Evolution of the Phosphatase Gene Family Across Nematode Worms and Flies

Abstract

Phosphatase genes have been shown to be involved in male meiosis in the nematode worm, Caenorhabditis elegans, and are expressed in the testis in the fruit fly, Drosophila melanogaster. However, the evolution of this multi-gene family among nematodes and flies had not previously been investigated. We conducted a phylogenetic analysis of all genes in the phosphatase gene family across nematodes and flies using sequences from a 6-way alignment of nematode worms and a 15- way alignment of insects, including 12 Drosophila species. We found that: 1) multiple alignments contain spurious alignments that should be filtered for quality control; 2) several gene sequences with incomplete open reading frames are highly conserved, so may actually be functional genes; and, 3) the phosphatase gene family appears to have expanded independently in the common ancestor of nematodes, and again in the common ancestor of flies (but not all insects).