Hypothalamic expression of Peg3 gene is associated with maternal care differences between SM/J and LG/J mouse strains

Brain and Behavior

Silvana Chiavegatto⁴  Bruno Sauce³  Guilherme Ambar¹  James M. Cheverud² 

[1]Department and Institute of Psychiatry, University of Sao Paulo Medical School, Sao Paulo, SP, Brazil

[2]Department of Anatomy and Neurobiology, Washington University School of Medicine, 63110, St. Louis, Missouri

[3]Department of Genetics and Evolution, Biological Science and Health Center, Federal University of Sao Carlos, Sao Carlos, SP, Brazil

[4]Department of Pharmacology, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil

关键词: Chromosome;    epigenetic;    FosB;    gene expression;    gene variation;    hypothalamus;    imprinting;    maternal behavior;    Oxt;    QTL;   

DOI  :  10.1002/brb3.58

来源: Wiley

【 摘 要 】

Abstract

Maternal care is essential in mammals, and variations in the environment provided by mothers may directly influence the viability of newborns and emotional behavior later in life. A previous study investigated genetic variations associated with maternal care in an intercross of LG/J and SM/J inbred mouse strains and identified two single-locus QTLs (quantitative trait loci). Here, we selected three candidate genes located within these QTLs intervals; Oxt on chromosome 2, and FosB and Peg3 on chromosome 7 and tested their association with maternal care. LG/J females showed impaired postpartum nest building and pup retrieval, a one-day delay in milk ejection, reduced exploratory activity, and higher anxiety-like behavior when compared to SM/J females. The nucleotide sequences of Oxt and FosB were similar between strains, as were their hypothalamic expression levels. Conversely, Peg3 nucleotide sequences showed four nonsynonymous replacement substitutions on LG/J dams, T11062G, G13744A, A13808G, and G13813A, and a 30 base pair (10 aa) in tandem repeat in the coding region with three copies in SM/J and five copies in LG/J. Maternal care impaired LG/J mothers express 37% lower Peg3 mRNA levels in the hypothalamus on the second postpartum day. We also found an association of the Peg3 repeat-variant and poor maternal care in F₂ heterozygote females derived from a LG/J × SM/J intercross. These results may suggest that the maternally imprinted Peg3 gene is responsible for the single-locus QTL on chromosome 7 that has been shown to influence maternal care in these strains. Furthermore, these data provide additional support for an epigenetic regulation of maternal behavior.

【 授权许可】

CC BY-NC   
© 2012 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.

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