scholarly journals Eight new genomes of organohalide-respiring Dehalococcoides mccartyi reveal evolutionary trends in reductive dehalogenase enzymes

2018 ◽  
Author(s):  
Olivia Molenda ◽  
Shuiquan Tang ◽  
Line Lomheim ◽  
Elizabeth A. Edwards

ABSTRACTBackgroundBioaugmentation is now a well-established approach for attenuating toxic groundwater and soil contaminants, particularly for chlorinated ethenes and ethanes. The KB-1 and WBC-2 consortia are cultures used for this purpose. These consortia contain organisms belonging to the Dehalococcoidia, including strains of Dehalococcoides mccartyi in KB-1 and of both D. mccartyi and Dehalogenimonas in WBC-2. These tiny anaerobic bacteria couple respiratory reductive dechlorination to growth and harbour multiple reductive dehalogenase genes (rdhA) in their genomes, the majority of which have yet to be characterized.ResultsUsing a combination of Illumina mate-pair and paired-end sequencing we closed the genomes of eight new strains of Dehalococcoides mccartyi found in three related KB-1 sub-cultures that were enriched on trichloroethene (TCE), 1,2-dichloroethane (1,2-DCA) and vinyl chloride (VC), bringing the total number of genomes available in NCBI to 24. A pangenome analysis was conducted on 24 Dehalococcoides genomes and five Dehalogenimonas genomes (2 in draft) currently available in NCBI. This Dehalococcoidia pangenome generated 2875 protein families comprising of 623 core, 2203 accessory, and 49 unique protein families. In Dehalococcoides mccartyi the complement of reductive dehalogenase genes varies by strain, but what was most surprising was how the majority of rdhA sequences actually exhibit a remarkable degree of synteny across all D. mccartyi genomes. Several homologous sequences are also shared with Dehalogenimonas genomes. Nucleotide and predicted protein sequences for all reductive dehalogenases were aligned to begin to decode the evolutionary history of reductive dehalogenases in the Dehalococcoidia.ConclusionsThe conserved synteny of the rdhA genes observed across Dehalococcoides genomes indicates that the major differences between strain rdhA gene complement has resulted from gene loss rather than recombination. These rdhA have a long evolutionary history and trace their origin in the Dehalococcoidia prior to the speciation of Dehalococcoides and Dehalogenimonas. The only rdhA genes suspected to have been acquired by lateral gene transfer are protein-coding rdhA that have been identified to catalyze dehalogenation of industrial pollutants. Sequence analysis suggests that evolutionary pressures resulting in new rdhA genes involve adaptation of existing dehalogenases to new substrates, mobilization of rdhA between genomes or within a genome, and to a lesser degree manipulation of regulatory regions to alter expression.

2019 ◽  
Vol 8 (33) ◽  
Author(s):  
Jun Yan ◽  
Yi Yang ◽  
Xiuying Li ◽  
Frank E. Löffler

Dehalococcoides mccartyi strain FL2 couples growth to hydrogen oxidation and reductive dechlorination of trichloroethene and cis- and trans-1,2-dichloroethenes. Strain FL2 has a 1.42-Mb genome with a G+C content of 47.0% and carries 1,465 protein-coding sequences, including 24 reductive dehalogenase genes.


2018 ◽  
Vol 13 (1) ◽  
pp. 24-38 ◽  
Author(s):  
Olivia Molenda ◽  
Shuiquan Tang ◽  
Line Lomheim ◽  
Vasu K. Gautam ◽  
Sofia Lemak ◽  
...  

Author(s):  
Kazuaki Yamaguchi ◽  
Yuichiro Hara ◽  
Kaori Tatsumi ◽  
Osamu Nishimura ◽  
Jeramiah J. Smith ◽  
...  

AbstractThe group of hagfishes (Myxiniformes) arose from agnathan (jawless vertebrate) lineages and is one of the only two extant cyclostome taxa, together with lampreys (Petromyzontiformes). Even though whole genome sequencing has been achieved for diverse vertebrate taxa, genome-wide sequence information has been highly limited for cyclostomes. Here we sequenced the genome of the inshore hagfish Eptatretus burgeri using DNA extracted from the testis, with a short-read sequencing platform, aiming at reconstructing a high-coverage coding gene catalogue. The obtained genome assembly, scaffolded with mate-pair reads and paired RNA-seq reads, exhibited an N50 scaffold length of 293 Kbp, which allowed the genome-wide prediction of coding genes. This computation resulted in the gene models whose completeness was estimated at the complete coverage of more than 83 % and the partial coverage of more than 93 % by referring to evolutionarily conserved single-copy orthologs. The high contiguity of the assembly and completeness of resulting gene models promises a high utility in various comparative analyses including phylogenomics and phylome exploration.


2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Yi Yang ◽  
Leitao Huo ◽  
Xiuying Li ◽  
Jun Yan ◽  
Frank E. Löffler

ABSTRACT Sulfurospirillum sp. strain ACSDCE couples growth with reductive dechlorination of tetrachloroethene to cis-1,2-dichloroethene at pH values as low as 5.5. The genome sequence of strain ACSDCE consists of a circular 2,737,849-bp chromosome and a 39,868-bp plasmid and carries 2,737 protein-coding sequences, including two reductive dehalogenase genes.


Author(s):  
Noé Cochetel ◽  
Andrea Minio ◽  
Mélanie Massonnet ◽  
Amanda M Vondras ◽  
Rosa Figueroa-Balderas ◽  
...  

Abstract Muscadinia rotundifolia, the muscadine grape, has been cultivated for centuries in the southeastern United States. M. rotundifolia is resistant to many of the pathogens that detrimentally affect Vitis vinifera, the grape species commonly used for winemaking. For this reason, M. rotundifolia is a valuable genetic resource for breeding. Single-molecule real-time reads were combined with optical maps to reconstruct the two haplotypes of each of the 20 M. rotundifolia cv. Trayshed chromosomes. The completeness and accuracy of the assembly were confirmed using a high-density linkage map of M. rotundifolia. Protein-coding genes were annotated using an integrated and comprehensive approach. This included using Full-length cDNA sequencing (Iso-Seq) to improve gene structure and hypothetical spliced variant predictions. Our data strongly support that Muscadinia chromosomes 7 and 20 are fused in Vitis and pinpoint the location of the fusion in Cabernet Sauvignon and PN40024 chromosome 7. Disease-related gene numbers in Trayshed and Cabernet Sauvignon were similar, but their clustering locations were different. A dramatic expansion of the Toll/Interleukin-1 Receptor-like Nucleotide-Binding Site Leucine-Rich Repeat (TIR-NBS-LRR) class was detected on Trayshed chromosome 12 at the Resistance to Uncinula necator 1 (RUN1)/ Resistance to Plasmopara viticola 1 (RPV1) locus, which confers strong dominant resistance to powdery and downy mildews. A genome browser for Trayshed, its annotation, and an associated Blast tool are available at .www.grapegenomics.com


2020 ◽  
Vol 21 (24) ◽  
pp. 9746
Author(s):  
Shahina Akter ◽  
Sun-Young Lee ◽  
Muhammad Zubair Siddiqi ◽  
Sri Renukadevi Balusamy ◽  
Md. Ashrafudoulla ◽  
...  

It is essential to develop and discover alternative eco-friendly antibacterial agents due to the emergence of multi-drug-resistant microorganisms. In this study, we isolated and characterized a novel bacterium named Terrabacter humi MAHUQ-38T, utilized for the eco-friendly synthesis of silver nanoparticles (AgNPs) and the synthesized AgNPs were used to control multi-drug-resistant microorganisms. The novel strain was Gram stain positive, strictly aerobic, milky white colored, rod shaped and non-motile. The optimal growth temperature, pH and NaCl concentration were 30 °C, 6.5 and 0%, respectively. Based on 16S rRNA gene sequence, strain MAHUQ-38T belongs to the genus Terrabacter and is most closely related to several Terrabacter type strains (98.2%–98.8%). Terrabacter humi MAHUQ-38T had a genome of 5,156,829 bp long (19 contigs) with 4555 protein-coding genes, 48 tRNA and 5 rRNA genes. The culture supernatant of strain MAHUQ-38T was used for the eco-friendly and facile synthesis of AgNPs. The transmission electron microscopy (TEM) image showed the spherical shape of AgNPs with a size of 6 to 24 nm, and the Fourier transform infrared (FTIR) analysis revealed the functional groups responsible for the synthesis of AgNPs. The synthesized AgNPs exhibited strong anti-bacterial activity against multi-drug-resistant pathogens, Escherichia coli and Pseudomonas aeruginosa. Minimal inhibitory/bactericidal concentrations against E. coli and P. aeruginosa were 6.25/50 and 12.5/50 μg/mL, respectively. The AgNPs altered the cell morphology and damaged the cell membrane of pathogens. This study encourages the use of Terrabacter humi for the ecofriendly synthesis of AgNPs to control multi-drug-resistant microorganisms.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hong-Yan Zhao ◽  
Lin Wen ◽  
Yu-Feng Miao ◽  
Yu Du ◽  
Yan Sun ◽  
...  

Abstract Background A comprehensive evaluation of the -omic profiles of venom is important for understanding the potential function and evolution of snake venom. Here, we conducted an integrated multi-omics-analysis to unveil the venom-transcriptomic and venomic profiles in a same group of spine-bellied sea snakes (Hydrophis curtus) from the South China Sea, where the snake is a widespread species and might generate regionally-specific venom potentially harmful to human activities. The capacity of two heterologous antivenoms to immunocapture the H. curtus venom was determined for an in-depth evaluation of their rationality in treatment of H. curtus envenomation. In addition, a phylogenetic analysis by maximum likelihood was used to detect the adaptive molecular evolution of full-length toxin-coding unigenes. Results A total of 90,909,384 pairs of clean reads were generated via Illumina sequencing from a pooled cDNA library of six specimens, and yielding 148,121 unigenes through de novo assembly. Sequence similarity searching harvested 63,845 valid annotations, including 63,789 non-toxin-coding and 56 toxin-coding unigenes belonging to 22 protein families. Three protein families, three-finger toxins (3-FTx), phospholipase A2 (PLA2), and cysteine-rich secretory protein, were detected in the venom proteome. 3-FTx (27.15% in the transcriptome/41.94% in the proteome) and PLA2 (59.71%/49.36%) were identified as the most abundant families in the venom-gland transcriptome and venom proteome. In addition, 24 unigenes from 11 protein families were shown to have experienced positive selection in their evolutionary history, whereas four were relatively conserved throughout evolution. Commercial Naja atra antivenom exhibited a stronger capacity than Bungarus multicinctus antivenom to immunocapture H. curtus venom components, especially short neurotoxins, with the capacity of both antivenoms to immunocapture short neurotoxins being weaker than that for PLA2s. Conclusions Our study clarified the venom-gland transcriptomic and venomic profiles along with the within-group divergence of a H. curtus population from the South China Sea. Adaptive evolution of most venom components driven by natural selection appeared to occur rapidly during evolutionary history. Notably, the utility of commercial N. atra and B. multicinctus antivenoms against H. curtus toxins was not comprehensive; thus, the development of species-specific antivenom is urgently needed.


Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 643
Author(s):  
Thibaud Kuca ◽  
Brandy M. Marron ◽  
Joana G. P. Jacinto ◽  
Julia M. Paris ◽  
Christian Gerspach ◽  
...  

Genodermatosis such as hair disorders mostly follow a monogenic mode of inheritance. Congenital hypotrichosis (HY) belong to this group of disorders and is characterized by abnormally reduced hair since birth. The purpose of this study was to characterize the clinical phenotype of a breed-specific non-syndromic form of HY in Belted Galloway cattle and to identify the causative genetic variant for this recessive disorder. An affected calf born in Switzerland presented with multiple small to large areas of alopecia on the limbs and on the dorsal part of the head, neck, and back. A genome-wide association study using Swiss and US Belted Galloway cattle encompassing 12 cases and 61 controls revealed an association signal on chromosome 29. Homozygosity mapping in a subset of cases refined the HY locus to a 1.5 Mb critical interval and subsequent Sanger sequencing of protein-coding exons of positional candidate genes revealed a stop gain variant in the HEPHL1 gene that encodes a multi-copper ferroxidase protein so-called hephaestin like 1 (c.1684A>T; p.Lys562*). A perfect concordance between the homozygous presence of this most likely pathogenic loss-of-function variant and the HY phenotype was found. Genotyping of more than 700 purebred Swiss and US Belted Galloway cattle showed the global spread of the mutation. This study provides a molecular test that will permit the avoidance of risk matings by systematic genotyping of relevant breeding animals. This rare recessive HEPHL1-related form of hypotrichosis provides a novel large animal model for similar human conditions. The results have been incorporated in the Online Mendelian Inheritance in Animals (OMIA) database (OMIA 002230-9913).


Heredity ◽  
2021 ◽  
Author(s):  
Yael S. Rodger ◽  
Alexandra Pavlova ◽  
Steve Sinclair ◽  
Melinda Pickup ◽  
Paul Sunnucks

AbstractConservation management can be aided by knowledge of genetic diversity and evolutionary history, so that ecological and evolutionary processes can be preserved. The Button Wrinklewort daisy (Rutidosis leptorrhynchoides) was a common component of grassy ecosystems in south-eastern Australia. It is now endangered due to extensive habitat loss and the impacts of livestock grazing, and is currently restricted to a few small populations in two regions >500 km apart, one in Victoria, the other in the Australian Capital Territory and nearby New South Wales (ACT/NSW). Using a genome-wide SNP dataset, we assessed patterns of genetic structure and genetic differentiation of 12 natural diploid populations. We estimated intrapopulation genetic diversity to scope sources for genetic management. Bayesian clustering and principal coordinate analyses showed strong population genetic differentiation between the two regions, and substantial substructure within ACT/NSW. A coalescent tree-building approach implemented in SNAPP indicated evolutionary divergence between the two distant regions. Among the populations screened, the last two known remaining Victorian populations had the highest genetic diversity, despite having among the lowest recent census sizes. A maximum likelihood population tree method implemented in TreeMix suggested little or no recent gene flow except potentially between very close neighbours. Populations that were more genetically distinctive had lower genetic diversity, suggesting that drift in isolation is likely driving population differentiation though loss of diversity, hence re-establishing gene flow among them is desirable. These results provide background knowledge for evidence-based conservation and support genetic rescue within and between regions to elevate genetic diversity and alleviate inbreeding.


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