FOUR CASPASE GENES FROM RED LIP MULLET Liza haematocheilus; CHARACTERIZATION AND IMMUNE RESPONSES AGAINST Lactococcus garvieae

N. C. N. Perera and Jehee Lee
 
E-mail: chathunp@gmail.com
Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self- Governing Province 690-756, Republic of Korea
 

Caspases are a group of conserved cysteine proteases which play vital role in cellular apoptosis. Mammalian caspases are again subdivided into three functional categories as initiator caspases (caspase 2, 8, 9 and 10); executioner caspases (caspase 3, 6 and 7) and inflammatory caspases (caspase 1, 4, 5, 11 and 12). In this study we have selected four caspases from red lip mullet including caspase 3, 7, 8 and 9. Initially, we have characterized all the four caspase members using bioinformatics tools. The tissue specific mRNA expression was then analyzed using healthy rockfish juveniles. An immune challenge was designed in order to determine the immune related responses of these caspases against selected immune stimuli. According to the ExPASy ProtParam tool MuCas3, MuCas7, MuCas8 and MuCas9 consist with 298 aa, 310 aa, 493 aa and 434 aa respectively. Domain architecture analysis revealed that all these four members possess CASc domain which is important for their biological function. According to spatial distribution a ubiquitous expression was observed among all the selected tissues of healthy mullet fish including, blood, head kidney, spleen, liver, gill, intestine, kidney, brain, muscle, skin, heart and stomach but with different magnitudes. Interestingly, the intense expressions of all the four caspases were observed in the blood tissue. Highly modulated expression profiles were observed in the immune challenge analysis by all the four caspase members. MuCas3 and MuCas7 started to up-regulate at 6 h p.i. against LPS and poly I:C. With regarding to the L. garviea MuCas3 and MuCas7 started to up-regulate at 24 h p.i. Interestingly, MuCas8 and MuCas9 has started to up-regulate at 6 h p.i. against LPS where both MuCas8 and MuCas9 has been up-regulated at 24 h p.i. against poly I:C and L. garviae. Collectively, in silico analysis revealed that MuCas3, MuCas7, MuCas8 and MuCas9 sequences are well conserved among the homologs and it shared relatively higher homology with teleosts. Additionally, the modulation of the transcription patterns of all four caspases against immune stimuli suggested that these caspases involve with the immune responses in red lip mullet.