title: Interspecific Y chromosome introgressions disrupt testis-specific gene expression and male reproductive phenotypes in Drosophila.
abstract: The Drosophila Y chromosome is a degenerated, heterochromatic chromosome with few functional genes. Nonetheless, natural variation on the Y chromosome in Drosophila melanogaster has substantial trans-acting effects on the regulation of X-linked and autosomal genes. However, the contribution of Y chromosome divergence to gene expression divergence between species is unknown. In this study, we constructed a series of Y chromosome introgression lines, in which Y chromosomes from either Drosophila sechellia or Drosophila simulans are introgressed into a common D. simulans genetic background. Using these lines, we compared genome-wide gene expression and male reproductive phenotypes between heterospecific and conspecific Y chromosomes. We find significant differences in expression for 122 genes, or 2.84% of all genes analyzed. Genes down-regulated in males with heterospecific Y chromosomes are significantly biased toward testis-specific expression patterns. These same lines show reduced fecundity and sperm competitive ability. Taken together, these results imply a significant role for Y/X and Y/autosome interactions in maintaining proper expression of male-specific genes, either directly or via indirect effects on male reproductive tissue development or function.
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA. tsackton@oeb.harvard.edu
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Sackton
authors.forename: Horacio
authors.initials: H
authors.lastname: Montenegro
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Hartl
authors.forename: Bernardo
authors.initials: B
authors.lastname: Lemos
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D005075:Biological Evolution; D004330:Drosophila / Q000235:genetics* / Q000502:physiology; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology; D015870:Gene Expression; D056084:Genetic Fitness / Q000235:genetics*; D008297:Male; D008660:Metabolism / Q000235:genetics; D009928:Organ Specificity; D010641:Phenotype; D013045:Species Specificity; D013737:Testis / Q000502:physiology; D014998:Y Chromosome / Q000235:genetics*