title: Sex determination in the parasitic nematode Strongyloides ratti.
abstract: The parasitic nematode Strongyloides ratti reproduces by both parthenogenesis and sexual reproduction, but its genetics are poorly understood. Cytological evidence suggests that sex determination is an XX/XO system. To investigate this genetically, we isolated a number of sex-linked DNA markers. One of these markers, Sr-mvP1, was shown to be single copy and present at a higher dose in free-living females than in free-living males. The inheritance of two alleles of Sr-mvP1 by RFLP analysis was consistent with XX female and XO male genotypes. Analysis of the results of sexual reproduction demonstrated that all progeny inherit the single paternal X chromosome and one of the two maternal X chromosomes. Therefore, all stages of the S. ratti life cycle, with the exception of the free-living males, are XX and genetically female. These findings are considered in relation to previous analyses of S. ratti and to other known sex determination systems.
authors.affiliation: Division of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom. sch1@stir.ac.uk
authors.forename: S C
authors.initials: SC
authors.lastname: Harvey
authors.forename: M E
authors.initials: ME
authors.lastname: Viney
mesh_terms: D000483:Alleles; D000818:Animals; D001769:Blood / Q000469:parasitology; D004247:DNA / Q000378:metabolism; D005260:Female; D005819:Genetic Markers; D005838:Genotype; D015151:Immunoblotting; D008297:Male; D008954:Models, Biological; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D051381:Rats; D017208:Rats, Wistar; D019849:Sex Determination Processes; D013321:Strongyloides / Q000235:genetics* / Q000502:physiology*; D014960:X Chromosome
chemical_list: D005819:Genetic Markers; D004247:DNA