Meeting Abstract

P2.23  Tuesday, Jan. 5  Does temperature affect Whole Body Regeneration (WBR) rate in Botrylloides spp? PINNICK, G.L.*; COHEN, C.S.; San Francisco State University; San Francisco State University sarahcoh@sfsu.edu

Botryllid ascidians, colonial marine chordates, possess unique modes of propagating and regenerating that make robust models for studying the biological pathways for tissue regeneration. Here, we test the effect of temperature on regeneration ability and rate, as mediated by the retinoic acid (RA) pathway that is common in chordate embryonic development. Colonies of Botrylloides sp from 2 sites in San Francisco Bay with differing seasonal salinity and temperature regimes were compared. A total of 10 genotypes were used to create 33 ampullar clumps (1-6 clumps per genotype) that consisted solely of ampullar tissue with all zooids removed. Ampullar fragments were treated with retinoic acid and regeneration was observed at 3 temperatures. WBR (regeneration of an entire functional zooid) occurred rapidly, within 1-4 days. This temperature also accounted for the majority of zooids produced across the 10 day observation period. At 13 and 23 degrees, multiple zooids (1-4 zooids) were produced within a single ampullar clump. The second most productive temperature was 13 degC, which produced WBR of zooids within 5-8 days. The intermediate temperature had the highest rate of non-regeneration across all ampullar clumps, together with the highest mortality rate. WBR of botryllid zooids from ampullar fragments occurred at all 3 temperatures within 5 days with 2 out of 4 genotypes successfully regenerating in all treatments. Temperature may have an effect on WBR in this species, with the warmest temperature producing the most zooids in the shortest time in this series of experiments.