Genome evolution trend of common carp ( Cyprinus carpio L.) as revealed by the analysis of microsatellite loci in a gynogentic family

Abstract

Genome evolution arises from two main ways of duplication and reduction. Fish specific genome duplication (FSGD) may have occurred before the radiation of the teleosts. Common carp ( Cyprinus carpio L.) has been considered to be a tetraploid species, because of its chromosome numbers (2n=100) and its high DNA content. Using 69 microsatellite primer pairs, the variations were studied to better understand the genome evolution (genome duplication and diploidization) of common carp from a gynogenetic family. About 48% of primer pairs were estimated to amplify duplicates based on the number of PCR amplification per individual. Segregation patterns in the family suggested a partially duplicated genome structure and disomic inheritance. This indicates that the common carp is tetraploid and polyploidy occurred by allotetraploidy. Two primer pairs (HLJ021 and HLJ332) were estimated to amplify reduction based on the number of PCR amplification per individual. One allele in HLJ002 locus and HLJ332 locus was clearly lost in the gynogenetic family and the same as in six wild populations. Segregation patterns in the family suggested a partially diplodization genome structure. A hypothesis transition (dynamic) and equilibrium (static) were proposed to explain the common carp genome evolution between genome duplication and diploidization.