Food-induced esterase electromorphs in Carinarion spp. And their effects on taxonomic data analysis (Gastropoda, Pulmonata, Arionidae)

Nonspecific esterases (EST) are often used to measure genetic variation, ye t they may be influenced by environmental factors such as food, climate and age. This may produce misleading similarity indices and genetic diversity estimates (i.e., clone or strain diversities in uniparental organisms). The refore, polyacrylamide gel electrophoresis (PAGE) and isoelectric focusing (IEF) were used to investigate environmental effects on the EST variation i n natural Carinarion populations, as well as in 45 individuals that were ra ised individually on carrots to produce offspring by selfing. Food effects on EST profiles in these progenies were examined by raising them on differe nt food items (lettuce, nettle, or paper). Our results indicated that: (i) Arion (Carinarion) fasciatus and A. (C.) silvaticus show species-specific E ST profiles, (ii) A. fasciatus-like outcrossers most probably are conspecif ic with A. fasciatus s.s., (iii) not all EST variation has a Mendelian basi s since lettuce acid nettle altered EST profiles, and (iv) food effects on EST profiles differed strongly between individuals. Although food-induced E ST profiles did not affect taxonomic interpretations, they did inflate gene tic diversity estimates and thus provided misleading population-genetic dat a.