Worm Breeder's Gazette 8(3): 29
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
5000 F1 clones have been screened for mutants causing defects in either the lineage of the somatic gonad or specific postembryonic germ line controls. Both classes have been identified. All mutations lead to a recessive sterile phenotype. Work on mutants affecting the somatic lineage is very preliminary, and therefore will be described in a later issue. Mutants affecting postembryonic germ line development fall into three phenotypic classes. These include 5 mutants (at least 3 genes) with a Fem phenotype (oocytes only in the hermaphrodite germ line), 5 mutants (at least 3 genes) with a Mgl phenotype (masculinization of the germ line), and 5 mutants (at least 2 genes) with a Glp phenotype (germ line proliferation defective). Mutants with a Mgl phenotype have a sexually transformed germ line leading to continuous sperm production into the distal arm of the hermaphrodite gonad. Most is known about the Glp mutants. The mutant phenotype of glp-1 is similar to the laser phenotype of animals in which the distal tip cell was ablated during L1. Z2 and Z3 divide a couple of times, and all their descendants enter meiosis and differentiate as sperm. The hermaphrodite and male germ line is affected equally. The distal tip cells, however, are present, and their role as leader cell in the hermaphrodite gonad is unaffected. The hermaphrodite somatic gonad thus possesses two U-shaped arms made of somatic epithelial or sheath cells and a small number of sperm scattered throughout the arm. No affect on the somatic structures of the gonad of either sex has been seen. The three alleles of glp-1 have this same gonadal phenotype leading to sterility. None are temperature sensitive. The map position is .1% to the right of unc-32. Its position with respect to lin-12 has not yet been determined. Two Glp alleles that do not map to glp-1 have a somewhat different phenotype. Z2 and Z3 divide only a couple of times, but no differentiation ensues. The distal tip cell is enlarged and vacuolated. The map position of these other alleles is not yet known.