scholarly journals Chromosome and Molecular Analyses Reveal Significant Intraspecific Karyotype Diversity and Provide New Evidence on the Origin of Tetraploid Grass Aegilops columnaris

2021 ◽  
Author(s):  
Ekaterina D. Badaeva ◽  
Nadezhda N. Chikida ◽  
Andrey N. Fisenko ◽  
Sergei A. Surzhikov ◽  
Maria Kh. Belousova ◽  
...  
Keyword(s):  
Intergenic Spacer ◽  
Geographic Region ◽  
Grass Species ◽  
Significant Heterogeneity ◽  
C Banding ◽  
Initial Stage ◽  
Western Asia ◽  
Fertile Crescent ◽  
Karyotype Structure ◽  
Genome Modifications

Aegilops columnaris Zhuk. is tetraploid grass species (2n=4x=28, UcUcXcXc) closely related to Ae. neglecta and growing in Western Asia and a western part of the Fertile Crescent. Genetic diversity of Ae. columnaris was assessed using C-banding, FISH, nuclear and chloroplast (cp)DNA analyses, and gliadin electrophoresis. Cytogenetically Ae. columnaris was subdivided into two groups, C-I and C-II, showing different karyotype structure, C-banding and FISH patterns. Group C-I was more similar to Ae. neglecta. All types of markers revealed significant heterogeneity of the C-II group, although group C-I was also polymorphic. Two chromosomal groups were consistent with plastogroups identified in a current study based on sequencing of three chloroplast intergenic spacer regions. The similarity of group C-I of Ae. columnaris with Ae. neglecta and their distinctness from C-II indicate that divergence of the C-I group was associated with minor genome modifications. Group C-II could emerge from C-I relatively recently, probably due to introgression from another Aegilops species followed by a reorganization of the parental genomes. Most C-II accessions were collected from the very narrow geographic region, and they might originate from a common ancestor. We suggest that the C-II group is at the initial stage of species divergence and undergoing an extensive speciation process.

scholarly journals Chromosome and Molecular Analyses Reveal Significant Karyotype Diversity and Provide New Evidence on the Origin of Aegilops columnaris

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 956
Author(s):  
Ekaterina D. Badaeva ◽  
Nadezhda N. Chikida ◽  
Andrey N. Fisenko ◽  
Sergei A. Surzhikov ◽  
Maria K. Belousova ◽  
...  
Keyword(s):  
Intergenic Spacer ◽  
Geographic Region ◽  
Grass Species ◽  
Significant Heterogeneity ◽  
C Banding ◽  
Initial Stage ◽  
Western Asia ◽  
Fertile Crescent ◽  
Karyotype Structure ◽  
Genome Modifications

Aegilops columnaris Zhuk. is tetraploid grass species (2n = 4x = 28, UcUcXcXc) closely related to Ae. neglecta and growing in Western Asia and a western part of the Fertile Crescent. Genetic diversity of Ae. columnaris was assessed using C-banding, FISH, nuclear and chloroplast (cp) DNA analyses, and gliadin electrophoresis. Cytogenetically Ae. columnaris was subdivided into two groups, C-I and C-II, showing different karyotype structure, C-banding, and FISH patterns. C-I group was more similar to Ae. neglecta. All types of markers revealed significant heterogeneity in C-II group, although group C-I was also polymorphic. Two chromosomal groups were consistent with plastogroups identified in a current study based on sequencing of three chloroplast intergenic spacer regions. The similarity of group C-I of Ae. columnaris with Ae. neglecta and their distinctness from C-II indicate that divergence of the C-I group was associated with minor genome modifications. Group C-II could emerge from C-I relatively recently, probably due to introgression from another Aegilops species followed by a reorganization of the parental genomes. Most C-II accessions were collected from a very narrow geographic region, and they might originate from a common ancestor. We suggest that the C-II group is at the initial stage of species divergence and undergoing an extensive speciation process.

The karyology of Vipera aspis, V. atra, V. hugyi, and Cerastes vipera

2006 ◽  
Vol 27 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Gaetano Odierna ◽  
Augusto Gentilli ◽  
Marco Zuffi ◽  
Gennaro Aprea
Keyword(s):  
Sex Chromosomes ◽  
Chromosome Pair ◽  
Current Paper ◽  
W Chromosome ◽  
C Banding ◽  
Initial Stage ◽  
Staining Methods ◽  
Almost All ◽  
Vipera Aspis

AbstractIn the current paper we show the results obtained using standard and banding staining methods (Ag-NOR-, CMA3-, C-banding and sequential colorations (or Alu I digestions) + CMA3 + DAPI) in specimens of Cerastes vipera, Vipera aspis, V. atra, and V. hugyi. Cerastes vipera presented chromosomal characters, primitive in snakes, as a karyotype of 2n = 36 chromosomes, with 16 biarmed macrochromosomes and 20 microchromosomes, NORs on one microchromosome pair and absence of cytologically evident sex chromosomes, at least with the methods used. The three taxa of Vipera studied showed chromosomal characters either derived, or primitive or at an initial stage of differentiation. All three species showed a karyotype (derived) of 2n = 42 chromosomes with 22 macro- and 20 micro-chromosomes; they all showed NORs on one micro-chromosome pair and presented Z and W chromosomes at an initial stage of differentiation. Sexchromosomes Z and W, were in fact homomorphic, but the former was near all euchromatic, while the W chromosome was almost completely heterochromatic. All the three taxa of Vipera resulted, however, karyologically diversified, mainly due to the number of macro-chromosomes pairs with a centromeric, CMA3 positive heterochromatin: almost all the pairs in V. aspis, two pairs in V. atra and absent in V. hugyi.

scholarly journals Review Essay: The Beginnings of Civilization

2021 ◽  
Vol 6 (1) ◽  
pp. 70-73
Author(s):  
Walter C. Clemens, Jr.
Keyword(s):  
Global History ◽  
Ancient History ◽  
Indus River ◽  
Social Scientists ◽  
Western Asia ◽  
Fertile Crescent ◽  
The Future ◽  
Key Features ◽  
Alphabetic Writing ◽  
Ways Of Life

What can contemporary social scientists learn from ancient history? Key features of modern civilization began in the fertile crescent of today’s Middle East many thousands of years ago. Thanks to geography and other factors, these innovations spread—east and west. Not just agriculture and engineering but monotheistic religion and alphabetic writing took root there. Parallels to or offshoots of Sumerian culture emerged in the Indus River, Persia, and Egypt. Their distinctive ways of life took shape, waxed, and then waned. Social scientists who try to keep up with a world in turmoil by listening to the BBC or reading Le Monde may be tempted to ask: “How did all this begin and where are we going?” The Singapore-based political analyst Parag Khanna answers: “Asia.” Civilization began in Western Asia and is now being shaped by “Asianization” of the planet. (See Khanna, The Future is Asian, 2019). Whether or not Khanna’s hypothesis about the future proves correct, the importance of Western Asia in global history is documented in the books Uruk and Mesopotamia.

An apomictic tetraploid Paspalum chaseanum cytotype and its cytogenetic relationship with P. plicatulum (Poaceae): taxonomic and genetic implications

2013 ◽  
Vol 61 (7) ◽  
pp. 538 ◽  
Author(s):  
Patricia E. Novo ◽  
Francisco Espinoza ◽  
Camilo L. Quarin
Keyword(s):  
Genetic Improvement ◽  
Seed Set ◽  
Meiotic Chromosome ◽  
Geographic Region ◽  
Grass Species ◽  
Pollen Donor ◽  
Chaco Region ◽  
Improvement Programs ◽  
Pairing Behaviour

Paspalum chaseanum Parodi (Poaceae) is a rare species seldom found in the vast phytogeographic Chaco region of South America. It occurs in some localities as a diploid with 20 somatic chromosomes, reproduces sexually and is self-incompatible. A tetraploid cytotype was recently collected in this geographic region. This accession was determined to reproduce of aposporous apomixis and was crossed, as pollen donor, onto a sexual autotetraploid plant of P. plicatulum Michx. The meiotic chromosome pairing behaviour of both parents and their hybrids was primarily as bivalents and quadrivalents, indicating that tetraploid P. chaseanum is likely to have an autoploid origin, and that both species share basically the same genome. Although some controversies exist regarding the subgeneric taxonomic classification of P. chaseanum, these results support its inclusion in the informal Plicatula group of Paspalum. The P. plicatulum × P. chaseanum hybrids segregated for apomixis. The amount of seed set in some hybrids (up to 17%) and the presence of sexual as well as facultative apomictic individuals in the progeny suggest that gene transfer through hybridisation is a feasible tool in genetic-improvement programs concerning these forage grass species.

scholarly journals The rise and fall of gluten!

2015 ◽  
Vol 74 (3) ◽  
pp. 221-226 ◽  
Author(s):  
Imran Aziz ◽  
Federica Branchi ◽  
David S. Sanders
Keyword(s):  
Coeliac Disease ◽  
Agricultural Production ◽  
Clinical Symptoms ◽  
Gluten Free Diet ◽  
Gluten Sensitivity ◽  
Gluten Free ◽  
Western Asia ◽  
Fertile Crescent ◽  
Gluten Sensitive Enteropathy ◽  
The Relationship

Mankind has existed for 2·5 million years but only in the last 10 000 years have we been exposed to wheat. Wheat was first cultivated in the Fertile Crescent (South Western Asia) with a farming expansion that lasted from about 9000BC to 4000BC. Thus it could be considered that wheat (and gluten) is a novel introduction to man's diet! Prior to 1939 the rationing system had already been devised. This led to an imperative to try to increase agricultural production. Thus it was agreed in 1941 that there was a need to establish a Nutrition Society. The very roots of the society were geared towards necessarily increasing the production of wheat. This goal was achieved and by the end of the 20th century, global wheat output had expanded 5-fold. Perhaps as a result the epidemiology of coeliac disease (CD) or gluten sensitive enteropathy has changed. CD is a state of heightened immunological responsiveness to ingested gluten in genetically susceptible individuals. CD now affects 1 % or more of all adults, for which the treatment is a strict lifelong gluten-free diet. However, there is a growing body of evidence to show that a far greater proportion of individuals without coeliac disease are taking a gluten-free diet of their own volition. This clinical entity has been termed non-coeliac gluten sensitivity (NCGS), although the condition is fraught with complexities due to overlap with other gluten-based constituents that can also trigger similar clinical symptoms. This review will explore the relationship between gluten, the rising prevalence of modern coeliac disease, and the new entity of NCGS along with its associated uncertainties.

scholarly journals Cytogenetic karyotype analysis in selected species of the Erinaceidae family

2019 ◽  
Vol 63 (3) ◽  
pp. 353-358
Author(s):  
Anna Grzesiakowska ◽  
Przemysław Baran ◽  
Marta Kuchta-Gładysz ◽  
Olga Szeleszczuk
Keyword(s):  
Karyotype Analysis ◽  
Chromosome Analysis ◽  
Differential Staining ◽  
C Banding ◽  
Repeat Sequences ◽  
New Information ◽  
Karyotype Structure ◽  
Staining Techniques ◽  
Erinaceus Roumanicus ◽  
Made In

Abstract Introduction Comparative analysis of the karyotype structure was made in two hedgehog species: the northern white-breasted hedgehog (Erinaceus roumanicus) and the African pygmy hedgehog (Atelerix albiventris). Material and Methods The cytogenetic analysis used differential staining techniques (DAPI, Ag-NOR, and C-banding/DAPI) and sequential QFQ/FISH banding with NOR20 and TEL20 probes which showed 45S rDNA and (TTAGGG)n repeat sequences, respectively, on hedgehog chromosomes. Results It was confirmed that the somatic cells of the hedgehogs have a constant number of chromosomes (2n = 48,XY). Differences were observed in the NOR number between the species. NORs were identified on three autosome pairs in the northern white-breasted hedgehog and on only two pairs in the African pygmy hedgehog. Chromosome analysis by C-banding/DAPI showed large segments of heterochromatin rich in A-T pairs on three autosome pairs in both the northern white-breasted and African pygmy hedgehogs. The heterochromatin segments encompassed large fragments of the longer arm of chromosome pairs 13, 14 and 20. The (TTAGGG)n repeat sequences on the hedgehog chromosomes were only observed in the terminal position of all the chromosomes in both species. Conclusion Our observations provide new information on the level of diversity within the Erinaceidae family.

scholarly journals How do we share data in COVID-19 research? A systematic review of COVID-19 datasets in PubMed Central Articles

2020 ◽  
Author(s):  
Xu Zuo ◽  
Yong Chen ◽  
Lucila Ohno-Machado ◽  
Hua Xu
Keyword(s):  
Systematic Review ◽  
Full Text ◽  
Geographic Region ◽  
Descriptive Statistics ◽  
Significant Heterogeneity ◽  
Pubmed Central ◽  
Data Formats ◽  
Share Data ◽  
Novel Coronavirus ◽  
Unique Dataset

Abstract Objective This study aims at reviewing novel coronavirus disease (COVID-19) datasets extracted from PubMed Central articles, thus providing quantitative analysis to answer questions related to dataset contents, accessibility and citations. Methods We downloaded COVID-19-related full-text articles published until 31 May 2020 from PubMed Central. Dataset URL links mentioned in full-text articles were extracted, and each dataset was manually reviewed to provide information on 10 variables: (1) type of the dataset, (2) geographic region where the data were collected, (3) whether the dataset was immediately downloadable, (4) format of the dataset files, (5) where the dataset was hosted, (6) whether the dataset was updated regularly, (7) the type of license used, (8) whether the metadata were explicitly provided, (9) whether there was a PubMed Central paper describing the dataset and (10) the number of times the dataset was cited by PubMed Central articles. Descriptive statistics about these seven variables were reported for all extracted datasets. Results We found that 28.5% of 12 324 COVID-19 full-text articles in PubMed Central provided at least one dataset link. In total, 128 unique dataset links were mentioned in 12 324 COVID-19 full text articles in PubMed Central. Further analysis showed that epidemiological datasets accounted for the largest portion (53.9%) in the dataset collection, and most datasets (84.4%) were available for immediate download. GitHub was the most popular repository for hosting COVID-19 datasets. CSV, XLSX and JSON were the most popular data formats. Additionally, citation patterns of COVID-19 datasets varied depending on specific datasets. Conclusion PubMed Central articles are an important source of COVID-19 datasets, but there is significant heterogeneity in the way these datasets are mentioned, shared, updated and cited.

Reaction couples of ceramic thin films prepared by CVD

1988 ◽  
Vol 46 ◽  
pp. 798-799
Author(s):  
D.W. Susnitzky ◽  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Thin Film ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Solid State Reactions ◽  
Spatial Distributions ◽  
Diffusion Couples ◽  
Kinetics Studies ◽  
Ceramic Thin Films ◽  
Initial Stage

Solid-state reactions have traditionally been studied in the form of diffusion couples. This ‘bulk’ approach has been modified, for the specific case of the reaction between NiO and Al2O3, by growing NiAl2O4 (spinel) from electron-transparent Al2O3 TEM foils which had been exposed to NiO vapor at 1415°C. This latter ‘thin-film’ approach has been used to characterize the initial stage of spinel formation and to produce clean phase boundaries since further TEM preparation is not required after the reaction is completed. The present study demonstrates that chemical-vapor deposition (CVD) can be used to deposit NiO particles, with controlled size and spatial distributions, onto Al2O3 TEM specimens. Chemical reactions do not occur during the deposition process, since CVD is a relatively low-temperature technique, and thus the NiO-Al2O3 interface can be characterized. Moreover, a series of annealing treatments can be performed on the same sample which allows both Ni0-NiAl2O4 and NiAl2O4-Al2O3 interfaces to be characterized and which therefore makes this technique amenable to kinetics studies of thin-film reactions.

Decoration technique and surface physics

1978 ◽  
Vol 36 (1) ◽  
pp. 436-437 ◽  
Author(s):  
H. Bethge
Keyword(s):  
Diffusion Path ◽  
Special Importance ◽  
Surface Physics ◽  
Step Structure ◽  
Initial Stage ◽  
Special Cases ◽  
Atomic Surface ◽  
The Mean ◽  
Bulk Structure ◽  
Decoration Technique

Besides the atomic surface structure, diverging in special cases with respect to the bulk structure, the real structure of a surface Is determined by the step structure. Using the decoration technique /1/ it is possible to image step structures having step heights down to a single lattice plane distance electron-microscopically. For a number of problems the knowledge of the monatomic step structures is important, because numerous problems of surface physics are directly connected with processes taking place at these steps, e.g. crystal growth or evaporation, sorption and nucleatlon as initial stage of overgrowth of thin films.To demonstrate the decoration technique by means of evaporation of heavy metals Fig. 1 from our former investigations shows the monatomic step structure of an evaporated NaCI crystal. of special Importance Is the detection of the movement of steps during the growth or evaporation of a crystal. From the velocity of a step fundamental quantities for the molecular processes can be determined, e.g. the mean free diffusion path of molecules.

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