Gene conversion as a possible factor influencing genetic polymorphism

The ostracode Cytherissa lacustris (Sars) has been obligatorily parthenogenetic at least since the Mesopleistocene. Old and large populations of it from the lakes of the Salzkammergut area in Austria exhibit quite high polymorphism and quasi-Mendelian proportions at the locus coding for glucose-6-phosphate isomerase. It is argued that this polymorphism has been attained through generations owing to gene conversion operating on the basis of the founder effect, mutations and migration; the effects of gene conversion were then amplified by selection and/or by random events.