Microsatellite analysis of genetic variation in sturgeon: New primer sequences for Scaphirhynchus and Acipenser

Low levels of genetic variation at traditional molecular markers have hampe red,genetic research within the family Acipenseridae. In an effort to devel op a large set of polymorphic genetic markers, 172 clones were sequenced fr om three subgenomic libraries of shovelnose sturgeon Scaphirhynchus platory nchus; the libraries were enriched for two dinucleotide and one tetranucleo tide microsatellite motifs (CA, GA, and TAGA). Primers were designed for 11 3 of the sequences and tested against shovelnose sturgeon, pallid sturgeon S. albus, white sturgeon Acipenser transmontanus, lake sturgeon A. fulvesce ns, and green sturgeon A. medirostris. Of the 113 primer sets tested, 96% a mplified in one or more species (58 dimeric and 50 tetrameric). In Scaphirh ynchus species, 93% of all loci amplified, and 76% were polymorphic. Within the individual Acipenser species, 65-80% of loci amplified, with 42-58% be ing polymorphic. Polymorphic systems for Scaphirhynchus species predominate ly displayed simple, disomic banding patterns, while those for Acipenser sp ecies typically displayed banding patterns characteristic of tetraploid or higher polyploid levels. These new microsatellite loci provide a group of g enetic markers that are detectable with noninvasive sampling and that shoul d prove useful in the preservation of threatened and endangered sturgeon sp ecies worldwide.