Population Genetic Structure of Pacific White Shrimp (Litopenaeus vannamei) from Mexico to Panama: Microsatellite DNA Variation

Abstract

Genetic variation and population structure of wild white shrimp (Litopenaeus vannamei) from 4 geographic locations from Mexico to Panama were investigated using 5 microsatellite DNA loci. The genetic diversity between populations was indicated by the mean number of alleles per locus and mean observed heterozygosity, which ranged from 7.4 to 8.6 and from 0.241 to 0.388, respectively. Significant departures from Hardy-Weinberg equilibrium were found at most locations at each locus, with the exception Guatemala at Pvan0013, and were caused by high heterozygote deficiencies. Genetic differences between localities were detected by pairwise comparison based on allelic and genotypic frequencies, with the exception of locus Pvan1003. Significant pairwise F (ST) values between locations and total F (ST) showed that the white shrimp population is structured into subpopulations. However, population differentiation does not follow an isolation-by-distance model. Knowledge of the genetic diversity and structure of L.vannamei populations will be of interest for aquaculture and fisheries management to utilize and preserve aquatic biodiversity.

Genetic variability of marine shrimp in the Brazilian industry

“…For commercial penaeid species other than L. vannamei, reported heterozygosities among natural populations, estimated through microsatellite loci, usually reach over 90% (Tsoi et al, 2007;You et al, 2008). However, average values reported for four populations of native L. vannamei from Mexico to Panama were 32 and 68%, for observed and expected heterozygosities, respectively (Valles-Jimenez et al, 2005). The genetic variability reported here for the group of hatcheries surveyed, at this specific point in time, considering the same class of molecular markers, seems to be at a level compatible with that of L. vannamei wild populations.…”

“…Null alleles have been reported for penaeid microsatellite loci (Ball & Chapman, 2003) and may be common for the studied markers (Cruz et al, 2002;Meehan et al, 2003). However, previous analysis performed on wild population samples indicates that the effects of null alleles for some of these markers could be negligible (Valles-Jimenez et al, 2005). In addition to that, the estimates of null alleles by Micro-Checker v2.2.3 are mostly based on the assumption of Hardy-Weinberg equilibrium (Oosterhout et al, 2006), which cannot be immediately assumed for commercial breeding stocks.…”

“…The increasing availability of advanced molecular tools has allowed obtaining new results on the genetics of shrimp broodstocks and natural populations, which have been accumulating quickly since the mid 1990's (Ball & Chapman, 2003;Francisco & Galetti Junior, 2005;Valles-Jimenez et al, 2005). DNA microsatellites have been the basis of the majority of the recent approaches.…”

“…They are considered ideal markers for characterizing inbreeding and for pedigree studies and, therefore, have been widely used to monitor genetic diversity in aquaculture species (Koljonen et al, 2002;Skaala et al, 2004). However, penaeid shrimp microsatellites have sometimes proven difficult to type and validate, and null alleles are often observed (Valles-Jimenez et al, 2005).…”

Cloning, characterization, and expression of the macrophage migration inhibitory factor gene from the Pacific white shrimp Litopenaeus vannamei (Penaeidae)

“…The Pacific white shrimp, Litopenaeus vannamei (Lee, 1931), has become the leading farm crustacean species in the world (Valles-Jimenez et al, 2004). Because of its huge economic value and important evolutionary status, an increasing number of studies have focused on the biology, physiology, genetics, and immunology of L. vannamei in recent years (Shen et al, 2007;Ciobanu et al, 2010;Gorbach et al, 2010).…”