Evolutionary trends in feminization and intersexuality in woodlice (Crustacea, Isopoda) infected with Wolbachia pipientis (alpha-Proteobacteria)
Year: 2003
Type: article
Abstract: Sex ratio distortion (SRD) and intersexuality are common phenomena among Isopoda (Arthropoda, Crustacea), caused by the feminizing action of the α-Proteobacterium Wolbachia (F) and/or an F DNA segment (f) integrated into the host genome, probably as a transposon.A dominant autosomal masculinizing allele (M) overrides the primary sex determinants (WZ: females; ZZ: males) and f but not F.The latter can be counterbalanced by the transmission suppressor polygenic system (R).The present study pursued a double object.(i) SRD was found in naturally isolated populations of three out of seven Belgian woodlouse species: Oniscus asellus, Armadillidium vulgare and A. pulchellum.They were (inter)sexed based on external and internal morphology, and specimens of the former two underwent PCR and/or microscopic detection of F. (ii) A deterministic but flexible model was set up to describe SRD changes in an initially F-infested A. vulgare population sampled during the last 25 years.Observed and predicted sex ratios fit best if natural transmission rates (i.e., in the absence of M and R) approach 100%, a condition fulfilled if f is carried on a multicopy transposon.Most often, such a population will then gradually lose its invader to the benefit of f.The stable end situation is a host population consisting of ZZ+f individuals of which 44% are neo-females (having mm), and 56% are reversed males (owing to Mm or MM).The model also explains the accelerated SRD evolution under variable degrees of F/f transmission.
Authors: Tom Vandekerckhove, Stephanie Watteyne, W. Bonne, Danny Vanacker, Stijn Devaere, B. Rumes, Jean‐Pierre Maelfait, Monique Gillis, Jean Swings, Henk R. Braig, Johan Mertens
Language: English
Subfield: Insect Science
Domain: Life Sciences
Open Access status: green
Funders: Universiteit Gent, Vlaamse regering
OpenAlex ID: W1486046377