GENETIC SELECTIVE BREEDING AND GENOME SEQUENCING OF PENAEID SHRIMP

Since 2008, the local cultured commercial line imported from Chia Tai, Kona Bay and OI (Ocean Institute) were collected, together with our own cultivated "Kehai 1 were selected as the breeding base group. Using the pure line breeding method combined with the cross-test breeding method, the individuals with the high performance in different families were selected. After seven consecutive generations of selection, four lines including fast growth group (A series),  high survival / high fecundity line (B series), high survival / fast line (C series), high fecundity line (D series) were established, and the two-hybrid breeding system were established: the A series were mated with B series to produce the female parent (AB), which shown advantage in growth and survival. The C series and D series were mated to produce male parents (CD), which shown advantage in both fecundity and high survival. AB and CD were mated to produce commercial line (ABCD), which was named as "Guangtai NO.1". The growth rate of Guangtai NO.1 increased by 37% and the survival rate increased by 20% compared with the local breed. In the high-level pool culture mode, the growth rate increased by 16%, breeding survival rate increased by 30% compared with the SIS.

Based on the second and third generation high-throughput sequencing technology, we obtained 828 Gb high quality Illumina data and 133 Gb PacBio sequencing data for Litopeneaus vannamei, covering 319 and 50 times of its genome respectively. The hybrid assembly method which was suitable for the characteristics of high repetition genome were successfully constructed, as as result we assembled the whole genome work frame. The Contig N50 is 57 KB and the Scaffold N50 is 600 KB, with the genome coverage 77%, gene region coverage reached 92%. The genome structure, the characteristics of the shrimp genome and the evolution characteristics of prawn were analyzed with comparative genomics method. Using the methods of integrating genomic method, including transcriptomic and proteomic data, the function genes related to the growth of shrimp, molting and resistance were selected and discovered, including prawn disease resistance related gene: VEGF3, SOCS, thrombospondin, Descam, genes related to the growth of the prawn molting: EH, crustacyanin, IGFB. Use similar method, we have assembled the Penaeus chinesis genome and obtained a better results (the Contig N50 was 53kb, the Scaffolg N50 was 127kb). Further investigation and improvements of the two prawn genomes are still ongoing.