Evidence for a Genomic Imprinting Sex Determination Mechanism in Nasonia vitripennis (Hymenoptera; Chalcidoidea)

Corresponding author: Stephen L. Dobson, Department of Epidemiology and Public Health, Yale University, 602 LEPH, New Haven, CT 06520, stephen.dobson{at}yale.edu (E-mail).

Communicating editor: T. SCHÜPBACH

Five different models have been proposed for the sex determination mechanism of Chalcidoidea (Hymenoptera). Except for the most recently proposed model (genomic imprinting sex determination; GISD), each of these models has required complicating additions to explain observed phenomena. This report provides the first experimental test of the GISD model while simultaneously examining the four previously proposed models of sex determination. This test utilizes the parasitic wasp Nasonia vitripennis, crossing polyploid females with males harboring the paternal sex ratio chromosome (PSR). The results of this study support the GISD model as the mechanism of sex determination in Chalcidoidea. Specifically, crosses demonstrate that sex determination is independent of embryonic heterozygosity, ploidy, and gametic syngamy but is directly correlated with the embryonic presence of correctly imprinted chromosomes of paternal origin. These crossing experiments also provide information about the poorly characterized mechanisms of PSR, a supernumerary chromosome that induces paternal autosome loss in early embryos. The results demonstrate that the poor transmission of PSR through females is not a result of the ploidy of the host but of an alternative sex-dependent process. Crossing data reveal that PSR consistently induces the loss of the entire paternal complement that it accompanies, regardless of whether this complement is haploid or diploid.

This article has been cited by other articles:

				A. Kamping, V. Katju, L. W. Beukeboom, and J. H. Werren Inheritance of Gynandromorphism in the Parasitic Wasp Nasonia vitripennis Genetics, March 1, 2007; 175(3): 1321 - 1333. [Abstract] [Full Text] [PDF]

				L. W. Beukeboom and A. Kamping No Patrigenes Required for Femaleness in the Haplodiploid Wasp Nasonia vitripennis Genetics, February 1, 2006; 172(2): 981 - 989. [Abstract] [Full Text] [PDF]

				D. P. Cowan and J. K. Stahlhut Functionally reproductive diploid and haploid males in an inbreeding hymenopteran with complementary sex determination PNAS, July 13, 2004; 101(28): 10374 - 10379. [Abstract] [Full Text] [PDF]

				Y. Fujiwara, K. Akita, W. Okumura, T. Kodaka, K. Tomioka, and T. Naito Estimation of Allele Numbers at the Sex-Determining Locus in a Field Population of the Turnip Sawfly (Athalia rosae) J. Hered., January 1, 2004; 95(1): 81 - 84. [Abstract] [Full Text] [PDF]

				M. A. Pultz, K. K. Zimmerman, N. M. Alto, M. Kaeberlein, S. K. Lange, J. N. Pitt, N. L. Reeves, and D. L. Zehrung A Genetic Screen for Zygotic Embryonic Lethal Mutations Affecting Cuticular Morphology in the Wasp Nasonia vitripennis Genetics, March 1, 2000; 154(3): 1213 - 1229. [Abstract] [Full Text]

				A. K. Holloway, M. R. Strand, W. C. Black , IV, and M. F. Antolin Linkage Analysis of Sex Determination in Bracon sp. Near hebetor (Hymenoptera: Braconidae) Genetics, January 1, 2000; 154(1): 205 - 212. [Abstract] [Full Text]

				M. Beye, G. J. Hunt, R. E. Page, M. K. Fondrk, L. Grohmann, and R. F. A. Moritz Unusually High Recombination Rate Detected in the Sex Locus Region of the Honey Bee (Apis mellifera) Genetics, December 1, 1999; 153(4): 1701 - 1708. [Abstract] [Full Text]