Flow cytometric analysis of DNA content for four commercially important crabs in China

The genome size (C-value) of an organism is referring to the DNA content of its non-replicated haploid chromosome complement, generally deduced from measuring somatic diploid nuclei. We presented genome size (C-value) data obtained by flow cytometry for four commercially important crabs (Portunus trituberculatus, Charybdis japonica, Scylla paramamosain, and Eriocheir sinensis) common in the coast of China. Gallus domesticus (2C=2.5 pg ) was used as the internal standard. The results showed that the C-value for P. trituberculatus, C. japonica, S. paramamosain, and E. sinensis were (2.31 +/- 0.01) pg, (2.33 +/- 0.03) pg, (1.64 +/- 0.02) pg, and (2.29 +/- 0.03) pg, respectively. The C-value of P. trituberculatus, C. japonica and S. paramamosain were reported for the first time. The data represented by the four species indicated that they had lower DNA contents than average DNA values in crustaceans ((4.99 +/- 0.48) pg), and three of the four values were very similar if not identical. The results provide useful data for future studies in the fields of biodiversity, species conservation, and phylogeny of these commercial crabs. They will also be helpful in instructing the hybridization breeding program and estimating the cost of the whole genome sequencing project.