Genome‐wide association studies reveal genetic loci associated with plasma cholinesterase activity in ducks

Plasma cholinesterase (PCHE) activity is an important auxiliary test in human clinical medicine. It can distinguish liver diseases from non-liver diseases and help detect organophosphorus poisoning. Animal experiments have confirmed that PCHE activity is associated with obesity and hypertension and changes with physiological changes in an animal's body. The objective of this study was to locate the genetic loci responsible for PCHE activity variation in ducks. PCHE activity of Pekin duck × mallard F2 ducks at 3 and 8 weeks of age were analyzed, and genome-wide association studies were conducted. A region of about 1.5 Mb (21.8-23.3 Mb) on duck chromosome 9 was found to be associated with PCHE activity at both 3 and 8 weeks of age. The top SNP, g.22643979C>T in the butyrylcholinesterase (BCHE) gene, was most highly associated with PCHE activity at 3 weeks (-logP = 21.45) and 8 weeks (-logP = 27.60) of age. For the top SNP, the strong associations of CC and CT genotypes with low PCHE activity and the TT genotype with high PCHE activity indicates the dominant inheritance of low PCHE activity. Problems with block inheritance or linkage exist in this region. This study supports that BCHE is a functional gene for determining PCHE levels in ducks and that the genetic variations around this gene can cause phenotypic variations of PCHE activity.