[Identification of a myeloid differentiation factor 88 (MyD88) in against infection].

OBJECTIVE

To identify a myeloid differentiation factor 88 (MyD88) in , and characterize the role of MyD88 against infection.

METHODS

The complete cDNA of MyD88 in was obtained by using rapid amplification of cDNA ends (RACE), and homologues sequences and conserved domains were aligned and the structure of MyD88 was predicted either. A phylogenetic tree of MyD88 was further constructed with other species. In addition, the mRNA expression level of MyD88 before and after infection was investigated by real-time quantitative PCR (RT-qPCR).

RESULTS

The cDNA of MyD88 consisted of 1 406 bp open reading frame (ORF), encoding 468 amino acid residues, which contained death domain and Toll/interlrukin-1 receptor (TIR) domain, the typical features of MyD88 family proteins. The predicted amino acid sequence of MyD88 shared 38%-52% identity with other mollusc. MyD88 was phylogenetically closeted to Biomphalaria glabrata MyD88. The MyD88 existed in all selected tissues and expressed highly in hemocyte, up-regulated after infection in all selected tissues except cephalopodium, especially higher in whole snail and hemocyte.

CONCLUSIONS

MyD88-dependent signaling pathway is present in and plays an important role in innate immune response against infection.