scholarly journals Relationship between amino acid changes in mitochondrial ATP6 and life-history variation in anguillid eels

2015 ◽  
Vol 11 (3) ◽  
pp. 20150014 ◽  
Author(s):  
Magnus W. Jacobsen ◽  
José Martin Pujolar ◽  
Michael M. Hansen
Keyword(s):  
Life History ◽  
Amino Acid ◽  
Positive Selection ◽  
Structural Changes ◽  
Life History Variation ◽  
Phase Duration ◽  
Larval Phase ◽  
Physico Chemical ◽  
Oxidative Phosphorylation Pathway ◽  
Positive Correlations

Mitochondrial genes are part of the oxidative phosphorylation pathway and important for energy production. Although evidence for positive selection at the mitochondrial level exists, few studies have investigated the link between amino acid changes and phenotype. Here we test the hypothesis that differences in two life-history related traits, migratory distance between spawning and foraging areas and larval phase duration, are associated with divergent selection within the mitochondrial ATP6 gene in anguillid eels. We compare amino acid changes among 18 species with the sequence of the putative ancestral species, believed to have shown short migratory distance and larval phase duration. We find positive correlations between both life-history related traits and (i) the number of amino acid changes and (ii) the strength of the combined physico-chemical and structural changes at positions previously identified as candidates for positive selection. This supports a link between genotype and phenotype driven by positive selection at ATP6.

scholarly journals An amino acid polymorphism in theDrosophilainsulin receptor demonstrates pleiotropic and adaptive function in life history traits

2014 ◽  
Author(s):  
Annalise B. Paaby ◽  
Alan O. Bergland ◽  
Emily L. Behrman ◽  
Paul S. Schmidt
Keyword(s):  
Life History ◽  
Amino Acid ◽  
Insulin Signaling ◽  
Evolutionary Biology ◽  
Life History Variation ◽  
Amino Acid Polymorphism ◽  
The North ◽  
Functional Regions ◽  
Climatic Environment ◽  
Life History Tradeoffs

Finding the specific nucleotides that underlie adaptive variation is a major goal in evolutionary biology, but polygenic traits pose a challenge because the complex genotype-phenotype relationship can obscure the effects of individual alleles. However, natural selection working in large wild populations can shift allele frequencies and indicate functional regions of the genome. Previously, we showed that the two most common alleles of a complex amino acid insertion-deletion polymorphism in theDrosophilainsulin receptor show independent, parallel clines in frequency across the North American and Australian continents. Here, we report that the cline is stable over at least a five-year period and that the polymorphism also demonstrates temporal shifts in allele frequency concurrent with seasonal change. We tested the alleles for effects on levels of insulin signaling, fecundity, development time, body size, stress tolerance, and lifespan. We find that the alleles are associated with predictable differences in these traits, consistent with patterns ofDrosophilalife history variation across geography that likely reflect adaptation to the heterogeneous climatic environment. These results implicate insulin signaling as a major mediator of life history adaptation inDrosophila, and suggest that life history tradeoffs can be explained by extensive pleiotropy at a single locus.

scholarly journals Positive selection on the killer whale mitogenome

2010 ◽  
Vol 7 (1) ◽  
pp. 116-118 ◽  
Author(s):  
Andrew D. Foote ◽  
Phillip A. Morin ◽  
John W. Durban ◽  
Robert L. Pitman ◽  
Paul Wade ◽  
...  
Keyword(s):  
Amino Acid ◽  
Positive Selection ◽  
Killer Whale ◽  
Functional Change ◽  
Ecological Niches ◽  
Physico Chemical ◽  
Pack Ice ◽  
Metabolic Performance ◽  
Property Changes ◽  
The Antarctic

Mitochondria produce up to 95 per cent of the eukaryotic cell's energy. The coding genes of the mitochondrial DNA may therefore evolve under selection owing to metabolic requirements. The killer whale, Orcinus orca , is polymorphic, has a global distribution and occupies a range of ecological niches. It is therefore a suitable organism for testing this hypothesis. We compared a global dataset of the complete mitochondrial genomes of 139 individuals for amino acid changes that were associated with radical physico-chemical property changes and were influenced by positive selection. Two such selected non-synonymous amino acid changes were found; one in each of two ecotypes that inhabit the Antarctic pack ice. Both substitutions were associated with changes in local polarity, increased steric constraints and α-helical tendencies that could influence overall metabolic performance, suggesting a functional change.

scholarly journals Molecular Evolution in Large Steps—Codon Substitutions under Positive Selection

2019 ◽  
Vol 36 (9) ◽  
pp. 1862-1873 ◽  
Author(s):  
Qingjian Chen ◽  
Ziwen He ◽  
Ao Lan ◽  
Xu Shen ◽  
Haijun Wen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Molecular Evolution ◽  
Positive Selection ◽  
Negative Selection ◽  
Chemical Properties ◽  
Molecular Models ◽  
Step Size ◽  
Biochemical Basis ◽  
Physico Chemical ◽  
Adaptive Signal

AbstractMolecular evolution is believed to proceed in small steps. The step size can be defined by a distance reflecting physico-chemical disparities between amino acid (AA) pairs that can be exchanged by single 1-bp mutations. We show that AA substitution rates are strongly and negatively correlated with this distance but only when positive selection is relatively weak. We use the McDonald and Kreitman test to separate the influences of positive and negative selection. While negative selection is indeed stronger on AA substitutions generating larger changes in chemical properties of AAs, positive selection operates by different rules. For 65 of the 75 possible pairs, positive selection is comparable in strength regardless of AA distance. However, the ten pairs under the strongest positive selection all exhibit large leaps in chemical properties. Five of the ten pairs are shared between Drosophila and Hominoids, thus hinting at a common but modest biochemical basis of adaptation across taxa. The hypothesis that adaptive changes often take large functional steps will need to be extensively tested. If validated, molecular models will need to better integrate positive and negative selection in the search for adaptive signal.

Biological Function and Chemistry of Endothelin. A Review

1999 ◽  
Vol 64 (8) ◽  
pp. 1211-1252 ◽  
Author(s):  
Jan Hlaváček ◽  
Renáta Marcová
Keyword(s):  
Biological Activity ◽  
Amino Acid ◽  
Biological Function ◽  
Biological Properties ◽  
Structural Basis ◽  
Amino Acid Residues ◽  
Snake Venoms ◽  
Vasoactive Peptides ◽  
Physico Chemical ◽  
Endothelin A

The first part of this review deals with the biosynthesis and a biological function of strongly vasoactive peptides named endothelins (ETs) including vasoactive intestinal contractor. Where it was useful, snake venoms sarafotoxins which are structural endothelin derivatives, were also mentioned. In the second part, an attention is paid to structural basis of the ETs biological activity, with respect to alterations of amino acid residues in the parent peptides modifying the conformation and consequently the physico-chemical and biological properties in corresponding ETs analogs. Special attention is focussed on the area of ETs receptors and their interaction with peptide and non peptide agonists and antagonists, important in designing selective inhibitors of ETs receptors potentially applicable as drugs in a medicine. A review with 182 references.

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