The direction of the effect was opposite to the male specific effect found in a meta-analysis investigating the association between the val66met polymorphism and major depression (Verhagen et al. 2010).
Further, these animal studies suggest that male-specific effects of pyrethroid exposure on the brain dopamine system underlie the observed sexual dimorphism in behavioral effects [ 23, 24].
This effect could be partially caused by the greater percentage of genes encoding very long proteins in the flower-specific dataset or by greater male-specific effects on codon usage for genes encoding longer proteins.
It would be worthwhile investigating both male-specific effects on egg hatch-rate and progenic sex ratio, as well as screening larger numbers of males and females for Rickettsia presence and testing for variation in bacterial density in FB and SR families of this species.
These results, as well as other male-specific effects such as foxo mutation interaction with p53 [ 20], should generally not be impacted by the positive effects of mifepristone in females reported here, and the opposing effects of p53 on life span in males and females is supported by analysis of endogenous p53 mutations [ 18].
For C. remanei, male-specific effects were tested by comparing P1 and P2 measures in a particular cross combination in order to estimate whether males from a particular strain performed better as first and/or second males compared to those of another strain.
Our hypothesis of the male-specific effect is the male only have single copy of MAOA, thus the carrying of risk haplotype lead more contribution to the diseased state.
Our results show that QTLs on Chr 2T, Chr 3, Chr 4 and Chr 13 have a male-specific effect, and the QTL on Chr 7T has a female-specific effect.
Various studies have shown a male-specific effect of exposure to smoking/nicotine in utero on development and on gene methylation in the offspring; we, therefore, hypothesized that effects would be more apparent in boys than girls.
Specifically, we consider a model of homogeneity (β M = β F ) as well as three models of heterogeneity: (i) male-specific effect (β F = 0); (ii) same direction effects (β F = 2β M ); and (iii) opposite direction effects (β F = −β M ).
That no similar effect was found for IQ is surprising: COMT genotype has a strong, male-specific effect on verbal IQ in this sample [Barnett et al., 2007[, and previous evidence has supported an effect of MAOA on IQ but not measures of executive function [Yu et al., 2005[.
