Prior Mating Experience Modulates the Dispersal of Drosophila in Males More Than in Females

Cues from both an animal’s internal physiological state and its local environment may influence its decision to disperse. However, identifying and quantifying the causative factors underlying the initiation of dispersal is difficult in uncontrolled natural settings. In this study, we automatically monitored the movement of fruit flies and examined the influence of food availability, sex, and reproductive status on their dispersal between laboratory environments. In general, flies with mating experience behave as if they are hungrier than virgin flies, leaving at a greater rate when food is unavailable and staying longer when it is available. Males dispersed at a higher rate and were more active than females when food was unavailable, but tended to stay longer in environments containing food than did females. We found no significant relationship between weight and activity, suggesting the behavioral differences between males and females are caused by an intrinsic factor relating to the sex of a fly and not simply its body size. Finally, we observed a significant difference between the dispersal of the natural isolate used throughout this study and the widely-used laboratory strain, Canton-S, and show that the difference cannot be explained by allelic differences in the foraging gene

Inheritance of isozyme and RFLP markers in Brassica campestris and comparison with B. oleracea

Using primarily cDNA restriction fragment length polymorphism markers (RFLPs) previously located to Brassica oleracea (cabbage, 2n=18) chromosomes, we initiated a comparative RFLP map in an F 2 population of B. campestris (turnip x mock pak-choi, 2n=20). As with B. oleracea , the genome of B. campestris showed extensive gene duplication, and the majority of detected duplicated loci were unlinked. Only 6 of the 49 identified loci were represented as a single copy, and 3 of these 6 were clustered on a single linkage group showing a distorted segregation ratio. Comparison with B. Oleracea indicates this synteny is conserved between species. Two other linkage groups also appeared syntenic between B. oleracea and B. campestris . One single copy locus appears to have changed synteny between B. oleracea and B. campestris . These observations suggest that B. oleracea and B. campestris share a common ancestor, but that chromosome repatterning has occurred during or after speciation. Within B. campestris , 5 loci appeared duplicated in one parent or the other, and 2 of these were linked. Differentiation through subspecies-specific duplication or deletion events is suggested as one mechansim for the evolution of numerous morphotypes within each of these species.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46007/1/122_2004_Article_BF00227309.pd