The phrase "under high constraint" is correct and can be used in written English.
You can use it when you want to convey that someone is feeling pressure or difficulty due to a certain situation or condition. For example, "The students were working under high constraint to finish the project before the deadline."
As for the evolutionary rate, our results suggest that in consideration of a long-term evolution, duplicated genes may be under higher evolutionary constraints compared to singleton genes, and among those duplicated genes, those having AS are the ones actually under higher constraints compared to those having no AS.
We reasoned that if these observations are biologically meaningful, then gene pairs under high evolutionary constraint would show limited co-expression divergence in the two parasite groups.
A large fraction of genes was found to be under high selective constraint, as most of the expressed genes appeared to be involved in developmental gene regulation.
One powerful strategy to dissect the regulatory genome has been to identify regions under high sequence constraint (Lindblad-Toh et al., 2011).
Except the sequences with high Ka/Ks, many sequences had Ka/Ks values equal to or only slightly greater than zero, suggesting that these genes have evolved under high selective constraint (See additional file 4) [ 39].
To produce the evolutionary constraint profile, the rates were then converted to relative constraint by normalizing to a range between 0 and 1, inverted by subtracting from 1 (because a region of low evolutionary rate is under high evolutionary constraint), and plotted against the position in the protein.
Genes that are under the highest constraint will have negative log2 Vg/Vm) ratios reflecting that expression variation is being removed by purifying selection.
Analyses demonstrate photosynthetic genes are under the highest constraint of any genes within the plastid genomes of Cuscuta, indicating a function involving RuBisCo and electron transport through photosystems is still the primary reason for retention of the plastid genome in these species.
The proteins involved in this vital process are under high functional constraints.
Given the functional relevance of these genes, it is expected that they are under high selective constraints.
