Addressing Long-Standing Questions with Advanced Approaches: The 4th B Chromosome Conference

2020 ◽  
Vol 160 (3) ◽  
pp. 111-117
Author(s):  
Cesar Martins ◽  
Vladimir Trifonov ◽  
Andreas Houben
Keyword(s):  
Molecular Cytogenetics ◽  
B Chromosome ◽  
Research Field ◽  
B Chromosomes ◽  
Chromosome Research ◽  
Functional Studies ◽  
Sequencing Technologies ◽  
The Subject ◽  
Scientific Meetings ◽  
In The Beginning

B chromosomes (Bs) are enigmatic accessory genomic elements extensively characterized in diverse eukaryotes. Since their discovery in the beginning of the 20th century, B chromosomes have been the subject of investigation in laboratories all around the world. As a consequence, scientific meetings have dealt with B chromosomes, including the most specific and important conference in the field, “The B Chromosome Conference.” The 4th B Chromosome Conference (4BCC) took place in Botucatu, Brazil, in 2019 and was an excellent opportunity to discuss the latest developments in the B chromosome research field. B chromosome science has advanced from classical and molecular cytogenetics to genomics and bioinformatics approaches. The recent advances in next-generation sequencing technologies and high-throughput molecular biology protocols have led Bs to be the subject of massive data analysis, thus enabling the investigation of structural and functional issues not considered before. Although extensive progress has been made, questions are still remaining to be answered. The advances in functional studies based on RNA, epigenetics, and gene ontologies open the perspective to a better understanding of the complex biology of B chromosomes.

scholarly journals Evolution of Plant B Chromosome Enriched Sequences

Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 515 ◽  
Author(s):  
André Marques ◽  
Sonja Klemme ◽  
Andreas Houben
Keyword(s):  
Repetitive Sequences ◽  
B Chromosome ◽  
B Chromosomes ◽  
Dna Elements ◽  
Formation And Evolution ◽  
The Subject ◽  
Chromosome Formation ◽  
The Impact ◽  
Normal Standard ◽  
Shed Light

B chromosomes are supernumerary chromosomes found in addition to the normal standard chromosomes (A chromosomes). B chromosomes are well known to accumulate several distinct types of repeated DNA elements. Although the evolution of B chromosomes has been the subject of numerous studies, the mechanisms of accumulation and evolution of repetitive sequences are not fully understood. Recently, new genomic approaches have shed light on the origin and accumulation of different classes of repetitive sequences in the process of B chromosome formation and evolution. Here we discuss the impact of repetitive sequences accumulation on the evolution of plant B chromosomes.

scholarly journals The U2 snDNA Is a Useful Marker for B Chromosome Detection and Frequency Estimation in the Grasshopper Abracris flavolineata

2017 ◽  
Vol 151 (1) ◽  
pp. 36-40 ◽  
Author(s):  
Diogo Milani ◽  
Octavio M. Palacios-Gimenez ◽  
Diogo C. Cabral-de-Mello
Keyword(s):  
Evolutionary History ◽  
Frequency Estimation ◽  
B Chromosome ◽  
B Chromosomes ◽  
Future Studies ◽  
Functional Studies ◽  
Chromosome Transmission ◽  
Somatic Tissues ◽  
Frequency Changes

In this study, we describe a strategy to determine the presence of B chromosomes in the living grasshopper Abracris flavolineata by FISH using U2 snDNA as a probe in interphase hemolymph nuclei. In individuals without B chromosomes, (0B) 2 dot signals were noticed, corresponding to A complement U2 snDNA clusters. In +1B and +2B individuals, 4 or 8 additional signals were noticed, respectively. In all cases, the absence or presence of 1 or 2 B chromosomes correlated in hemolymph and in somatic or germline tissues, validating the efficiency of the marker. Our data suggest that the B chromosome of A. flavolineata is present in all somatic tissues. B-carrying individuals showed the same number of B chromosomes in germ and somatic cells, suggesting that the B is mitotically stable. The marker was used to compare B chromosome frequency in the analyzed population with a sample collected previously, in order to test for B frequency changes and differences of B chromosome prevalence among sexes, but no statistically significant differences were noticed. The identification of living animals harboring B chromosomes will be very useful in future studies of B chromosome transmission, as well as in functional studies involving RNA analysis, thus contributing to the understanding of evolutionary history and the possible role of the B chromosome in A. flavolineata.

scholarly journals Repetitive DNA landscape in essential A and supernumerary B chromosomes of Festuca pratensis Huds

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rahman Ebrahimzadegan ◽  
Andreas Houben ◽  
Ghader Mirzaghaderi
Keyword(s):  
Repetitive Sequences ◽  
Nuclear Genome ◽  
B Chromosome ◽  
B Chromosomes ◽  
Festuca Pratensis ◽  
Ltr Retrotransposons ◽  
Chromosome Identification ◽  
Satellite Repeats ◽  
Low Pass ◽  
Illumina Sequence

AbstractHere, we characterized the basic properties of repetitive sequences in essential A and supernumerary B chromosomes of Festuca pratensis Huds. This was performed by comparative analysis of low-pass Illumina sequence reads of B chromosome lacking (−B) and B chromosome containing (+B) individuals of F. pratensis. 61% of the nuclear genome is composed of repetitive sequences. 43.1% of the genome are transposons of which DNA transposons and retrotransposons made up 2.3% and 40.8%, respectively. LTR retrotransposons are the most abundant mobile elements and contribute to 40.7% of the genome and divided into Ty3-gypsy and Ty1-copia super families with 32.97% and 7.78% of the genome, respectively. Eighteen different satellite repeats were identified making up 3.9% of the genome. Five satellite repeats were used as cytological markers for chromosome identification and genome analysis in the genus Festuca. Four satellite repeats were identified on B chromosomes among which Fp-Sat48 and Fp-Sat253 were specific to the B chromosome of F. pratensis.

scholarly journals Spatial organization of fibroblast and spermatocyte nuclei with different B-chromosome content in Korean field mouse, Apodemus peninsulae (Rodentia, Muridae)

Genome ◽  
2017 ◽  
Vol 60 (10) ◽  
pp. 815-824 ◽  
Author(s):  
Tatyana V. Karamysheva ◽  
Anna A. Torgasheva ◽  
Yaroslav R. Yefremov ◽  
Anton G. Bogomolov ◽  
Thomas Liehr ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Spatial Organization ◽  
Constitutive Heterochromatin ◽  
B Chromosome ◽  
B Chromosomes ◽  
Laser Scanning Microscopy ◽  
Field Mouse ◽  
Apodemus Peninsulae ◽  
Basic Set ◽  
Korean Field Mouse

Korean field mouse (Apodemus peninsulae) shows a wide variation in the number of B chromosomes composed of constitutive heterochromatin. For this reason, it provides a good model to study the influence of the number of centromeres and amount of heterochromatin on spatial organization of interphase nuclei. We analyzed the three-dimensional organization of fibroblast and spermatocyte nuclei of the field mice carrying a different number of B chromosomes using laser scanning microscopy and 3D fluorescence in situ hybridization. We detected a co-localization of the B chromosomes with constitutive heterochromatin of the chromosomes of the basic set. We showed a non-random distribution of B chromosomes in the spermatocyte nuclei. Unpaired B chromosomes showed a tendency to occur in the compartment formed by the unpaired part of the XY bivalent.

scholarly journals From Genetics to Genomics of Epilepsy

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Silvio Garofalo ◽  
Marisa Cornacchione ◽  
Alfonso Di Costanzo
Keyword(s):  
Dna Sequencing ◽  
Dna Microarrays ◽  
Molecular Cytogenetics ◽  
Entire Genome ◽  
Sequencing Technologies ◽  
Genomic Approach ◽  
Molecular Karyotype ◽  
High Throughput Dna Sequencing ◽  
Laboratory Technology ◽  
Near Future

The introduction of DNA microarrays and DNA sequencing technologies in medical genetics and diagnostics has been a challenge that has significantly transformed medical practice and patient management. Because of the great advancements in molecular genetics and the development of simple laboratory technology to identify the mutations in the causative genes, also the diagnostic approach to epilepsy has significantly changed. However, the clinical use of molecular cytogenetics and high-throughput DNA sequencing technologies, which are able to test an entire genome for genetic variants that are associated with the disease, is preparing a further revolution in the near future. Molecular Karyotype and Next-Generation Sequencing have the potential to identify causative genes or loci also in sporadic or non-familial epilepsy cases and may well represent the transition from a genetic to a genomic approach to epilepsy.

scholarly journals B Chromosomes in Populations of Mammals Revisited

Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 487 ◽  
Author(s):  
Mladen Vujošević ◽  
Marija Rajičić ◽  
Jelena Blagojević
Keyword(s):  
Mammalian Species ◽  
B Chromosome ◽  
Molecular Techniques ◽  
B Chromosomes ◽  
General View ◽  
Protein Coding ◽  
Host Parasite Interactions ◽  
Quantitative Characteristics ◽  
Host Parasite

The study of B chromosomes (Bs) started more than a century ago, while their presence in mammals dates since 1965. As the past two decades have seen huge progress in application of molecular techniques, we decided to throw a glance on new data on Bs in mammals and to review them. We listed 85 mammals with Bs that make 1.94% of karyotypically studied species. Contrary to general view, a typical B chromosome in mammals appears both as sub- or metacentric that is the same size as small chromosomes of standard complement. Both karyotypically stable and unstable species possess Bs. The presence of Bs in certain species influences the cell division, the degree of recombination, the development, a number of quantitative characteristics, the host-parasite interactions and their behaviour. There is at least some data on molecular structure of Bs recorded in nearly a quarter of species. Nevertheless, a more detailed molecular composition of Bs presently known for six mammalian species, confirms the presence of protein coding genes, and the transcriptional activity for some of them. Therefore, the idea that Bs are inert is outdated, but the role of Bs is yet to be determined. The maintenance of Bs is obviously not the same for all species, so the current models must be adapted while bearing in mind that Bs are not inactive as it was once thought.

3. Professor Forbes then read the following Letter from Professor Gordon, of Glasgow, on the subject of the Viscous Theory of Glaciers.

1851 ◽  
Vol 2 ◽  
pp. 19-20
Author(s):  
Lewis Gordon
Keyword(s):  
The Subject ◽  
To Come ◽  
In The Beginning

When you requested me to give you a memorandum of what appeared to me to be thevery glacier-like motionand appearance of Stockholm pitch flowing from a barrel, I considered my observation to have been too casual to be worth writing, and having foreseen that I could arrange an experiment at Gateshead in the beginning of the year, I delayed giving you the memorandum you wished. I had hoped to have been able to inspect and report on my experiment about this time; but I cannot go to Gateshead for some time to come, nor have I had any report of the progress of my pitch glacier since the 6th January, when I was informed it had not moved since the day after I left it, on the 28th December. Your note of yesterday induces me to offer you the following still perfectly vivid impressions of the analogy betweeniceandStockholm pitch.

scholarly journals Transmission rate variation among three B chromosome variants in the fish Prochilodus lineatus (Characiformes, Prochilodontidae)

2013 ◽  
Vol 85 (4) ◽  
pp. 1371-1377 ◽  
Author(s):  
MANOLO PENITENTE ◽  
TATIANA A. VOLTOLIN ◽  
JOSE A. SENHORINI ◽  
JEHUD BORTOLOZZI ◽  
FAUSTO FORESTI ◽  
...  
Keyword(s):  
Transmission Rate ◽  
B Chromosome ◽  
B Chromosomes ◽  
Rate Variation ◽  
Parental Line ◽  
Prochilodus Lineatus ◽  
Extinction Process ◽  
Cytogenetic Studies ◽  
Acrocentric Chromosomes ◽  
Interesting System

Cytogenetic studies were developed in Prochilodus lineatus (Valenciennes 1836), describing an interesting system of small supernumerary chromosomes. The purpose of this work is to study the frequency and morphology of B chromosomes in individuals from the parental line and the inheritance patterns of these elements in individuals obtained from controlled crosses in the species P. lineatus. The transmission rate of B chromosomes revealed a kB=0.388 for the acrocentric type, a kB=0.507 for the metacentric type and a kB=0.526 for the submetacentric type. The obtained results raise hypothesis that B-acrocentric chromosomes are involved in an extinction process in this species, while the metacentric and submetacentric supernumerary elements comprises a neutral mechanism and follows a Mendelian transmission rate.

scholarly journals Tutkimusaineiston avoin jakaminen – tutkimusorganisaatioiden jäsenten käsityksiä, kokemuksia ja mielipiteitä

2018 ◽  
Vol 37 (4) ◽  
Author(s):  
Heidi Enwald
Keyword(s):  
Data Sharing ◽  
Data Storage ◽  
Online Survey ◽  
Open Science ◽  
Research Data ◽  
Research Field ◽  
Open Research ◽  
Research Organizations ◽  
Data Collection Instrument ◽  
In The Beginning

Open research data is data that is free to access, reuse, and redistribute. This study focuses on the perceptions, opinions and experiences of staff and researchers of research institutes on topics related to open research data. Furthermore, the differences across gender, role in the research organization and research field were investigated. An international questionnaire survey, translated into Finnish and Swedish, was used as the data collection instrument. An online survey was distributed through an open science related network to Finnish research organizations. In the end, 469 responded to all 24 questions of the survey. Findings indicate that many are still unaware or uncertain about issues related to data sharing and long-term data storage. Women as well as staff and researchers of medical and health sciences were most concerned about the possible problems associated with data sharing. Those in the beginning of their scientific careers, hesitated about sharing their data.

scholarly journals Style in Jakarta Post Editorial

2018 ◽  
Vol 8 (2) ◽  
Author(s):  
Faiza Hawa ◽  
Ajeng Setyorini
Keyword(s):  
Main Topic ◽  
Simple Sentence ◽  
Complex Sentences ◽  
The Subject ◽  
In The Beginning

The objectives of the study is to find out whether the writers’ articles of the Jakarta Post issued in January 2015 have good style in their writing or not and to find out the element of  style used in Jakarta Post articles issued on January 2015. The subject of the study is the Jakarta Post Issued  in January 2015. There are five editorials selected and then analyzed based on Seyler’s theory. Based on the analysis, the editorials applied formal words. From the analysis, it was found that the total sentence for simple sentence is 34, 14 compound sentences, 24 complex sentences, 24 expanded sentences, 2 antithesis, and 1 metaphor.  In organizating the text, the writer of the editorial placed the main topic in the beginning paragraph. A writer can make good style in his/her writing by applying more active sentences in his/her writing, use familiar words and not using cliché, use short sentences, and write with nouns and verbs.

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