Analysis of differential gene expression by SRAP-cDNA in mantle tissue of Meretrix petechialis with different external shell color.

Gene expression of two shell colors in Meretrix petechialis were analyzed by sequence related amplified polymorphism-cDNA to screen the associated molecular markers. The two shell color genomes of M. petechialis were amplified using combinations of 30 primers; 11 pairs of primers showed differential fragments, and by recovery, cloning and sequencing, 18 different differential sequences were obtained. The sequencing results were analyzed by BlastX. Only one fragment shared high homology with memory-related protein-2 and TonB-dependent receptor was found that related to shell color. Sequence characterized amplified region primers were designed according to the difference sequences, and PCR amplification was performed in both 'yellow' and 'red' M. petechialis. Four pairs of differential primers were obtained. Using the population to verify the four markers (Me1-Em2, Me2-Em3, Me4-The Em11 and Me4-Em12), it was found that Me1-Em2 and Me2-Em3 were positive in the 'yellow' and Me4-The Em11 and Me4-Em12 were positive in the 'red' M. petechialis populations. All four markers can, therefore, be used as M. petechialis shell color related markers. This provides a theoretical basis for studying shell color regulation in M. petechialis, which may help to reveal the underlying molecular mechanisms more comprehensively.