A Tandemly Arranged Pattern of Two 5S rDNA Arrays in Amolops mantzorum (Anura, Ranidae)

2017 ◽  
Vol 151 (3) ◽  
pp. 161-170 ◽  
Author(s):  
Ting Liu ◽  
Menghuan Song ◽  
Yun Xia ◽  
Xiaomao Zeng
Keyword(s):  
Satellite Dna ◽  
Centromeric Region ◽  
5S Rdna ◽  
Type I ◽  
Type Ii ◽  
Mitotic Chromosomes ◽  
Coding Sequences ◽  
Coding Sequence ◽  
Rdna Sequences ◽  
Rdna Organization

In an attempt to extend the knowledge of the 5S rDNA organization in anurans, the 5S rDNA sequences of Amolops mantzorum were isolated, characterized, and mapped by FISH. Two forms of 5S rDNA, type I (209 bp) and type II (about 870 bp), were found in specimens investigated from various populations. Both of them contained a 118-bp coding sequence, readily differentiated by their non-transcribed spacer (NTS) sizes and compositions. Four probes (the 5S rDNA coding sequences, the type I NTS, the type II NTS, and the entire type II 5S rDNA sequences) were respectively labeled with TAMRA or digoxigenin to hybridize with mitotic chromosomes for samples of all localities. It turned out that all probes showed the same signals that appeared in every centromeric region and in the telomeric regions of chromosome 5, without differences within or between populations. Obviously, both type I and type II of the 5S rDNA arrays arranged in tandem, which was contrasting with other frogs or fishes recorded to date. More interestingly, all the probes detected centromeric regions in all karyotypes, suggesting the presence of a satellite DNA family derived from 5S rDNA.

scholarly journals Chromosome Banding in Amphibia. XXXII. The Genus Xenopus (Anura, Pipidae)

2015 ◽  
Vol 145 (3-4) ◽  
pp. 201-217 ◽  
Author(s):  
Michael Schmid ◽  
Claus Steinlein
Keyword(s):  
Chromosome Pair ◽  
Repetitive Sequences ◽  
5S Rdna ◽  
Mitotic Chromosomes ◽  
Banding Patterns ◽  
Single Chromosome ◽  
Replication Banding ◽  
Rdna Sequences ◽  
High Degree ◽  
Replication Bands

Mitotic chromosomes of 16 species of the frog genus Xenopus were prepared from kidney and lung cell cultures. In the chromosomes of 7 species, high-resolution replication banding patterns could be induced by treating the cultures with 5-bromodeoxyuridine (BrdU) and deoxythymidine (dT) in succession, and in 6 of these species the BrdU/dT-banded chromosomes could be arranged into karyotypes. In the 3 species of the clade with 2n = 20 and 4n = 40 chromosomes (X. tropicalis, X. epitropicalis, X. new tetraploid 1), as well as in the 3 species with 4n = 36 chromosomes (X. laevis, X. borealis, X. muelleri), the BrdU/dT-banded karyotypes show a high degree of homoeology, though differences were detected between these groups. Translocations, inversions, insertions or sex-specific replication bands were not observed. Minor replication asynchronies found between chromosomes probably involve heterochromatic regions. BrdU/dT replication banding of Xenopus chromosomes provides the landmarks necessary for the exact physical mapping of genes and repetitive sequences. FISH with an X. laevis 5S rDNA probe detected multiple hybridization sites at or near the long-arm telomeric regions in most chromosomes of X. laevis and X. borealis, whereas in X. muelleri, the 5S rDNA sequences are located exclusively at the long-arm telomeres of a single chromosome pair. Staining with the AT base pair-specific fluorochrome quinacrine mustard revealed brightly fluorescing heterochromatic regions in the majority of X. borealis chromosomes which are absent in other Xenopus species.

scholarly journals Structure of cDNA clones coding for human type II procollagen. The α 1(II) chain is more similar to the α 1(I) chain than two other α chains of fibrillar collagens

1989 ◽  
Vol 262 (2) ◽  
pp. 521-528 ◽  
Author(s):  
C T Baldwin ◽  
A M Reginato ◽  
C Smith ◽  
S A Jimenez ◽  
D J Prockop
Keyword(s):  
Amino Acid ◽  
Selective Pressure ◽  
Cdna Clones ◽  
Type I ◽  
Type Ii ◽  
Coding Sequences ◽  
Type Iii ◽  
Human Type ◽  
Fibrillar Collagens ◽  
Triple Helical Domain

Overlapping cDNA clones were isolated for human type II procollagen. Nucleotide sequencing of the clones provided over 2.5 kb of new coding sequences for the human pro alpha 1(II) gene and the first complete amino acid sequence of type II procollagen from any species. Comparison with published data for cDNA clones covering the entire lengths of the human type I and type III procollagens made it possible to compare in detail the coding sequences and primary structures of the three most abundant human fibrillar collagens. The results indicated that the marked preference in the third base codons for glycine, proline and alanine previously seen in other fibrillar collagens was maintained in type II procollagen. The domains of the pro alpha 1(II) chain are about the same size as the same domains of the pro alpha chains of type I and type III procollagens. However, the major triple-helical domain is 15 amino acid residues less than the triple-helical domain of type III procollagen. Comparison of hydropathy profiles indicated that the alpha chain domain of type II procollagen is more similar to the alpha chain domain of the pro alpha 1(I) chain than to the pro alpha 2(I) chain or the pro alpha 1(III) chain. The results therefore suggest that selective pressure in the evolution of the pro alpha 1(II) and pro alpha 1(I) genes is more similar than the selective pressure in the evolution of the pro alpha 2(I) and pro alpha 1(III) genes.

Karyotype variation in the albino rainbow trout (Oncorhynchus mykiss (Walbaum))

Genome ◽  
2009 ◽  
Vol 52 (4) ◽  
pp. 347-352 ◽  
Author(s):  
K. Ocalewicz ◽  
S. Dobosz
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
X Chromosome ◽  
5S Rdna ◽  
Mitotic Chromosomes ◽  
Dapi Staining ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Rdna Sequences ◽  
Cytogenetic Location

A Robertsonian polymorphism resulting in diploid chromosome number ranging from 59 to 61 and constant chromosome arm number (fundamental number = 104) was observed in the albino rainbow trout ( Oncorhynchus mykiss (Walbaum)) from the yellow color strain. In one individual, 90 mitotic chromosomes and 156 chromosome arms were counted, indicating the fish as a triploid. Morphology of the chromosomes, DAPI staining, and the cytogenetic location of 5S rDNA sequences showed sex-related chromosomal heteromorphism in the specimens. Additionally, length polymorphism of the X chromosome was detected in the studied individuals and two morphs of the X chromosome were described, XL and XS, according to the size of its short arm (p). The XS was observed in the female as well as male albino rainbow trout; however, among females, no XSXS genotype was found. After primed in situ labeling with 5S rDNA primers, the p-arms of both types of the X chromosome showed similar hybridization signals. On the other hand, fluorescence in situ hybridization with telomeric PNA (peptide nucleic acid) probe exhibited weak hybridization spots on the p-arm of the XS chromosome compared with the distinct hybridization spots observed on the XL p-arm. This could reflect a different telomere length on the p-arm of the XS and XL chromosomes. Partial translocation and deletion of the X chromosome p-arm are considered to be responsible for the p-arm length difference between the two morphological variants of X chromosome.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

1984 ◽  
Vol 42 ◽  
pp. 250-251
Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson
Keyword(s):  
Endoplasmic Reticulum ◽  
Experimental Infection ◽  
Uranyl Acetate ◽  
Type I ◽  
Cellular Injury ◽  
Type Ii ◽  
Tubular Structures ◽  
Type Iii ◽  
Type Iv ◽  
Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

Comparative surface and ultrastructural views of methylotrophic bacteria by TEM, STEM, SE, and freeze-etch electron microscopy.

1987 ◽  
Vol 45 ◽  
pp. 792-793
Author(s):  
T.A. Fassel ◽  
M.J. Schaller ◽  
M.E. Lidstrom ◽  
C.C. Remsen
Keyword(s):  
Cytoplasmic Membrane ◽  
Structural Features ◽  
Methylotrophic Bacteria ◽  
Type I ◽  
Type Ii ◽  
Membrane Complex ◽  
Oxidation Of Methane ◽  
Methane Oxidizing Bacteria ◽  
Wall Structures ◽  
Methylomonas Albus

Methylotrophic bacteria play an Important role in the environment in the oxidation of methane and methanol. Extensive intracytoplasmic membranes (ICM) have been associated with the oxidation processes in methylotrophs and chemolithotrophic bacteria. Classification on the basis of ICM arrangement distinguishes 2 types of methylotrophs. Bundles or vesicular stacks of ICM located away from the cytoplasmic membrane and extending into the cytoplasm are present in Type I methylotrophs. In Type II methylotrophs, the ICM form pairs of peripheral membranes located parallel to the cytoplasmic membrane. Complex cell wall structures of tightly packed cup-shaped subunits have been described in strains of marine and freshwater phototrophic sulfur bacteria and several strains of methane oxidizing bacteria. We examined the ultrastructure of the methylotrophs with particular view of the ICM and surface structural features, between representatives of the Type I Methylomonas albus (BG8), and Type II Methylosinus trichosporium (OB-36).

OPTICAL STUDIES OF TYPE I AND TYPE II RECOMBINATION IN GaAs-AlAs QUANTUM WELLS

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-525-C5-528 ◽  
Author(s):  
K. J. MOORE ◽  
P. DAWSON ◽  
C. T. FOXON
Keyword(s):  
Quantum Wells ◽  
Type I ◽  
Type Ii ◽  
Optical Studies

An old friend is better than two new ones? Approaches to market research in the context of digital transformation for the antitrust laws enforcement

2020 ◽  
pp. 37-55 ◽  
Author(s):  
A. E. Shastitko ◽  
O. A. Markova
Keyword(s):  
Business Models ◽  
Rapid Development ◽  
Digital Transformation ◽  
Market Definition ◽  
Type I ◽  
Type Ii ◽  
Digital Platforms ◽  
Advantages And Disadvantages ◽  
Pass Through ◽  
Type Ii Errors

Digital transformation has led to changes in business models of traditional players in the existing markets. What is more, new entrants and new markets appeared, in particular platforms and multisided markets. The emergence and rapid development of platforms are caused primarily by the existence of so called indirect network externalities. Regarding to this, a question arises of whether the existing instruments of competition law enforcement and market analysis are still relevant when analyzing markets with digital platforms? This paper aims at discussing advantages and disadvantages of using various tools to define markets with platforms. In particular, we define the features of the SSNIP test when being applyed to markets with platforms. Furthermore, we analyze adjustment in tests for platform market definition in terms of possible type I and type II errors. All in all, it turns out that to reduce the likelihood of type I and type II errors while applying market definition technique to markets with platforms one should consider the type of platform analyzed: transaction platforms without pass-through and non-transaction matching platforms should be tackled as players in a multisided market, whereas non-transaction platforms should be analyzed as players in several interrelated markets. However, if the platform is allowed to adjust prices, there emerges additional challenge that the regulator and companies may manipulate the results of SSNIP test by applying different models of competition.

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