scholarly journals Evidence for purifying selection on conserved noncoding elements in the genome of Drosophila melanogaster

2019 ◽  
Author(s):  
Berr Tristan ◽  
Peticca Aurelie ◽  
Haudry Annabelle
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Sequences ◽  
Structural Characteristics ◽  
Purifying Selection ◽  
Whole Genome ◽  
Regulatory Regions ◽  
Functional Regions ◽  
A Genome ◽  
Functional Relevance ◽  
Conserved Noncoding Elements

AbstractIdentification of regulatory regions within genomes is a key challenge for understanding the influence of functional traits on species evolution. Development of whole-genome sequencing programs in the early 2000s has been associated with the rise of comparative genomics as a powerful tool for predicting functional regions in genomes, using structural characteristics of DNA sequences. Conserved Noncoding Elements (CNEs, i.e. untranslated sequences highly similar across divergent species) were early identified as candidate regulatory regions in metazoans, plants, and fungi. CNEs have been repeatedly discriminated from mutational cold-spots, but only few studies have assessed their functional relevance at a genome-wide scale. In the present study, we used a whole-genome alignment of 27 insect species to build a coherent mapping of CNEs in the genome of Drosophila melanogaster. We then exploited polymorphism data from 48 European populations of D. melanogaster to estimate levels of nucleotide diversity and adaptive evolution in CNEs. We show here that about 35% of D. melanogaster autosomes fall into conserved noncoding regions that exhibit reduced genetic diversity and undergo purifying selection. In addition, we report six insertions of Transposable Elements (TEs) in the genome of D. melanogaster showing high levels of conservation across Drosophila species. Half of these insertions are located in untranslated transcribed regions (UTRs) of genes involved in developmental pathways and thus represent potential relics of ancient TE domestication events.

scholarly journals Genome-wide survey of sucrose non-fermenting 1-related protein kinase 2 in Rosaceae and expression analysis of PbrSnRK2 in response to ABA stress

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Guodong Chen ◽  
Jizhong Wang ◽  
Xin Qiao ◽  
Cong Jin ◽  
Weike Duan ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Gene Family ◽  
Structural Characteristics ◽  
Purifying Selection ◽  
Related Protein ◽  
Rosaceae Species ◽  
Genome Wide ◽  
A Genome ◽  
Genes Encoding ◽  
Genome Wide Survey

Abstract Background The members of the sucrose non-fermenting 1-related protein kinase 2 (SnRK2) family are specific serine/threonine protein kinases in plants that play important roles in stress signal transduction and adaptation. Because of their positive regulatory roles in response to adverse conditions, the genes encoding thes proteins are considered potential candidates for breeding of plants for disease resistance and genetic improvement. However, there is far less information about this kinase family, and the function of these genes has not been explored in Rosaceae. Results A genome-wide survey and analysis of the genes encoding members of the SnRK2 family were performed in pear (Pyrus bretschneideri) and seven other Rosaceae species. A total of 71 SnRK2 genes were identified from the eight Rosaceae species and classified into three subgroups based on phylogenetic analysis and structural characteristics. Purifying selection played a crucial role in the evolution of SnRK2 genes, and whole-genome duplication and dispersed duplication were the primary forces underlying the characteristics of the SnRK2 gene family in Rosaceae. Transcriptome data and qRT-PCR assay results revealed that the distribution of PbrSnRK2s was very extensive, including across the roots, leaves, pollen, styles, and flowers, although most of them were mainly expressed in leaves. In addition, under stress conditions, the transcript levels of some of the genes were upregulated in leaves in response to ABA treatment. Conclusions This study provides useful information and a theoretical introduction for the study of the evolution, expression, and functions of the SnRK2 gene family in plants.

scholarly journals Genome-wide survey of sucrose non-fermenting 1-related protein kinase 2 in Rosaceae and expression analysis of PbrSnRK2 in response to ABA stress

2020 ◽  
Author(s):  
Guodong Chen ◽  
Jizhong Wang ◽  
Xin Qiao ◽  
Cong Jin ◽  
Weike Duan ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Gene Family ◽  
Structural Characteristics ◽  
Purifying Selection ◽  
Related Protein ◽  
Rosaceae Species ◽  
Genome Wide ◽  
A Genome ◽  
Genes Encoding ◽  
Genome Wide Survey

Abstract Background: The members of the sucrose non-fermenting 1-related protein kinase 2 (SnRK2) family are specific serine/threonine protein kinases in plants that play important roles in stress signal transduction and adaptation. Because of their positive regulatory roles in response to adverse conditions, the genes encoding thes proteins are considered potential candidates for breeding of plants for disease resistance and genetic improvement. However, there is far less information about this kinase family, and the function of these genes has not been explored in Rosaceae. Results: A genome-wide survey and analysis of the genes encoding members of the SnRK2 family were performed in pear ( Pyrus bretschneideri ) and seven other Rosaceae species. A total of 71 SnRK2 genes were identified from the eight Rosaceae species and classified into three subgroups based on phylogenetic analysis and structural characteristics. Purifying selection played a crucial role in the evolution of SnRK2 genes, and whole-genome duplication and dispersed duplication were the primary forces underlying the characteristics of the SnRK2 gene family in Rosaceae. Transcriptome data and qRT-PCR assay results revealed that the distribution of PbrSnRK2s was very extensive, including across the roots, leaves, pollen, styles, and flowers, although most of them were mainly expressed in leaves. In addition, under stress conditions, the transcript levels of some of the genes were upregulated in leaves in response to ABA treatment. Conclusions: This study provides useful information and a theoretical introduction for the study of the evolution, expression, and functions of the SnRK2 gene family in plants.

scholarly journals A genome Tree of Life for the Fungi kingdom

2017 ◽  
Vol 114 (35) ◽  
pp. 9391-9396 ◽  
Author(s):  
JaeJin Choi ◽  
Sung-Hou Kim
Keyword(s):  
Dna Sequences ◽  
Gene Tree ◽  
Complete Information ◽  
Whole Genome ◽  
Gene Trees ◽  
Multiple Sequence ◽  
A Genome ◽  
Conserved Genes ◽  
Genome Information ◽  
Genome Tree

Fungi belong to one of the largest and most diverse kingdoms of living organisms. The evolutionary kinship within a fungal population has so far been inferred mostly from the gene-information–based trees (“gene trees”), constructed commonly based on the degree of differences of proteins or DNA sequences of a small number of highly conserved genes common among the population by a multiple sequence alignment (MSA) method. Since each gene evolves under different evolutionary pressure and time scale, it has been known that one gene tree for a population may differ from other gene trees for the same population depending on the subjective selection of the genes. Within the last decade, a large number of whole-genome sequences of fungi have become publicly available, which represent, at present, the most fundamental and complete information about each fungal organism. This presents an opportunity to infer kinship among fungi using a whole-genome information-based tree (“genome tree”). The method we used allows comparison of whole-genome information without MSA, and is a variation of a computational algorithm developed to find semantic similarities or plagiarism in two books, where we represent whole-genomic information of an organism as a book of words without spaces. The genome tree reveals several significant and notable differences from the gene trees, and these differences invoke new discussions about alternative narratives for the evolution of some of the currently accepted fungal groups.

scholarly journals Genome-wide survey of sucrose non-fermenting 1-related protein kinase 2 in Rosaceae and expression analysis of PbrSnRK2 in response to ABA stress

2020 ◽  
Author(s):  
Guodong Chen ◽  
Jizhong Wang ◽  
Xin Qiao ◽  
Cong Jin ◽  
Weike Duan ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Gene Family ◽  
Structural Characteristics ◽  
Purifying Selection ◽  
Related Protein ◽  
Rosaceae Species ◽  
Genome Wide ◽  
A Genome ◽  
Genes Encoding ◽  
Genome Wide Survey

Abstract Background The members of the sucrose non-fermenting 1-related protein kinase 2 (SnRK2) family are specific serine/threonine protein kinases in plants, which play important roles in stress signal transduction and adaptation. Because of these positive regulatory roles in response to adversity, the genes encoding them are considered potential candidates for breeding of plants for disease resistance and genetic improvement. However, there is far less information about this kinase family and the function of these genes has not been explored in Rosaceae. Results A genome-wide survey and analysis of the genes encoding members of the SnRK2 family were performed in pear (Pyrus bretschneideri) and seven other Rosaceae species. A total of 71 SnRK2 genes were identified from the eight Rosaceae species and classified into three subgroups based on phylogenetic analysis and structural characteristics. Purifying selection played a crucial role in the evolution of SnRK2 genes, and whole-genome duplication and dispersed duplication were the main forces underlying the characteristics of the SnRK2 gene family in Rosaceae. Transcriptome data and qRT-PCR assays revealed that the distribution of PbrSnRK2s was very extensive including across the roots, leaves, pollen, styles, and flowers, although most of them were mainly expressed in leaves. In addition, under stress conditions, the transcript levels of some of the genes were upregulated in leaves in response to ABA treatments. Conclusions This study provides useful information and a theoretical introduction for the study of the evolution, expression, and functions of the SnRK2 gene family in plants.

scholarly journals Genome-wide identification of PbrbHLH family genes, and expression analysis in response to drought and cold stresses in pear (Pyrus bretschneideri)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Huizhen Dong ◽  
Qiming Chen ◽  
Yuqin Dai ◽  
Wenjie Hu ◽  
Shaoling Zhang ◽  
...  
Keyword(s):  
Abiotic Stresses ◽  
Structural Characteristics ◽  
Purifying Selection ◽  
Functional Roles ◽  
Kegg Pathways ◽  
Helix Loop Helix ◽  
Chinese White ◽  
Genome Wide ◽  
A Genome ◽  
Bhlh Transcription Factors

Abstract Background The basic helix-loop-helix (bHLH) transcription factors play important roles in many processes in plant growth, metabolism and responses to abiotic stresses. Although, the sequence of Chinese white pear genome (cv. ‘Dangshansuli’) has already been reported, there is still a lack of clarity regarding the bHLH family genes and their evolutionary history. Results In this work, a genome-wide identification of the bHLH genes in Chinese white pear was performed, and we characterized the functional roles of these PbrbHLH genes in response to abiotic stresses. Based on the phylogenetic analysis and structural characteristics, 197 identified bHLH genes could be well classified into 21 groups. Expansion of PbrbHLH gene family was mainly driven by WGD and dispersed duplication with the purifying selection from the recent WGD. The functional annotation enrichment showed that the majority of PbrbHLHs were enriched in the GO terms and KEGG pathways involved in responds to stress conditions as TFs. Transcriptomic profiles and qRT-PCR revealed that PbrbHLH7, PbrbHLH8, PbrbHLH128, PbrbHLH160, PbrbHLH161 and PbrbHLH195 were significantly up-regulated under cold and drought treatments. In addition, PbrbHLH195-silenced pear seedlings display significant reduced cold tolerance, exhibiting reduced chlorophyll content, as well as increased electrolyte leakage and concentrations of malondialdehyde and H2O2. Conclusion For the first time, a comprehensive analysis identified the bHLH genes in Chinese white pear and demonstrated that PbrbHLH195 is involved in the production of ROS in response to cold stress, suggesting that members of the PbrbHLH family play an essential role in the stress tolerance of pear.

scholarly journals Genome-wide Identification of PbrbHLH Family Genes, and Expression Analysis in Response to drought and Cold Stresses in Pear (Pyrus Bretschneideri)

2020 ◽  
Author(s):  
Huizhen Dong ◽  
Qiming Chen ◽  
Yuqin Dai ◽  
Wenjie Hu ◽  
Shaoling Zhang ◽  
...  
Keyword(s):  
Abiotic Stresses ◽  
Structural Characteristics ◽  
Purifying Selection ◽  
Functional Roles ◽  
Kegg Pathways ◽  
Helix Loop Helix ◽  
Chinese White ◽  
Genome Wide ◽  
A Genome ◽  
Bhlh Genes

Abstract Background: The basic helix-loop-helix (bHLH) transcription factors play important roles in many processes in plant growth, metabolism and responses to abiotic stresses. Although, the sequence of Chinese white pear genome (cv. ‘Dangshansuli’) has already been reported, there is still a lack of clarity regarding the bHLH family genes and their evolutionary history. Results: In this work, a genome-wide identification of the bHLH genes in Chinese white pear was performed, and we characterized the functional roles of these PbrbHLH genes in response to abiotic stresses. Based on the phylogenetic analysis and structural characteristics, 197 identified bHLH genes could be well classified into 21 groups. Expansion of PbrbHLH gene family were mainly driven by WGD and dispersed duplication with the purifying selection from the recent WGD. The functional annotation enrichment showed that the majority of PbrbHLHs were enriched in the GO terms and KEGG pathways involved in responds to stress conditions as TFs. Transcriptomic profiles and qRT-PCR revealed that PbrbHLH7, PbrbHLH8, PbrbHLH116, PbrbHLH128, PbrbHLH160 and PbrbHLH195 were significantly up-regulated under cold and drought treatments. In addition, PbrbHLH195-silenced pear seedlings display significant reduced cold tolerance, exhibiting reduced chlorophyll content, as well as increased Electrolyte leakage and concentrations of malondialdehyde and H2O2.Conclusion: For the first time, a comprehensive analysis identified the bHLH genes in Chinese white pear and demonstrated that PbrbHLH195 is involved in the production of ROS in response to cold stress, suggesting that members of the PbrbHLH family play an essential role in the stress tolerance of pear.

scholarly journals Evolution of regulatory networks associated with traits under selection in cichlids

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Tarang K. Mehta ◽  
Christopher Koch ◽  
Will Nash ◽  
Sara A. Knaack ◽  
Padhmanand Sudhakar ◽  
...  
Keyword(s):  
Visual System ◽  
Regulatory Sequence ◽  
Potential Candidate ◽  
East African ◽  
Regulatory Regions ◽  
A Genome ◽  
Opsin Genes ◽  
East African Cichlids ◽  
Gene Regulatory ◽  
African Cichlids

Abstract Background Seminal studies of vertebrate protein evolution speculated that gene regulatory changes can drive anatomical innovations. However, very little is known about gene regulatory network (GRN) evolution associated with phenotypic effect across ecologically diverse species. Here we use a novel approach for comparative GRN analysis in vertebrate species to study GRN evolution in representative species of the most striking examples of adaptive radiations, the East African cichlids. We previously demonstrated how the explosive phenotypic diversification of East African cichlids can be attributed to diverse molecular mechanisms, including accelerated regulatory sequence evolution and gene expression divergence. Results To investigate these mechanisms across species at a genome-wide scale, we develop a novel computational pipeline that predicts regulators for co-extant and ancestral co-expression modules along a phylogeny, and candidate regulatory regions associated with traits under selection in cichlids. As a case study, we apply our approach to a well-studied adaptive trait—the visual system—for which we report striking cases of network rewiring for visual opsin genes, identify discrete regulatory variants, and investigate their association with cichlid visual system evolution. In regulatory regions of visual opsin genes, in vitro assays confirm that transcription factor binding site mutations disrupt regulatory edges across species and segregate according to lake species phylogeny and ecology, suggesting GRN rewiring in radiating cichlids. Conclusions Our approach reveals numerous novel potential candidate regulators and regulatory regions across cichlid genomes, including some novel and some previously reported associations to known adaptive evolutionary traits.

The Age of Nonsynonymous and Synonymous Mutations in Animal mtDNA and Implications for the Mildly Deleterious Theory

Genetics ◽  
1999 ◽  
Vol 153 (1) ◽  
pp. 497-506 ◽  
Author(s):  
Rasmus Nielsen ◽  
Daniel M Weinreich
Keyword(s):  
Dna Sequences ◽  
Purifying Selection ◽  
Data Sets ◽  
Deleterious Mutations ◽  
Synonymous Mutations ◽  
Weak Evidence ◽  
Mitochondrial Data ◽  
The Mean ◽  
Excess Number ◽  
Neutral Mutations

Abstract McDonald/Kreitman tests performed on animal mtDNA consistently reveal significant deviations from strict neutrality in the direction of an excess number of polymorphic nonsynonymous sites, which is consistent with purifying selection acting on nonsynonymous sites. We show that under models of recurrent neutral and deleterious mutations, the mean age of segregating neutral mutations is greater than the mean age of segregating selected mutations, even in the absence of recombination. We develop a test of the hypothesis that the mean age of segregating synonymous mutations equals the mean age of segregating nonsynonymous mutations in a sample of DNA sequences. The power of this age-of-mutation test and the power of the McDonald/Kreitman test are explored by computer simulations. We apply the new test to 25 previously published mitochondrial data sets and find weak evidence for selection against nonsynonymous mutations.

scholarly journals Comparative whole-genome and proteomics analyses of the next seed bank and the original master seed bank of MucoRice-CTB 51A line, a rice-based oral cholera vaccine

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ai Sasou ◽  
Yoshikazu Yuki ◽  
Ayaka Honma ◽  
Kotomi Sugiura ◽  
Koji Kashima ◽  
...  
Keyword(s):  
Seed Bank ◽  
Dna Sequences ◽  
Storage Proteins ◽  
Oral Vaccine ◽  
Rice Genome ◽  
Major Allergen ◽  
Selection Marker ◽  
Cholera Toxin B Subunit ◽  
Whole Genome ◽  
Allergen Protein

Abstract Background We have previously developed a rice-based oral vaccine against cholera diarrhea, MucoRice-CTB. Using Agrobacterium-mediated co-transformation, we produced the selection marker–free MucoRice-CTB line 51A, which has three copies of the cholera toxin B subunit (CTB) gene and two copies of an RNAi cassette inserted into the rice genome. We determined the sequence and location of the transgenes on rice chromosomes 3 and 12. The expression of alpha-amylase/trypsin inhibitor, a major allergen protein in rice, is lower in this line than in wild-type rice. Line 51A was self-pollinated for five generations to fix the transgenes, and the seeds of the sixth generation produced by T5 plants were defined as the master seed bank (MSB). T6 plants were grown from part of the MSB seeds and were self-pollinated to produce T7 seeds (next seed bank; NSB). NSB was examined and its whole genome and proteome were compared with those of MSB. Results We re-sequenced the transgenes of NSB and MSB and confirmed the positions of the three CTB genes inserted into chromosomes 3 and 12. The DNA sequences of the transgenes were identical between NSB and MSB. Using whole-genome sequencing, we compared the genome sequences of three NSB with three MSB samples, and evaluated the effects of SNPs and genomic structural variants by clustering. No functionally important mutations (SNPs, translocations, deletions, or inversions of genic regions on chromosomes) between NSB and MSB samples were detected. Analysis of salt-soluble proteins from NSB and MSB samples by shot-gun MS/MS detected no considerable differences in protein abundance. No difference in the expression pattern of storage proteins and CTB in mature seeds of NSB and MSB was detected by immuno-fluorescence microscopy. Conclusions All analyses revealed no considerable differences between NSB and MSB samples. Therefore, NSB can be used to replace MSB in the near future.

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