scholarly journals Genetic Diversity among Botulinum Neurotoxin-Producing Clostridial Strains

2006 ◽  
Vol 189 (3) ◽  
pp. 818-832 ◽  
Author(s):  
K. K. Hill ◽  
T. J. Smith ◽  
C. H. Helma ◽  
L. O. Ticknor ◽  
B. T. Foley ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Common Property ◽  
Animal Species ◽  
Fragment Length Polymorphism ◽  
Aflp Analysis ◽  
Rrna Gene ◽  
Botulinum Neurotoxins ◽  
The Common ◽  
Multiple Strains ◽  
The 16S Rrna Gene

ABSTRACT Clostridium botulinum is a taxonomic designation for many diverse anaerobic spore-forming rod-shaped bacteria that have the common property of producing botulinum neurotoxins (BoNTs). The BoNTs are exoneurotoxins that can cause severe paralysis and death in humans and other animal species. A collection of 174 C. botulinum strains was examined by amplified fragment length polymorphism (AFLP) analysis and by sequencing of the 16S rRNA gene and BoNT genes to examine the genetic diversity within this species. This collection contained representatives of each of the seven different serotypes of botulinum neurotoxins (BoNT/A to BoNT/G). Analysis of the16S rRNA gene sequences confirmed previous identifications of at least four distinct genomic backgrounds (groups I to IV), each of which has independently acquired one or more BoNT genes through horizontal gene transfer. AFLP analysis provided higher resolution and could be used to further subdivide the four groups into subgroups. Sequencing of the BoNT genes from multiple strains of serotypes A, B, and E confirmed significant sequence variation within each serotype. Four distinct lineages within each of the BoNT A and B serotypes and five distinct lineages of serotype E strains were identified. The nucleotide sequences of the seven toxin genes of the serotypes were compared and showed various degrees of interrelatedness and recombination, as was previously noted for the nontoxic nonhemagglutinin gene, which is linked to the BoNT gene. These analyses contribute to the understanding of the evolution and phylogeny within this species and assist in the development of improved diagnostics and therapeutics for the treatment of botulism.

scholarly journals Genetic Diversity and Phylogeny of Rhizobia That Nodulate Acacia spp. in Morocco Assessed by Analysis of rRNA Genes

1998 ◽  
Vol 64 (12) ◽  
pp. 4912-4917 ◽  
Author(s):  
Bouchaib Khbaya ◽  
Marc Neyra ◽  
Philippe Normand ◽  
Karim Zerhari ◽  
Abdelkarim Filali-Maltouf
Keyword(s):  
Genetic Diversity ◽  
Fragment Length Polymorphism ◽  
Rflp Analysis ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
The Third ◽  
The 16S Rrna Gene ◽  
Rdna Analysis ◽  
Restriction Fragment Length

ABSTRACT Forty rhizobia nodulating four Acacia species (A. gummifera, A. raddiana, A. cyanophylla, and A. horrida) were isolated from different sites in Morocco. These rhizobia were compared by analyzing both the 16S rRNA gene (rDNA) and the 16S-23S rRNA spacer by PCR with restriction fragment length polymorphism (RFLP) analysis. Analysis of the length of 16S-23S spacer showed a considerable diversity within these microsymbionts, but RFLP analysis of the amplified spacer revealed no additional heterogeneity. Three clusters were identified when 16S rDNA analysis was carried out. Two of these clusters include some isolates which nodulate, nonspecifically, the four Acacia species. These clusters, A and B, fit within the Sinorhizobiumlineage and are closely related to S. meliloti and S. fredii, respectively. The third cluster appeared to belong to theAgrobacterium-Rhizobium galegae phylum and is more closely related to the Agrobacterium tumefaciens species. These relations were confirmed by sequencing a representative strain from each cluster.

scholarly journals Genetic Diversity of Rhubarb Cultivars

2008 ◽  
Vol 133 (4) ◽  
pp. 587-592 ◽  
Author(s):  
Joseph C. Kuhl ◽  
Veronica L. DeBoer
Keyword(s):  
Genetic Diversity ◽  
Central Asia ◽  
Length Polymorphism ◽  
Genetic Relationship ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
18Th Century ◽  
Pedigree Information ◽  
Aflp Analysis ◽  
Fingerprint Analysis

The genus Rheum L., commonly known as rhubarb, is composed of ≈60 species, primarily distributed throughout northern and central Asia. Rhubarb species have been used for medicinal purposes for thousands of years; however, it was not until the 18th century that the culinary use of petioles was first reported. Although the origin(s) of culinary rhubarb is not clear, it is thought that they originated from hybridization of rhubarb species originally brought to Europe for medicinal purposes. Most rhubarb cultivars lack pedigree information, and the genetic relationship among cultivars is largely unknown. Amplified fragment length polymorphism (AFLP) markers were generated for fingerprint analysis of 37 cultivars and four putative Rheum species accessions. Ten EcoRI and MseI primer combinations were analyzed for a total of 1400 scored polymorphisms, with an average of 140 polymorphisms per primer combination. Results show at least two clusters of related cultivars, as well as distantly related accessions. This study provides an estimate of rhubarb cultivar genetic diversity using AFLP analysis.

A new species of Puddle Frog, genus Phrynobatrachus (Amphibia: Anura: Phrynobatrachidae) from Ghana

Zootaxa ◽  
2018 ◽  
Vol 4374 (4) ◽  
pp. 565 ◽  
Author(s):  
CALEB OFORI-BOATENG ◽  
ADAM D. LEACHÉ ◽  
BRIGHT OBENG-KANKAM ◽  
N’GORAN GERMAIN KOUAMÉ ◽  
ANNIKA HILLERS ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
New Species ◽  
Sequence Data ◽  
Face Mask ◽  
West African ◽  
Rrna Gene ◽  
Forest Region ◽  
Mtdna Sequence ◽  
A New Species ◽  
The 16S Rrna Gene

We describe a new species of Phrynobatrachus from the eastern part of the Upper Guinea forest region, Ghana, West Africa. Morphologically, the new species can be distinguished from all of its congeners by the combination of a slender body, short and pointed snout, a relatively warty dorsum, a black-spotted throat in both sexes, a gular flap in males, a dark spotted chest, a white-greyish venter with occasional blackish spots, rudimentary pedal webbing, none to slightly dilated finger tips and strongly delated toe tips, presence of both inner and outer metatarsal tubercles and absence of a dark face mask, eyelid tubercles and longer dorsal ridges. We collected mitochondrial DNA (mtDNA) sequence data from the 16S rRNA gene to measure the genetic diversity of the new species, and to estimate phylogenetic relationships. The new species is a distinct and monophyletic evolutionary lineage most closely related to Phrynobatrachus gutturosus, P. fraterculus and P. maculiventris. The discovery of this new species highlights that the biodiversity of West African forests is still incompletely known and that the few remaining forests need urgent protection. 

scholarly journals Genetic diversity of Ehrlichia canisstrains from naturally infected dogs in Rio de Janeiro, Brazil

2014 ◽  
Vol 23 (3) ◽  
pp. 301-308 ◽  
Author(s):  
Renata Fernandes Ferreira ◽  
Aloysio de Mello Figueiredo Cerqueira ◽  
Tatiana Xavier de Castro ◽  
Eliane de Oliveira Ferreira ◽  
Felipe Piedade Gonçalves Neves ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Rio De Janeiro ◽  
Complete Sequence ◽  
Rrna Gene ◽  
Hybrid Strain ◽  
The Us ◽  
Polymerase Chain ◽  
Hematological Manifestations ◽  
Pcr Targeting ◽  
The 16S Rrna Gene

The aim of this study was to characterize Ehrlichia canis strains from naturally infected dogs in Rio de Janeiro, Brazil. In addition, all the clinical and hematological findings observed in these dogs were reported. PCR targeting the 16S rRNA gene was used for diagnostic purposes, and the TRP19 and TRP36 genes were sequenced to evaluate the genetic diversity. Fifteen samples were positive for E. canis. The polymerase chain reaction for the TRP19 gene resulted in 11 amplicons (11/15), which were cloned into the pGEM-T easy vector for sequencing. The complete sequence of TRP19 gene was compared to those in the GenBank, revealing high identicalness. Phylogenetic analysis on the TRP36 gene sequences demonstrated two distinct strains from two dogs, named 56C and 70C. The 56C strain was grouped with the strain Cuiaba 16, which is a hybrid strain formed by Brazilian and US genogroups; and the 70C strain was grouped with other strains of the US genogroup, thus suggesting that there are at least two genogroups of E. canis in Rio de Janeiro (US and Brazilian). Those animals, in which the 70C and 56C strains were isolated, showed distinct clinical and hematological manifestations of 1the disease. The appearance of different genotypes may express new phenotypes, thus resulting in different forms of presentation of the disease and making its diagnosis more complex.

scholarly journals AFLP Analysis for Genetic Diversity in Capsicum Annuum and Related Species

2006 ◽  
Vol 1 (3) ◽  
pp. 1934578X0600100
Author(s):  
Sanjog T. Thul ◽  
Ajit K. Shasany ◽  
Mahendra P. Darokar ◽  
Suman P. S. Khanuja
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Length Polymorphism ◽  
Great Degree ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Aflp Analysis ◽  
Variation Analysis ◽  
Average Similarity ◽  
Geographical Locations

Intra- and inter-specific genetic variation analysis was conducted using amplified fragment length polymorphism (AFLP) profiling in Capsicum accessions in the germplasms collected from different geographical locations in India. A total of 24 accessions were investigated belonging to six species, namely C. annuum, C. baccatum, C. chinence, C. eximium, C. frutescens and C. luteum. Average similarity within the 15 accessions of C. annuum was highest (100%) between accessions CIMAP/CA45 and CIMAP/CA49 obtained from IISR, Kerala and 43% among the species CIMAP/CC1 and CIMAP/CB2. In this analysis, accessions were clustered more pronouncedly according to their geographical locations than to their taxonomic labels. A great degree of intermixing of present day domesticated chillies is evident from the present study.

Genetic analysis of mango landraces from Mexico based on molecular markers

2009 ◽  
Vol 7 (03) ◽  
pp. 244-251 ◽  
Author(s):  
Didiana Gálvez-López ◽  
Sanjuana Hernández-Delgado ◽  
Maurilio González-Paz ◽  
Enrique Noe Becerra-Leor ◽  
Miguel Salvador-Figueroa ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Fragment Length Polymorphism ◽  
Geographical Origin ◽  
Genetic Recombination ◽  
Genetic Relationships ◽  
Mangifera Indica ◽  
Aflp Analysis ◽  
Significant Genetic Differentiation ◽  
Simple Sequence

Genetic diversity and relationships among 112 mango (Mangifera indica) plants native to 16 states of Mexico and four controls [three mango cultivars (Ataulfo, Manila and Tommy Atkins) and one accession ofMangifera odorata] were evaluated based on amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) molecular markers. Mango germplasm shows broad dispersion through Mexico and genetically similar germplasm from different agroecological regions has previously been found by our group. Both AFLP and SSR analyses indicated high genetic similarity among mango populations that were clustered in two major groups: mangos from Gulf of Mexico coastline and mangos from Pacific Ocean coastline and locations far away from the sea. The highest genetic diversity was found within plants from each state, and significant genetic differentiation (FST = 0.1921, AFLPs and 0.1911, SSRs) was also observed among mango populations based on geographical origin and genetic status (cultivars versus landraces). Heterozygosity values ranged from low (0.38) to moderate (0.68), and no heterozygote deficits were found. The highest genetic variability was found in mango populations from Tabasco, Michoacán and Oaxaca. Data suggested that mangoes are subjected to natural or induced pollination, so segregation as well as genetic recombination plays major roles on genetic diversification of Mexican mangos. AFLP analysis was more robust than SSR for determining the genetic relationships among mango landraces from Mexico.

Genetic diversity analysis of kenaf ( Hibiscus cannabinus L.) using AFLP (amplified fragment length polymorphism) markers

2008 ◽  
Vol 7 (02) ◽  
pp. 122-126 ◽  
Author(s):  
Rouxlene Coetzee ◽  
Liezel Herselman ◽  
Maryke T. Labuschagne
Keyword(s):  
South Africa ◽  
Genetic Diversity ◽  
North America ◽  
El Salvador ◽  
Fragment Length Polymorphism ◽  
Hibiscus Cannabinus ◽  
Aflp Analysis ◽  
Diversity Analysis ◽  
Genetic Diversity Analysis ◽  
The Usa

Nineteen kenaf genotypes from Cuba, Taiwan, the USA, El Salvador, Guatemala, Russia, Spain and Indonesia, and three wild types collected in South Africa were analysed for genetic diversity using AFLP analysis. All could be uniquely distinguished from one another, but only a low level of genetic diversity was present. The most distinct accession, Guatemala 4, was 85% similar to all other accessions. The accessions clustered more or less according to known pedigree and/or origin. Two of the three wild types (Hibiscus cannabinusc andH. cannabinusa) clustered separately from the commercial and Russian accessions. One of the wild types,H. cannabinusb clustered with some of the commercial accessions. Commercial accessions in the first subgroup all originated from central and North America, and surrounding islands (Cuba and El Salvador). The Russian accessions are all grouped together. The second subgroup was the only group that contained accessions from different geographical origins.

scholarly journals Structure and Function of Bacterial Communities Emerging from Different Sources under Identical Conditions

2006 ◽  
Vol 72 (1) ◽  
pp. 212-220 ◽  
Author(s):  
Silke Langenheder ◽  
Eva S. Lindström ◽  
Lars J. Tranvik
Keyword(s):  
Environmental Conditions ◽  
Bacterial Communities ◽  
Fragment Length Polymorphism ◽  
Bacterial Community Composition ◽  
Rrna Gene ◽  
Polymorphism Analysis ◽  
Scale Functions ◽  
And Function ◽  
Different Sources ◽  
The 16S Rrna Gene

ABSTRACT The aim of this study was to compare two major hypotheses concerning the formation of bacterial community composition (BCC) at the local scale, i.e., whether BCC is determined by the prevailing local environmental conditions or by “metacommunity processes.” A batch culture experiment where bacteria from eight distinctly different aquatic habitats were regrown under identical conditions was performed to test to what extent similar communities develop under similar selective pressure. Differently composed communities emerged from different inoculum communities, as determined by terminal restriction fragment length polymorphism analysis of the 16S rRNA gene. There was no indication that similarity increased between communities upon growth under identical conditions compared to that for growth at the ambient sampling sites. This suggests that the history and distribution of taxa within the source communities were stronger regulating factors of BCC than the environmental conditions. Moreover, differently composed communities were different with regard to specific functions, such as enzyme activities, but maintained similar broad-scale functions, such as biomass production and respiration.

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