Inheritance of behavioral and neuroanatomical phenotypical variance: Hybrid mice are not always more stable than inbreds

Wim E. Crusio
Behav Genet. 2006-01-25; 36(5): 723-731
DOI: 10.1007/s10519-005-9039-2

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1. Behav Genet. 2006 Sep;36(5):723-31.

Inheritance of behavioral and neuroanatomical phenotypical variance: hybrid mice
are not always more stable than inbreds.

Crusio WE(1).

Author information:
(1)Laboratoire de Neurosciences Cognitives, CNRS UMR 5106, Bat B2 – Avenue des
Facultés, 33405 Talence Cedex, France.

Many investigators have attempted to confirm the prediction that increased levels
of heterozygosity entail greater developmental stability, manifesting itself
through decreased phenotypical variation. The evidence presented so far is
equivocal. The predicted relationship has been found in some morphological
studies, but not in others. I propose that the variability of a character should
be seen as different from the character itself. For most morphological
characters, natural selection promotes strong canalization of development but, to
facilitate responses to environmental changes, the organism needs to retain
malleability of physiological and behavioral traits. These different types of
selection should lead to distinct genetic architectures for these phenotypes. I
report on the results of a diallel cross between four inbred mouse strains.
Qualitatively different genetic architectures were in fact revealed for variation
in behaviors in the open-field. In a second study, variances of inbred and hybrid
populations for hippocampal morphometry were studied. Again, hybrids were not
always less variable than inbreds and sometimes even more variable. It follows
that there exists no one-to-one relation between heterozygosity and developmental

DOI: 10.1007/s10519-005-9039-2
PMID: 16435161 [Indexed for MEDLINE]

Auteurs Bordeaux Neurocampus