Work

Incompatibility Between X Chromosome Factor and Pericentric Heterochromatic Region Causes Lethality in Hybrids Between Drosophila melanogaster and Its Sibling Species

Year: 2012

Type: article

Abstract: The Dobzhansky-Muller model posits that postzygotic reproductive isolation results from the evolution of incompatible epistatic interactions between species: alleles that function in the genetic background of one species can cause sterility or lethality in the genetic background of another species. Progress in identifying and characterizing factors involved in postzygotic isolation in Drosophila has remained slow, mainly because Drosophila melanogaster, with all of its genetic tools, forms dead or sterile hybrids when crossed to its sister species, D. simulans, D. sechellia, and D. mauritiana. To circumvent this problem, we used chromosome deletions and duplications from D. melanogaster to map two hybrid incompatibility loci in F(1) hybrids with its sister species. We mapped a recessive factor to the pericentromeric heterochromatin of the X chromosome in D. simulans and D. mauritiana, which we call heterochromatin hybrid lethal (hhl), which causes lethality in F(1) hybrid females with D. melanogaster. As F(1) hybrid males hemizygous for a D. mauritiana (or D. simulans) X chromosome are viable, the lethality of deficiency hybrid females implies that a dominant incompatible partner locus exists on the D. melanogaster X. Using small segments of the D. melanogaster X chromosome duplicated onto the Y chromosome, we mapped a dominant factor that causes hybrid lethality to a small 24-gene region of the D. melanogaster X. We provide evidence suggesting that it interacts with hhl(mau). The location of hhl is consistent with the emerging theme that hybrid incompatibilities in Drosophila involve heterochromatic regions and factors that interact with the heterochromatin.

Source: Genetics

DOI: 10.1534/genetics.112.139683

Authors: M Victoria Cattani, Daven C Presgraves

Institution: University of Rochester

Language: English

Topic: Chromosomal and Genetic Variations

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

Open Access status: bronze

Funders: David and Lucile Packard Foundation, University of Rochester, National Institutes of Health, National Institute of General Medical Sciences

Award: G4445232488