title: The gene csd is the primary signal for sexual development in the honeybee and encodes an SR-type protein.
abstract: Haplodiploid organisms comprise about 20% of animals. Males develop from unfertilized eggs while females are derived from fertilized eggs. The underlying mechanisms of sex determination, however, appear to be diverse and are poorly understood. We have dissected the complementary sex determiner (csd) locus in the honeybee to understand its molecular basis. In this species, csd acts as the primary sex-determining signal with several alleles segregating in populations. Males are hemizygous and females are heterozygous at this locus; nonreproducing diploid males occur when the locus is homozygous. We have characterized csd by positional cloning and repression analysis. csd alleles are highly variable and no transcription differences were found between sexes. These results establish csd as a primary signal that governs sexual development by its allelic composition. Structural similarity of csd with tra genes of Dipteran insects suggests some functional relation of what would otherwise appear to be unrelated sex-determination mechanisms.
authors.affiliation: Martin-Luther-Universität Halle/Wittenberg, Institut für Zoologie, Biozentrum, Weinberg Weg 22, 06120, Halle, Germany. beye@zoologie.uni-halle.de
authors.forename: Martin
authors.initials: M
authors.lastname: Beye
authors.forename: Martin
authors.initials: M
authors.lastname: Hasselmann
authors.forename: M Kim
authors.initials: MK
authors.lastname: Fondrk
authors.forename: Robert E
authors.initials: RE
authors.lastname: Page
authors.forename: Stig W
authors.initials: SW
authors.lastname: Omholt
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001120:Arginine / Q000378:metabolism; D001516:Bees / Q000196:embryology / Q000502:physiology*; D003001:Cloning, Molecular; D005260:Female; D017344:Genes, Insect; D005838:Genotype; D006066:Gonads / Q000254:growth & development; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D010641:Phenotype; D034622:RNA Interference; D016415:Sequence Alignment; D012694:Serine / Q000378:metabolism; D019849:Sex Determination Processes
chemical_list: D019476:Insect Proteins; D012694:Serine; D001120:Arginine