Sea Grant Program: Mississippi Alabama Sea Grant Consortium
Title: The crustacean molt-inhibiting hormone receptor and induction of molting in blue crabs (Callinectes sapidus)
Start Date: 02/01/08
Duration: 2 years
Project Leader: Watson, R. Douglas
Affiliation: University of Alabama at Birmingham
Sea Grant Funds (2 years): $100,000 (State Appropriations)
Matching Funds: $0
Keywords: blue crab, soft-shelled crab, ecdysteroid, molt-inhibiting hormone (MIH), MIH receptor
Objectives:
A major gap in knowledge of the regulation of crustacean growth and molting is lack of information on the molt-inhibiting hormone (MIH) receptor. We have recently cloned from blue crab (Callinectes sapidus) molting glands a putative MIH receptor (CsGC-YO1), and have developed a candidate receptor blocker (anti-CsGC-YO1).
The objective of studies proposed for year 1 is to determine whether the cloned receptor is an authentic MIH receptor.
The objective of studies proposed for year 2 is to determine whether the candidate receptor blocker is effective in inducing molting in blue crabs.
Methodology:
Year 1:
To determine whether the cloned receptor is an authentic MIH receptor, we will (a) express the receptor in mammalian (COS-7) cells, and (b) test the ability of recombinant MIH to bind and activate the expressed receptor.
Year 2:
To test the effectiveness of the receptor blocker, we will inject the blocker into blue crabs and then (a) monitor the level of ecydsteroids in hemolymph, and (b) score morphological indicants of the molt stage and the time to molting. Once an effect has been established in vivo, titration experiments will be conducted to determine the lowest effective dose.
Rationale:
Year 1
Despite the central role of MIH in regulation of growth and postembryonic development in this economically and ecologically important group of organisms, the MIH receptor has not been isolated or thoroughly characterized for any crustacean species. Identification and characterization of the MIH receptor would constitute a significant contribution to the field of invertebrate endocrinology, and would lead (in year 2) to experiments designed to permit the induction of molting in blue crabs, a benefit to the soft crab industry and to consumers of seafood.
Year 2
The soft crab industry is limited by a supply of premolt blue crabs (Callinectes sapidus) that is both seasonal and unpredictable. Controlled induction of molting could provide an abundant and predictable supply of soft-shelled crabs, a benefit to the soft crab industry and to consumers of seafood.
For More Information Contact: the MASGC Research Coordinator, Loretta Leist (Loretta.leist@usm.edu).
Please reference the project number R/SP-19.
(Annual Report)
