scholarly journals Phylogenetic Diversity of Marine Cyanophage Isolates and Natural Virus Communities as Revealed by Sequences of Viral Capsid Assembly Protein Gene g20

2002 ◽  
Vol 68 (4) ◽  
pp. 1576-1584 ◽  
Author(s):  
Yan Zhong ◽  
Feng Chen ◽  
Steven W. Wilhelm ◽  
Leo Poorvin ◽  
Robert E. Hodson
Keyword(s):  
Genetic Diversity ◽  
Geographic Distance ◽  
Open Ocean ◽  
Viral Capsid ◽  
Capsid Assembly ◽  
Sequencing Analysis ◽  
Phylogenetic Groups ◽  
High Genetic Diversity ◽  
Natural Virus ◽  
Capsid Assembly Protein

ABSTRACT In order to characterize the genetic diversity and phylogenetic affiliations of marine cyanophage isolates and natural cyanophage assemblages, oligonucleotide primers CPS1 and CPS8 were designed to specifically amplify ca. 592-bp fragments of the gene for viral capsid assembly protein g20. Phylogenetic analysis of isolated cyanophages revealed that the marine cyanophages were highly diverse yet more closely related to each other than to enteric coliphage T4. Genetically related marine cyanophage isolates were widely distributed without significant geographic segregation (i.e., no correlation between genetic variation and geographic distance). Cloning and sequencing analysis of six natural virus concentrates from estuarine and oligotrophic offshore environments revealed nine phylogenetic groups in a total of 114 different g20 homologs, with up to six clusters and 29 genotypes encountered in a single sample. The composition and structure of natural cyanophage communities in the estuary and open-ocean samples were different from each other, with unique phylogenetic clusters found for each environment. Changes in clonal diversity were also observed from the surface waters to the deep chlorophyll maximum layer in the open ocean. Only three clusters contained known cyanophage isolates, while the identities of the other six clusters remain unknown. Whether or not these unidentified groups are composed of bacteriophages that infect different Synechococcus groups or other closely related cyanobacteria remains to be determined. The high genetic diversity of marine cyanophage assemblages revealed by the g20 sequences suggests that marine viruses can potentially play important roles in regulating microbial genetic diversity.

Genetic Diversity and Genetic Differentiation of Rheum palmatum by Chloroplast matK Sequences

2020 ◽  
Vol 10 (2) ◽  
pp. 96-103
Author(s):  
Xiaoqin Zhang ◽  
Na Lin ◽  
Liping Chen ◽  
Zunjing Zhang ◽  
Houxing Lei ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Distance ◽  
Diversity Index ◽  
Geographic Distance ◽  
High Genetic Diversity ◽  
Rheum Palmatum ◽  
Wild Resources ◽  
Nj Tree ◽  
Matk Sequence ◽  
Over Exploitation

Background: Rheum palmatum is a medically important plant in the Polygonaceae family. Its wild resources have been declining due to over-exploitation. It is important and urgent to investigate the genetic diversity for the conservation of R. palmatum. Methods: The Chloroplast DNA matK sequences were used to assess genetic diversity among and within populations in this species. The genetic diversity index was calculated by Dnasp, PERMUT and Arlequin 3.0 software, and a Neighbor-Joining (NJ)-tree was constructed by MEGA 5.0 software. Results: Nine haplotypes were obtained based on the matK sequence analysis in fifteen populations. We found a relatively high genetic diversity in species level (Hd = 0.7414), and the genetic diversity among populations (FST = 0.81582) was higher than that within populations (FSC = 0.69526) according to the AMOVA analysis. The genetic distance between populations ranged from 0 to 0.0044, which within populations ranged from 0 to 0.001761. There was a significant correlation between genetic distance and geographic distance (r = 0.601, P < 0.001) according to the SPSS analysis. Conclusion: The genetic diversity among populations was higher than that within populations due to geographic isolation and decline in gene flow among populations. This study is significant for further studies concerned with efficient collection and preservation of wild resource of R. palmatum.

scholarly journals Genetic diversity and structure among natural populations of Mytilaria laosensis (Hamamelidaceae) revealed by microsatellite markers

2018 ◽  
Vol 67 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Niu Yu ◽  
Jie Yuan ◽  
Guangtian Yin ◽  
Jinchang Yang ◽  
Rongsheng Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Geographic Distance ◽  
Natural Populations ◽  
Magnetic Bead ◽  
Mantel Test ◽  
High Genetic Diversity ◽  
Information Index ◽  
Genetic Diversity And Structure ◽  
High Level ◽  
Mytilaria Laosensis

Abstract Mytilaria laosensis is a fast-growing tropical broadleaf tree that is extensively used for wood production and has significant ecological benefits. To investigate the genetic diversity and population structure of M. laosensis, eight major natural popu­lations in China were analyzed by using simple sequence repeat (SSR) markers. A total of 88 microsatellite-containing fragments were obtained by the method of magnetic bead enrichment, among which 26 pairs of SSR primers were scree­ned out and used to generate a total of 190 alleles among 152 individuals. The average of observed number of alleles, Shannon’s information index and polymorphism information content per locus were 18.3, 1.1577 and 0.7759, respectively, implying a high level of genetic diversity in M. laosensis popu­lations. The variation within populations accounted for 81.74 % of total variation based on analysis of molecular variance. Clus­ter analysis divided the eight populations into four groups, among which five populations from the southern parts of Guangxi province were classified as one major group. Mantel test showed that there was highly significant correlation bet­ween Euclidean genetic distance and geographic distance, suggesting that geographic isolation contribute to the high genetic diversity of M. laosensis. Together, these could provide support for the feasibility of exploration and utilization of M. laosensis in subtropical areas of East Asia including Jiangxi, Hunan and Fujian province of China.

Unique viral capsid assembly protein gene (g20) of cyanophages in the floodwater of a Japanese paddy field

2009 ◽  
Vol 46 (2) ◽  
pp. 93-102 ◽  
Author(s):  
Guanghua Wang ◽  
Jun Murase ◽  
Susumu Asakawa ◽  
Makoto Kimura
Keyword(s):  
Paddy Field ◽  
Protein Gene ◽  
Viral Capsid ◽  
Capsid Assembly ◽  
Capsid Assembly Protein

scholarly journals Identification of Local Citrus Breeds Using the Start-Codon Targeted Polymorphism Technique Combined with Clonal Sequencing

2021 ◽  
Vol 25 (01) ◽  
pp. 68-74
Author(s):  
Yanjun Guo
Keyword(s):  
Genetic Diversity ◽  
Start Codon ◽  
Sequencing Analysis ◽  
Similarity Coefficients ◽  
High Genetic Diversity ◽  
Protein Coding ◽  
Scot Marker ◽  
Citrus Germplasm ◽  
Mutational Hotspots ◽  
Citrus Varieties

This study explored the genetic diversity of 35 citrus accessions using start-codon targeted (SCoT) markers. Total 15 primers were used to amplify products ranging in length from 100 to 2000 bp. A total of 133 fragments were amplified and found that 126 (95%) were polymorphic. The genetic similarity coefficients among the 35 accessions ranged from 0.67 to 1.00, indicating that the SCoT markers could reveal high genetic diversity in the citrus germplasm. A cluster analysis showed that local citrus breeds of Sihui city fell into one cluster, possibly reflecting the geographical distribution of the tested samples. The sizesof the fragments of eight local citrus cultivars amplified by one of the primers ranged from 951 to 1001 bp, and the similitude was 95.17%high. Both single-base mutations, insertions and deletions were identified among the fragments and comparison with asequence database suggested that the amplified region was part of a ribosomal protein-coding sequence. Using Scot marks combined with clonal sequencing, each of the test samples had one or more mutation sites that could be used as markers to differentiate from the other seven test samples. Thus, the resolution of the genetic diversity among the local citrus breeds revealed by the SCoT technique was enhanced by the subsequent sequencing analysis of specific fragments. The experimental results also provide evidence that the relationship between CitrusnobilisL our. ‘gonggan’ and C. hanianaHort. ex Tseng ‘Sihuihanggan’ is that between parent and offspring hybrids and not between bud-mutation strains. The SCoT marker is a targeted gene molecular marker, based on the characteristic bands of primers, it can be used as a marker to isolate genes of local citrus varieties and also for investigating mutational hotspots of the segene.© 2021Friends Science Publishers

scholarly journals Association between spatial genetic variation and potential distribution in tree fern Alsophila gigantea (Cyatheaceae) in Hainan Island, China

2021 ◽  
Vol 49 (3) ◽  
pp. 12407
Author(s):  
Ting WANG ◽  
Zhen WANG ◽  
Shufeng LI ◽  
Zhanming YING ◽  
Xiaoxian RUAN ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Geographic Distance ◽  
Population Level ◽  
Hainan Island ◽  
Mantel Test ◽  
High Genetic Diversity ◽  
Spatial Genetic Variation

Spatial genetic variation involves spatial genetic structure (SGS) and genetic diversity is important genetic features of plants. We first evaluated spatial genetic structure (SGS) and genetic diversity among four populations of Alsophila gigantea from Hainan Island, China, using inter-simple sequence repeat (ISSR) markers. Significant but weak FSGS was found in A. gigantea. High genetic diversity was identified at the species level and the population level. AMOVA analysis revealed a low level of genetic differentiation among the four populations with high gene flow. Mantel test showed no significant correlation between genetic distance and geographic distance. It was found that association between annual mean temperature and annual precipitation with FSGS. Combined with these spatial genetic variation, abundant precipitation and suitable temperature create a stable environment for A. gigantea in Hainan Island, which allows the fern to expand rapidly during the LGM. These results further emphasized the role of outcrossing, and history and environmental factors in the evolution of A. gigantea. This study also provided new insights on in local adaptation of A. gigantea to environmental fluctuations, and available genetic data to enhance the conservation for relict tree ferns.

scholarly journals Environmental Heterogeneity Leads to Spatial Differences in Genetic Diversity and Demographic Structure of Acer caudatifolium

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1646
Author(s):  
Min-Xin Luo ◽  
Hsin-Pei Lu ◽  
Min-Wei Chai ◽  
Jui-Tse Chang ◽  
Pei-Chun Liao
Keyword(s):  
Genetic Diversity ◽  
Spatial Genetic Structure ◽  
Geographic Distance ◽  
Range Shift ◽  
Species Dispersal ◽  
Genetic Rescue ◽  
High Genetic Diversity ◽  
Local Climate ◽  
The North ◽  
Spatial Differences

Under climate fluctuation, species dispersal may be disturbed by terrain and local climate, resulting in uneven spatial-genetic structure. In addition, organisms at different latitudes may be differentially susceptible to climate change. Here, we tracked the seed dispersal of Acer caudatifolium using chloroplast DNA to explore the relationships of terrain and local climate heterogeneity with range shifts and demography in Taiwan. Our results showed that the extant populations have shifted upward and northward to the mountains since the Last Glacial Maximum. The distributional upshift of A. caudatifolium is in contrast to the downward expansion of its closest relative in Taiwan, A. morrisonense. The northern populations of A. caudatifolium have acquired multiple-source chlorotypes and harbor high genetic diversity. However, effective gene flow between the north and south is interrupted by topography, geographic distance, north-south differences in October rainfall, and other climate heterogeneities, blocking southward genetic rescue. In addition, winter monsoon-driven rainfall may cause regional differences in the phenological schedule, resulting in adaptive effects on the timing of range shift and the genetic draft of chlorotype distribution. Terrain, distance, and local climate also differentiate the northernmost populations from the others, supporting the previous taxonomic treatment of Acer kawakamii var. taitonmontanum as an independent variety.

scholarly journals High prevalence and genetic diversity of porcine bocaviruses in pigs in the USA, and identification of multiple novel porcine bocaviruses

2014 ◽  
Vol 95 (2) ◽  
pp. 453-465 ◽  
Author(s):  
Yong-Hou Jiang ◽  
Chao-Ting Xiao ◽  
Shuang-Hui Yin ◽  
Priscilla F. Gerber ◽  
Patrick G. Halbur ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Sequencing Analysis ◽  
Structural Protein ◽  
High Genetic Diversity ◽  
Vp2 Gene ◽  
Wild Pigs ◽  
Faecal Samples ◽  
High Prevalence ◽  
Complete Genomes ◽  
The Usa

Viruses in the genus Bocavirus are associated with respiratory and enteric disease in dogs and cattle. In addition, novel porcine bocaviruses (PBoVs) have been identified in domestic and wild pigs in recent years, but are of unknown relevance to date. The objectives of this study were to determine the prevalence ra tes and genetic diversity of PBoVs in pigs in the USA. Using newly established multiplex real-time PCR assays, 385 lung, lymph node, serum and faecal samples from pigs with various disease conditions were investigated. A high PBoV prevalence rate ranging from 21.3 to 50.8 % was identified in the investigated samples and often two or more PBoV species were detected in the same sample. Cloning and sequencing analysis of the partial non-structural protein NS1 and the capsid proteins VP1 and VP2 of DNA samples positive for PBoV groups 1 (n = 6), 2 (n = 16) and 3 (n = 42), including subgroups 3A, 3B or 3C, revealed a high genetic diversity especially for the PBoV G3 VP2 gene, whereas the PBoV group 1 VP1 gene displayed a low nucleotide polymorphism. Using primer walking, 18 partial or nearly complete genomes of PBoVs were obtained and six of the 18 nearly complete genomes represented novel PBoV species. Recombination analysis using partial NS1, VP1 and VP2 genes and the nearly complete genomes indicated possible recombination events within and between PBoVs. Further studies will be required to reveal the possible pathogenic role of these diverse PBoVs.

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