Identification of duck HSP70 gene, polymorphism analysis and tissue expression under control and heat stress conditions.

1. This study was designed to characterise the duck heat shock protein 70 gene (HSP70) and identify sequence variation. 2. Chicken HSP70 sequence (GenBank: AY143693) was used as a template to design a primer pair to amplify partial duck HSP70 gene. Primers were subsequently designed with the duck HSP70 gene as a template to amplify the complete duck HSP70 sequence. 3. Twelve commercial Sanshui White ducklings were subjected to a heat stress experiment. Tissue samples were collected for RNA extraction and real-time PCR to analyse the expression mechanism of duck HSP70. 4. A DNA pool was constructed from three different species for single nucleotide polymorphism (SNP) screening. The genotypes of the identified SNPs were detected in 145 Sanshui White ducklings. 5. Duck HSP70 gene was identified and characterised (GenBank: EU678246) and shown to contain no introns. Fifteen variations were identified within the open reading frame. Quantitative real-time PCR results showed that the expression of duck HSP70 gene was tissue specific and the highest expression level was seen in pectoral muscle.