Abstract # 2422 Poster # 33:

Scheduled for Thursday, June 19, 2008 05:00 PM-07:00 PM: Session 4 (Ball Rooms A and B) Poster Presentation

Association of Self Injurious Behavior in Rhesus Macaques with a Polymorphism in the Tryptophan Hydroxylase 2 Gene but not with a Polymorphism in the Serotonin Transporter Promoter

J. A. Henderson, K. Coleman and C. L. Bethea
Oregon National Primate Research Center, 505 NW 185th Ave, Beaverton, OR 97006, USA
     Several lines of evidence suggest a dysregulation of the serotonergic system is involved in the expression of self injurious behavior (SIB) in both human and non-human primates. We recently reported that macaques which exhibited SIB had higher tryptophan hydroxylase (TPH) protein levels and lower serotonin transporter (5HTT) protein levels than monkeys that did not exhibit SIB. We hypothesized that polymorphisms in the TPH-2 and rh5HTT genes would be associated with the expression of SIB. Genomic DNA samples of 64 non-SIB and 45 SIB rhesus macaques, Macaca mulatta, were acquired from the Genetic Research Program of the Oregon National Primate Research Center. Genotyping was accomplished with polymerase chain reaction followed by agarose gel electrophoresis visualization. Using a Fishers Exact Test we found a significant association between 3’-UTR TPH-2 alleles and SIB expression [2 sided a=0.05]. Monkeys exhibiting SIB were more likely to be ss than sl. Additionally, all of the monkeys expressing the sl genotype had low overall SIB scores while all of the animals with higher overall SIB scores expressed the ss genotype. A Chi-Squared Test found no association between rh5HTTLPR alleles and SIB [c2(2)=1.4, p=0.49] and allelic frequency did not appear to vary with overall SIB score. The TPH-2 polymorphism may be one mechanism by which serotonergic function is altered in SIB.