A NOVEL SATELLITE MICROSATELLITE COMBINATION IN THE GENOME OF THE MARINE SHRIMP, PENAEUS-VANNAMEI/

In our studies of repeated sequences in the genome of the marine shrim p, Penaeus vannamei (Pv), we have discovered a novel combination of se quence elements. We inserted restriction fragments of genomic DNA into a plasmid vector and screened for recombinant plasmids containing rep eated sequences. Ten of the resulting isolates contained representativ es of the same repeated element, a satellite sequence present in one o r more blocks of tandemly repeated units. The cloned repeat units rang e in size from 139 to 188 bp. Embedded within each cloned repeat unit are 6-15 copies of a tandemly repeated pentanucleotide microsatellite. The genome of Pv contains approx. 1 000 000 copies of this satellite/ microsatellite unit. Sequences that cross-hybridize strongly with this structure were found in the genomes of lobster and crayfish, but not in other species of the genus Penaeus.