scholarly journals Karyotypic variability in some species of the genus Chondrilla (Asteraceae)

2018 ◽  
Vol 11 ◽  
pp. 00031
Author(s):  
Alena Parkhomenko ◽  
Aleksandr Kashin ◽  
Lyudmila Grebenyuk

Karyotypic variability of plants was evaluated in 17 populations of six species of the genus Chondrilla (C. ambigua Fisch., C. brevirostris Fisch, et Mey., C. laticoronata Leonova, C. canescens Kar., Kir., C. juncea, C. pauciflora Ledeb.) in the Astrakhan, Voronezh and Saratov regions, the Republic of Kalmykia, and Western Kazakhstan. It is maintained that C. ambigua is a strict diploid (2n = 2x = 10) species, while its close relative - C. pauciflora - is a strict triploid (2n = 3x = 15) taxon. The research demonstrates that the plants of the apomictic taxa C. brevirostris, C. canescens, C. juncea and C. laticoronata are characterized by the genomic instability in the form of chromosome instability which results in these species’ mixed-ploidy populations.

2019 ◽  
Vol 116 (14) ◽  
pp. 6975-6984 ◽  
Author(s):  
Yunqiu Zhang ◽  
Jiuyi Li ◽  
Kaikai Yi ◽  
Jing Feng ◽  
Zhengmin Cong ◽  
...  

Genomic instability (GI) drives tumor heterogeneity and promotes tumor progression and therapy resistance. However, causative factors underlying GI and means for clinical detection of GI in glioma are inadequately identified. We describe here that elevated expression of a gene module coexpressed with CDC20 (CDC20-M), the activator of the anaphase-promoting complex in the cell cycle, marks GI in glioma. The CDC20-M, containing 139 members involved in cell proliferation, DNA damage response, and chromosome segregation, was found to be consistently coexpressed in glioma transcriptomes. The coexpression of these genes was conserved across multiple species and organ systems, particularly in human neural stem and progenitor cells. CDC20-M expression was not correlated with the morphological subtypes, nor with the recently defined molecular subtypes of glioma. CDC20-M signature was an independent and robust predictor for poorer prognosis in over 1,000 patients from four large databases. Elevated CDC20-M signature enabled the identification of individual glioma samples with severe chromosome instability and mutation burden and of primary glioma cell lines with extensive mitotic errors leading to chromosome mis-segregation. AURKA, a core member of CDC20-M, was amplified in one-third of CDC20-M–high gliomas with gene-dosage–dependent expression. MLN8237, a Food and Drug Administration-approved AURKA inhibitor, selectively killed temozolomide-resistant primary glioma cells in vitro and prolonged the survival of a patient-derived xenograft mouse model with a high–CDC20-M signature. Our findings suggest that application of the CDC20-M signature may permit more selective use of adjuvant therapies for glioma patients and that dysregulated CDC20-M members may provide a therapeutic vulnerability in glioma.


Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3001
Author(s):  
Monique Oliveira Freitas ◽  
John Gartner ◽  
Aline Rangel-Pozzo ◽  
Sabine Mai

Circulating tumor cells (CTCs) can promote distant metastases and can be obtained through minimally invasive liquid biopsy for clinical assessment in cancer patients. Having both genomic heterogeneity and instability as common features, the genetic characterization of CTCs can serve as a powerful tool for a better understanding of the molecular changes occurring at tumor initiation and during tumor progression/metastasis. In this review, we will highlight recent advances in the detection and quantification of tumor cell heterogeneity and genomic instability in CTCs. We will focus on the contribution of chromosome instability studies to genetic heterogeneity in CTCs at the single-CTC level by discussing data from different cancer subtypes and their impact on diagnosis and precision medicine.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Benilde García-de Teresa ◽  
Mariana Hernández-Gómez ◽  
Sara Frías

DNA is constantly exposed to endogenous and exogenous mutagenic stimuli that are capable of producing diverse lesions. In order to protect the integrity of the genetic material, a wide array of DNA repair systems that can target each specific lesion has evolved. Despite the availability of several repair pathways, a common general program known as the DNA damage response (DDR) is stimulated to promote lesion detection, signaling, and repair in order to maintain genetic integrity. The genes that participate in these pathways are subject to mutation; a loss in their function would result in impaired DNA repair and genomic instability. When the DDR is constitutionally altered, every cell of the organism, starting from development, will show DNA damage and subsequent genomic instability. The cellular response to this is either uncontrolled proliferation and cell cycle deregulation that ensues overgrowth, or apoptosis and senescence that result in tissue hypoplasia. These diverging growth abnormalities can clinically translate as cancer or growth retardation; both features can be found in chromosome instability syndromes (CIS). The analysis of the clinical, cellular, and molecular phenotypes of CIS with intrauterine growth retardation allows inferring that replication alteration is their unifying feature.


2014 ◽  
Vol 4 (2) ◽  
pp. 75-84 ◽  
Author(s):  
N. M. Okulova ◽  
L. A. Khlyap ◽  
F. G. Bidashko ◽  
A. A. Warshavskyi ◽  
A. K. Grazhdanov ◽  
...  

Zootaxa ◽  
2017 ◽  
Vol 4341 (2) ◽  
pp. 229 ◽  
Author(s):  
SHALVA BARJADZE ◽  
SEBASTIANO BARBAGALLO ◽  
ROGER BLACKMAN ◽  
IŞIL ÖZDEMIR

Apterous and alate viviparous females and the alate males of Macrosiphum eastopi Barjadze & Blackman sp. n. living on Oberna multifida Ikonn. (=Silene multifida Rohrb.) (Caryophyllaceae) are described from the Republic of Georgia (Caucasus). Type specimens are deposited at the Institute of Zoology, Ilia State University (IZISU), Tbilisi, Georgia; the Natural History Museum (BMNH), London, U.K.; and the University of Catania (UCI), Sicily, Italy. Apterous and alate viviparous females of its close relative M. hartigi Hille Ris Lambers, 1947, living on Silene vulgaris (Moench) Garcke and Stellaria holostea L. (Caryophyllaceae) are redescribed, based on co-types and other material from Austria, France, Italy and Switzerland. The hitherto unknown fundatrix, oviparous females and alate males of M. hartigi are described from Italy and Switzerland. Macrosiphum eastopi sp. n. is differentiated from the morphologically similar M. hartigi and compared with other Macrosiphum species living on Caryophyllaceae. A key is provided to apterous viviparous females of all aphid species recorded on Oberna multifida.  


2020 ◽  
Vol 8 (E) ◽  
pp. 138-142
Author(s):  
Zhangeldy Shaimbetov ◽  
Umit Satybaldieva ◽  
Arstan Mamyrbayev

BACKGROUND: The article deals with regional employment and occupational morbidity indicators in Western Kazakhstan. AIM: The purpose is to study the employment indicators in hazardous working conditions and the dynamics of occupational morbidity in the West Kazakhstan region for the period 2013–2017. MATERIAL AND METHODS: Materials obtained from the Public Health Departments of the Aktobe, Atyrau, West Kazakhstan, and Mangystau regions were studied based on the results of periodic medical examinations of workers employed in hazardous working conditions for the period 2013–2017. The indicators of the dynamics of occupational morbidity in the region are derived from the annual reports of the West Kazakhstan branch of the RSE at the National Hygiene Center for Occupation and Occupational Diseases of the Ministry of Healthcare of the Republic of Kazakhstan for the period 2013–2017. RESULTS: The Atyrau, West Kazakhstan, and Mangystau regions saw an annual increase in the number of workers employed in hazardous production. In the Aktobe region, the number of people employed in hazardous working conditions decreased due to the decline in industrial production. There is a positive trend in this region to identify occupational diseases. In the Atyrau, West Kazakhstan, and Mangystau regions, the occupational morbidity rate is close to zero. CONCLUSION: It is necessary to revise the existing orders of the Ministry of Healthcare of the Republic of Kazakhstan concerning the improvement of the occupational health service.


Genes ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 379 ◽  
Author(s):  
Ivan Y. Iourov ◽  
Svetlana G. Vorsanova ◽  
Yuri B. Yurov ◽  
Sergei I. Kutsev

Intercellular karyotypic variability has been a focus of genetic research for more than 50 years. It has been repeatedly shown that chromosome heterogeneity manifesting as chromosomal mosaicism is associated with a variety of human diseases. Due to the ability of changing dynamically throughout the ontogeny, chromosomal mosaicism may mediate genome/chromosome instability and intercellular diversity in health and disease in a bottleneck fashion. However, the ubiquity of negligibly small populations of cells with abnormal karyotypes results in difficulties of the interpretation and detection, which may be nonetheless solved by post-genomic cytogenomic technologies. In the post-genomic era, it has become possible to uncover molecular and cellular pathways to genome/chromosome instability (chromosomal mosaicism or heterogeneity) using advanced whole-genome scanning technologies and bioinformatic tools. Furthermore, the opportunities to determine the effect of chromosomal abnormalities on the cellular phenotype seem to be useful for uncovering the intrinsic consequences of chromosomal mosaicism. Accordingly, a post-genomic review of chromosomal mosaicism in the ontogenetic and pathogenetic contexts appears to be required. Here, we review chromosomal mosaicism in its widest sense and discuss further directions of cyto(post)genomic research dedicated to chromosomal heterogeneity.


1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.


Author(s):  
Jean-Paul Revel

The last few years have been marked by a series of remarkable developments in microscopy. Perhaps the most amazing of these is the growth of microscopies which use devices where the place of the lens has been taken by probes, which record information about the sample and display it in a spatial from the point of view of the context. From the point of view of the biologist one of the most promising of these microscopies without lenses is the scanned force microscope, aka atomic force microscope.This instrument was invented by Binnig, Quate and Gerber and is a close relative of the scanning tunneling microscope. Today's AFMs consist of a cantilever which bears a sharp point at its end. Often this is a silicon nitride pyramid, but there are many variations, the object of which is to make the tip sharper. A laser beam is directed at the back of the cantilever and is reflected into a split, or quadrant photodiode.


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