Long-term exposure of adult purple sea urchins, Strongylocentrotus purpuratus, to sunlight protects embryos from ultraviolet radiation


Meeting Abstract

15.8  Monday, Jan. 4  Long-term exposure of adult purple sea urchins, Strongylocentrotus purpuratus, to sunlight protects embryos from ultraviolet radiation ADAMS, N*; CAMPANALE, J; GRAVEM, S; MALLICOAT, A; MALLONEE, M; California Polytechnic State University, San Luis Obispo; ; ; ; nadams@calpoly.edu

Purple sea urchins, Strongylocentrotus purpuratus, were reared on controlled algal diets with or without exposure to natural solar ultraviolet radiation (UVR) in flow-through aquaria at the Cal Poly Center for Coastal Marine Sciences Pier Facility to identify whether we could alter the accumulation of mycosporine-like amino acids (MAAs) in their tissues and whether subsequent eggs and embryos from UV-exposed or MAA-enriched adults varied in resistance to UVR. S. purpuratus, were exposed to one of four solar UVR-MAA diet conditions as follows: 1) –UVR –MAA, 2) –UVR +MAA, 3) +UVR –MAA, 4) +UVR +MAA from October 2007 to February 2008. Each batch of experimental eggs was analyzed for MAA content using HPLC to determine whether there was a correlation between the amount of delay and the concentration of MAAs in eggs. Embryos resulting from the fertilization of remaining eggs were either exposed to or protected from a 60-minute exposure to UVR. All embryos exposed to UVR experienced a delay in mitosis. Delays in division did not correlate with the MAA concentration of each batch of eggs (ANOVA, linear regression, P>0.05). Nevertheless, the concentration of MAAs was considerably lower in these eggs than in previous studies with green sea urchins. Embryos from +UVR adults experienced significantly shorter amount of delay, both in percent and minutes, than those from UV-protected adults (P<0.05). There was no difference in delay due to the diet of adults and there was no interaction in cleavage delay between adult UV-treatment and MAA diet. These data indicate that adult sea urchins exposed to sunlight transmit some protective effect to their eggs and embryos.

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