Genetic structure of populations of Ostertagia ostertagi.
Most genetic work to distinguish strains of parasitic helminths focuses on searching for genetic markers to correlate with phenotypes of interest, but in this study genetic diversity among individual Ostertagia ostertagi adults is partitioned into components within and between populations. Restriction fragment polymorphism data on mitochondrial DNA from ten individual worms from each of five different parasite populations are analyzed. Three of these populations are characterized by arrested larval development (hypobiosis) over the summer months, and the other two by hypobiosis over the winter months. Sequence divergence is scored by the presence or absence of 37 different restriction sites. Although the populations are genetically differentiated with respect to the timing of hypobiosis, greater than 98% of the total mitochondrial DNA sequence diversity is partitioned within a single population, and the geographic distribution of individual mitochondrial DNA haplotypes suggests high gene flow among populations. Further, estimates of within-population mitochondrial DNA diversity are five to ten times greater in O. ostertagi than typical estimates reported for species in other taxa.
Dame
J B
JB
Department of Infectious Diseases, College of Veterinary Medicine, University of Florida, Gainesville, 32611.
Blouin
M S
MS
Courtney
C H
CH
D000818:Animals; D003001:Cloning, Molecular; D004272:DNA, Mitochondrial / Q000235:genetics* / Q000302:isolation & purification; D005260:Female; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes / Q000235:genetics; D010028:Ostertagia / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D014481:United States
D004272:DNA, Mitochondrial