DNA Fragmentation in Blue Mussel Gametes: Aquaculture and Fisheries Implications

The objective of the present study was to assess sperm DNA longevity in Blue Mussels (BM) (Mytilus edulis) using a dynamic assessment of sperm DNA fragmentation (SDF) after sperm activation. Mature BM (n=57) in Vigo (Galicia, Spain) were obtained, specifically, rope farmed BM (n=38) and wild BM (n=19). After sperm collection, a subsample was assessed for SDF (0 h) while the rest of the sample was incubated for 6, 9, 12, 24 and 48h at 15ºC, assessing each time point using the Sperm-Halomax kit (Halotech DNA, Madrid, Spain) with GelRed™ (Biotium, Hayward, CA, USA). The Kaplan-Meier estimator, Log Rank (Mantel-Cox) test, and Mann-Whitney U test were used for statistical analyses (SPSS v.16.0), α=0.05. The rate of SDF (r-SDF) between both groups 0-6 h was not significantly different (P=0.278), but was for 6-24 h (P=0.004). Differences in r-SDF were observed when comparing the means between the two groups (P<0.0001). Individual differences in r-SDF existed among the rope farmed (P<0.0001) and wild BM (P<0.0001). Wild BM presented a higher DNA longevity than the farmed BM. Selection of BM males with a low level of sperm DNA damage and greater sperm DNA longevity may help to obtain better fertilization and seed production.