Understanding the lipopolysaccharide induced liver proteome changes and identification of immune genes in Lampetra morii

Lamprey is considered to be an excellent model for studying the origin of adaptive immunity. In the present study, three up-regulated and ten down-regulated proteins were identified in the lipopolysaccharide (LPS) induced liver proteome of Lampetra morii. Quantitative real-time PCR (qPCR) was used to characterize in the liver the abundance of transcripts encoding the differentially expressed proteins. The abundance of transcripts and the corresponding differentially expressed proteins revealed that expression of cystathionase and Zgc:112210-201 was not correlated with protein expression level. Polyl 4-hydroxylase, serum lectin, Zgc:112210-201, and cofilin 1 mRNA expression was significantly upregulated in liver tissue after treatment with LPS. Transcript abundance of differentially expressed proteins in the gill, kidney, heart, intestine, liver, and supraneural body was determined. Transcripts of Zgc:112210-201 were almost undetectable in the tissues while polyl 4-hydroxylase, protein disulfide isomerase family A (member 4), cystathionase, and serum lectin were low abundance unlike the protein which was easily detected. This study represents the first attempt at understanding the LPS induced liver proteome of L. morii and our findings contribute to the identification of novel immune genes in lamprey.