Yang, Hainan et al. (2013) International Worm Meeting "SRD-1 is required for C. elegans males to respond to the Caenorhabditis remanei female sex-pheromone."

Yang, Hainan, ZHOU, Yuan, CHOW, King-Lau

[International Worm Meeting, 2013]

Dioecious Caenorhabditis remanei and androdioecious C. elegans are two closely related species. Despite their distinct mating systems and evolutionary divergence, our lab has demonstrated that virgin C. remanei females secrete a potent sex-specific pheromone that attracts young adult males of both species from afar. Intriguingly, this chemotaxic behavior requires AWA and CEM neurons in male C. elegans, probably via different receptors expressed on these neurons. Here I will present our experiment data suggesting the requirement of the G-protein coupled receptor SRD-1 in AWA neurons in male C. elegans for sensing the pheromone secreted by C. remanei females. The srd-1 was found expressed in both AWA and ASI neurons. The sub-cellular localization of SRD-1 receptor in male AWA neuron was found in the tip of cilia. Using the chemotaxis assay, we found that the srd-1 mutant males lose their pheromone responsiveness. This defect can be rescued using srd-1 cDNA driven by AWA specific promoter of gene odr-7. Ectopic expression of srd-1 in AWB neuron in srd-1 mutant male elicits a mild repulsive behavior against the pheromone. We visualized the excitation of AWA neurons upon treatments of multiple odors and found that AWA neurons of the srd-1 mutant males cannot be stimulated by the pheromone extract, but is responsive to other chemoattractants. Consistent with this finding, heterologously expressing srd-1 cDNA in HEK293 FT mammalian cell line can mildly confer the host sensitivity to concentrated pheromone extract. Moreover, we employed the C. elegans ARR-1 protein from the desensitization pathway and constructed a protein complementation system with two split beta-lactamase fragments separately tagged onto ARR-1 and GPCRs (ODR-10 and SRD-1). When expressing the system in HEK293 FT cell line, we visualized the desensitization of both ODR-10 and SRD-1 upon the stimuli of diacetyl and concentrated pheromone extract, respectively, using an auto FRET substrate of beta-lactamase, CCF-2 AM. With the above evidence, we conclude that SRD-1 is one receptor responsible for sensing active pheromone extract component derived from virgin females of C. remanei. (This research is supported by Research Grants Council, Hong Kong).

Alison Slinskey Legg et al. (2007) International Worm Meeting "C. elegans research for high school teachers and students: The Gene Team."

Lew Jacobson, Alison Slinskey Legg

[International Worm Meeting, 2007]

The Gene Team is a 5-year program to explore and refine a novel mechanism for engaging high school teachers and high school students in biomedical research and inquiry-based learning, with a focus on the genetics of model organisms. The objectives are: (a) To improve the knowledge and process skills of high school biology teachers; (b) To introduce high school students to the practice of scientific research and develop their skills in scientific thinking; (c) To design and implement inquiry-based curricular modules using model organisms for high school biology classes. The core of the program is a 7-week summer session (40 hrs/week), during which participants in a single dedicated 1000 sq. ft. lab work in parallel on three distinct research projects involving bacteria, yeast and C. elegans. Nine participating research labs provide projects (3 each year), with the intention that the "products" (mutants, constructs, data) of the summer research are returned to the originating labs for further investigation. The novelty of the team concept is that the participants work as peers despite a wide diversity of age and experience: The 2006 Gene Team was composed of 3 high school teachers, 6 high-school students, 2 research-experienced undergraduates and 3 graduate students, under the daily supervision of a faculty member and a program staff member. Simultaneously, the teacher-participants work at the Curriculum Roundtable with a group of master teachers and University faculty to design and refine inquiry-based learning modules, targeted at state curricular standards for biology in grades 9-12. Modules may be classroom-based or lab-based, and we provide equipment, supplies and staff support for implementation during the school year. Modules are field-tested and iteratively refined through one academic year before wider dissemination. The Gene Team is supported by a Science Education Partnership Award (SEPA) from the National Center for Research Resources, NIH.