The Drosophila primo locus encodes two low-molecular-weight tyrosine phosphatases

The fine modulation of tyrosine phosphorylation by protein tyrosine phospha tases and protein tyrosine kinases is a key regulatory mechanism for many c ell signaling pathways active during development. In a screen for genes wit h interesting expression patterns in the developing Drosophila pupal retina , we identified a novel pair of protein tyrosine phosphatases that exhibit an expression pattern suggesting a role in multiple steps of Drosophila neu rogenesis. Together, these phosphatases define the prime locus. Their seque nce is approx. 50% identical to each other and to low-molecular-weight prot ein tyrosine phosphatases (LMW-PTPs) identified in other species. Little is understood of the biological role of LMW-PTPs, and the powerful tools avai lable in Drosophila should provide important insight into their role in sig naling and development. (C) 2000 Elsevier Science B.V. All rights reserved.