Op-molb140139 2267..2282
نویسندگان
چکیده
Partially recessive variants under positive selection are expected to go to fixation more quickly on the X chromosome as a result of hemizygosity, an effect known as faster-X. Conversely, purifying selection is expected to reduce substitution rates more effectively on the X chromosome. Previous work in humans contrasted divergence on the autosomes and X chromosome, with results tending to support the faster-X effect. However, no study has yet incorporated both divergence and polymorphism to quantify the effects of both purifying and positive selection, which are opposing forces with respect to divergence. In this study, we develop a framework that integrates previously developed theory addressing differential rates of X and autosomal evolution with methods that jointly estimate the level of purifying and positive selection via modeling of the distribution of fitness effects (DFE). We then utilize this framework to estimate the proportion of nonsynonymous substitutions fixed by positive selection (a) using exome sequence data from a West African population. We find that varying the female to male breeding ratio (b) has minimal impact on the DFE for the X chromosome, especially when compared with the effect of varying the dominance coefficient of deleterious alleles (h). Estimates of a range from 46% to 51% and from 4% to 24% for the X chromosome and autosomes, respectively. While dependent on h, the magnitude of the difference between a values estimated for these two systems is highly statistically significant over a range of biologically realistic parameter values, suggesting faster-X has been operating in humans.
منابع مشابه
Beringian Brown Bears Dynamics of Pleistocene Population Extinctions in
http://www.sciencemag.org/cgi/content/full/295/5563/2267 version of this article at: including high-resolution figures, can be found in the online Updated information and services, http://www.sciencemag.org/cgi/content/full/295/5563/2267/DC1 can be found at: Supporting Online Material found at: can be related to this article A list of selected additional articles on the Science Web sites http:/...
متن کاملOn the edge-density of 4-critical graphs
Gallai conjectured that every 4-critical graph on n vertices has at least 53n − 23 edges. We prove this conjecture for 4-critical graphs in which the subgraph induced by vertices of degree 3 is connected.
متن کاملLipid molecular shape affects erythrocyte morphology: a study involving replacement of native phosphatidylcholine with different species followed by treatment of cells with sphingomyelinase C or phospholipase A2
In a previous report it was shown that the replacement of native erythrocyte phosphatidylcholine (PC) with different PC species which have defined acyl chain compositions can lead to morphological changes (Kuypers, F.A., W. Berendsen, B. Roelofsen, J. A. F. Op den Kamp, and L.L.M. van Deenen, 1984, J. Cell Biol., 99:2260-2267). It was proposed that differences in molecular shape between the int...
متن کاملOpsec Working Group
Service Provider Infrastructure Security draft-ietf-opsec-infrastructure-security-00 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2014