Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 8 (1), e992743

Extended Epigenotype in a Rattus Novergicus - Toxoplasma Gondii Association


Extended Epigenotype in a Rattus Novergicus - Toxoplasma Gondii Association

Ajai Vyas. Commun Integr Biol.


Several studies demonstrate that rats (Rattus novergicus) infected with protozoan parasite Toxoplasma gondii exhibit lesser fear to cat odors. This is thought to increase transmission of the parasite to its definitive hosts, i.e. cats. This is an example of extended phenotype where a gene of an organism allegedly creates a phenotype in another organism. We examined a possible proximate mechanism for this phenotype, describing an epigenetic change in arginine vasopressin gene in medial amygdala of male rats. Exogenously mimicking medial amygdala DNA hypomethylation resulted in reduction of fear to cat odors in uninfected animals, thus suggesting sufficiency. Systemic blockade of infection-induced DNA hypomethylation countermanded infection-induced behavioral change, thus suggesting necessity. This leads us to propose an epigenetic basis for this extended phenotype.

Keywords: DNA methylation; MSRE; behavioral manipulation; fear; nonapeptide; parasite; testosterone.

Similar articles

See all similar articles


    1. Thomas F, Adamo S, Moore J. Parasitic manipulation: where are we and where should we go? Behav Processes 2005; 68:185-99; PMID:15792688; - DOI - PubMed
    1. Vyas A, Sapolsky R. Manipulation of host behaviour by Toxoplasma gondii: what is the minimum a proposed proximate mechanism should explain? Folia Parasitol 2010; 57:88-94; PMID:20608470; - DOI - PubMed
    1. Webster JP, McConkey GA. Toxoplasma gondii-altered host behaviour: clues as to mechanism of action. Folia Parasitol 2010; 57:95-104; PMID:20608471; - DOI - PubMed
    1. Berdoy M, Webster JP, Macdonald D. Fatal attraction in rats infected with Toxoplasma gondii. Proc Biol Sci 2000; 267:1591-4; PMID:11007336; - DOI - PMC - PubMed
    1. Vyas A, Kim S-K, Giacomini N, Boothroyd JC, Sapolsky RM. Behavioral changes induced by Toxoplasma infection of rodents are highly specific to aversion of cat odors. Proc Natl Acad Sci 2007; 104:6442-7; PMID:17404235; - DOI - PMC - PubMed

LinkOut - more resources