In situ spine sampling and Inter-Simple Sequence Repeat (ISSR) PCRs proved relevant methods for molecular studies on the sea urchin Paracentrotus lividus

In France, there are raising concerns about the edible sea urchin Paracentrotus lividus, whose populations decline. In this context, molecular analyses contribute to the better understanding of processes that shape populations, which is required to adapt management and conservation programmes. The present study aimed at developing an in situ non-destructive spine sampling method and an ISSR-PCR approach, both dedicated to the genetic analysis of individuals and populations. Forty-five individuals of 3 close populations were studied. In situ spine sampling proved relevant, leading to the clear genotyping of all purified DNAs without any contamination. Molecular analysis revealed high genetic diversity with a large proportion of low-frequency ISSR markers. Six ISSR primers produced 154 scorable polymorphic markers of which 118 (77%) were present at a frequency lower than 25%. Based on genotyping profiles obtained with 3 ISSR primers, significant genetic differentiation between the studied populations was detected. Taken together, these results revealed that both in situ spine sampling and ISSR method are relevant for molecular analyses and that they will likely find their application in future conservation and management programmes.

► Underwater (in situ) sea urchin spine sampling is useful for molecular analysis.
► Close populations of sea urchin Paracentrotus lividus were studied (France).
► Inter Simple Sequence Repeats (ISSR) are useful to assess genetic variability.
► In situ sampling strategy and ISSR for population genetic studies were evidenced.
► A moderate but significant genetic differentiation was observed.