scholarly journals GWideCodeML: A Python Package for Testing Evolutionary Hypotheses at the Genome-Wide Level

2020 ◽  
Vol 10 (12) ◽  
pp. 4369-4372
Author(s):  
Laura G. Macías ◽  
Eladio Barrio ◽  
Christina Toft

One of the most widely used programs for detecting positive selection, at the molecular level, is the program codeml, which is implemented in the Phylogenetic Analysis by Maximum Likelihood (PAML) package. However, it has a limitation when it comes to genome-wide studies, as it runs on a gene-by-gene basis. Furthermore, the size of such studies will depend on the number of orthologous genes the genomes have income and these are often restricted to only account for instances where a one-to-one relationship is observed between the genomes. In this work, we present GWideCodeML, a Python package, which runs a genome-wide codeml with the option of parallelization. To maximize the number of analyzed genes, the package allows for a variable number of taxa in the alignments and will automatically prune the topology to fit each of them, before running codeml.

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Dong Yu ◽  
Yuan Jin ◽  
Zhiqiu Yin ◽  
Hongguang Ren ◽  
Wei Zhou ◽  
...  

Currently, there is particular interest in the molecular mechanisms of adaptive evolution in bacteria.Neisseriais a genus of gram negative bacteria, and there has recently been considerable focus on its two human pathogenic speciesN. meningitidisandN. gonorrhoeae. Until now, no genome-wide studies have attempted to scan for the genes related to adaptive evolution. For this reason, we selected 18Neisseriagenomes (14N. meningitidis, 3N. gonorrhoeaeand 1 commensalN. lactamics) to conduct a comparative genome analysis to obtain a comprehensive understanding of the roles of natural selection and homologous recombination throughout the history of adaptive evolution. Among the 1012 core orthologous genes, we identified 635 genes with recombination signals and 10 genes that showed significant evidence of positive selection. Further functional analyses revealed that no functional bias was found in the recombined genes. Positively selected genes are prone to DNA processing and iron uptake, which are essential for the fundamental life cycle. Overall, the results indicate that both recombination and positive selection play crucial roles in the adaptive evolution ofNeisseriagenomes. The positively selected genes and the corresponding amino acid sites provide us with valuable targets for further research into the detailed mechanisms of adaptive evolution inNeisseria.


2015 ◽  
Vol 2 (9) ◽  
pp. 150156 ◽  
Author(s):  
Georgia Tsagkogeorga ◽  
Michael R. McGowen ◽  
Kalina T. J. Davies ◽  
Simon Jarman ◽  
Andrea Polanowski ◽  
...  

Recent studies have reported multiple cases of molecular adaptation in cetaceans related to their aquatic abilities. However, none of these has included the hippopotamus, precluding an understanding of whether molecular adaptations in cetaceans occurred before or after they split from their semi-aquatic sister taxa. Here, we obtained new transcriptomes from the hippopotamus and humpback whale, and analysed these together with available data from eight other cetaceans. We identified more than 11 000 orthologous genes and compiled a genome-wide dataset of 6845 coding DNA sequences among 23 mammals, to our knowledge the largest phylogenomic dataset to date for cetaceans. We found positive selection in nine genes on the branch leading to the common ancestor of hippopotamus and whales, and 461 genes in cetaceans compared to 64 in hippopotamus. Functional annotation revealed adaptations in diverse processes, including lipid metabolism, hypoxia, muscle and brain function. By combining these findings with data on protein–protein interactions, we found evidence suggesting clustering among gene products relating to nervous and muscular systems in cetaceans. We found little support for shared ancestral adaptations in the two taxa; most molecular adaptations in extant cetaceans occurred after their split with hippopotamids.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Yibo Dong ◽  
Shichao Chen ◽  
Shifeng Cheng ◽  
Wenbin Zhou ◽  
Qing Ma ◽  
...  

Although geographic isolation is a leading driver of speciation, the tempo and pattern of divergence at the genomic level remain unclear. We examine genome-wide divergence of putatively single-copy orthologous genes (POGs) in 20 allopatric species/variety pairs from diverse angiosperm clades, with 16 pairs reflecting the classic eastern Asia-eastern North America floristic disjunction. In each pair, >90% of POGs are under purifying selection, and <10% are under positive selection. A set of POGs are under strong positive selection, 14 of which are shared by 10–15 pairs, and one shared by all pairs; 15 POGs are annotated to biological processes responding to various stimuli. The relative abundance of POGs under different selective forces exhibits a repeated pattern among pairs despite an ~10 million-year difference in divergence time. Species divergence times are positively correlated with abundance of POGs under moderate purifying selection, but negatively correlated with abundance of POGs under strong purifying selection.


2021 ◽  
Vol 17 ◽  
pp. 117693432110413
Author(s):  
Chaoxin Zhang ◽  
Tao Wang ◽  
Tongyan Cui ◽  
Shengwei Liu ◽  
Bing Zhang ◽  
...  

The CCAAT/enhancer binding protein (C/EBP) transcription factors (TFs) regulate many important biological processes, such as energy metabolism, inflammation, cell proliferation etc. A genome-wide gene identification revealed the presence of a total of 99 C/EBP genes in pig and 19 eukaryote genomes. Phylogenetic analysis showed that all C/EBP TFs were classified into 6 subgroups named C/EBPα, C/EBPβ, C/EBPδ, C/EBPε, C/EBPγ, and C/EBPζ. Gene expression analysis showed that the C/EBPα, C/EBPβ, C/EBPδ, C/EBPγ, and C/EBPζ genes were expressed ubiquitously with inconsistent expression patterns in various pig tissues. Moreover, a pig C/EBP regulatory network was constructed, including C/EBP genes, TFs and miRNAs. A total of 27 feed-forward loop (FFL) motifs were detected in the pig C/EBP regulatory network. Based on the RNA-seq data, gene expression patterns related to FFL sub-network were analyzed in 27 adult pig tissues. Certain FFL motifs may be tissue specific. Functional enrichment analysis indicated that C/EBP and its target genes are involved in many important biological pathways. These results provide valuable information that clarifies the evolutionary relationships of the C/EBP family and contributes to the understanding of the biological function of C/EBP genes.


2016 ◽  
Vol 41 ◽  
pp. 213-217 ◽  
Author(s):  
Jagadesan Sankarasubramanian ◽  
Udayakumar S. Vishnu ◽  
Paramasamy Gunasekaran ◽  
Jeyaprakash Rajendhran

2020 ◽  
Author(s):  
Muhammad Zulfiqar Ahmad ◽  
Xiangsheng Zeng ◽  
Qiang Dong ◽  
Sehrish Manan ◽  
Huanan Jin ◽  
...  

Abstract Background: Members of the BAHD acyltransferase (ACT) family play important roles in plant defence against biotic and abiotic stresses. Previous genome-wide studies explored different acyltransferase gene families, but not a single study was found so far on the overall genome-wide or positive selection analyses of the BAHD family genes in Glycine max . A better understanding of the functions that specific members of this family play in stress defence can lead to better breeding strategies for stress tolerance. Results: A total of 103 genes of the BAHD family (GmACT genes) were mined from the soybean genome, which could be grouped into four phylogenetic clades (I- IV). Clade III was further divided into two sub-clades (IIIA and IIIB). In each clade, the constituent part of the gene structures and motifs were relatively conserved. These 103 genes were distributed unequally on all 20 chromosomes, and 16 paralogous pairs were found within the family. Positive selection analysis revealed important amino acids under strong positive selection, which suggests that the evolution of this gene family modulated soybean domestication. Most of the expression of ACT genes in soybean was repressed with Al 3+ and fungal elicitor exposure, except for GmACT84 , which expression increased in these conditions 2- and 3-fold, respectively. The promoter region of GmACT84 contains the maximum number of stress-responsive elements among all GmACT genes and is especially enriched in MYB-related elements. Some GmACT genes showed expression specific under specific conditions, while others showed constitutive expression in all soybean tissues or conditions analysed. Conclusions: This study provided a genome-wide analysis of the BAHD gene family and assessed their expression profiles. We found evidence of a strong positive selection of GmACT genes. Our findings will help efforts of functional characterisation of ACT genes in soybean in order to discover their involvement in growth, development, and defence mechanisms.


2021 ◽  
Author(s):  
Abhirup Paul ◽  
Archita Chatterjee ◽  
shreya Subrahmanya ◽  
Guoxin Shen ◽  
Neelam Mishra

Abstract Background Salt stress affects the plant growth and productivity worldwide and NHX is one of those genes that are well known to improve salt tolerance in transgenic plants. It is well characterized in several plants such as Arabidopsis and cotton however not much is known about NHXs in tea plant. Result In the present study, NHX genes of tea were obtained through a genome wide search using Arabidopsis thaliana as reference genome. Out of the 9 NHX genes in tea, 7 genes were localized in vacuole while the remaining 2 genes were localized in the endoplasmic reticulum (ER) (TEA014468.1) and plasma membrane (PM) (TEA006997.1) respectively. Furthermore, phylogenetic relationships along with structural analysis which includes gene structure, location as well as protein conserved motifs and domains, were systematically examined and further, predictions were validated by the expression analysis. The dN/dS values show that the majority of tea NHX genes are subjected to strong purifying selection under the course of evolution. Also, functional interaction was carried out in C. sinensis based on the orthologous genes in Arabidopsis. The expression profiles linked to various stress treatments revealed wide involvement of NHX genes from tea in response to various abiotic factors. Conclusion This study provides the targets for further comprehensive identification, functional study, and also contributed for a better understanding of the NHX regulatory network in C. sinensis.


Sign in / Sign up

Export Citation Format

Share Document