Biotechnology and Bioprocess Engineering 2019; 24(6): 1007-1012  
Comparative Evaluation of Sensitivity to Hexanal Between Human and Canine Olfactory Receptors
Sang Won Cho1 and Tai Hyun Park1,2,*
1School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, Korea
2Institute of Chemical Processes, Seoul National University, Seoul 08826, Korea
Correspondence to: Tai Hyun Park*
Institute of Chemical Processes, Seoul National University, Seoul 08826, Korea
Tel: +82-2-880-8020; Fax: +82-2-875-9348
Received: July 8, 2019; Revised: August 29, 2019; Accepted: September 7, 2019; Published online: December 31, 2019.
© The Korean Society for Biotechnology and Bioengineering. All rights reserved.

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
It is known that a dog possesses much better sense of smell than a human. It has been reported that a dog has advantages (compared to a human) in the number of olfactory receptor (OR) genes, proteins and cells, and also nasal structure. However, a definitive reason for superior sensitivity of the canine olfactory system remains controversial. In this study, we compared sensitivity of human and canine olfactory receptors relative to the same condition. Human OR (hOR2W1) and canine OR (cfOR0312), previously identified to recognize hexanal, were inserted to the pcDNA3 vector. This vector was transfected to HEK293 cells. Hexanal-discriminating ability of ORs was confirmed using Fura-2 AM, a dye which illuminates when binding to calcium ions flowing into cells once olfactory signaling occurs. Consequently, cfOR0312 was more sensitive to hexanal than hOR2W1. Comparison of OR sensitivity would be one of the major factors in clarifying difference of sensitivity between human and canine olfactory systems.
Keywords: canine olfactory receptor, human olfactory receptor, olfactory receptor sensitivity, hexanal

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