Prophenoloxidase activating factor from the blue crab, Callinectes sapidus

UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
Elizabeth S. Buda (Creator)
The University of North Carolina Wilmington (UNCW )
Web Site:
Thomas Shafer

Abstract: Crustaceans are encased in a hard exoskeleton, making it necessary for them to shed this cuticle in order to grow. Once the old exoskeleton is shed, the newly synthesized cuticle can begin to harden. Tanning, or sclerotization, initially hardens the cuticle by crosslinking cuticular proteins attached to the chitin-fiber matrix. This process is catalyzed by an enzyme, phenoloxidase, whose activation is controlled by a serine protease cascade. The cDNA of a prophenoloxidase activating factor (PPAF) was cloned and sequenced from the blue crab, Callinectes sapidus. The expression pattern was determined by quantitative PCR and Northern blotting in both calcified and arthrodial tissue before, during, and after molting. High signal intensity was found in premolt RNA from the hypodermis of both cuticle types. This implies that PPAF gene is being transcribed in premolt tissue for translation and use of the protein in the tanning process, which occurs within a few hours after ecdysis. An increase in arthrodial signal at three to four hours post-molt may signify that arthrodial cuticle laid down in post-molt stages is being tanned. This pattern is not seen in calcified cuticle, as biomineralization of the endocuticle occurs simultaneously with deposition.

Additional Information

A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment Of the Requirements for the Degree of Master of Science
Language: English
Date: 2009
Blue crab--Physiology, Blue crab--Research, Callinectes, Crabs--Physiology, Crustacea
Blue crab -- Research
Crabs -- Physiology
Blue crab -- Physiology

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