scholarly journals Estimating the tempo and mode of gene family evolution from comparative genomic data

2005 ◽  
Vol 15 (8) ◽  
pp. 1153-1160 ◽  
Author(s):  
M. W. Hahn
Author(s):  
Diana Moreno Santillan ◽  
Tanya Lama ◽  
Yocelyn Gutiérrez Guerrero ◽  
Alexis Brown ◽  
Paul Donat ◽  
...  

Comprising more than 1400 species, bats possess adaptations unique among mammals including powered flight, unexpected longevity given small body size, and extraordinary immunity. Some of the molecular mechanisms underlying these unique adaptations includes DNA repair, metabolism and immunity. However, analyses have been limited to a few divergent lineages, reducing the scope of inferences on gene family evolution across the Order Chiroptera. We conducted an exhaustive comparative genomic study of 37 bat species encompassing a large number of lineages, with a particular emphasis on multi-gene family evolution across immune system and metabolic genes. In agreement with previous analyses, we found lineage-specific expansions of the APOBEC3 and MHC-I gene families, and loss of the proinflammatory PYHIN gene family. We inferred more than 1,000 gene losses unique to bats, including genes involved in the regulation of inflammasome pathways such as epithelial defense receptors, the natural killer gene complex and the interferon-gamma induced pathway. Gene set enrichment analyses revealed genes lost in bats are involved in defense response against pathogen-associated molecular patterns and damage-associated molecular patterns. Gene family evolution and selection analyses indicate bats have evolved fundamental functional differences compared to other mammals in both innate and adaptive immune system, with the potential to enhance anti-viral immune response while dampening inflammatory signaling. In addition, metabolic genes have experienced repeated expansions related to convergent shifts to plant-based diets. Our analyses support the hypothesis that, in tandem with flight, ancestral bats had evolved a unique set of immune adaptations whose functional implications remain to be explored.


2020 ◽  
Author(s):  
Rui-Ling Zhang ◽  
Qian Zhang ◽  
Zhong Zhang

Abstract Background: The longhorned tick, Haemaphysalis longicornis Neumann, is widely distributed across temperate regions. It can parasitize terrestrial vertebrates, including birds and a large number of mammals. They are a concern in human and animal health notably for their potential to transmit infectious agents. Methods: Genome survey was investigated using GenomeScope v1.0.0 with a maximum k-mer coverage cutoff of 1,000. Non-redundant assembly was polished with Illumina short reads using two rounds of NextPolish v1.1.0. Genome completeness was assessed using BUSCO v3.0.2 pipeline analyses against arthropod gene set (n = 1, 066). Ab initio predictions were generated using BRAKER v2.1.5. Transcriptomic reads were mapped to the genome with HISAT2 v2.2.0 and assembled with StringTie v2.1.2. Gene functions were assigned against UniProtKB database using Diamond v0.9.24. Orthogroups of 16 Chelicerata species were inferred using OrthoFinder v2.3.8 and gene family evolution was estimated using CAFÉ v4.2.1. Gene families related to digestion and detoxification, i.e. cytochrome P450 (CYP), carboxyl/cholinesterase (CCE), glutathione-S-transferase (GST), ATP-binding cassette (ABC) transporter were annotated by searching in the genome assembly. Results: The final genome assembly has a size of 3.12 Gb, a scaffold N50 of 1.09 Mb, and captured 92.4% of the BUSCO gene set (n=1,066). Genome architecture pattern of the longhorned tick resembles another tick, Ixodes scapularis (Say), particularly in large size, highly repetitive DNA (~65%) and protein-coding genes (21,550). We also identified 5,601 non-coding RNAs with a high ratio of tRNAs (4,271). Gene family evolution revealed 350 rapidly evolving gene families. Combining function enrichment analyses of gene ontology (GO) and KEGG pathway, 255 families experiencing significant expansions mainly involves in cuticle synthesis, digestion and detoxification. Conclusions: The new genome assembly, annotation and comparative genomic analyses provide a valuable resource for insights into parasitic life mode of the longhorned tick.


2021 ◽  
Author(s):  
Arthur Zwaenepoel ◽  
Yves Van de Peer

AbstractPhylogenetic models of gene family evolution based on birth-death processes (BDPs) vide an awkward fit to comparative genomic data sets. A central assumption of these models is the constant per-gene loss rate in any particular family. Because of the possibility of partial functional redundancy among gene family members, gene loss dynamics are however likely to be dependent on the number of genes in a family, and different variations of commonly employed BDP models indeed suggest this is the case. We propose a simple two-type branching process model to better approximate the stochastic evolution of gene families by gene duplication and loss and perform Bayesian statistical inference of model parameters in a phylogenetic context. We evaluate the statistical methods using simulated data sets and apply the model to gene family data for Drosophila, yeasts and primates, providing new quantitative insights in the long-term maintenance of duplicated genes.


Author(s):  
Diana Moreno Santillan ◽  
Tanya Lama ◽  
Yocelyn Gutiérrez Guerrero ◽  
Alexis Brown ◽  
Paul Donat ◽  
...  

Comprising more than 1400 species, bats possess adaptations unique among mammals including powered flight, unexpected longevity given small body size, and extraordinary immunity. Some of the molecular mechanisms underlying these unique adaptations includes DNA repair, metabolism and immunity. However, analyses have been limited to a few divergent lineages, reducing the scope of inferences on gene family evolution across the Order Chiroptera. We conducted an exhaustive comparative genomic study of 37 bat species encompassing a large number of lineages, with a particular emphasis on multi-gene family evolution across immune system and metabolic genes. In agreement with previous analyses, we found lineage-specific expansions of the APOBEC3 and MHC-I gene families, and loss of the proinflammatory PYHIN gene family. We inferred more than 1,000 gene losses unique to bats, including genes involved in the regulation of inflammasome pathways such as epithelial defense receptors, the natural killer gene complex and the interferon-gamma induced pathway. Gene set enrichment analyses revealed genes lost in bats are involved in defense response against pathogen-associated molecular patterns and damage-associated molecular patterns. Gene family evolution and selection analyses indicate bats have evolved fundamental functional differences compared to other mammals in both innate and adaptive immune system, with the potential to enhance anti-viral immune response while dampening inflammatory signaling. In addition, metabolic genes have experienced repeated expansions related to convergent shifts to plant-based diets. Our analyses support the hypothesis that, in tandem with flight, ancestral bats had evolved a unique set of immune adaptations whose functional implications remain to be explored.


Author(s):  
Diana Moreno Santillan ◽  
Tanya Lama ◽  
Yocelyn Gutiérrez Guerrero ◽  
Alexis Brown ◽  
Paul Donat ◽  
...  

Comprising more than 1400 species, bats possess adaptations unique among mammals including powered flight, unexpected longevity given small body size, and extraordinary immunity. Some of the molecular mechanisms underlying these unique adaptations includes DNA repair, metabolism and immunity. However, analyses have been limited to a few divergent lineages, reducing the scope of inferences on gene family evolution across the Order Chiroptera. We conducted an exhaustive comparative genomic study of 37 bat species encompassing a large number of lineages, with a particular emphasis on multi-gene family evolution across immune system and metabolic genes. In agreement with previous analyses, we found lineage-specific expansions of the APOBEC3 and MHC-I gene families, and loss of the proinflammatory PYHIN gene family. We inferred more than 1,000 gene losses unique to bats, including genes involved in the regulation of inflammasome pathways such as epithelial defense receptors, the natural killer gene complex and the interferon-gamma induced pathway. Gene set enrichment analyses revealed genes lost in bats are involved in defense response against pathogen-associated molecular patterns and damage-associated molecular patterns. Gene family evolution and selection analyses indicate bats have evolved fundamental functional differences compared to other mammals in both innate and adaptive immune system, with the potential to enhance anti-viral immune response while dampening inflammatory signaling. In addition, metabolic genes have experienced repeated expansions related to convergent shifts to plant-based diets. Our analyses support the hypothesis that, in tandem with flight, ancestral bats had evolved a unique set of immune adaptations whose functional implications remain to be explored.


Author(s):  
Andrew W Legan ◽  
Christopher M Jernigan ◽  
Sara E Miller ◽  
Matthieu F Fuchs ◽  
Michael J Sheehan

Abstract Independent origins of sociality in bees and ants are associated with independent expansions of particular odorant receptor (OR) gene subfamilies. In ants, one clade within the OR gene family, the 9-exon subfamily, has dramatically expanded. These receptors detect cuticular hydrocarbons (CHCs), key social signaling molecules in insects. It is unclear to what extent 9-exon OR subfamily expansion is associated with the independent evolution of sociality across Hymenoptera, warranting studies of taxa with independently derived social behavior. Here we describe odorant receptor gene family evolution in the northern paper wasp, Polistes fuscatus, and compare it to four additional paper wasp species spanning ∼40 million years of evolutionary divergence. We find 200 putatively functional OR genes in P. fuscatus, matching predictions from neuroanatomy, and more than half of these are in the 9-exon subfamily. Most OR gene expansions are tandemly arrayed at orthologous loci in Polistes genomes, and microsynteny analysis shows species-specific gain and loss of 9-exon ORs within tandem arrays. There is evidence of episodic positive diversifying selection shaping ORs in expanded subfamilies. Values of omega (d  N/dS) are higher among 9-exon ORs compared to other OR subfamilies. Within the Polistes OR gene tree, branches in the 9-exon OR clade experience relaxed negative (purifying) selection relative to other branches in the tree. Patterns of OR evolution within Polistes are consistent with 9-exon OR function in CHC perception by combinatorial coding, with both natural selection and neutral drift contributing to interspecies differences in gene copy number and sequence.


Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 19
Author(s):  
Peng Jin ◽  
Shiqi Gao ◽  
Long He ◽  
Miaoze Xu ◽  
Tianye Zhang ◽  
...  

Histone acetylation is a dynamic modification process co-regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs). Although HDACs play vital roles in abiotic or biotic stress responses, their members in Triticumaestivum and their response to plant viruses remain unknown. Here, we identified and characterized 49 T. aestivumHDACs (TaHDACs) at the whole-genome level. Based on phylogenetic analyses, TaHDACs could be divided into 5 clades, and their protein spatial structure was integral and conserved. Chromosomal location and synteny analyses showed that TaHDACs were widely distributed on wheat chromosomes, and gene duplication has accelerated the TaHDAC gene family evolution. The cis-acting element analysis indicated that TaHDACs were involved in hormone response, light response, abiotic stress, growth, and development. Heatmaps analysis of RNA-sequencing data showed that TaHDAC genes were involved in biotic or abiotic stress response. Selected TaHDACs were differentially expressed in diverse tissues or under varying temperature conditions. All selected TaHDACs were significantly upregulated following infection with the barley stripe mosaic virus (BSMV), Chinese wheat mosaic virus (CWMV), and wheat yellow mosaic virus (WYMV), suggesting their involvement in response to viral infections. Furthermore, TaSRT1-silenced contributed to increasing wheat resistance against CWMV infection. In summary, these findings could help deepen the understanding of the structure and characteristics of the HDAC gene family in wheat and lay the foundation for exploring the function of TaHDACs in plants resistant to viral infections.


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