Andrew Singson Associate Professor Rutgers University Waksman Institute Room 123 Piscataway. NJ 08854 (732) 445-0836 FAX - 5735 singson@waksman.rutgers.edu

Reproductive biology and cell-cell interactions in C. elegans

Fertilization is a biological process that has important social. economic and medical implications. Our primary research interest is the mechanisms of sperm-egg interactions. The long-term goal of research in the lab is to understand the molecular events that mediate gamete recognition. adhesion. signaling and fusion. The genetic and molecular dissection of these events will also provide insights relevant to other important cell-cell interactions during the development of multicellular organisms.

We are helping to pioneer the use of the nematode worm Caenorhabditis elegans for addressing the mechanisms of sperm-egg interactions. The powerful tools of classical and molecular genetics developed for the worm are not available or are very difficult to utilize in the other organisms traditionally used for studying fertilization. The ameboid sperm of C. elegans. despite lacking an acrosome and flagellum. carry out the same basic functions common to all spermatozoa. The reproductive biology of C. elegans facilitates the identification of mutations that affect sperm and no other cells. The worm exists as a hermaphrodite that makes both sperm and oocytes or as a male that makes only sperm. Mutant hermaphrodites that are spermatogenesis-defective (spe) are self-sterile and
lay unfertilized oocytes. However. when these otherwise healthy worms are crossed to wild type males (a source of sperm) they can produce outcrossed progeny. We have focused on a set of spe genes that produce sperm with normal morphology and motility that cannot fertilize eggs even after contact. From this phenotype we infer that these mutants disrupt either sperm-egg recognition. adhesion. signaling or fusion. The characterization of these genes is a critical step in formulating a model concerning their role in wild-type fertilization.

Since we expect that not every gene required for fertilization will be sperm specific. we are employing both forward and reverse genetic approaches to identify additional genes required for fertility in C. elegans. Our work on C. elegans reproductive biology complements studies of fertilization in other organisms and provides insights relevant to the understanding of cell-cell interactions.

Selected Publications

Hang JS, Grant BD, Singson A. (2008) Meiotic maturation: receptor trafficking is the key.
Curr Biol. 18(10):R416-8.

Maruyama R, Velarde NV, Klancer R, Gordon S, Kadandale P, Parry JM, Hang JS, Rubin J, Stewart-Michaelis A, Schweinsberg P, Grant BD, Piano F, Sugimoto A, Singson A. (2007) EGG-3 regulates cell-surface and cortex rearrangements during egg activation in Caenorhabditis elegans. Curr Biol. 17(18):1555-60.

Maruyama R, Singson A. (2006) Taking care of Dad's DNA. Genome Biol. 7(12):244.

Chatterjee I, Kadandale P, Singson A. (2006) Meiotic diapause: how a sperm signal sets you free. Curr Biol. 16(13):R496-9.

Singson A. (2006) Sperm activation: time and tide wait for no sperm. Curr Biol. 16(5):R160-2.

Geldziler B. Chatterjee I. Kadandale P. Putiri E. Patel R. Singson A. (2006) A comparative study of sperm morphology. cytology and activation in Caenorhabditis elegans. Caenorhabditis remanei and Caenorhabditis briggsae. Dev Genes Evol. 216(4):198-208.

Kadandale P. Stewart-Michaelis A. Gordon S. Rubin J. Klancer R. Schweinsberg P. Grant BD. Singson A. (2005) The egg surface LDL receptor repeat-containing proteins EGG-1 and EGG-2 are required for fertilization in Caenorhabditis elegans. Curr Biol. 15(24):2222-9.

Gleason EJ. Lindsey WC. Kroft TL. Singson AW. L'hernault SW. (2006) spe-10 encodes a DHHC-CRD zinc-finger membrane protein required for endoplasmic reticulum/Golgi membrane morphogenesis during Caenorhabditis elegans spermatogenesis. Genetics. 172(1):145-58.

Geldziler. B. Chatterjee. I and A. Singson,A . (2005) The genetic and molecular analysis of spe-19. a gene required for sperm activation in Caenorhabditis elegans. Dev Bio. 283(2):424-36.

Chatterjee. I. Richmond. A. Putiri. E. Shakes. D and Singson. A. (2005) The Caenorhabditis elegans spe-38 gene encodes a novel four-pass integral membrane protein required for sperm function at fertilization. Development. 132: 2795-2808.

Kadandale. P. Geldziler. B. M. Hoffmann. M and Singson. A. (2005) Use of SNPs to determine the breakpoints of complex deficiencies. facilitating gene mapping in Caenorhabditis elegans. BMC Genetics. 6:28.

E. Putiri. Zannoni. S. Kadandale. P and Singson. A. (2004) Functional domains and temperature-sensitive mutations in SPE-9. an EGF repeat-containing protein required for fertility in Caenorhabditis elegans. Developmental Biology 272: 448-459.

Kadandale. P and Singson. A. (2004) Oocyte production and sperm utilization patterns in semi-fertile strains of Caenorhabditis elegans. BMC Developmental Biology. 4:3.

Geldziler. B. Kadandale. P and Singson. A. (2004) Molecular genetic approaches to studying fertilization in model systems. Reproduction. 127: 409-416.

Zannoni. S. . L'Hernault. S. and Singson. A. W. (2002) Dynamic localization of SPE-9 in sperm: A protein required for sperm-oocyte interactions in Caenorhabditis elegans. BMC Developmental Biology. 3:10.

Lindsey. W. C. . Singson. A. W. and L'Hernault. S. W. (2002) spe-10 encodes a DHHC-CRD zinc finger containing tetraspan protein required for ER/Golgi membrane morphogenesis during Caenorhabditis elegans spermatogenesis. (In Revision).

Bandyopadhyay. J. . Lee. J.. Lee. J.. Lee. J. I. . Yu. J. R.. Jee. C.. Cho. J. H.. Jung. S. Lee. M. H.. Zannoni. S.. Singson. A.. Koo. H. S. and Ahnn. J. (2002) Calcineurin. a component of G-protein coupled phosphorylation pathways. is involved in movement. fertility. egg laying and growth in C. elegans. Molecular Biology of the Cell. 13: 3281-3293.

Park. B. . Lee. D. . Jung. S.. Yu. J.. Choi. K.. Kwon. J. Y.. Lee. J.. Lee. J.. Singson. A.. Song. W. K. . Park. C. S.. Kim. D. H.. Bandyopadhyay. J. and Ahnn. J. (2001) Calreticulin. a calcium-binding molecular chaperone is required for stress response and sperm fertility in C. elegans. Molecular Biology of the Cell. 12: 2835-2845.

Singson. A. . Kadandale. P. and Zannoni. S. (2001) Molecules that function in the steps of fertilization. Cytokine & Growth Factor Reviews. 12: 299-304.

Navarro. R. E. . Shim. E. Y. . Kohara. Y.. Singson. A. and Blackwell. T.K. (2001) cgh-1. a conserved predicted RNA helicase required for gametogenesis and inhibition of germline apoptosis in C. elegans. Development. 128: 3221-3232.

Singson. A. (2001) Every sperm is sacred: Fertilization in C. elegans. Developmental Biology. 230: 101-109.

L'Hernault. S. W. and Singson. A. (2000) Developmental genetics of spermatogenesis in the nematode Caenorhabditis elegans. In: "The Testes: From Stem Cell to Sperm Function". Serono Symposium USA. 109-119.