TWO BCL-2 FAMILY MEMBERS FROM BIG BELLY SEAHORSE Hippocampus abdominalis; CHARACTERISATION AND IMMUNE RELATED RESPONSES AGAINST BACTERIAL AND VIRAL STIMULI

Apoptosis is an essential mechanism that involved in several biological functions including, developmental sculpturing, removal of unwanted cells and tissue homeostasis. Bcl-2 (B-cell lymphoma-2) family proteins are key regulators of the programmed cell death. Functionally this family can be classified as either pro-apoptotic or anti-apoptotic groups. Herein, we have characterized two cDNA and their translated proteins of Bcl 2-like 1 and Bax from Hippocampus abdominalis. The seahorse Bcl 2-like 1 (HaBcl2-L1) and Bax like (HaBaxL) full-length cDNAs were identified from previously constructed seahorse cDNA library. HaBcl2-L1 and HaBaxL mRNA expression analysis were conducted by performing quantitative real time PCR (qPCR). Heart, gill, liver, spleen, kidney, intestine, stomach, skin, muscle, pouch, brain, testis and ovary were carefully dissected from the healthy juveniles. Besides, gill was isolated after immunization with Edverdiselly tarda, Streptococcus iniae, LPS and Poly I:C. The ORF of HaBcl2-L1 encodes for a putative protein of 232 aa, with a deduced molecular weight of 25.7 kDa polypeptide and a pi of 4.85 where the ORF of HaBaxL encodes a putative protein of 204 aa, a molecular weight of 23.4 kDa and a pi of 5.19. Interestingly, both HaBcl2-L1 and HaBaxL possessed Bcl-2-like conserved domain which is essential for their anti or pro-apoptotic function. Pairwise alignment analysis revealed that HaBcL2-L1 was shared the highest identity with Stegastes partitus (82%) where HaBaxL was shared the highest identity with Larimichthys crocea (81%). A ubiquitous expression was observed in both HaBcL2-L1 and HaBaxL in selected seahorse tissues and their highest expression was observed in the gill tissues. Temporal distribution against E. tarda, S. iniae, LPS and poly I:C revealed a late responses (72 h p.i.). Finally, it could be suggested that HaBxL and HaBcL2-L1 play important role in the defense mechanism of big belly seahorse.