|
|
||||||||
The Biological Bulletin, Vol 197, Issue 1 94-103, Copyright © 1999 by Marine Biological Laboratory
DEVELOPMENT AND REPRODUCTION |
P. J. Krug and A. E. Manzi
Department of Biology, University of California, Box 951606, Los Angeles, California 90095-1606
Larvae of the specialist marine herbivore Alderia modesta (Opisthobranchia: Ascoglossa) metamorphose in response to a chemical settlement cue from the alga Vaucheria longicaulis, the obligate adult prey. Bioactivity coeluted with both high and low molecular weight carbohydrates in solution, and with insoluble high molecular weight carbohydrates associated with the algal cell wall. Larvae metamorphosed in response to water conditioned by V. longicaulis, as well as to frozen and homogenized algal tissue. The inducer was efficiently extracted from the algae with boiling water, but after all soluble activity was extracted, residual tissue still induced larval settlement. Ethanol precipitation of a boiled-water extract followed by gel filtration chromatography showed that the precipitate contained carbohydrates of >100,000 Da molecular weight, while the supernatant contained only low molecular weight carbohydrates (<2,000 Da); in both cases all activity was associated with the carbohydrate peak. An aqueous-insoluble 4% NaOH extract was chromatographed in 7 M urea to yield a bioactive high molecular weight carbohydrate peak. Activity was not affected by proteinase K or mild acid hydrolysis, but was significantly decreased by periodate treatment. The results indicate that larvae of A. modesta metamorphose in response to both water-soluble and surface-associated carbohydrates of V. longicaulis, and that the soluble cue exists as both high and low molecular weight isoforms.
This article has been cited by other articles:
![]() |
R. L. Swanson, D. J. Marshall, and P. D. Steinberg Larval desperation and histamine: how simple responses can lead to complex changes in larval behaviour J. Exp. Biol., September 15, 2007; 210(18): 3228 - 3235. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. J. Krug, R. A. Ellingson, R. Burton, and A. Valdes A new poecilogonous species of sea slug (Opisthobranchia: Sacoglossa) from California: comparison with the planktotrophic congener Alderia modesta (Loven, 1844) J. Mollus. Stud., February 1, 2007; 73(1): 29 - 38. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. L. Swanson, J. E. Williamson, R. De Nys, N. Kumar, M. P. Bucknall, and P. D. Steinberg Induction of Settlement of Larvae of the Sea Urchin Holopneustes purpurascens by Histamine From a Host Alga Biol. Bull., June 1, 2004; 206(3): 161 - 172. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Krug and R. Zimmer Developmental dimorphism and expression of chemosensory-mediated behavior: habitat selection by a specialist marine herbivore J. Exp. Biol., January 6, 2000; 203(11): 1741 - 1754. [Abstract] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |