scholarly journals Comparative genomic investigation of high-elevation adaptation in ectothermic snakes

2018 ◽  
Vol 115 (33) ◽  
pp. 8406-8411 ◽  
Author(s):  
Jia-Tang Li ◽  
Yue-Dong Gao ◽  
Liang Xie ◽  
Cao Deng ◽  
Peng Shi ◽  
...  
Keyword(s):  
De Novo ◽  
Hot Spring ◽  
High Elevation ◽  
Comparative Genomic ◽  
The Tibetan Plateau ◽  
Functional Assays ◽  
Damage Repair ◽  
Genomic Studies ◽  
Genetic Mechanisms ◽  
High Elevations

Several previous genomic studies have focused on adaptation to high elevations, but these investigations have been largely limited to endotherms. Snakes of the genus Thermophis are endemic to the Tibetan plateau and therefore present an opportunity to study high-elevation adaptations in ectotherms. Here, we report the de novo assembly of the genome of a Tibetan hot-spring snake (Thermophis baileyi) and then compare its genome to the genomes of the other two species of Thermophis, as well as to the genomes of two related species of snakes that occur at lower elevations. We identify 308 putative genes that appear to be under positive selection in Thermophis. We also identified genes with shared amino acid replacements in the high-elevation hot-spring snakes compared with snakes and lizards that live at low elevations, including the genes for proteins involved in DNA damage repair (FEN1) and response to hypoxia (EPAS1). Functional assays of the FEN1 alleles reveal that the Thermophis allele is more stable under UV radiation than is the ancestral allele found in low-elevation lizards and snakes. Functional assays of EPAS1 alleles suggest that the Thermophis protein has lower transactivation activity than the low-elevation forms. Our analysis identifies some convergent genetic mechanisms in high-elevation adaptation between endotherms (based on studies of mammals) and ectotherms (based on our studies of Thermophis).

scholarly journals High-Quality Genome Assembly of Peronospora destructor, the Causal Agent of Onion Downy Mildew

2020 ◽  
Vol 33 (5) ◽  
pp. 718-720
Author(s):  
Karthi Natesan ◽  
Ji Yeon Park ◽  
Cheol-Woo Kim ◽  
Dong Suk Park ◽  
Young-Seok Kwon ◽  
...  
Keyword(s):  
Downy Mildew ◽  
De Novo ◽  
Gc Content ◽  
Comparative Genomic ◽  
High Quality ◽  
Sequencing Platform ◽  
Peronospora Destructor ◽  
Genomic Studies ◽  
Genome Assemblies ◽  
High Quality Genome

Peronospora destructor is an obligate biotrophic oomycete that causes downy mildew on onion (Allium cepa). Onion is an important crop worldwide, but its production is affected by this pathogen. We sequenced the genome of P. destructor using the PacBio sequencing platform, and de novo assembly resulted in 74 contigs with a total contig size of 29.3 Mb and 48.48% GC content. Here, we report the first high-quality genome sequence of P. destructor and its comparison with the genome assemblies of other oomycetes. The genome is a very useful resource to serve as a reference for analysis of P. destructor isolates and for comparative genomic studies of the biotrophic oomycetes.

scholarly journals Genomic and Phenotypic Characterization of Chloracidobacterium Isolates Provides Evidence for Multiple Species

2021 ◽  
Vol 12 ◽  
Author(s):  
Mohit Kumar Saini ◽  
Aswathy Sebastian ◽  
Yoshiki Shirotori ◽  
Nathan T. Soulier ◽  
Amaya M. Garcia Costas ◽  
...  
Keyword(s):  
Growth Medium ◽  
Microbial Mats ◽  
Hot Spring ◽  
Enrichment Culture ◽  
Green Sulfur Bacteria ◽  
Phenotypic Characterization ◽  
Comparative Genomic ◽  
Phenotypic Properties ◽  
New Family ◽  
Genomic Studies

Chloracidobacterium is the first and until now the sole genus in the phylum Acidobacteriota (formerly Acidobacteria) whose members perform chlorophyll-dependent phototrophy (i.e., chlorophototrophy). An axenic isolate of Chloracidobacterium thermophilum (strain BT) was previously obtained by using the inferred genome sequence from an enrichment culture and diel metatranscriptomic profiling analyses in situ to direct adjustments to the growth medium and incubation conditions, and thereby a defined growth medium for Chloracidobacterium thermophilum was developed. These advances allowed eight additional strains of Chloracidobacterium spp. to be isolated from microbial mat samples collected from Mushroom Spring, Yellowstone National Park, United States, at temperatures of 41, 52, and 60°C; an axenic strain was also isolated from Rupite hot spring in Bulgaria. All isolates are obligately photoheterotrophic, microaerophilic, non-motile, thermophilic, rod-shaped bacteria. Chloracidobacterium spp. synthesize multiple types of (bacterio-)chlorophylls and have type-1 reaction centers like those of green sulfur bacteria. Light harvesting is accomplished by the bacteriochlorophyll a-binding, Fenna-Matthews-Olson protein and chlorosomes containing bacteriochlorophyll c. Their genomes are approximately 3.7 Mbp in size and comprise two circular chromosomes with sizes of approximately 2.7 Mbp and 1.0 Mbp. Comparative genomic studies and phenotypic properties indicate that the nine isolates represent three species within the genus Chloracidobacterium. In addition to C. thermophilum, the microbial mats at Mushroom Spring contain a second species, tentatively named Chloracidobacterium aggregatum, which grows as aggregates in liquid cultures. The Bulgarian isolate, tentatively named Chloracidobacterium validum, will be proposed as the type species of the genus, Chloracidobacterium. Additionally, Chloracidobacterium will be proposed as the type genus of a new family, Chloracidobacteriaceae, within the order Blastocatellales, the class Blastocatellia, and the phylum Acidobacteriota.

scholarly journals Structural and functional characterization of a putative de novo gene in Drosophila

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Andreas Lange ◽  
Prajal H. Patel ◽  
Brennen Heames ◽  
Adam M. Damry ◽  
Thorsten Saenger ◽  
...  
Keyword(s):  
De Novo ◽  
Functional Characterization ◽  
Comparative Genomic ◽  
Noncoding Dna ◽  
Protein Coding ◽  
Ancestral Sequences ◽  
De Novo Gene ◽  
Genomic Studies ◽  
Biochemical Genetic

AbstractComparative genomic studies have repeatedly shown that new protein-coding genes can emerge de novo from noncoding DNA. Still unknown is how and when the structures of encoded de novo proteins emerge and evolve. Combining biochemical, genetic and evolutionary analyses, we elucidate the function and structure of goddard, a gene which appears to have evolved de novo at least 50 million years ago within the Drosophila genus. Previous studies found that goddard is required for male fertility. Here, we show that Goddard protein localizes to elongating sperm axonemes and that in its absence, elongated spermatids fail to undergo individualization. Combining modelling, NMR and circular dichroism (CD) data, we show that Goddard protein contains a large central α-helix, but is otherwise partially disordered. We find similar results for Goddard’s orthologs from divergent fly species and their reconstructed ancestral sequences. Accordingly, Goddard’s structure appears to have been maintained with only minor changes over millions of years.

scholarly journals Annotated Draft Genomes of Two Caddisfly Species Plectrocnemia conspersa CURTIS and Hydropsyche tenuis NAVAS (Insecta: Trichoptera)

2019 ◽  
Vol 11 (12) ◽  
pp. 3445-3451 ◽  
Author(s):  
Jacqueline Heckenhauer ◽  
Paul B Frandsen ◽  
Deepak K Gupta ◽  
Juraj Paule ◽  
Stefan Prost ◽  
...  
Keyword(s):  
De Novo ◽  
Low Cost ◽  
Gene Clusters ◽  
Genomic Region ◽  
Ecological Niches ◽  
Comparative Genomic ◽  
Insect Order ◽  
Wide Range ◽  
Sequencing Strategy ◽  
Genomic Studies

Abstract Members of the speciose insect order Trichoptera (caddisflies) provide important ecosystem services, for example, nutrient cycling through breaking down of organic matter. They are also of industrial interest due to their larval silk secretions. These form the basis for their diverse case-making behavior that allows them to exploit a wide range of ecological niches. Only five genomes of this order have been published thus far, with variable qualities regarding contiguity and completeness. A low-cost sequencing strategy, that is, using a single Oxford Nanopore flow cell per individual along with Illumina sequence reads was successfully used to generate high-quality genomes of two Trichoptera species, Plectrocnemia conspersa and Hydropsyche tenuis. Of the de novo assembly methods compared, assembly of low coverage Nanopore reads (∼18×) and subsequent polishing with long reads followed by Illumina short reads (∼80–170× coverage) yielded the highest genome quality both in terms of contiguity and BUSCO completeness. The presented genomes are the shortest to date and extend our knowledge of genome size across caddisfly families. The genomic region that encodes for light (L)-chain fibroin, a protein component of larval caddisfly silk was identified and compared with existing L-fibroin gene clusters. The new genomic resources presented in this paper are among the highest quality Trichoptera genomes and will increase the knowledge of this important insect order by serving as the basis for phylogenomic and comparative genomic studies.

scholarly journals Genomic Exploration of Within-Host Microevolution Reveals a Distinctive Molecular Signature of PersistentStaphylococcus aureusBacteraemia

2018 ◽  
Author(s):  
Stefano G. Giulieri ◽  
Sarah L. Baines ◽  
Romain Guerillot ◽  
Torsten Seemann ◽  
Anders Gonçalves da Silva ◽  
...  
Keyword(s):  
Large Scale ◽  
Point Mutations ◽  
Molecular Signature ◽  
Comparative Genomic ◽  
Structural Genomic ◽  
Large Scale Analysis ◽  
Genomic Studies ◽  
Genetic Mechanisms ◽  
Small Colony ◽  
Host Evolution

ABSTRACTBackgroundLarge-scale genomic studies of within-host evolution duringStaphylococcus aureusbacteraemia (SAB) are needed to understanding bacterial adaptation underlying persistence and thus refining the role of genomics in management of SAB. However, available comparative genomic studies of sequential SAB isolates have tended to focus on selected cases of unusually prolonged bacteraemia, where secondary antimicrobial resistance has developed. To understand the bacterial genomic evolution during SAB more broadly, we applied whole genome sequencing to a large collection of sequential isolates obtained from patients with persistent or relapsing bacteraemia.ResultsWe show that, while adapation pathways are heterogenous and episode-specific, isolates from persistent bacteraemia have a distinctive molecular signature, characterised by a low mutation frequency and high proportion of non-silent mutations. By performing an extensive analysis of structural genomic variants in addition to point mutations, we found that these often overlooked genetic events are commonly acquired during SAB. We discovered that IS256insertion may represent the most effective driver of within-host microevolution in selected lineages, with up to three new insertion events per isolate even in the absence of other mutations. Genetic mechanisms resulting in significant phenotypic changes, such as increases in vancomycin resistance, development of small colony phenotypes, and decreases in cytotoxicity, included mutations in key genes (rpoB, stp, agrA) and anIS256insertion upstream of thewalKRoperon.ConclusionsThis study provides for the first time a large-scale analysis of within-host evolution during invasiveS. aureusinfection and describes specific patterns of adaptation that will be informative for both understandingS. aureuspathoadaptation and utilising genomics for management of complicatedS. aureusinfections.

scholarly journals Structural and functional characterization of a putative de novo gene in Drosophila

2021 ◽  
Author(s):  
Andreas Lange ◽  
Prajal H. Patel ◽  
Brennen Heames ◽  
Adam M. Damry ◽  
Thorsten Saenger ◽  
...  
Keyword(s):  
De Novo ◽  
Functional Characterization ◽  
Comparative Genomic ◽  
Protein Coding ◽  
Ancestral Sequences ◽  
De Novo Gene ◽  
Genomic Studies ◽  
Biochemical Genetic ◽  
Α Helix

AbstractComparative genomic studies have repeatedly shown that new protein-coding genes can emerge de novo from non-coding DNA. Still unknown is how and when the structures of encoded de novo proteins emerge and evolve. Combining biochemical, genetic and evolutionary analyses, we elucidate the function and structure of goddard, a gene which appears to have evolved de novo at least 50 million years ago within the Drosophila genus.Previous studies found that goddard is required for male fertility. Here, we show that Goddard protein localizes to elongating sperm axonemes and that in its absence, elongated spermatids fail to undergo individualization. Combining modelling, NMR and CD data, we show that Goddard protein contains a large central α-helix, but is otherwise partially disordered. We find similar results for Goddard’s orthologs from divergent fly species and their reconstructed ancestral sequences. Accordingly, Goddard’s structure appears to have been maintained with only minor changes over millions of years.

scholarly journals Whole-genome sequence of the Tibetan frog Nanorana parkeri and the comparative evolution of tetrapod genomes

2015 ◽  
Vol 112 (11) ◽  
pp. E1257-E1262 ◽  
Author(s):  
Yan-Bo Sun ◽  
Zi-Jun Xiong ◽  
Xue-Yan Xiang ◽  
Shi-Ping Liu ◽  
Wei-Wei Zhou ◽  
...  
Keyword(s):  
De Novo ◽  
Structural Evolution ◽  
Whole Genome Sequence ◽  
Comparative Genomic ◽  
Whole Genome ◽  
Protein Coding ◽  
Comparable Rate ◽  
Evolutionary Studies ◽  
Genomic Studies ◽  
The Difference

The development of efficient sequencing techniques has resulted in large numbers of genomes being available for evolutionary studies. However, only one genome is available for all amphibians, that of Xenopus tropicalis, which is distantly related from the majority of frogs. More than 96% of frogs belong to the Neobatrachia, and no genome exists for this group. This dearth of amphibian genomes greatly restricts genomic studies of amphibians and, more generally, our understanding of tetrapod genome evolution. To fill this gap, we provide the de novo genome of a Tibetan Plateau frog, Nanorana parkeri, and compare it to that of X. tropicalis and other vertebrates. This genome encodes more than 20,000 protein-coding genes, a number similar to that of Xenopus. Although the genome size of Nanorana is considerably larger than that of Xenopus (2.3 vs. 1.5 Gb), most of the difference is due to the respective number of transposable elements in the two genomes. The two frogs exhibit considerable conserved whole-genome synteny despite having diverged approximately 266 Ma, indicating a slow rate of DNA structural evolution in anurans. Multigenome synteny blocks further show that amphibians have fewer interchromosomal rearrangements than mammals but have a comparable rate of intrachromosomal rearrangements. Our analysis also identifies 11 Mb of anuran-specific highly conserved elements that will be useful for comparative genomic analyses of frogs. The Nanorana genome offers an improved understanding of evolution of tetrapod genomes and also provides a genomic reference for other evolutionary studies.

scholarly journals Deciphering tea tree chloroplast and mitochondrial genomes of Camellia sinensis var. assamica

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Fen Zhang ◽  
Wei Li ◽  
Cheng-wen Gao ◽  
Dan Zhang ◽  
Li-zhi Gao
Keyword(s):  
Rna Editing ◽  
De Novo ◽  
Comparative Genomic ◽  
Protein Coding ◽  
Tea Tree ◽  
Repeat Sequences ◽  
Genomic Studies ◽  
Cp Genome ◽  
Mt Genome

Abstract Tea is the most popular non-alcoholic caffeine-containing and the oldest beverage in the world. In this study, we de novo assembled the chloroplast (cp) and mitochondrial (mt) genomes of C. sinensis var. assamica cv. Yunkang10 into a circular contig of 157,100 bp and two complete circular scaffolds (701719 bp and 177329 bp), respectively. We correspondingly annotated a total of 141 cp genes and 71 mt genes. Comparative analysis suggests repeat-rich nature of the mt genome compared to the cp genome, for example, with the characterization of 37,878 bp and 149 bp of long repeat sequences and 665 and 214 SSRs, respectively. We also detected 478 RNA-editing sites in 42 protein-coding mt genes, which are ~4.4-fold more than 54 RNA-editing sites detected in 21 protein-coding cp genes. The high-quality cp and mt genomes of C. sinensis var. assamica presented in this study will become an important resource for a range of genetic, functional, evolutionary and comparative genomic studies in tea tree and other Camellia species of the Theaceae family.

scholarly journals High-Density Genetic Map Construction and Identification of QTLs Controlling Leaf Abscission Trait in Poncirus trifoliata

2021 ◽  
Vol 22 (11) ◽  
pp. 5723
Author(s):  
Yuan-Yuan Xu ◽  
Sheng-Rui Liu ◽  
Zhi-Meng Gan ◽  
Ren-Fang Zeng ◽  
Jin-Zhi Zhang ◽  
...  
Keyword(s):  
Qtl Mapping ◽  
Linkage Map ◽  
Genetic Map ◽  
Expression Patterns ◽  
High Density ◽  
Poncirus Trifoliata ◽  
Leaf Abscission ◽  
Comparative Genomic ◽  
Map Comparison ◽  
Genomic Studies

A high-density genetic linkage map is essential for genetic and genomic studies including QTL mapping, genome assembly, and comparative genomic analysis. Here, we constructed a citrus high-density linkage map using SSR and SNP markers, which are evenly distributed across the citrus genome. The integrated linkage map contains 4163 markers with an average distance of 1.12 cM. The female and male linkage maps contain 1478 and 2976 markers with genetic lengths of 1093.90 cM and 1227.03 cM, respectively. Meanwhile, a genetic map comparison demonstrates that the linear order of common markers is highly conserved between the clementine mandarin and Poncirus trifoliata. Based on this high-density integrated citrus genetic map and two years of deciduous phenotypic data, two loci conferring leaf abscission phenotypic variation were detected on scaffold 1 (including 36 genes) and scaffold 8 (including 107 genes) using association analysis. Moreover, the expression patterns of 30 candidate genes were investigated under cold stress conditions because cold temperature is closely linked with the deciduous trait. The developed high-density genetic map will facilitate QTL mapping and genomic studies, and the localization of the leaf abscission deciduous trait will be valuable for understanding the mechanism of this deciduous trait and citrus breeding.

scholarly journals Jacobsen syndrome and neonatal bleeding: report on two unrelated patients

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Gregorio Serra ◽  
Luigi Memo ◽  
Vincenzo Antona ◽  
Giovanni Corsello ◽  
Valentina Favero ◽  
...  
Keyword(s):  
Developmental Delay ◽  
De Novo ◽  
Comparative Genomic ◽  
Fish Analysis ◽  
Variable Degree ◽  
Jacobsen Syndrome ◽  
Contiguous Gene ◽  
Clinical Consequences ◽  
11Q Deletion

Abstract Introduction In 1973, Petrea Jacobsen described the first patient showing dysmorphic features, developmental delay and congenital heart disease (atrial and ventricular septal defect) associated to a 11q deletion, inherited from the father. Since then, more than 200 patients have been reported, and the chromosomal critical region responsible for this contiguous gene disorder has been identified. Patients’ presentation We report on two unrelated newborns observed in Italy affected by Jacobsen syndrome (JBS, also known as 11q23 deletion). Both patients presented prenatal and postnatal bleeding, growth and developmental delay, craniofacial dysmorphisms, multiple congenital anomalies, and pancytopenia of variable degree. Array comparative genomic hybridization (aCGH) identified a terminal deletion at 11q24.1-q25 of 12.5 Mb and 11 Mb, in Patient 1 and 2, respectively. Fluorescent in situ hybridization (FISH) analysis of the parents documented a de novo origin of the deletion for Patient 1; parents of Patient 2 refused further genetic investigations. Conclusions Present newborns show the full phenotype of JBS including thrombocytopenia, according to their wide 11q deletion size. Bleeding was particularly severe in one of them, leading to a cerebral hemorrhage. Our report highlights the relevance of early diagnosis, genetic counselling and careful management and follow-up of JBS patients, which may avoid severe clinical consequences and lower the mortality risk. It may provide further insights and a better characterization of JBS, suggesting new elements of the genotype-phenotype correlations.

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