scholarly journals The saccharibacterium TM7x elicits differential responses across its host range

2020 ◽  
Vol 14 (12) ◽  
pp. 3054-3067 ◽  
Author(s):  
Daniel R. Utter ◽  
Xuesong He ◽  
Colleen M. Cavanaugh ◽  
Jeffrey S. McLean ◽  
Batbileg Bor
Keyword(s):  
Host Range ◽  
Growth Dynamics ◽  
Comparative Genomic ◽  
Bacterial Host ◽  
Genomic Features ◽  
Initial Infection ◽  
Symbiotic Interactions ◽  
Ideal System ◽  
Genomic Analyses ◽  
Crash Recovery

Abstract Host range is a fundamental component of symbiotic interactions, yet it remains poorly characterized for the prevalent yet enigmatic subcategory of bacteria/bacteria symbioses. The recently characterized obligate bacterial epibiont Candidatus Nanosynbacter lyticus TM7x with its bacterial host Actinomyces odontolyticus XH001 offers an ideal system to study such a novel relationship. In this study, the host range of TM7x was investigated by coculturing TM7x with various related Actinomyces strains and characterizing their growth dynamics from initial infection through subsequent co-passages. Of the twenty-seven tested Actinomyces, thirteen strains, including XH001, could host TM7x, and further classified into “permissive” and “nonpermissive” based on their varying initial responses to TM7x. Ten permissive strains exhibited growth/crash/recovery phases following TM7x infection, with crash timing and extent dependent on initial TM7x dosage. Meanwhile, three nonpermissive strains hosted TM7x without a growth-crash phase despite high TM7x dosage. The physical association of TM7x with all hosts, including nonpermissive strains, was confirmed by microscopy. Comparative genomic analyses revealed distinguishing genomic features between permissive and nonpermissive hosts. Our results expand the concept of host range beyond a binary to a wider spectrum, and the varying susceptibility of Actinomyces strains to TM7x underscores how small genetic differences between hosts can underly divergent selective trajectories.

scholarly journals Comparative Genomic Insights Into the Taxonomic Classification, Diversity, and Secondary Metabolic Potentials of Kitasatospora, a Genus Closely Related to Streptomyces

2021 ◽  
Vol 12 ◽  
Author(s):  
Yisong Li ◽  
Meng Wang ◽  
Zhong-Zhi Sun ◽  
Bin-Bin Xie
Keyword(s):  
Secondary Metabolism ◽  
Comparative Genomic ◽  
Metabolic Potential ◽  
Genomic Features ◽  
Separate Genus ◽  
The Family ◽  
Genomic Analyses ◽  
Genome Content ◽  
Phylogenomic Analyses ◽  
Close Relatives

While the genus Streptomyces (family Streptomycetaceae) has been studied as a model for bacterial secondary metabolism and genetics, its close relatives have been less studied. The genus Kitasatospora is the second largest genus in the family Streptomycetaceae. However, its taxonomic position within the family remains under debate and the secondary metabolic potential remains largely unclear. Here, we performed systematic comparative genomic and phylogenomic analyses of Kitasatospora. Firstly, the three genera within the family Streptomycetaceae (Kitasatospora, Streptomyces, and Streptacidiphilus) showed common genomic features, including high G + C contents, high secondary metabolic potentials, and high recombination frequencies. Secondly, phylogenomic and comparative genomic analyses revealed phylogenetic distinctions and genome content differences among these three genera, supporting Kitasatospora as a separate genus within the family. Lastly, the pan-genome analysis revealed extensive genetic diversity within the genus Kitasatospora, while functional annotation and genome content comparison suggested genomic differentiation among lineages. This study provided new insights into genomic characteristics of the genus Kitasatospora, and also uncovered its previously underestimated and complex secondary metabolism.

scholarly journals Draft Genome Sequences of Elsinoë fawcettii and Elsinoë australis Causing Scab Diseases on Citrus

2020 ◽  
Vol 33 (2) ◽  
pp. 135-137 ◽  
Author(s):  
Gnanendra Shanmugam ◽  
Junhyun Jeon ◽  
Jae-Wook Hyun
Keyword(s):  
Ab Initio ◽  
Host Range ◽  
Draft Genome ◽  
Phytopathogenic Fungi ◽  
Comparative Genomic ◽  
Sequence Information ◽  
Genome Sequences ◽  
High Quality ◽  
Genomic Analyses ◽  
Genome Sequence Information

Elsinoë fawcettii and E. australis (phylum Ascomycota) are phytopathogenic fungi causing scab diseases on citrus plants. We report here the high-quality draft genome sequences and ab initio gene predictions of two E. fawcettii strains and one E. australis strain, which differ in their host range. This genome sequence information will provide valuable resources to underpin genomic attributes for determining host range through comparative genomic analyses of citrus scab fungi.

scholarly journals The domestication of Cucurbita argyrosperma as revealed by the genome of its wild relative

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Josué Barrera-Redondo ◽  
Guillermo Sánchez-de la Vega ◽  
Jonás A. Aguirre-Liguori ◽  
Gabriela Castellanos-Morales ◽  
Yocelyn T. Gutiérrez-Guerrero ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Population Level ◽  
Growth Hormones ◽  
Comparative Genomic ◽  
Structural Variants ◽  
Closely Related Species ◽  
Level Data ◽  
Genomic Analyses ◽  
Genotype By Sequencing ◽  
Regulation Of Growth

AbstractDespite their economic importance and well-characterized domestication syndrome, the genomic impact of domestication and the identification of variants underlying the domestication traits in Cucurbita species (pumpkins and squashes) is currently lacking. Cucurbita argyrosperma, also known as cushaw pumpkin or silver-seed gourd, is a Mexican crop consumed primarily for its seeds rather than fruit flesh. This makes it a good model to study Cucurbita domestication, as seeds were an essential component of early Mesoamerican diet and likely the first targets of human-guided selection in pumpkins and squashes. We obtained population-level data using tunable Genotype by Sequencing libraries for 192 individuals of the wild and domesticated subspecies of C. argyrosperma across Mexico. We also assembled the first high-quality wild Cucurbita genome. Comparative genomic analyses revealed several structural variants and presence/absence of genes related to domestication. Our results indicate a monophyletic origin of this domesticated crop in the lowlands of Jalisco. We found evidence of gene flow between the domesticated and wild subspecies, which likely alleviated the effects of the domestication bottleneck. We uncovered candidate domestication genes that are involved in the regulation of growth hormones, plant defense mechanisms, seed development, and germination. The presence of shared selected alleles with the closely related species Cucurbita moschata suggests domestication-related introgression between both taxa.

Complete chloroplast genomes of Leptodermis scabrida complex: comparative genomic analyses and phylogenetic relationships

Gene ◽  
2021 ◽  
pp. 145715
Author(s):  
Ying Zhang ◽  
Zhengfeng Wang ◽  
Yanan Guo ◽  
Sheng Chen ◽  
Xianyi Xu ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Comparative Genomic ◽  
Chloroplast Genomes ◽  
Genomic Analyses

scholarly journals The chloroplast genome evolution of Venus slipper (Paphiopedilum): IR expansion, SSC contraction, and highly rearranged SSC regions

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yan-Yan Guo ◽  
Jia-Xing Yang ◽  
Ming-Zhu Bai ◽  
Guo-Qiang Zhang ◽  
Zhong-Jian Liu
Keyword(s):  
Gene Order ◽  
Inverted Repeat ◽  
Single Copy ◽  
Gene Content ◽  
Comparative Genomic ◽  
Substitution Rates ◽  
Plastome Evolution ◽  
Chloroplast Genomes ◽  
Ideal System ◽  
Small Single Copy

Abstract Background Paphiopedilum is the largest genus of slipper orchids. Previous studies showed that the phylogenetic relationships of this genus are not well resolved, and sparse taxon sampling documented inverted repeat (IR) expansion and small single copy (SSC) contraction of the chloroplast genomes of Paphiopedilum. Results Here, we sequenced, assembled, and annotated 77 plastomes of Paphiopedilum species (size range of 152,130 – 164,092 bp). The phylogeny based on the plastome resolved the relationships of the genus except for the phylogenetic position of two unstable species. We used phylogenetic and comparative genomic approaches to elucidate the plastome evolution of Paphiopedilum. The plastomes of Paphiopedilum have a conserved genome structure and gene content except in the SSC region. The large single copy/inverted repeat (LSC/IR) boundaries are relatively stable, while the boundaries of the inverted repeat and small single copy region (IR/SSC) varied among species. Corresponding to the IR/SSC boundary shifts, the chloroplast genomes of the genus experienced IR expansion and SSC contraction. The IR region incorporated one to six genes of the SSC region. Unexpectedly, great variation in the size, gene order, and gene content of the SSC regions was found, especially in the subg. Parvisepalum. Furthermore, Paphiopedilum provides evidence for the ongoing degradation of the ndh genes in the photoautotrophic plants. The estimated substitution rates of the protein coding genes show accelerated rates of evolution in clpP, psbH, and psbZ. Genes transferred to the IR region due to the boundary shift also have higher substitution rates. Conclusions We found IR expansion and SSC contraction in the chloroplast genomes of Paphiopedilum with dense sampling, and the genus shows variation in the size, gene order, and gene content of the SSC region. This genus provides an ideal system to investigate the dynamics of plastome evolution.

Evidence from comparative genomic analyses indicating that Lactobacillus-mediated irritable bowel syndrome alleviation is mediated by the conjugated linoleic acid synthesis

2021 ◽  
Author(s):  
Yang Liu ◽  
Wei Xiao ◽  
Leilei Yu ◽  
Fengwei Tian ◽  
Gang Wang ◽  
...  
Keyword(s):  
Irritable Bowel Syndrome ◽  
Linoleic Acid ◽  
Gut Microbiota ◽  
Acid Synthesis ◽  
Comparative Genomic ◽  
Low Grade ◽  
Genomic Analyses ◽  
Irritable Bowel ◽  
Low Grade Inflammation ◽  
Gut Microbiota Dysbiosis

Irritable bowel syndrome (IBS) is a chronic intestinal disorder accompanied by low-grade inflammation, visceral hypersensitivity, and gut microbiota dysbiosis. Several studies have indicated that Lactobacillus supplementation can help to alleviate...

scholarly journals Comparative genomic analyses of a virulent pseudorabies virus and a series of its in vitro passaged strains

2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Chao Ye ◽  
Jiqiang Wu ◽  
Wu Tong ◽  
Tongling Shan ◽  
Xuefei Cheng ◽  
...  
Keyword(s):  
Pseudorabies Virus ◽  
Comparative Genomic ◽  
Genomic Analyses

scholarly journals Rapid evolution and molecular convergence in cryptorchidism-related genes associated with inherently undescended testes in mammals

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Simin Chai ◽  
Ran Tian ◽  
Juanjuan Bi ◽  
Shixia Xu ◽  
Guang Yang ◽  
...  
Keyword(s):  
Muscle Development ◽  
Rapid Evolution ◽  
Genetic Material ◽  
Comparative Genomic ◽  
Testicular Descent ◽  
Ancestral State ◽  
Undescended Testes ◽  
Genomic Analyses ◽  
Genetic Mechanisms ◽  
Molecular Convergence

Abstract Background The mammalian testis is an important male exocrine gland and spermatozoa-producing organ that usually lies in extra-abdominal scrotums to provide a cooler environment for spermatogenesis and sperm storage. Testicles sometimes fail to descend, leading to cryptorchidism. However, certain groups of mammals possess inherently ascrotal testes (i.e. testes that do not descend completely or at all) that have the same physiological functions as completely descended scrotal testes. Although several anatomical and hormonal factors involved in testicular descent have been studied, there is still a paucity of comprehensive research on the genetic mechanisms underlying the evolution of testicular descent in mammals and how mammals with ascrotal testes maintain their reproductive health. Results We performed integrative phenotypic and comparative genomic analyses of 380 cryptorchidism-related genes and found that the mammalian ascrotal testes trait is derived from an ancestral scrotal state. Rapidly evolving genes in ascrotal mammals were enriched in the Hedgehog pathway—which regulates Leydig cell differentiation and testosterone secretion—and muscle development. Moreover, some cryptorchidism-related genes in ascrotal mammals had undergone positive selection and contained specific mutations and indels. Genes harboring convergent/parallel amino acid substitutions between ascrotal mammals were enriched in GTPase functions. Conclusions Our results suggest that the scrotal testis is an ancestral state in mammals, and the ascrotal phenotype was derived multiple times in independent lineages. In addition, the adaptive evolution of genes involved in testicular descent and the development of the gubernaculum contributed to the evolution of ascrotal testes. Accurate DNA replication, the proper segregation of genetic material, and appropriate autophagy are the potential mechanisms for maintaining physiological normality during spermatogenesis in ascrotal mammals. Furthermore, the molecular convergence of GTPases is probably a mechanism in the ascrotal testes of different mammals. This study provides novel insights into the evolution of the testis and scrotum in mammals and contributes to a better understanding of the pathogenesis of cryptorchidism in humans.

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