Pelagic larval duration of the Caribbean wrasse, Thalassoma bifasciatum.

Abstract

was highly specific to Alexandrium when tested against members of three other dinoflagellate genera, Gymnodinium sp. (CCMP1937), Lingulodinium polyedra (GPES22), and Amphidinium carterae (Amphi) (Fig. 1B). The LSU primers were tested on A. fundyense clonal culture DNA, extracted from a range of known cell quantities. QPCR was performed using SYBR green fluorescent dye with amplification conditions established previously from gradient PCR. Successful amplification resulted in a standard curve (Fig. 1C) that compares the PCR cycle number that crosses a designated fluorescence threshold (CT) to cell density (R 2 0.98). The specific rbcL primers designed and tested during this project may be used for further research on rbcL expression to determine if there is a correlation between growth rate and rbcL message abundance. This could be a valuable tool for rapid analysis of Alexandrium growth rate in field populations. The LSU primers described here may be useful for analysis of Alexandrium cell densities within mixed field samples, augmenting our abilities to monitor Alexandrium fundyense population density in the field. Future work is needed to optimize conditions for DNA extraction from mixed samples containing known A. fundyense cell densities. If successful, A. fundyense cell numbers in field samples could be quantified by QPCR determination of LSU abundance through comparison to a standard curve. This work was supported by NSF-REU site grant (OCE0097498), Boston University Marine Program and Woods Hole Oceanographic Institution.