminants in Pakistan

“…Analysis of ND4 sequences from Pakistani isolates revealed 81 haplotypes with an overall haplotype diversity of 0.998. The nucleotide and haplotype diversity observed in Pakistani Haemonchus population were found to be comparable to the reports on Chinese isolates, while a much higher diversity was observed in Yemenese and Malaysian isolates (Gharamah et al, 2012;Yin et al, 2013). All the genetic diversity parameters including nucleotide diversity, average number of nucleotide differences and haplotype diversity were observed to be higher in H. contortus than H. placei.…”

“…KC415117-KC415134), six (four H. contortus and two H. placei) among Brazilian isolates (Brasil et al, 2012;accession nos. JQ342246-JQ342249, JN128897-98) and six (all H. contortus) among Yemen and Malaysian isolates (Gharamah et al, 2012;accession nos. HQ683710-HQ683715).…”

“…It has to be noted that the intra-population diversity estimates were higher in Yemenese H. contortus populations. Gharamah et al (2012) attributed this to the existence of host specific sub-population structure among H. contortus infecting sheep and goat in Yemen.…”

“…The genetic structure of Haemonchus population s may be influenced by several factors including geographical barriers, effective population sizes, host movement and multiple host species being reared together in common grazing lands/pastures. High rate of gene flow across Haemonchus populations has been reported especially within a geographical region in concordance with the host movement (Brasil et al, 2012;Gharamah et al, 2012;Yin et al, 2013). Nuclear and mitochondrial DNA markers of nematodes have been used for species identification and genetic diversity studies.…”

“…Until now, information on sympatric species distribution, diversity and structure of Haemonchus isolates from Pakistan are lacking. Genetic diversity of Haemonchus populations from countries like Brazil (Brasil et al, 2012), Tunisia (Akkari et al, 2013), China (Yin et al, 2013), Malaysia and Yemen (Gharamah et al, 2012) have been reported. However, only limited information is available on global genetic structure, gene flow and influence of selective forces across different geographical regions.…”