Proteins are under selection to maintain central functions and to accommodate needs that arise in ever-changing environments. The positive selection and neutral drift that preserve functions result in a diversity of protein variants. The amount of diversity differs between proteins: multifunctional or disease-related proteins tend to have fewer variants than proteins involved in some aspects of immunity.
View Article and Find Full Text PDFPhilos Trans R Soc Lond B Biol Sci
August 2022
Supergenes link allelic combinations into non-recombining units known to play an essential role in maintaining adaptive genetic variation. However, because supergenes can be maintained over millions of years by balancing selection and typically exhibit strong recombination suppression, both the underlying functional variants and how the supergenes are formed are largely unknown. Particularly, questions remain over the importance of inversion breakpoint sequences and whether supergenes capture pre-existing adaptive variation or accumulate this following recombination suppression.
View Article and Find Full Text PDFNascent pairs of ecologically differentiated species offer an opportunity to get a better glimpse at the genetic architecture of speciation. Of particular interest is our recent ability to consider a wider range of genomic variants, not only single-nucleotide polymorphisms (SNPs), thanks to long-read sequencing technology. We can now identify structural variants (SVs) such as insertions, deletions and other rearrangements, allowing further insights into the genetic architecture of speciation and how different types of variants are involved in species differentiation.
View Article and Find Full Text PDFSelection, genetic drift, and gene flow affect genetic variation within populations and genetic differences among populations. Both drift and selection tend to decrease variation within populations and increase differences among populations, whereas gene flow increases variation within populations but leads to populations being related. In brown trout (Salmo trutta L.
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