Location: Warmwater Aquaculture Research Unit
Title: Genetic diversity of cultured and wild populations of the freshwater prawn Macrobrachium rosenbergii based on microsatellite analysis Authors
|Schneider, Kyle -|
|Tidwell, James -|
|Gomelsky, Boris -|
|Pomper, Kirk -|
|Saillant, Eric -|
|Mather, Peter -|
Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 27, 2012
Publication Date: N/A
Interpretive Summary: Most culture of freshwater prawn, Macrobrachium rosenbergii, in the Western hemisphere is based on 36 individuals brought from Malaysia to Hawaii in the 1960’s. The goal of this research was to characterize the current genetic relationships of cultured prawns in North America. Researchers from Kentucky State University, in collaboration with researchers from the USDA, ARS, Catfish Genetics Research Unit in Stoneville, MS, obtained DNA fingerprint data on cultured prawns from two wild populations (Myanmar and India) and seven cultured populations (Hawaii, Kentucky, Mississippi, and Texas; India and Israel). Analysis revealed that the wild populations were distinct from the Hawaiian populations, and both were distinct from the Kentucky, Mississippi, and Texas populations. The findings of this research will be beneficial to ensure future stock stability and provide a baseline genetic assessment for selective breeding.
Technical Abstract: Freshwater prawn Macrobrachium rosenbergii culture in the Western Hemisphere is primarily, if not entirely, based on thirty-six individual prawn introduced to Hawaii from Malaysia in 1965 and 1966. Little information is available regarding the genetic background or current population status of cultured prawns. The goal of this research was to genetically characterize different prawn populations with an emphasis on those cultured North American. Five Microsatellite loci were utilized to evaluated genetic diversity in two wild (Myanmar and India) and seven cultured (Hawaii-1, Hawaii-2, India, Israel, Kentucky, Mississippi and Texas) populations of the freshwater prawn. A total of 128 different alleles were amplified over all five primers. The average number of alleles per locus ranged from 4.00 (Israel) to 22.20 (Myanmar) and average allelic richness ranged from 3.96 (Israel) to 20.45 (Myanmar). Average observed heterozygosity ranged from 0.657 (Kentucky) to 0.919 (Myanmar) and average expected heterozygosity ranged from 0.580 (Israel) to 0.935 (Myanmar). Many of the cultured populations exhibited reduced genetic diversity when compared to the Myanmar and the India-cultured population. Overall estimates of fixation index Fst (0.157) revealed moderately high levels of overall differentiation between the populations. An Un-weighted Pair Group Method with Arithmetic Mean (UPGMA) dendrogram revealed three separate clusters, illustrating relatively close relationships between some populations. The first cluster included the two Hawaii populations. The second cluster included the wild Myanmar and India-cultured populations and the third cluster consisted of the Kentucky, Mississippi and Texas populations. The findings of this research will be beneficial to ensure future stock stability and provide a baseline genetic assessment for selective breeding.