MOLECULAR CHARACTERIZATION AND EXPRESSION PROFILE OF CASPASE-7 FROM BLACK ROCKFISH, Sebastes schlegelii

Seongdo Lee*, Minyoung Oh, Sukkyoung Lee, Jiyeon Ko, Eunyoung Jo, Jehee Lee
 
Department of Marine Life Sciences,
School of Marine Biomedical Sciences,
Jeju National University,
Jeju Self-Governing province,
690-756,
Republic of Korea
lsd0081@gamil.com

Apoptosis is known as one of the programmed cell death types that regulate many biological processes including the development, growth and immune responses. Caspases or aspartate-specific cysteine proteases (Caspase) are central components of inflammation and apoptosis. Caspase 7 can serve as an executioner caspase in caspase depended death cascade pathways in animals. Herein, caspase-7 gene (designated as SScasp-7) was molecular characterized from black rockfish, Sebastes schlegelii which is an economically important species in East Asia region, encountering considerable production loss due to pathogen infections. The main objectives of this study, to investigate the immune modulation of SScasp-7 in host immunity and facilitate the disease management strategies SScasp-7 was identified from our previously constructed cDNA database. In silico analysis was conducted to compere the evolutionary relationship of SScasp-7 with other species. Real-time quantitative PCR was performed to investigate the tissue distribution of SScasp-7 and transcriptional response of SScasp-7 upon immune challenge. The full-length SScasp-7 was 2972 bp consisting of 924 bp open reading frame encoding 308 amino acids. The SScasp-7 had calculated molecular mass of 35.0 kDa and isoelectric point (PI) of 5.23. The SScasp-7 contains Caspase family p20 domain, Caspase family p10 domain, Caspase family histidine active site 134 HSDSSCFACILLSHG191, Caspase family cysteine active site 180 KPKLFFIQACRG191. The SScasp-7 was ubiquitously expressed in all tissues examined and the highest expression level was detected in blood. According to the Pairwise sequence alignment, SScasp-7 exhibited 94.5%, 94.2% identity with Rainbow trout, European seabass respectively. Phylogenetic analysis showed that SScasp-7 had a closer evolutionary proximity with it counterpart from Atlantic salmon. After immune stimulation with Streptococcus iniae (S.iniae) and polyinosinic:polycytidylic (Poly I:C), SScasp-7 mRNA expression was significantly up-regulated in liver.