Open AccessInbreeding reveals mode of past selection on male reproductive characters in D rosophila melanogaster
Author(s) -
AlaHonkola Outi,
Hosken David J.,
Manier Mollie K.,
Lüpold Stefan,
DrogeYoung Elizabeth M.,
Berben Kirstin S.,
Collins William F.,
Belote John M.,
Pitnick Scott
Publication year - 2013
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.625
Subject(s) - inbreeding depression , biology , inbreeding , outbreeding depression , sperm competition , reproductive success , genetics , sperm , evolutionary biology , directional selection , sexual selection , mating , mate choice , fixation (population genetics) , selection (genetic algorithm) , zoology , genetic variation , population , demography , gene , sociology , artificial intelligence , computer science
Directional dominance is a prerequisite of inbreeding depression. Directionality arises when selection drives alleles that increase fitness to fixation and eliminates dominant deleterious alleles, while deleterious recessives are hidden from it and maintained at low frequencies. Traits under directional selection (i.e., fitness traits) are expected to show directional dominance and therefore an increased susceptibility to inbreeding depression. In contrast, traits under stabilizing selection or weakly linked to fitness are predicted to exhibit little‐to‐no inbreeding depression. Here, we quantify the extent of inbreeding depression in a range of male reproductive characters and then infer the mode of past selection on them. The use of transgenic populations of D rosophila melanogaster with red or green fluorescent‐tagged sperm heads permitted in vivo discrimination of sperm from competing males and quantification of characteristics of ejaculate composition, performance, and fate. We found that male attractiveness (mating latency) and competitive fertilization success (P 2 ) both show some inbreeding depression, suggesting they may have been under directional selection, whereas sperm length showed no inbreeding depression suggesting a history of stabilizing selection. However, despite having measured several sperm quality and quantity traits, our data did not allow us to discern the mechanism underlying the lowered competitive fertilization success of inbred ( f = 0.50) males.