This model suggests that 31% of sites are under positive selection (ω2 = 2.00), while half (54%) are under weak purifying selection (ω1 = 0.6) and the other 15% constrained under extreme purifying selection (ω0 = 0.01) (listed in table 4).
Although 5′-UTR may have been under weaker purifying selection, the 5′-UTR is important for the regulation of translation in eukaryotes.
Consistent with a smaller Ne in D. miranda, a larger fraction of newly arising synonymous mutations are under weaker purifying selection in this species (i.e., 1 < Ne s < 100; see fig. 2).
Using functional clustering based on gene ontology annotation of gene pairs, we show that some duplicated genes, such as defense response genes, are under weaker purifying selection or under stronger diversifying selection than other duplicated genes, such as protein translation genes, as measured by the ratio of nonsynonymous to synonymous divergence (dN/ dS).
Specifically, we have shown that human disease genes with vertebrate-specific origins tend to be under weaker levels of purifying selection within mammals than human disease genes of pre-vertebrate origins.
With respect to the set of k loci, when the covariance between q eq (1− q eq ) s and t/ s is negative, alleles under weak purifying selection or positive selection in sex 2 will contribute disproportionately to disease in sex 1.
As high divergence is a hallmark of relaxin sequences, it is somewhat unsurprising that RLN2 is under only weak purifying selection.
Thus it remains unresolved, whether Latimeria v1r genes are truly under neutral selection, or merely under weak purifying selection, undetected by the stringent search criteria applied.
