RNA preservation of Antarctic marine invertebrates

Fifteen species of marine invertebrate commonly occurring in the near-shore environment of Rothera base, Antarctica, were used to test tissue sample storage protocols with regard to preservation of RNA integrity. After animal collection, the tissues were either immediately extracted for RNA or stored at -80C after having been, either directly flash frozen in liquid nitrogen or preserved in a commercial RNA storage solution, for extraction in the UK. In four cases, direct flash freezing produced enhanced RNA integrity compared with samples in the commercial storage solution. A subset of samples were further tested for the preferred temperature of storage in the commercial reagent. RNA integrity was well preserved at both ?4 and -20C over periods of 2 months, but degradation was rapid in tissues stored at room temperature. Eight out of the fifteen species only produced a single ribosomal band on gel electrophoresis. This survey provides a guide for tissue transport of Polar cold water marine invertebrates. Keywords Tissue preservation Tissue transport 28 s ribosomal RNA Echinoderms Molluscs Introduction RNA preservation is sometimes problematic in non-model species but this is particularly the case when dealing with environmental species. Logistical issues often surround the ability to effectively preserve field-collected samples for RNA analyses. Whilst rapid flash freezing in liquid nitrogen generally solves this problem, it is not often available because of the remote nature of the work. Even when such a facility is available on site at a field station, it usually cannot be transported to the actual, more remote specimen collection site. Also, -80C storage may not be possible during transportation from the field site to the main research institute, often thousands of miles away. Antarctic specimens have the additional issue of operating at temperatures that most species would consider cold and hence cool stow is less effective at reducing tissue degradation than with, for example, those taken from mammalian species. Hence, we decided to carry out a study of effective storage protocols for the most common invertebrates found in the near-shore marine environment in Marguerite Bay close to Rothera research station, Antarctica.

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