Worm Breeder's Gazette 14(1): 40 (October 1, 1995)
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.
Okayama University, Faculty of Science Okayama, Japan 700 email@example.com
The tropomyosin gene tmy-1 of C. elegans spans 14 kb and encodes three isoforms CeTMI, CeTMII and CeTMIII with 14 exons. Tissue specific expression of the tmy-1 gene was determined by microinjection of promoter/lacZ fusion plasmids. The 5'end promoter common to CeTMI and CeTMII control expression in the body wall, vulva, anus and male tail muscles. Interestingly expression of CeTMIII was transspliced with SL1. The internal promoter in intron 3 controls the expression CeTMIII in the pharyngeal muscles1). Map position of tmy-1 locates on the lev-11 site1). Determination of the mutation site in the tmy-1/lev-11 gene will help to know how signal from troponin could reach to actin filament through tropomyosin. C-element for cell specific and B element a putative ceh-22 binding site for tissue specific expressions control the pharynx specific expressing of the myo-2 gene2). We found B element in intron 4 (8100-8135) and two C-elements in intron 3 (5185-5219; 7466-7494) of the tmy-1 gene. Deleting BglII fragment including one of C-element from pTMIZ3256 (4583-8277) had little effect on expression in the pharynx. Myo-2 B sub-element could function on the tmy-1 gene expression in the pharynx. We are constructing the fusion plasmids to know which regions exactly control the tissue specific expression. On the contrary to the tmy-1 gene, unc-15 the paramyosin gene encodes only one isoform and expresses in the pharynx and the body wall muscles. There was a promoter like sequence in the 5' end of the gene and contained a putative enhancer sequence in intron 5 which could form a stem and loop structure. We have not isolated a pharyngeal specific unc-15/lacZ fusion plasmid yet. The tmy-1 and unc-15 genes are a good example for studying how one gene was controlled with a different expression mechanism. myo-2 B sub-element B207 AAGTGGTTGTGTGG-----ATAAGAGTAGCAAAATG tmy-1 AAGTGGcTGctcctgctGctTAtttGTcttAgAATa (17/31) 8100-8135 myo-2 C sub-element C183 TCTCGTTGTTTGCCG-TCGGATGTCTGCC tmy-1 TCTCtaTGTTTGtaGagaGGcTGggcGCC (18/28) 7466-7494 C183 TCTCGTTGTTTGCC-------GTCGGATGTCTGCC tmy-1 aCgaGaTGTTTGCtttacaacaaCtccTccCcGCC (15/28) 5185-5219 1) Kagawa et al, J. Mol. Biol. 1995, 251(5),603-613. 2) Okkema & Fire, Development, 1994, 120, 2175-2186.