Wang, D., Lu, L., Tian, Y., Li, J., Shen, J., Tao, Z., Li, G. and Xu, N. 2012. Molecular cloning, characterization and expression patterns of heat shock protein 60 (HSP60) in the laying duck (Anas platyrhynchos). Can. J. Anim. Sci. 92: 425-432. In the present study, we cloned and characterized the HSP60 cDNA from Anas platyrhyncho (designated as ApHSP60) using a combination of homology and rapid amplification of cDNA ends (RACE). The full-length of ApHSP60 is 2027 bp in length, with an open reading frame of 1707 bp encoding a putative protein of 569 amino acids. Comparison of amino acid sequences of HSP60 revealed ApHSP60 is highly conserved, especially in the domains of classical HSP60 family signatures. ApHSP60 transcripts were at low expression levels throughout embryo development. ApHSP60 transcripts were constitutively expressed in all tested tissues of untreated laying duck, with a maximum level in the liver. Fluorescent real-time quantitative reverse transcription-polymerase chain reaction was applied to determine ApHSP60 expression after exposure to different thermal shocks. Under long term treatment with both 30°C and 35°C, ApHSP60 transcripts in heart and liver were significantly up-regulated. Otherwise, ApHSP60 transcripts were remarkably down-regulated in heart and liver under acute challenge with 40°C (a fatal temperature for laying duck). A time-dependent expression pattern of ApHSP60 was found in the recovery period after heat shock reaction. ApHSP60 expression levels in liver and heart were immediately up-regulated to the maximum at 1 h post-challenge, and then decreased to pre-challenge levels by 2 h and 3 h post-challenge, respectively. These results suggest that mRNA expression of the ApHSP60 gene is constitutive and inducible. Meanwhile, it plays an important role in response to heat stressors.