Covariance between direct and maternal genetic effects in mice, with a model of persistent environmental influences

Abstract

SummaryCovariance between direct and maternal genetic effects on body weight in random-bred ICR mice at 2 through 10 weeks of age was estimated from cross-fostering experiments. The covariance contributes only a few percent of phenotypic variance at 2 weeks, but increases to 10–15% at later ages. Nearly all estimates are positive. We suggest that genes active during later parts of growth affect maternal performance more than those active during early growth, causing increased covariance at later ages. A model of combined genetic and persistent environmental effects on maternal performance is presented. Persistent effects of genetic or environmental variation in recent ancestors can influence covariance between relatives and response to selection.

Contribution of maternal effect QTL to genetic architecture of early growth in mice

“…Variance in early growth was partitioned into four components (dam, nurse-dam, dam-bynurse-dam interaction and residual variance) using restricted maximum likelihood (REML) in the Mixed pro- Riska et al, 1985). Upper and lower confidence limits (␣ = 0.05) on the estimated variance components were estimated using Wald Z-scores and normal quantiles (see SAS  Institute Inc, 1992 for details).…”

“…Upper and lower confidence limits (␣ = 0.05) on the estimated variance components were estimated using Wald Z-scores and normal quantiles (see SAS  Institute Inc, 1992 for details). The dam component (V dam ) is an estimate of the covariance of full-sibs raised by different dams and has an expected value of: V m(post) , the postnatal maternal effect variance, which includes both genetic and non-genetic sources of maternal effects (Riska et al, 1985). The dam-by-nurse-dam interaction term is an estimate of the interaction variance of the dam effect (direct genetic effects and the pre-natal maternal effect) with the nursedam effect (postnatal maternal effect).…”

“…The dam-by-nurse-dam interaction term is an estimate of the interaction variance of the dam effect (direct genetic effects and the pre-natal maternal effect) with the nursedam effect (postnatal maternal effect). This term can be seen as an estimate of half the genotype-by-maternalenvironment interaction (Legates, 1972;Riska et al, 1985).…”

“…The genetic covariance between direct and maternal effects [cov(A o , A m )] was estimated following the approach of Riska et al (1985); see also Newman et al (1989). This approach relies on the fact that the expected covariance of full sibs raised by their own mother contains the direct-maternal genetic covariance, while the covariance of full sibs nursed by an unrelated dam does not.…”

Within- and between-generation effects of temperature on early fecundity of Drosophila melanogaster

“…Many life-history traits of organisms are affected by maternal (Riska et al, 1985;Kirkpatrick & Lande, 1989;Daan et al, 1990;Mousseau & Dingle, 1991) and even paternal (Giesel, 1988) environments. Significant cross-generational effects have important implications (Mousseau & Dingle, 1991) not only for the design of experiments to estimate heritability (Riska et al, 1989), but also for attempts to predict short-term evolutionary responses to selection (Kirkpatrick & Lande, 1989).…”