Transpositions of mobile dispersed genes in Drosophila melanogaster and fitness of stocks

Publisher Website
Google Scholar
Abstract
Summary In situ hybridization with polytene chromosomes was used to demonstrate the transposition of mobile dispersed genes (mdg)-1 and 3 following the selection of flies from low reproductive activity and vability (LA stock) for high reproductive activity, viability and fitness (LA+ and HA stocks). The inbred LA stock is continuously selected for low reproductive activity and viability and maintains at least for twentyfive generations a characteristic pattern of mdg-1 distribution in 14–15 sites. Inbred LA+ and HA stocks exhibit a changed pattern of mdg-1 locations and the number of sites reaches 21–25. Parallel and independent selection for higher viability may lead to similar characteristic changes in the localization of mdg-1. In several independent experiments we observed, within one generation, a spontaneous and saltatory growth of viability and fitness in the mass-bred LA stock. In these cases new mdg-1 and mdg-3 sites reproducibly appeared to within several bands, some of them characteristic of LA+ and HA stocks. We discuss the possible role of mdg in determining the quantitative characters of individuals and their fitness.