Evaluation of Seven Microsatellite DNA Markers for Their Genetic Variation and Application to Paternity Determination in Pacific White Shrimp, Penaeus vannamei

Pacific white shrimp, Penaeus vannamei, is the most economically important shrimp species farmed worldwide, constituting about 75%  of global farmed shrimp production.  P. vannamei has been bred for commercially valuable traits such as growth rate and disease resistance. However, selectively bred shrimp populations are susceptible to inbreeding. DNA-based testing can be used for pedigree tracking to control inbreeding. Microsatellite DNA markers have been an effective genetic tool for parental assignment. The main objective of this research was to evaluate 7 microsatellite DNA markers (Pvan 0013, Pvan 1003, Pvan 1758, Pvan 1815, M1, TUGAPv 7-9.115, and TUGAPv 7-9.132) and determine the paternity of 9 families of shrimp progeny. All microsatellite markers were highly polymorphic, with more than 4 alleles and PIC of more than 0.5.  The expected heterozygosities of these microsatellite markers, except M1, were also above 0.5.  Among all microsatellites, Pvan 1758 was the most highly polymorphic marker having the highest PIC value of 0.814, highest expected heterozygosity of 0.840, and the most number of alleles (k =7). The power of exclusion per locus was not high when microsatellites were individually evaluated, and ranged from 0.186 to 0.665 when the genotype of one parent or the dam was known However, when all 7 microsatellites were evaluated together, the combined exclusion probabilities increased to 0.974 for known dam, and 0.874 for unknown both parents.  This suggests that these 7 microsatellite markers are highly polymorphic and appropriate for paternal determination in P. vannamei breeding programs.