Population specific fitness response of Drosophila subobscura to lead pollution

Abstract

Differences in heavy metal tolerance among separate populations of the same species have often been interpreted as local adaptation. Persistence of differences after removing the stressor indicates that mechanisms responsible for the increased tolerance were genetically determined. Drosophila subobscura Collin (Diptera: Drosophilidae) populations were sampled from two localities with different history of heavy metal pollution, and reared for eight generations in the laboratory on a standard medium and on media with different concentrations of lead (Pb). To determine whether flies from different natural populations exposed to the Pb-contaminated media in the laboratory show population specific variability in fitness components over generations, experimental groups with different concentrations of lead were assayed in three generations (F2 , F5 , and F8 ) for fecundity, developmental time, and egg-to-adult viability. On the contaminated medium, fecundity was reduced in later generations and viability was increased, irrespective of the environmental origin of populations. For both populations, developmental time showed a tendency of slowing down on media with lead. Faster development was observed in later generations. Preadaptation to contamination, meaning higher fecundity, higher viability, and faster egg to adult development in all studied generations, was found in D. subobscura originating from the locality with a higher level of heavy metal pollution.

Effect of lead pollution on fitness and its dependence on heterozygosity in Drosophila subobscura

“…It shows that for all groups, the presence of lead was an environment with a low level of stress (Lopes et al 2004(Lopes et al , 2006. These results are in agreement with Kenig et al (2013) where authors found no intergenerational differences in viability between the groups from analysed populations of D. subobscura reared on different lead concentrations, which indicates that a low concentration is not sufficient to be a stress agent. Despite the fact that lead has no significant influence on viability in D. subobscura, our results of egg-to-adult viability showed significant differences between the types of crosses, such that the viability of intraline crosses was reduced on both media.…”

“…Development time showed significant increase and the same pattern of response in all groups reared under lead contamination. The obtained result is not in agreement with some previously reported data (Shirley and Sibly 1999;Kenig et al 2013) which suggests that individuals exposed to lead pollution during several generations showed faster development compared to those reared on the standard medium, explaining that shorter development time is an advantage, at least, for Drosophila species, because the larval stage is less exposed to the stressful environment. Wu et al (2006) detected that the total duration of the development from larva to adult of Boettcherisca peregrine was (Schmidt et al 1991), Lymantria dispar (Gintenreiter et al 1993), Chironmus riparius (McCadhon and Pascoe 1991) and Oncopeltus fasciatus (Cervera et al 2004).…”

“…Gene arrangements are differently favoured in diverse microhabitats despite high gene flow and large effective population sizes (Kurbalija Novicic et al 2013). Also, Kenig et al (2013) showed difference in tolerance to lead pollution between two populations of D. subobscura from different habitats indicating local genetic adaptation to heavy metal pollution. Under such conditions, selection is effective in driving the evolution of a population.…”

“…Marine gastropods with higher levels of genetic diversity, have increased tolerance to heavy metal pollution (Nevo et al 1986). In Drosophila, lead pollution affects various fitness components such as development (Cohn et al 1992;Stark and Banks 2003;Kenig et al 2013), longevity, fecundity and even complex behavioural traits such as courtship (Cohn et al 1992;Massie et al 1992;Hirsch et al 2003). On the other hand, studies on the effects of different levels of population heterozygosity on fitness components in many species showed both benefits and outbreeding depression (Tallmon et al 2004;Kurbalija et al 2010).…”

Synergistic effect of environmental and genomic stress on wing size of drosophila subobscura

“…They are genetically diverse (according to putatively adaptive polymorphism), even on a small geographic scale, with frequently strong and unpredictable consequences of inter-population hybridization (KURBALIJA et al, 2010). There is also an indication of local genetic adaptation to heavy metal pollution and population specific fitness response to heavy metal pollution (KENIG et al, 2013). In recent years, geometric morphometric analysis of D. subobscura wings proved to be useful model for genetic and evolution studies and evaluation of number of factors, including genetic and environmental stress (HUEY et al, 2000;GILCHRIST and HUEY, 2004;SANTOS et al, 2004SANTOS et al, , 2005KURBALIJA NOVIČIĆ et al, 2012, PATENKOVIC et al, 2015.…”