Unusually High Recombination Rate Detected in the Sex Locus Region of the Honey Bee (Apis mellifera)

Corresponding author: Martin Beye, Department of Entomology, University of California, Davis, CA 95616., mbeye{at}ucdavis.edu (E-mail)

Communicating editor: W. STEPHAN

Sex determination in Hymenoptera is controlled by haplo-diploidy in which unfertilized eggs develop into fertile haploid males. A single sex determination locus with several complementary alleles was proposed for Hymenoptera [so-called complementary sex determination (CSD)]. Heterozygotes at the sex determination locus are normal, fertile females, whereas diploid zygotes that are homozygous develop into sterile males. This results in a strong heterozygote advantage, and the sex locus exhibits extreme polymorphism maintained by overdominant selection. We characterized the sex-determining region by genetic linkage and physical mapping analyses. Detailed linkage and physical mapping studies showed that the recombination rate is <44 kb/cM in the sex-determining region. Comparing genetic map distance along the linkage group III in three crosses revealed a large marker gap in the sex-determining region, suggesting that the recombination rate is high. We suggest that a "hotspot" for recombination has resulted here because of selection for combining favorable genotypes, and perhaps as a result of selection against deleterious mutations. The mapping data, based on long-range restriction mapping, suggest that the Q DNA-marker is within 20,000 bp of the sex locus, which should accelerate molecular analyses.

This article has been cited by other articles:

				J. G. de Boer, P. J. Ode, A. K. Rendahl, L. E. M. Vet, J. B. Whitfield, and G. E. Heimpel Experimental Support for Multiple-Locus Complementary Sex Determination in the Parasitoid Cotesia vestalis Genetics, November 1, 2008; 180(3): 1525 - 1535. [Abstract] [Full Text] [PDF]

				S. Cho, Z. Y. Huang, D. R. Green, D. R. Smith, and J. Zhang Evolution of the complementary sex-determination gene of honey bees: Balancing selection and trans-species polymorphisms Genome Res., November 1, 2006; 16(11): 1366 - 1375. [Abstract] [Full Text] [PDF]

				M. Beye, I. Gattermeier, M. Hasselmann, T. Gempe, M. Schioett, J. F. Baines, D. Schlipalius, F. Mougel, C. Emore, O. Rueppell, et al. Exceptionally high levels of recombination across the honey bee genome Genome Res., November 1, 2006; 16(11): 1339 - 1344. [Abstract] [Full Text] [PDF]

				M. Hasselmann and M. Beye Pronounced Differences of Recombination Activity at the Sex Determination Locus of the Honeybee, a Locus Under Strong Balancing Selection Genetics, November 1, 2006; 174(3): 1469 - 1480. [Abstract] [Full Text] [PDF]

				O. Ruppell, T. Pankiw, and R. E. Page Jr. Pleiotropy, Epistasis and New QTL: The Genetic Architecture of Honey Bee Foraging Behavior J. Hered., November 1, 2004; 95(6): 481 - 491. [Abstract] [Full Text] [PDF]

				O. Rueppell, T. Pankiw, D. I. Nielsen, M. K. Fondrk, M. Beye, and R. E. Page Jr. The Genetic Architecture of the Behavioral Ontogeny of Foraging in Honeybee Workers Genetics, August 1, 2004; 167(4): 1767 - 1779. [Abstract] [Full Text] [PDF]

				R. E. Page Jr., J. Gadau, and M. Beye The Emergence of Hymenopteran Genetics Genetics, February 1, 2002; 160(2): 375 - 379. [Full Text] [PDF]

				S. Palsson Selection on a Modifier of Recombination Rate Due to Linked Deleterious Mutations J. Hered., January 1, 2002; 93(1): 22 - 26. [Abstract] [Full Text] [PDF]