Polymorphism of mtDNA in St Petersburg population of Adalia bipunctata and its relation with infection by symbiotic bacterium Spiroplasma

Abstract

Polymorphism of the mtDNA gene COI was studied in a St. Petersburg population of two spot ladybird Adalia bipunctata and analyzed in relation with the presence of a symbiotic bacterium Spiroplasma. Variable nucleotide sequences in the middle part of the gene COI formed 13 mitotypes. 84 ladybirds were studied, 21 of these were found to be infected by Spiroplasma. Mean pairwise difference of nucleotides in the COI sequence was 0.001 for uninfected and 0.020 for infected individuals, thus mtDNA polymorphism was considerably higher among uninfected ladybirds compared with infected ones.