title: Alternative splicing of a single transcription factor drives selfish reproductive behavior in honeybee workers (Apis mellifera).
abstract: In eusocial insects the production of daughters is generally restricted to mated queens, and unmated workers are functionally sterile. The evolution of this worker sterility has been plausibly explained by kin selection theory [Hamilton W (1964) J Theor Biol 7:1-52], and many traits have evolved to prevent conflict over reproduction among the females in an insect colony. In honeybees (Apis mellifera), worker reproduction is regulated by the queen, brood pheromones, and worker policing. However, workers of the Cape honeybee, Apis mellifera capensis, can evade this control and establish themselves as social parasites by activating their ovaries, parthenogenetically producing diploid female offspring (thelytoky) and producing queen-like amounts of queen pheromones. All these traits have been shown to be strongly influenced by a single locus on chromosome 13 [Lattorff HMG, et al. (2007) Biol Lett 3:292-295]. We screened this region for candidate genes and found that alternative splicing of a gene homologous to the gemini transcription factor of Drosophila controls worker sterility. Knocking out the critical exon in a series of RNAi experiments resulted in rapid worker ovary activation-one of the traits characteristic of the social parasites. This genetic switch may be controlled by a short intronic splice enhancer motif of nine nucleotides attached to the alternative splice site. The lack of this motif in parasitic Cape honeybee clones suggests that the removal of nine nucleotides from the altruistic worker genome may be sufficient to turn a honeybee from an altruistic worker into a parasite.
authors: Institut für Biologie, Martin-Luther-Universität Halle-Wittenberg, 06099 Halle, Saale, Germany. antje.jarosch@zoologie.uni-halle.de
authors: Antje
authors: A
authors: Jarosch
authors: Eckart
authors: E
authors: Stolle
authors: Robin M
authors: RM
authors: Crewe
authors: Robin F A
authors: RF
authors: Moritz
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D000818:Animals; D001516:Bees / Q000235:genetics*; D005091:Exons / Q000235:genetics; D005260:Female; D055785:Gene Knockdown Techniques; D006608:Hierarchy, Social; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D007438:Introns / Q000235:genetics; D008957:Models, Genetic; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D012098:Reproduction / Q000235:genetics; D012726:Sexual Behavior, Animal / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D019476:Insect Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014157:Transcription Factors