Isolation and characterization of 18 polymorphic microsatellite markers for the critically endangered stellate sturgeon, Acipenser stellatus

The stellate sturgeon, Acipenser stellatus, is a critically endangered fish species. Knowledge on its genetic diversity and population structure is urgently needed to enable the identification of management units in order to prevent extinction. Therefore, 18 species-specific, polymorphic microsatellite loci have been isolated using GS-FLX Titanium pyrosequencing, arranged into 6 multiplex PCR sets, and characterized in 52 individuals (20 farmed and 32 wild). The total number of alleles per locus varied between 3 and 36 with an average of 8.44. The wild individuals were more diverse with an average number of 8.17 alleles per locus than the farmed ones with 3.28 alleles per locus. Observed heterozygosities ranged from 0.050 to 0.950 in the farmed and from 0.094 to 0.969 in the wild individuals. Significant deviations from Hardy-Weinberg equilibrium were found at 3 loci of the farmed and 5 loci of the wild individuals. The two sturgeon groups were significantly differentiated (FST = 0.118). The high sensitivity and discriminatory power of the 18 loci were proven by a very low overall probability of identity for siblings (PIsib = 8.73 × 10−6) and a high accuracy of self-classification (98%). Thus, these newly developed markers represent a valuable genetic toolbox to identify management units for species conservation and sustainable fisheries.