scholarly journals Comparison of Whole Plastome Sequences between Thermogenic Skunk Cabbage Symplocarpus renifolius and Nonthermogenic S. nipponicus (Orontioideae; Araceae) in East Asia

2019 ◽  
Vol 20 (19) ◽  
pp. 4678 ◽  
Author(s):  
Seon-Hee Kim ◽  
JiYoung Yang ◽  
Jongsun Park ◽  
Takayuki Yamada ◽  
Masayuki Maki ◽  
...  
Keyword(s):  
Hot Spot ◽  
Evolutionary Relationship ◽  
Early Spring ◽  
Base Pairs ◽  
Complete Chloroplast Genome ◽  
Noncoding Regions ◽  
Species Pairs ◽  
Skunk Cabbage ◽  
Basal Position ◽  
Simple Sequence

Symplocarpus, a skunk cabbage genus, includes two sister groups, which are drastically different in life history traits and thermogenesis, as follows: The nonthermogenic summer flowering S. nipponicus and thermogenic early spring flowering S. renifolius. Although the molecular basis of thermogenesis and complete chloroplast genome (plastome) of thermogenic S. renifolius have been well characterized, very little is known for that of S. nipponicus. We sequenced the complete plastomes of S. nipponicus sampled from Japan and Korea and compared them with that of S. renifolius sampled from Korea. The nonthermogenic S. nipponicus plastomes from Japan and Korea had 158,322 and 158,508 base pairs, respectively, which were slightly shorter than the thermogenic plastome of S. renifolius. No structural or content rearrangements between the species pairs were found. Six highly variable noncoding regions (psbC/trnS, petA/psbJ, trnS/trnG, trnC/petN, ycf4/cemA, and rpl3/rpl22) were identified between S. nipponicus and S. renifolius and 14 hot-spot regions were also identified at the subfamily level. We found a similar total number of SSR (simple sequence repeat) motifs in two accessions of S. nipponicus sampled from Japan and Korea. Phylogenetic analysis supported the basal position of subfamily Orontioideae and the monophyly of genus Symplocarpus, and also revealed an unexpected evolutionary relationship between S. nipponicus and S. renifolius.

scholarly journals Targeting the ALS/FTD-associated A-DNA kink with anthracene-based metal complex causes DNA backbone straightening and groove contraction

2021 ◽  
Author(s):  
Cyong-Ru Jhan ◽  
Roshan Satange ◽  
Shun-Ching Wang ◽  
Jing-Yi Zeng ◽  
Yih-Chern Horng ◽  
...  
Keyword(s):  
Hot Spot ◽  
Hydration Shell ◽  
Repeat Motif ◽  
Dna Duplex ◽  
Base Pairs ◽  
Dna And Rna ◽  
Detailed Structural Analysis ◽  
Small Molecule Compound ◽  
Dna Backbone ◽  
Locomotor Deficits

Abstract The use of a small molecule compound to reduce toxic repeat RNA transcripts or their translated aberrant proteins to target repeat-expanded RNA/DNA with a G4C2 motif is a promising strategy to treat C9orf72-linked disorders. In this study, the crystal structures of DNA and RNA–DNA hybrid duplexes with the -GGGCCG- region as a G4C2 repeat motif were solved. Unusual groove widening and sharper bending of the G4C2 DNA duplex A-DNA conformation with B-form characteristics inside was observed. The G4C2 RNA–DNA hybrid duplex adopts a more typical rigid A form structure. Detailed structural analysis revealed that the G4C2 repeat motif of the DNA duplex exhibits a hydration shell and greater flexibility and serves as a ‘hot-spot’ for binding of the anthracene-based nickel complex, NiII(Chro)2 (Chro = Chromomycin A3). In addition to the original GGCC recognition site, NiII(Chro)2 has extended specificity and binds the flanked G:C base pairs of the GGCC core, resulting in minor groove contraction and straightening of the DNA backbone. We have also shown that Chro-metal complexes inhibit neuronal toxicity and suppresses locomotor deficits in a Drosophila model of C9orf72-associated ALS. The approach represents a new direction for drug discovery against ALS and FTD diseases by targeting G4C2 repeat motif DNA.

scholarly journals Effects of floral thermogenesis on pollen function in Asian skunk cabbage Symplocarpus renifolius

2009 ◽  
Vol 5 (4) ◽  
pp. 568-570 ◽  
Author(s):  
Roger S. Seymour ◽  
Yuka Ito ◽  
Yoshihiko Onda ◽  
Kikukatsu Ito
Keyword(s):  
Growth Rate ◽  
Pollen Germination ◽  
Narrow Range ◽  
Temperature Tolerance ◽  
Early Spring ◽  
Long Period ◽  
Pollen Tube Growth Rate ◽  
Skunk Cabbage ◽  
Effects Of Temperature

The effects of temperature on pollen germination and pollen tube growth rate were measured in vitro in thermogenic skunk cabbage, Symplocarpus renifolius Schott ex Tzvelev, and related to floral temperatures in the field. This species has physiologically thermoregulatory spadices that maintain temperatures near 23°C, even in sub-freezing air. Tests at 8, 13, 18, 23, 28 and 33°C showed sharp optima at 23°C for both variables, and practically no development at 8°C. Thermogenesis is therefore a requirement for fertilization in early spring. The narrow temperature tolerance is probably related to a long period of evolution in flowers that thermoregulate within a narrow range.

Organization of the noncontiguous promoter components of adenovirus VAI RNA gene is strikingly similar to that of eucaryotic tRNA genes

1983 ◽  
Vol 3 (11) ◽  
pp. 1996-2005
Author(s):  
R A Bhat ◽  
B Metz ◽  
B Thimmappaya
Keyword(s):  
Dna Sequences ◽  
Transcriptional Control ◽  
Transcriptional Activity ◽  
Evolutionary Relationship ◽  
Trna Genes ◽  
Wild Type ◽  
Base Pairs ◽  
Internal Promoter ◽  
Cell Extracts

The intragenic transcriptional control region (internal promoter) of the adenovirus type 2 VAI RNA gene was mutated by deletion, insertion, and substitution of DNA sequences at the plasmid level. The mutant plasmids were assayed for in vitro transcriptional activity by using HeLa cell extracts. The mutant clones with substitution or insertion of DNA sequences or both between nucleotides +18 and +53 of the VAI RNA gene were all transcriptionally active, although to various extents. Substitution of unrelated DNA sequences up to +26 or between +54 and +61 abolished the transcriptional activity completely. Based on these results, the intragenic promoter sequences of the VAI RNA gene can be subdivided into two components: element A, +10 to +18; and element B, +54 to +69. The distance between the A and B components could be enlarged from its normal 35 base pairs to 75 base pairs without destroying the transcriptional activity. However, a deletion of 4 or 6 base pairs in the DNA segment separating the A and B components (segment C) reduced the transcriptional activity of the genes to less than 2% of that of the wild type. When the VAI RNA gene with its element A or B was substituted for the corresponding element A or B of the Xenopus laevis tRNAMet gene, the hybrid genes transcribed close to the level of the wild-type VAI RNA gene and about 10- to 20-fold more efficiently than the tRNAMet gene. Thus, the organization of DNA sequences in the internal promoter of the VAI RNA gene appears to be very similar to that of eucaryotic tRNA genes. This similarity suggests an evolutionary relationship of the VAI RNA gene to tRNA genes.

scholarly journals Analysis of genetic diversity and population structure in Asparagus species using SSR markers

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Manish Kapoor ◽  
Pooja Mawal ◽  
Vikas Sharma ◽  
Raghbir Chand Gupta
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Mean Value ◽  
Discrete Groups ◽  
Base Pairs ◽  
High Genetic Diversity ◽  
Pharmaceutical Industries ◽  
Improvement Programs ◽  
Northwest India ◽  
Simple Sequence

Abstract Background Various Asparagus species constitute the significant vegetable and medicinal genetic resource throughout the world. Asparagus species serve as important commodity of food and pharmaceutical industries in India. A diverse collection of Asparagus species from different localities of Northwest India was investigated for its genetic diversity using simple sequence repeat (SSR) markers. Results Polymorphic SSR markers revealed high genetic diversity. Primer SSR-15 amplified maximum of 8 fragments while 3 primers, namely, SSR-43, SSR-63, and AGA1 amplified minimum of 3 fragments. Collectively, 122 alleles were amplified in a range between 3 and 8 with an average of 5 alleles per marker. The size of the amplified alleles ranged between 90 and 680 base pairs. Polymorphism information content (PIC) value varied from a highest value of 0.499 in primer AGA1 to a lowest value of 0.231 in primer SSR-63 with a mean value of 0.376 showing considerable SSR polymorphism. Dendrogram developed on the basis of Jaccard’s similarity coefficient and neighbor-joining tree segregated all the studied Asparagus species into two discrete groups. Structure analysis based on Bayesian clustering allocated different accessions to two independent clusters and exhibited low level of individual admixture. Conclusions The genetic diversity analysis showed a conservative genetic background for maximum species of asparagus. Only Accessions of Asparagus adscendens were split into two diverse clusters suggesting a wide genetic base of this species as compared to other species. Overall genetic diversity was high, and this germplasm of Asparagus can be used in future improvement programs. The findings of current research on Asparagus germplasm can make a momentous contribution to initiatives of interbreeding, conservation, and improvement of Asparagus in future.

scholarly journals Genetic Variability and Taxonomic Status of the Nihoa and Laysan Millerbirds

The Condor ◽  
2007 ◽  
Vol 109 (4) ◽  
pp. 954-962
Author(s):  
Robert C. Fleischer ◽  
Beth Slikas ◽  
Jon Beadell ◽  
Colm Atkins ◽  
Carl E. McINTOSH ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Microsatellite Loci ◽  
Sequence Divergence ◽  
Taxonomic Status ◽  
Small Population ◽  
Base Pairs ◽  
Stochastic Effects ◽  
Mtdna Sequence ◽  
Species Pairs ◽  
Two Populations

Abstract The Millerbird (Acrocephalus familiaris) is an endemic Northwestern Hawaiian Islands reed warbler that existed until about 1923 on Laysan Island (A. f. familiaris) and currently occurs in a small population on Nihoa Island (A. f. kingi). The two populations are described as separate subspecies or species on the basis of size and plumage differences. We assessed genetic variation in blood samples from 15 individuals in the modern Nihoa population using approximately 3000 base pairs (bp) of mitochondrial DNA (mtDNA) sequence and 14 microsatellite loci. We also obtained up to 1028 bp of mtDNA sequence from the fragmented DNA of museum specimens of three birds collected on Nihoa in 1923 and five birds collected on Laysan in 1902 and 1911 (ancient samples). Genetic variation in both marker types was extremely low in the modern Nihoa population (nucleotide diversity [π]  =  0.00005 for mtDNA sequences; observed heterozygosity was 7.2% for the microsatellite loci). In contrast, we found three mtDNA haplotypes among the five Laysan individuals (π  =  0.0023), indicating substantially greater genetic variation. The Nihoa and Laysan taxa differed by 1.7% uncorrected mtDNA sequence divergence, a magnitude that would support designation at the subspecies, and perhaps species, level relative to other closely related Acrocephalus species pairs. However, in light of strong ecological similarity between the two taxa, and a need to have additional populations to prevent extinction from stochastic effects and catastrophes, we believe these genetic differences should not deter a potential translocation of individuals from Nihoa to Laysan.

Complete chloroplast genome sequence of Magnolia kwangsiensis (Magnoliaceae): implication for DNA barcoding and population genetics

Genome ◽  
2011 ◽  
Vol 54 (8) ◽  
pp. 663-673 ◽  
Author(s):  
Dai-Yong Kuang ◽  
Hong Wu ◽  
Ya-Ling Wang ◽  
Lian-Ming Gao ◽  
Shou-Zhou Zhang ◽  
...  
Keyword(s):  
Population Genetics ◽  
Gc Content ◽  
Single Copy ◽  
Phylogenetic Study ◽  
Complete Chloroplast Genome ◽  
Noncoding Regions ◽  
Its Gene ◽  
Study Population ◽  
Chloroplast Genome Sequence ◽  
Small Single Copy

Here, we report a completely sequenced plastome using Illumina/Solexa sequencing-by-synthesis (SBS) technology. The plastome of Magnolia kwangsiensis Figlar & Noot. is 159 667 bp in length with a typical quadripartite structure: 88 030 bp large single-copy (LSC) and 18 669 bp small single-copy (SSC) regions, separated by two 26 484 bp inverted repeat (IR) regions. The overall predicted gene number is 129, among which 17 genes are duplicated in IR regions. The plastome of M. kwangsiensis is identical in its gene order to previously published plastomes of magnoliids. Furthermore, the C-to-U type RNA editing frequency of 114 seed plants is positively correlated with plastome GC content and plastome length, whereas plastome length is not correlated with GC content. A total of 16 potential putative barcoding or low taxonomic level phylogenetic study markers in Magnoliaceae were detected by comparing the coding and noncoding regions of the plastome of M. kwangsiensis with that of Liriodendron tulipifera L. At least eight markers might be applied not only to Magnoliaceae but also to other taxa. The 86 mononucleotide cpSSRs that distributed in single-copy noncoding regions are highly valuable to study population genetics and conservation genetics of this endangered rare species.

A new stochastic model of microsatellite evolution

1999 ◽  
Vol 36 (3) ◽  
pp. 621-631 ◽  
Author(s):  
Richard Durrett ◽  
Semyon Kruglyak
Keyword(s):  
Markov Chain ◽  
Continuous Time ◽  
Markov Chain Model ◽  
Chain Model ◽  
Continuous Time Markov Chain ◽  
Base Pairs ◽  
Microsatellite Evolution ◽  
Experimental Findings ◽  
Best Fit ◽  
Simple Sequence

We introduce a continuous-time Markov chain model for the evolution of microsatellites, simple sequence repeats in DNA. We prove the existence of a unique stationary distribution for our model, and fit the model to data from approximately 106 base pairs of DNA from fruit flies, mice, and humans. The slippage rates from the best fit for our model are consistent with experimental findings.

scholarly journals Homologous Crossovers among Molecules of Brome Mosaic Bromovirus RNA1 or RNA2 Segments In Vivo

2005 ◽  
Vol 79 (9) ◽  
pp. 5732-5742 ◽  
Author(s):  
Anna Urbanowicz ◽  
Magdalena Alejska ◽  
Piotr Formanowicz ◽  
Jacek Błażewicz ◽  
Marek Figlerowicz ◽  
...  
Keyword(s):  
Hot Spot ◽  
Rna Replication ◽  
Viral Rna ◽  
Noncoding Regions ◽  
Genome Variability ◽  
Coding Regions ◽  
Virus Life Cycle ◽  
Brome Mosaic Bromovirus ◽  
Rna Genome

ABSTRACT Previously we demonstrated frequent homologous crossovers among molecules of the RNA3 segment in the tripartite brome mosaic bromovirus (BMV) RNA genome (A. Bruyere, M. Wantroba, S. Flasinski, A. Dzianott, and J. J. Bujarski, J. Virol. 74:4214-4219, 2000). To further our knowledge about mechanisms of viral RNA genome variability, in this paper we have studied homologous recombination in BMV RNA1 and RNA2 components during infection. We have found that basal RNA-RNA crossovers could occur within coding regions of both RNAs, although recombination frequencies slightly varied at different RNA sections. In all cases, the frequencies were much lower than the rate observed for the intercistronic recombination hot spot in BMV RNA3. Probability calculations accounted for at least one homologous crossover per RNA molecule per replication cycle. In addition, we have demonstrated an efficient repair of mutations within the conserved 3′ and 5′ noncoding regions, most likely due to error-prone BMV RNA replication. Overall, our data verify that homologous crossovers are common events a during virus life cycle, and we discuss their importance for viral RNA genetics.

scholarly journals Genetic variation in Hydrangea macrophylla (Thunb.) Ser. in Russia based on simple sequence repeat markers

2018 ◽  
Vol 47 (4) ◽  
pp. 937-943
Author(s):  
Natalia Sukhikh ◽  
Valentina Malyarovskaya ◽  
Anastasiya Kamionskaya ◽  
Lidia Samarina ◽  
Svetlana Vinogradova
Keyword(s):  
Simple Sequence Repeat ◽  
Genetic Relationships ◽  
Effective Number ◽  
Sequence Repeat ◽  
Base Pairs ◽  
Breeding Programs ◽  
Simple Sequence Repeat Markers ◽  
Hydrangea Macrophylla ◽  
High Level ◽  
Simple Sequence

Genetic diversity and genetic relationships among 39 accessions of Hydrangea macrophylla (Thunb.) Ser. were analyzed using 38 previously developed simple sequence repeat markers (SSRs). A total of 38 polymorphic primers representing 166 bands with an average of 4.53 polymorphic bands per primer were selected. The number of alleles detected per locus ranged from two to eight with a total of 163 alleles amplified. The size of the amplified fragments ranged from 70 to180 base pairs. The effective multiallelic markers with high level of heterozygosity (more than 0.7) and effective number of alleles (more than 3.5) were identified. In this study nine SSR markers showed clear polymorphisms. The dendrogram grouped all hybrids in three major clusters, and two of these clusters included only mophead cultivars. The lacecap cultivars clustered more closely to each other. The results of this research could be used in breeding programs of H. macrophylla.

scholarly journals The Complete Chloroplast Genome of Critically Endangered Chimonobambusa hirtinoda (Poaceae: Chimonobambusa) and Phylogenetic Analysis

2021 ◽  
Author(s):  
yanjiang liu ◽  
Xiao Zhu ◽  
Mingli Wu ◽  
Xue Xu ◽  
Zhaoxia Dai ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Gc Content ◽  
Trna Genes ◽  
Protein Coding ◽  
Complete Chloroplast Genome ◽  
Usage Frequency ◽  
Cp Genome ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing ◽  
Simple Sequence

Abstract Chimonobambusa hirtinoda is a threatened species and only naturally distributed in Doupeng Mountain, Duyun, Guizhou, China. Next-generation sequencing (NGS) is used obtained the complete chloroplast (cp) genome sequence of C. hirtinoda, and then the sequence was assembled and analyze for phylogenetic and evolutionary. We also analyzed comparing the cp genome among Chimonobambusa species with previously published. The complete cp genome of C. hirtinoda has the total length of 139, 561 bp, 38.90% GC content was detected. A total of 130 genes were founded in the cp genome, including 85 protein coding genes, 37 tRNA genes, 8 rRNA. Some genes are missing and the introns occur lost in the cp genome of C. hirtinoda. A total of 48 simple sequence repeat (SSR) were detected and by measuring the codon usage frequency of amino acids, the A/U preference of the third nucleotide in the cp genome of C. hirtinoda was obtained. Furthermore, phylogenetic analysis using complete cp sequences, matk gene exhibited genetic relationship within the Chimonobambusa genus.

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