Characterization of microsatellite DNA markers in a critically endangered species, Mekong giant catfish, Pangasianodon gigas

Abstract

Microsatellite DNA markers for a critically endangered Mekong giant catfish (Pangasianodon gigas Roberts and Vidthayanon, 1991) were developed from fin clips collected from captive fish using (GT)15 probe. The number of alleles per locus ranged from two to four. The expected heterozygosities ranged from 0.13 to 0.68. Also, these primers were successfully amplified in four closely related species, Pangasius bocourti, Pangasius conchophilus, Pangasius larnaudii and Pangasius sanitwongsei with the number of alleles per locus ranged from 1 to 13, 1 to 16, 1 to 12 and 1 to 4, respectively. These markers should prove to be very useful for the evaluation of genetic diversity for this species and other related Pangasius species.

Genetic diversity of wild Mekong giant catfish Pangasianodon gigas collected from Thailand and Cambodia

“…Ten microsatellite loci, i.e. Pdgi‐1 , Pdgi‐3 , Pdgi‐4 , Pdgi‐6 , Pdgi‐8 , Pdgi‐ 9, Pdgi‐11 , Pdgi‐20 , Pdgi‐21 and Pdgi‐24 , developed from DNA of Mekong giant catfish were used for the amplification of the microsatellite regions 10 . The polymerase chain reactions (PCRs) were conducted as described in Ngamsiri et al 10 .…”

“…Pdgi‐1 , Pdgi‐3 , Pdgi‐4 , Pdgi‐6 , Pdgi‐8 , Pdgi‐ 9, Pdgi‐11 , Pdgi‐20 , Pdgi‐21 and Pdgi‐24 , developed from DNA of Mekong giant catfish were used for the amplification of the microsatellite regions 10 . The polymerase chain reactions (PCRs) were conducted as described in Ngamsiri et al 10 . The PCR products were separated on 4% polyacrylamide gel, visualized on a FMBIO‐II Multi‐View fluoroimager (Hitachi, Tokyo, Japan), and sized using a CXR fluorescent ladder (Promega, Madison, WI, USA).…”

Inverted migration of rare whisker sheatfish in Nong-Han Lake, northeastern Thailand: Implications for conservation

“…Estimates of recent effective population size (N E ) using linkage disequilibrium (Tallmon et al, 2008) and migration rate and directions for MN and LN populations of whisker sheatfish estimated in BAYESASS (Wilson and Rannala, 2003 (Silurus soldatovi). Surprisingly, the genetic diversity of whisker sheatfish was lower compared to the critically endangered Mekong giant catfish, Pangasainodon gigas, observed by Na-Nakorn et al (2006) and Ngamsiri et al (2006). These authors obtained averages of 0.55 and 0.37 for H O and 0.49 and 0.44 for H E , respectively, for these 2 critically endangered species.…”

“…Microsatellites have been successfully used to estimate genetic variation in wild and hatchery stocks of many fish species (Hogan and May, 2002;Na-Nakorn et al, 2006;So et al, 2006). In Thailand, several freshwater catfish species have been subject to genetic and population structure studies, including the walking catfish (Na-Nakorn et al, 2004), the striped catfish (Na-Nakorn and Moeikum, 2009), and the giant catfish (Na-Nakorn et al, 2006;Ngamsiri et al, 2006); however, such studies have not been conducted on wild populations of whisker sheatfish. Knowledge about the genetic variation and population characteristics of the whisker sheatfish is thus currently unavailable; yet, it is important to obtain genetic information about this species to assist effective fishery management programs and to safeguard the genetic diversity of the species.…”

Isolation and characterization of eight novel microsatellite loci in whisker sheatfish (Micronema bleekeri Günther, 1864)

“…The decline in the distribution of whisker sheatfish populations is due to habitat degradation, overexploitation and geographical barriers during the dry season. In Thailand, genetic diversity and population structure have been studied in other commercial freshwater fish species, such as the walking catfish (Na-Nakorn et al 2004) and the giant catfish Ngamsiri et al 2006), but not for the whisker sheatfish.…”