Association between Polymorphism rs1799732 of DRD2 Dopamine Receptor Gene and Personality Traits among MMA Athletes

Four factors—namely, harm avoidance, novelty seeking, reward addiction and persistence—represent the nature of temperament that is not genetically determined in itself. It was shown in earlier studies that a strong propensity to look for novelty or a tendency to engage in risky behavior is correlated with genetic variants in the area of the genes encoding dopamine receptors. Therefore, the aim of this study is to determine whether there is a relationship between personality traits and genetic variants in the area of the DRD2 dopamine receptor gene in MMA athletes. The participants consisted of 85 mixed martial arts (MMA) athletes and 284 healthy, non-MMA male participants. Their personality traits were measured using the Revised Temperament and Character Inventory. Blood was collected for genetic assays and all samples were genotyped using the real-time PCR method. We observed a statistically significant effect of a complex factor of the DRD2 rs1799732 genotype on MMA participants’ control and reward dependence. Engaging in high-risk sport may be associated with several personality characteristics. The DRD2 rs1799732 polymorphism may be associated with reduced harm avoidance in martial arts athletes, thereby modulating athletes’ predisposition to participate in high-risk sport.

The possible role of dopamine receptors DOP-1 and DOP-3 in behavior thermotolerance regulation of Caenorhabditis elegans Maupas

The paper investigates dopamine influence on the tolerance of swimming, induced by mechanical stimulus, to the temperature of 36C during the experiments with nematodes of wild type strain N2 and mutant strains LX636 ( dop-1 ( vs101 )) and LX703 ( dop-3 ( vs106 )) with null-mutations of genes of dopamine receptors DOP-1 and DOP-3. The authors have shown that dopamine in concentrations 0,5-1,0 mM increased the behavior thermotolerance of C. elegans while in concentrations 7,5-15,0 dopamine caused its decrease. Null-mutation of dopamine receptor gene dop-3 prevented the decrease of C. elegans thermotolerance by dopamine. On the contrary, null-mutation of dopamine receptor gene dop-1 caused significant rise in sensitivity of behavior thermotolerance to dopamine. In connection with well-known conceptions assuming that the reason of heat damage of C. elegans behavior is acetylcholine deficiency due to inhibition of its secretion by hyperthermia, the dopamine influence on behavior thermotolerance can be accounted for the dopamine influence on acetylcholine secretion by motor neurons. It is known that in C. elegans motor neurons the coexpression of genes of receptors DOP-1 and DOP-3 takes place. Activation of these receptors in turn causes opposite changes in dopamine secretion.