Identification and characterization of myostatin in litopenaeus stylirostris

The overall objective of this research was to identify and characterize the myostatin or myostatin-like gene sequence in the commercially important aquaculture species Litopenaeus stylirostris. Myostatin is a negative regulator of muscle growth and when disrupted can cause a "double muscled" phenotype (McPherron et al., 1997). Two main approaches were taken: the first was to isolate an mRNA (eDNA) copy and the second was to identify a genomic copy of the gene. The methodologies used were a eDNA PCR screen, screening a genomic library and a genomic PCR screen. Our results indicate there is at least one form of the TGF-B superfamily of genes present in the L. stylirostris genome. The isolated gene fragment is an exact match to the L. vannamei TGF-B sequence. Additional characterization of our sequence indicates that it most closely resembles a BMP6 type TGF-B gene. Our fragment is located in the 3' highly conserved C terminus region, common to all TGF-B gene members, and just downstream of the proteolytic processing site. This research lays the groundwork and provides promising progress towards the isolation and characterization of important TGF-B genes in L. stylirostris that potentially control or regulate growth in this important aquaculture shrimp. The characterization of growth related genes from an animal of commercial importance such as L. stylirostris can lead to important contributions that will positively impact the shrimp aquaculture industry. Key words: Litopenaeus stylirostris, shrimp, myostatin, transforming growth factor beta superfamily (TGF-B).