Various genetic news have called my attention today.
From the latest PLoS ONE:
Bad prospects for genetic-association medicine.
Yudi Pawitan et al. throw cold water to the hopes of getting simple Mendelian gene-disease associations and even discovering them at all:
Assuming similar allele frequencies and effect sizes of the currently validated SNPs, complex phenotypes such as type-2 diabetes would need approximately 800 variants to explain its 40% heritability. Much smaller numbers of variants are needed if we assume rare-variants but higher penetrance models. We estimate that up to 50,000 cases and an equal number of controls are needed to discover 800 common low-penetrant variants among the top 5000 SNPs. Under common and rare low-penetrance models, the very large studies required to discover the numerous variants are probably at the limit of practical feasibility.
Eigenvectors versus Principal Components.
Jun Zhang et al. argue that Laplacian eigenvector analysis and their LAPSTRUCT method provides better analysis of population structure than the "classical" but somewhat limited Principal Components Analysis (PCA).
From Human Reproduction:
Two mothers, no father mice live even longer.
M. Kawahara and T. Kono found that two-mother (2M) mice live some 20% longer on average than normal mice, having smaller and more slender bodies and much better antioxidative processes. They argue that this may be caused by a gene at chromosome 9, which is generally activated at pregnancy to act by the father side, but in this case, without father, the epigenetics is activated differently resulting in these sturdier and smaller mice (all female, of course).
This story (found originally at Science Daily) made me recall the radical feminist S.C.U.M. Manifesto by the late Valerie Solanas and her defense of a female-only humankind. The technology for in vitro female-female reproduction is available (and has been for long) but illegal in humans for obvious ideological reasons (patriarchy, homophobia). On light of these results and the widespread desire for longer and healthier lives, one wonders if Ms. Solanas was not more correct than even she herself believed.
All three papers are freely available (links in text).