Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.651400
Title: Tyrosinases of C. elegans
Author: Gerrits, Daphne D.
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 1998
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Abstract:
The cuticle of C. elegans is extensively cross-linked by covalent disulphide bridges, tyrosine bonds and possibly glutamyl-lysine bonds. Four genes predicted to be involved in the formation of tyrosine bonds have been identified in C. elegans. tyr-1 and tyr-2 map to chromosome III, tyr-3 and tyr-4 map to chromosome I. These encode tyrosinase-like enzymes. The tyrosinase genes are very similar in structure: all genes have two Cu active sites (CuA and CuB), predicted secretory leader peptides and sxc domains (found in other proteins from C. elegans and Toxocara canis). tyr-1 has an additional polyglutamine region which may be involved in protein-protein interactions. A set of cDNAs prepared from a synchronous population of worms, harvested at two hour intervals through the lifecycle, starting shortly after hatching, was used in semi-quantitative fluorescent PCR. Steady state levels of tyr-1, -2 and -4 genes are upregulated at each moult, suggesting their involvement in the synthesis of the new cuticle. tyr-3 transcripts could not be detected in this set of cDNAs, however it was isolated from a population of worms enriched in males. Studies using lacZ- and GFP-reporter genes driven by promoter fragments of the tyrosinase genes showed that tyr-4 and tyr-1 are expressed in specific subsets of hypodermal cells. In addition tyr-1 is expressed in the vulval cells. tyr-2 was found to be expressed only faintly in hypodermal cells, and showed strong expression in the uterine cells. No expression of tyr-3 was observed. These data imply that tyrosinases are not only involved of cross-linking of cuticular proteins, but are probably also involved in the generation of the egg shell.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.651400  DOI: Not available
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