[Abstract Title]. - Society for Neuroscience

Support: NIH Grant T32 MH75880
NIH Grant R01MH072956
Title: Epigenetic contribution to sex differences in the brain
Authors: *J. KURIAN, K. M. OLESEN, A. P. AUGER;
Psychol, Univ. Wisconsin-Madison, Madison, WI
Abstract: Early experience, such as maternal care, is known to modify gender typical rat
behaviors including juvenile social and adult sexual behaviors (Olesen, in preparation; Cameron,
2008). The mechanisms associated with these modifications are not understood, however, it is
likely that an epigenetic mechanism such as DNA methylation of specific gene promoters is
involved. For example, natural variations in maternal care are associated with differential ERα
promoter DNA methylation and gene expression in female pups (Champagne, 2006). As
maternal anogenital licking is also naturally sexually dimorphic, with males experiencing more
than female pups, we chose to examine the methylation patterns of ERα in males and females.
Bisulfite sequencing of the stat5b region of this promoter indicated ERα promoter methylation in
the anterior hypothalamus is sexually dimorphic on post-natal day 8 (PN8), with males
exhibiting greater methylation than females. This methylation pattern was correlated with ERα
mRNA and protein expression such that increased methylation was associated with decreased
expression. Interestingly, methylation of this promoter was increased and ERα expression was
decreased in PN8 females that were either treated with estradiol (two 100µg peripheral injections
on PN0-1) or simulated maternal grooming (SMG). These data suggest that sexually dimorphic
gene expression in a region associated with gender typical rat behavior can be modified through
epigenetic mechanisms. They further suggest that internal (i.e. hormonal) and external cues from
the social environment converge within the developing brain to modify DNA and have lasting
effects on social development.
Disclosures: J. Kurian , None; A.P. Auger, None; K.M. Olesen, None.
Poster
278. Sex Differences I
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 278.18/MM11
Topic: E.01.d. Development
Support: Natural Sciences and Engineering Research Council of Canada