 |
|
|
|
|
|
|
|
|
 |
 |
 |
 |
 |
 |
 |
 |
|
| Robyn Lints received her M.S. from the University of Auckland, New Zealand and her PhD in Molecular Genetics from the University of Melbourne, Australia. As a post-doctoral fellow Dr. Lints studied the genetics of touch response behavior in the nematode C. elegans with Dr. Monica Driscoll (Rutgers University, NJ). During the period she became interested in the sensory systems used by the C. elegans male during mating and joined Dr. Scott Emmons' group (Albert Einstein College of Medicine, NY) to study their development. With anatomist Dr. David Hall, she also generated a web-based guide to C. elegans male anatomy (see www.wormatlas.org ). Dr. Lints joined the Department of Biology at Texas A&M University in the fall of 2005. |
Robyn Lints 3258 TAMU Office: Lab: Fax: 979-845-2891 |
| Genetic control of nervous system development and function
Some of the most fascinating and elaborate behaviors that animals engage in are those used to find a mate and to copulate. Males and females often have quite different roles in the reproductive process and this is reflected in sex-specific differences in their morphology and behavior. Relatively little is known about the genetic mechanism that establish sexual dimorphism during development or that control its expression in the mature adult. The tiny soil nematode C.elegans exhibits striking sexual dimorphism in its mating behavior. Males execute a complex series of maneuvers directed at finding the hermaphrodite vulva, inserting his copulatory spicules and transferring sperm. Hermaphrodites, on the other hand, exhibit an apparent indifference to the whole process.
1. How is cellular heterogeneity genetically programmed during development? 2. How does this heterogeneity (and ray identity in general) contribute to functional specialization among rays in mating behavior? So far the data points to a model in which all ray neurotransmitter profiles are based on a ground state that is modified in each ray during development by distinct combinations of factors to generate the characteristic profile of a ray. These developmental factors include mediators of the sex-determination pathway (Doublesex-Mab-3 transcription factors) and axial patterning factors (a TGF-beta signaling pathway, Hox genes, a Pax-6 transcription factor) which, acting together, ensure that neurons of the correct fate arise in the appropriate axial location in the right sex. |
|
|
Yang, Y., Sun, Y., Luo, X., Zhang, Y., Chen, Y., Tian, E., Lints, R., Zhang H. (2007). Polycomb-like genes are necessary for specification of dopaminergic and serotonergic neurons in Caenorhabditis elegans. Proc Natl Acad Sci U S A. 104(3): 852-857. J. Lipton, J., Kleemann, G., Ghosh, R., Lints, R. and Emmons, S. W. Male mate-searching in C. elegans - a genetic model for sex drive in a simple invertebrate (2004). J. Neurosci . 24:7427-7434 . Lints, R., Jia, L., Kim, K., Li, C. and Emmons, S. W. (2004). Axial patterning of C. elegans male sensilla identities by selector genes. Dev. Biol. 269:137-151. Liang, J., Lints, R., Foehr, M. L.,Tokarz, R., Yu, L., Emmons, S. W., Liu, J. and Savage-Dunn, C. (2003). The Caenorhabditis elegans schnurri homolog, sma-9, mediates stage- and cell type-specific responses to dbl-1 BMP-related signaling. Development 130: 6453-6464. Lints, R. and Emmons, S. W. (2002). Regulation of sex-specific differentiation and mating behavior in C. elegans by a new member of the DM domain transcription factor family. Genes & Dev. 16: 2390-2402. Lints, R. and Emmons, S. W. (1999). Patterning of dopaminergic neurotransmitter identity among C. elegans ray sensory neurons by a TGFß family signaling pathway and a Hox gene . Development . 126: 5819-5831. |
The male is equipped with a variety of male-specific sense organs that he uses in mating behavior. Among these are the sensory rays, finger-like structures extending from the left and right of the male's tail. The rays have an extremely simple structure, each consisting essentially of two sensory neurons and a glial cell. Although uniform in composition and structure, the rays are not identical. Each left/right ray pair has a unique identity due to the expression of distinct combinations of characteristics in its constituent cells (morphology, neuron trajectory, connectivity and sensory receptor expression). The rays participate in multiple steps in mating behavior so identities may reflect functional specialization among rays in these different tasks. Perhaps the most heterogeneous characteristic of all, and certainly an important variable in behavioral output, is neurotransmitter fate. Transmitters synthesized by ray neurons include acetylcholine, several classes of neuropeptides, and the clinically important monoamines dopamine and serotonin. We are using these patterns of neurotransmitter fate to explore two major questions: 