Protein Repeats Show Clade-Specific Volatility in Aves

Mol Biol (Mosk). 2023 Nov-Dec;57(6):11-20.ABSTRACTProtein repeats are a source of rapid evolutionary and functional novelty. Repeats are crucial in development, neurogenesis, immunity, and disease. Repeat length variability and purity can alter the outcome of a pathway by altering the protein structure and affecting the protein-protein interaction affinity. Such rampant alterations can facilitate species to rapidly adapt to new environments or acquire various morphological/physiological features. With more than 11000 species, the avian clade is one of the most speciose vertebrate clades, with near-ubiquitous distribution globally. Explosive adaptive radiation and functional diversification facilitated the birds to occupy various habitats. High diversity in morphology, physiology, flight pattern, behavior, coloration, and life histories make birds ideal for studying protein repeats' role in evolutionary novelty. Our results demonstrate a similar repeat diversity and proportion of repeats across all the avian orders considered, implying an essential role of repeats in necessary pathways. We detected positively selected sites (PSS) in the polyQ repeat of RUNX2 in the avian clade; and considerable repeat length contraction in the Psittacopasserae. The repeats show a species-wide bias towards a contraction in Galloanseriformes. Interestingly, we detected the length contrast of polyS repeat in PCDH20 between Galli-formes and Anseriformes. We speculate the length variability of seri...
Source: Molekuliarnaia Biologiia - Category: Molecular Biology Authors: Source Type: research