The C-elegans gene lin-9, which acts in an Rb-related pathway, is requiredfor gonadal sheath cell development and encodes a novel protein

The Caenorhabditis elegans gene lin-9 functions in an Rb-related pathway ch at acts antagonistically to a receptor tyrosine kinase/Ras signal transduct ion pathway controlling vulval induction. We show that lin-9 is also requir ed for the development of the sheath cells in the hermaphrodite gonad and f or the development of the male spicule, rays and gonad. lin-9 is transcribe d as two alternatively spliced 2.4 kb messages, which use two distinct poly adenylation sites and are SL1 trans-spliced. The conceptual translation of lin-9 cDNA sequences predicts proteins of 642 and 644 amino acids with a si gnificant similarity to predicted Drosophila and vertebrate proteins. We su ggest that lin-9 is the founding member of a new protein family that functi ons in Rb-related pathways in many species. (C) 2000 Elsevier Science B.V. All rights reserved.