关于智商有关的遗传因素的不同表达，反映了一种倾向性：母亲的基因表达涉及胎儿成
长、新陈代谢、脂肪储存，而父亲的基因表达调控着成人的社会行为。
Nature. 2011 Jan 27;469(7331):534-8.
Distinct physiological and behavioural functions for parental alleles
of imprinted Grb10.
Garfield AS, Cowley M, Smith FM, Moorwood K, Stewart-Cox JE, Gilroy K,
Baker S, Xia J, Dalley JW, Hurst LD, Wilkinson LS, Isles AR, Ward A.
Department of Biology & Biochemistry and Centre for Regenerative
Medicine, University of Bath, Claverton Down, Bath BA2 7AY, UK.
Abstract
Imprinted genes, defined by their preferential expression of a single
parental allele, represent a subset of the mammalian genome and often
have key roles in embryonic development, but also postnatal functions
including energy homeostasis and behaviour. When the two parental
alleles are unequally represented within a social group (when there is
sex bias in dispersal and/or variance in reproductive success),
imprinted genes may evolve to modulate social behaviour, although so
far no such instance is known. Predominantly expressed from the
maternal allele during embryogenesis, Grb10 encodes an intracellular
adaptor protein that can interact with several receptor tyrosine
kinases and downstream signalling molecules. Here we demonstrate that
within the brain Grb10 is expressed from the paternal allele from
fetal life into adulthood and that ablation of this expression
engenders increased social dominance specifically among other aspects
of social behaviour, a finding supported by the observed increase in
allogrooming by paternal Grb10-deficient animals. Grb10 is, therefore,
the first example of an imprinted gene that regulates social
behaviour. It is also currently alone in exhibiting imprinted
expression from each of the parental alleles in a tissue-specific
manner, as loss of the peripherally expressed maternal allele leads to
significant fetal and placental overgrowth. Thus Grb10 is, so far, a
unique imprinted gene, able to influence distinct physiological
processes, fetal growth and adult behaviour, owing to actions of the
two parental alleles in different tissues.
