Sentence examples for more selective constraints from inspiring English sources

Given that synonymous sites can be subject to selection for specific tRNA anticodons, one might expect them to be under more selective constraints than intergenic regions; therefore, it is not surprising that nucleotide diversity for the intergenic regions is greater than πsyn.

These results reveal a dual character of promoters during evolution: they exert more impact on gene divergence, and meanwhile, they are subject to more selective constraints.

These results may suggest more selective constraints in upstream genes than in downstream genes; however, we did not find a significant correlation between rates of sequence divergence and pathway position for any of the branches of the pathway studied.

More specifically, the first domain was found to evolve under more selective constraints, with a mean ω value being significantly lower than those observed for domain II, domain III or the rest of the sequence (Mann-Whitney P < 0.05, Additional file 6: Table S2 and Additional file 7: Table S3).

This may reflect either 1) more selective constraints on intergenic sequences than intronic, i.e. parts of the annotated intergenic sequences are indeed genic, or 2) a bias in the construction of the human-mouse alignment that make it easier to align sequence close to the conserved exons so that somewhat more divergent intronic sequence can be detected.

That is, compared to the genome-wide levels of selective pressure, genes that were identified as involved in cold response based on functional studies (i.e., CRG genes) displayed significantly lower levels of selective pressure, while cold responsive (CGO) genes were under more selective constraints.

For example, as shown in Table 1, the ω estimate (ω0) assigned to site class 1 (strong purifying selection) suggests that there has been more selective constraint on UCP2, which is expressed in many tissues, than on UCP3, which is expressed in just a few tissues [ 15, 16].

Given the numerous reports that have shown that first introns tend to be under more selective constraint (see Introduction), it seems likely that there could be many different sequence elements present in these early introns.

The UTR regions shows more selective constraint than introns.

The proportion of polymorphic sites (Table 1, last column) is similar among protein coding genes and lower for RNA coding genes, which are under more selective constraint.

Our results therefore suggest that the correlation between expression divergence and protein divergence is not directly linked to between-gene variation in one or more specific gene characteristics but instead is the result of more general selective constraints on gene function.