More genes on the fly Y

The Drosophila Y chromosome has several features (including its heterochromatic state) that have made mapping and sequencing difficult. The Y chromosome contains genes directly involved with male fertility. In the November 6 Proceedings of the National Academy of Sciences, Carvalho et al. describe a search for more novel Y-linked genes (Proc Natl Acad Sci USA 2001, 98:13225-13230). They used a strategy involving staggered TBLASTN screening of 500,000 proteins against the armU database of unmapped Drosophila sequences. This led to the identification of five novel Y-linked genes; three of these encode serine-threonine protein phosphatases, one is related to occludin and the other encodes a coiled-coil protein. This study raises the number of identified single-copy genes on the Y chromosome to nine.