Molecular cloning and expression analysis of cDNA ends of chicken neuropathy target esterase.

Neuropathy target esterase (NTE) was proposed as the initial target during the process of organophosphate-induced delayed neuropathy (OPIDN) in human and some sensitive animals. Adult hens are usually the animal model for experimental studies of OPIDN. However, little is known about the sequence and characteristics of chicken NTE. We report here the cloning of the 5' and 3' cDNA ends of chicken NTE through rapid amplification of cDNA ends (RACE) and their expression profiles in different tissues with northern blotting. The cloned 3' cDNA end of chicken NTE is 801 base pair (bp) in length with an open reading frame (ORF) of 379 bp. It contains a termination codon (TAG) and a 422-nucleotide noncoding sequence with the polyA sequence (GenBank accession no. DQ126678). The chicken NTE 5' cDNA end is 665 bp in length with an ORF of 552 bp. It contains an initiation codon (ATG) and a 113-bp untranslated region (GenBank accession no. DQ126677). The deduced proteins from 5' and 3' cDNA ends have a high degree of homology to humans and mouse NTE at the amino acid level. Chicken NTE is suggested to be a transmembrane protein by the transmembrane helix prediction of the deduced N-terminal sequence. The chicken NTE gene is expressed as a 4.5k b transcript in different tissues, including brain, kidney, liver and testis. Moreover, the mRNA expression of chicken NTE is highest in brain, and the mRNA levels of chicken NTE in testis, kidney and liver are about 75%, 47% and 24% of that in brain, respectively. These results should be helpful in cloning chicken full-length NTE gene.