ABSTRACT
We describe 35 microsatellite markers from the human parasitic nematode Ascaris lumbricoides. We found 7 sex-linked markers and demonstrate that 26 autosomal loci can be scored reliably. These markers have high genetic variability and provide the tools to address multiple questions concerning the epidemiology, fine-scale genetic structure, host specificity, and mating systems of this parasite.
Subject(s)
Ascariasis/parasitology , Ascaris lumbricoides/genetics , Microsatellite Repeats , Alleles , Animals , Ascariasis/diagnosis , Ascaris lumbricoides/classification , Ascaris lumbricoides/physiology , Female , Genetic Linkage/genetics , Genetic Variation , Genotype , Heterozygote , Host-Parasite Interactions/genetics , Humans , Linkage Disequilibrium , Male , Nepal , Sex FactorsABSTRACT
Trichuris trichiura is an helminthic infection with potentially severe health consequences. The hypothesis that host genetic factors can account for the distribution of Trichuris was tested using familial data on egg counts available for two populations, the Jirels of Nepal and the population of Jishan Island in Jiangxi Province of the People's Republic of China. Whipworm is highly prevalent in the Jishan Island population (86%), but occurs at a low rate in the Jirel population (14%). A quantitative genetic analysis was performed on each data set, using a variance component approach. Approximately 28% of the variation in Trichuris trichiura loads was attributable to genetic factors in both populations. Common household effects accounted for only 4% of the variation in the Jirels and none of the variation in the Jishan Island population. These concordant results from two separate populations provide strong evidence of the important role of genetics in determining differential susceptibility to whipworm infection.
