title: Toxoplasma gondii infection reduces predator aversion in rats through epigenetic modulation in the host medial amygdala.
abstract: Male rats (Rattus novergicus) infected with protozoan Toxoplasma gondii relinquish their innate aversion to the cat odours. This behavioural change is postulated to increase transmission of the parasite to its definitive felid hosts. Here, we show that the Toxoplasma gondii infection institutes an epigenetic change in the DNA methylation of the arginine vasopressin promoter in the medial amygdala of male rats. Infected animals exhibit hypomethylation of arginine vasopressin promoter, leading to greater expression of this nonapeptide. The infection also results in the greater activation of the vasopressinergic neurons after exposure to the cat odour. Furthermore, we show that loss of fear in the infected animals can be rescued by the systemic hypermethylation and recapitulated by directed hypomethylation in the medial amygdala. These results demonstrate an epigenetic proximate mechanism underlying the extended phenotype in the Rattus novergicus-Toxoplasma gondii association.
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore.
authors.forename: Shantala Arundhati
authors.initials: SA
authors.lastname: Hari Dass
authors.forename: Ajai
authors.initials: A
authors.lastname: Vyas
mesh_terms: D000679:Amygdala / Q000469:parasitology*; D000818:Animals; D001127:Arginine Vasopressin / Q000235:genetics; D001522:Behavior, Animal; D002415:Cats; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005239:Fear; D006790:Host-Parasite Interactions; D008297:Male; D009812:Odorants; D011401:Promoter Regions, Genetic; D051381:Rats; D017208:Rats, Wistar; D014122:Toxoplasma / Q000502:physiology; D014124:Toxoplasmosis, Animal / Q000235:genetics* / Q000469:parasitology
chemical_list: D001127:Arginine Vasopressin
keywords: DNA methylation; arginine vasopressin; behavioural manipulation; extended phenotype; fear; testosterone