Determining geographical variations in Ascaris suum isolated from different regions in northwest China through sequences of three mitochondrial genes

Abstract

The sequence diversities in three mitochondrial DNA (mtDNA) regions, namely portions of NADH dehydrogenase subunit 1 (pnad1), cytochrome c oxidase subunit 1 (pcox1), and NADH dehydrogenase subunit 4 (pnad4), were investigated in all Ascaris suum samples isolated from four regions in northwestern China. Those genes were amplified by PCR method and the lengths of pnad1, pcox1, and pnad4 were 419 bp, 711 bp, and 723 bp, respectively. The intraspecific sequence variations within A. suum samples were 0-2.9% for pnad1, 0-2.1% for pcox1, and 0-3.1% for pnad4. Phylogenetic analysis combined with three sequences of mtDNA fragments showed that all A. suum samples were monophyletic groups, but samples from the same geographical origin did not always cluster together. The results suggested that the three mtDNA fragments could not be used as molecular markers to identify the A. suum isolates from four regions, and have important implications for studying molecular epidemiology and population genetics of A. suum.

Molecular evidence of hybridization between pig and human Ascaris indicates an interbred species complex infecting humans

“…The mitochondrial cox-1 gene has been frequently used to infer evolutionary distances between species as well as between populations ( Cavallero et al, 2013 ; Amor et al, 2016 ; Springer et al, 2001 ; Wiens et al, 2010 ; Zardoya and Meyer, 1996 ; Zou et al, 2017 ) due to its rapid mutation rate, lack of recombination and relatively constant rate of change over time ( Brown et al, 1979 ; Giles et al, 1980 ; Harrison, 1989 ). Existing data suggest that mitochondria are inherited maternally in C. elegans ( Lim et al, 2019 ; Zhou et al, 2011 ; Sato and Sato, 2011 ; Wang et al, 2017 ) and Ascaris ( Anderson et al, 1995 ).…”