Parental Care, Destabilizing Selection, and the Evolution of Tetrapod Endothermy

Physiology ◽  
2020 ◽  
Vol 35 (3) ◽  
pp. 160-176 ◽  
Author(s):  
C. G. Farmer
Keyword(s):  
Parental Care ◽  
Positive Selection ◽  
Convergent Evolution ◽  
Terrestrial Environment ◽  
Strong Positive Selection ◽  
Selection For ◽  
Destabilizing Selection

Parental care has evolved convergently an extraordinary number of times among tetrapods that reproduce terrestrially, suggesting strong positive selection for this behavior in the terrestrial environment. This review speculates that destabilizing selection on parental care, and especially embryo incubation, drove the convergent evolution of many tetrapod traits, including endothermy.

scholarly journals Retinal transcriptome sequencing sheds light on the adaptation to nocturnal and diurnal lifestyles in raptors

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yonghua Wu ◽  
Elizabeth A. Hadly ◽  
Wenjia Teng ◽  
Yuyang Hao ◽  
Wei Liang ◽  
...  
Keyword(s):  
Positive Selection ◽  
Transcriptome Sequencing ◽  
Bright Light ◽  
Photon Absorption ◽  
Evolutionary Analysis ◽  
Night Time ◽  
Low Light ◽  
Strong Positive Selection ◽  
Nocturnal Vision ◽  
Selection For

Abstract Owls (Strigiformes) represent a fascinating group of birds that are the ecological night-time counterparts to diurnal raptors (Accipitriformes). The nocturnality of owls, unusual within birds, has favored an exceptional visual system that is highly tuned for hunting at night, yet the molecular basis for this adaptation is lacking. Here, using a comparative evolutionary analysis of 120 vision genes obtained by retinal transcriptome sequencing, we found strong positive selection for low-light vision genes in owls, which contributes to their remarkable nocturnal vision. Not surprisingly, we detected gene loss of the violet/ultraviolet-sensitive opsin (SWS1) in all owls we studied, but two other color vision genes, the red-sensitive LWS and the blue-sensitive SWS2, were found to be under strong positive selection, which may be linked to the spectral tunings of these genes toward maximizing photon absorption in crepuscular conditions. We also detected the only other positively selected genes associated with motion detection in falcons and positively selected genes associated with bright-light vision and eye protection in other diurnal raptors (Accipitriformes). Our results suggest the adaptive evolution of vision genes reflect differentiated activity time and distinct hunting behaviors.

scholarly journals A novel positive selection for identifying cold-sensitive myosin II mutants in Dictyostelium.

Genetics ◽  
1995 ◽  
Vol 140 (2) ◽  
pp. 505-515 ◽  
Author(s):  
B Patterson ◽  
J A Spudich
Keyword(s):  
Positive Selection ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Time Scale ◽  
Myosin Ii ◽  
Rapid Onset ◽  
Chemical Mutagenesis ◽  
Wild Type ◽  
Cold Sensitive ◽  
Selection For

Abstract We developed a positive selection for myosin heavy chain mutants in Dictyostelium. This selection is based on the fact that brief exposure to azide causes wild-type cells to release from the substrate, whereas myosin null cells remain adherent. This procedure assays myosin function on a time scale of minutes and has therefore allowed us to select rapid-onset cold-sensitive mutants after random chemical mutagenesis of Dictyostelium cells. We developed a rapid technique for determining which mutations lie in sequences of the myosin gene that encode the head (motor) domain and localized 27 of 34 mutants to this domain. We recovered the appropriate sequences from five of the mutants and demonstrated that they retain their cold-sensitive properties when expressed from extrachromosomal plasmids.

scholarly journals Evolution and lineage dynamics of a transmissible cancer in Tasmanian devils

PLoS Biology ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. e3000926 ◽  
Author(s):  
Young Mi Kwon ◽  
Kevin Gori ◽  
Naomi Park ◽  
Nicole Potts ◽  
Kate Swift ◽  
...  
Keyword(s):  
Positive Selection ◽  
Cancer Cells ◽  
Cell Lines ◽  
Copy Number ◽  
Convergent Evolution ◽  
Evolutionary History ◽  
Genome Instability ◽  
Copy Number Variants ◽  
Tasmanian Devil ◽  
Transmissible Cancer

Devil facial tumour 1 (DFT1) is a transmissible cancer clone endangering the Tasmanian devil. The expansion of DFT1 across Tasmania has been documented, but little is known of its evolutionary history. We analysed genomes of 648 DFT1 tumours collected throughout the disease range between 2003 and 2018. DFT1 diverged early into five clades, three spreading widely and two failing to persist. One clade has replaced others at several sites, and rates of DFT1 coinfection are high. DFT1 gradually accumulates copy number variants (CNVs), and its telomere lengths are short but constant. Recurrent CNVs reveal genes under positive selection, sites of genome instability, and repeated loss of a small derived chromosome. Cultured DFT1 cell lines have increased CNV frequency and undergo highly reproducible convergent evolution. Overall, DFT1 is a remarkably stable lineage whose genome illustrates how cancer cells adapt to diverse environments and persist in a parasitic niche.

scholarly journals Is formal employment sector hereditary? Determinants of formal/informal sector choice for Mexican male workers

2019 ◽  
pp. 91-121
Author(s):  
Adelaido García-Andrés ◽  
Ernesto Aguayo-Téllez ◽  
Jose N. Martínez
Keyword(s):  
Positive Selection ◽  
Social Mobility ◽  
Informal Sector ◽  
Formal Sector ◽  
Strong Connection ◽  
Employment Sector ◽  
Formal Employment ◽  
Selection For ◽  
The Relationship ◽  
Employment Choices

Understanding the relationship between parents’ and sons’ formal employment is essential for promoting social mobility in Mexico. Using the 2011 Survey of Social Mobility in Mexico (EMOVI), this paper contributes to the literature by addressing the intergenerational mobility of employment. Findings show a strong connection between intergenerational employment choices and suggest a positive selection for workers. Individuals with parents who worked in the formal sector are more likely to be enrolled in formal work and vice versa. Also, after controlling for parent’s employment sector, schooling remains as a significant vehicle to transit to the formal sector.

scholarly journals Positive Selection on Two Mitochondrial Coding Genes and Adaptation Signals in Hares (Genus Lepus) from China

2020 ◽  
Author(s):  
Asma Awadi ◽  
Hichem Ben Slimen ◽  
Helmut Schaschl ◽  
Felix Knauer ◽  
Franz Suchentrunk
Keyword(s):  
Amino Acid ◽  
Positive Selection ◽  
Protein Function ◽  
Transmembrane Domain ◽  
Proton Translocation ◽  
Introgressive Hybridization ◽  
Vibrational Entropy ◽  
Mutant Type ◽  
Selection For ◽  
Protein Variants

Abstract Background: Animal mitochondria play a central role in energy production in the cells through the oxidative phosphorylation (OXPHOS) pathway. Recent studies of selection on different mitochondrial OXPHOS genes have revealed the adaptive implications of amino acid changes in these subunits. In hares, climatic variation and/or introgression were suggested to be at the origin of such adaptation. Here we looked for evidence of positive selection in three mitochondrial OXPHOS genes, using tests of selection, protein structure modelling and effects of amino acid substitutions on the protein function and stability. We also used statistical models to test for climate and introgression effects on sites under positive selection. Results: Our results revealed seven sites under positive selection in ND4 and three sites in Cytb. However, no sites under positive selection were observed in the COX1 gene. All three subunits presented a high number of codons under negative selection. Sites under positive selection were mapped on the tridimensional structure of the predicted models for the respective mitochondrial subunit. Of the ten amino acid replacements inferred to have evolved under positive selection for both subunits, six were located in the transmembrane domain. On the other hand, three codons were identified as sites lining proton translocation channels. Furthermore, four codons were identified as destabilizing with a significant variation of Δ vibrational entropy energy between wild and mutant type. Moreover, the PROVEAN analysis suggested that among all positively selected sites two fixed amino acid replacements altered the protein functioning. The statistical model runs indicated significant effects of climate on the presence of ND4 and Cytb protein variants, but no effect by trans-specific mitochondrial DNA introgresson.Conclusions: Positive selection was observed in several codons in two OXPHOS genes. We found that substitutions in the positively selected codons have structural and functional impacts on the encoded proteins. Our results are concordantly suggesting that adaptations have strongly affected the evolution of mtDNA of hare species with potential effects on the protein function. Environmental/climatic changes appear to be a major trigger of this adaptation, whereas trans-specific introgressive hybridization seems to play no major role for the occurrence of protein variants.

scholarly journals Frequent transmission of the Mycobacterium tuberculosis Beijing lineage and positive selection for the EsxW Beijing variant in Vietnam

2018 ◽  
Vol 50 (6) ◽  
pp. 849-856 ◽  
Author(s):  
Kathryn E. Holt ◽  
Paul McAdam ◽  
Phan Vuong Khac Thai ◽  
Nguyen Thuy Thuong Thuong ◽  
Dang Thi Minh Ha ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Positive Selection ◽  
Selection For
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