DNA MICROSATELLITE-BASED EVALUATION OF GENETIC DIVERSITY OF STRAIN GI MACRO II (GENETIC IMPROVEMENT OF  MACROBRACHIUM II)      

Fajar Anggraeni*, Hary Krettiawan, Asep Sopian, Huria Marnis, Khairul Syahputra and Imron
 
Research Institute for Fish Breeding
Jalan Raya 2 Sukamandi Pantura
Patokbeusi, Subang 41263
West Java, Indonesia
anggra_xl@yahoo.com

Five microsatellite DNA loci were used to assess genetic diversity of strain GI Macro II.  Strain GI Macro II has been set up through individual selection on growth character. GI Macro II has formed by four strains of prawns nature geographically came from different places, Barito, Musi, Asahan and Ciasem and strain prawns GI Macro.  Overall, these strains is a strain of prawns in western Indonesia. Otherwise, GI Macro is a strain of freshwater prawn was released in 2001. The purpose of this study was to evaluated genetic diversity of GI Macro II one of strain freshwater prawn using DNA microsatellite.

Twenty five sample of freshwater prawn was extracted from swimmeret tissues using GenejetTM Genomic DNA Purification (Fermentas) commercial kit. Five microsatellite primers (Mbr-2, Mbr-3, Mbr-4, Mbr-5 and Mbr-9 with accession numbers DQ019864.1, DQ019865.1, DQ019866.1, DQ019867.1, and DQ019873.1) developed from M. Rosenbergii genomic library were used to amplify DNA samples as described by Charoentawee et al. (2006). PCR reactions were performed in 25 μl reactions which used Type-It™ Microsatellite, Qiagen. The PCR profile was initial denaturation at 95 °C for 5 min; then 30 cycles of 95 °C for 30 s, annealing temperature for 90 s, and extention 72 °C for 30 s; then final extention 1 cycle of 60 °C for 30 min. Following amplification, PCR products were fragment analyzed using qiaxcel screning gel.

Genetic characteristics of GI Macro II has obtained from analyzes using markers microsattelite presented in Table 1. Genetic parameters profile of this population such as the Hardy-Weinberg equilibrium (HW), fixation index (Fis), observed heterozygosity (Ho) and expected heterozygosity (He) all confirmed that the selection process has occurred. For example, parameter P (HW) on an ideal natural populations, ie population size is very large, the mating process occurs randomly, no migration and selection occurs, the value is not significant, which means that the population in balance genetically. Instead the p-value of  (HW) significantly show that the population in the genetic imbalances. In this case an imbalance occurs because of the selection process. Similarly, Ho value lower  than  He and Fis positive values, ​​all of which are typical of populations experiencing genetic code selection. The selection process of the growth character has been fixing some alleles resulting in lower observed heterozygosity and improve fixation index (Fis) so that is positive.