C-banded karyotypes of Brassica campestris, B. oleracea, and B. napus

Genome ◽  
1992 ◽  
Vol 35 (4) ◽  
pp. 583-589 ◽  
Author(s):  
Majlis Olin-Fatih ◽  
W. K. Heneen
Keyword(s):  
Banding Pattern ◽  
Chromosome Pair ◽  
Brassica Campestris ◽  
Brassica Species ◽  
Conclusive Evidence ◽  
Metaphase Chromosomes ◽  
Late Prophase ◽  
Nucleolar Chromosome ◽  
Centromeric Position ◽  
Similar Banding Pattern

The chromosome complements of three Brassica species, namely B. campestris (2n = 20), B. oleracea (2n = 18), and B. napus (2n = 38), were studied using the air-dry method and C-banding. Karyotypes and ideograms of late prophase chromosomes were constructed, since contracted metaphase chromosomes were generally not suitable for this purpose. The three species generally had a similar banding pattern, manifested in the presence of a centromeric C-band in all chromosomes and heterochromatic knobs at the telomeric end of some chromosomes. The centromeric C-bands were more pronounced in B. campestris than in B. oleracea. Depending on the centromeric position, the chromosomes were grouped into median, submedian, subterminal, and terminal types. All chromosome pairs were morphologically distinguishable. Only one nucleolar chromosome pair, with heterochromatic satellites, was observed in each species. When compared, it was possible to distinguish chromosomes of both B. campestris and B. oleracea type in B. napus, but conclusive evidence as to the origin of all chromosome pairs in B. napus was not at hand.Key words: Brassica, chromosomes, late prophase, C-bands, knob structures, karyotypes, idiograms.

Banding in mitotic chromosomes of Brassica campestris var. pekinensis with a trypsin–Giemsa method

Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 899-901 ◽  
Author(s):  
Soryu Nishibayasahi
Keyword(s):  
Banding Pattern ◽  
Brassica Campestris ◽  
Chromosome Size ◽  
Mitotic Chromosomes ◽  
Metaphase Chromosomes ◽  
Secondary Constrictions

In Brassica campestris var. pekinensis cv. CR-strong, the karyotype comprised 12 median, 6 submedian, and 2 sub-terminal chromosomes. Secondary constrictions were observed in the two subterminal chromosomes. Banding pattern appeared very clearly in metaphase chromosomes with a trypsin–Giemsa method. It was possible to classify the chromosomes into 10 types (C1–C10), based on the chromosome size, shape, and banding pattern.Key words: Brassica campestris var. pekinensis, mitotic chromosomes, G-banding.

Structure and variability of nucleolar organizer regions in Parodontidae fish

1984 ◽  
Vol 26 (5) ◽  
pp. 564-568 ◽  
Author(s):  
Orlando Moreira-Filho ◽  
Luiz Antonio Carlos Bertollo ◽  
Pedro Manoel Galetti Jr.
Keyword(s):  
Chromosome Pair ◽  
Constitutive Heterochromatin ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Mitotic Chromosomes ◽  
Homozygous Condition ◽  
Nucleolar Organizing Regions ◽  
Nucleolar Chromosome

Nucleolar organizer regions (NORs) were studied in mitotic chromosomes of four species of fish of family Parodontidae: Parodon tortuosus, Apareiodon affinis, Apareiodon ibitiensis, and Apareiodon piracicabae. All four species exhibited only a single nucleolar chromosome pair in their karyotypes. Intraspecific differences were observed in the size of these chromosomes; however, these were not very clear for A. affinis and A. piracicabae, Apareiodon piracicabae exhibited two clearly visible NORs in each of the nucleolar chromosomes, which was the only configuration practically found in this species. This trait therefore predominates in a homozygous condition in the population investigated. Regions of constitutive heterochromatin adjacent to the two NORs were detected. Possible mechanisms that may have originated the two NORs are discussed.Key words: nucleolar organizing regions, fish.

scholarly journals A Karyological Study in Some Species of Coffea L. and in the Closest Relative Psilanthus travancorensis (Wight & Arn.) J.-F. Leroy

2012 ◽  
Vol 40 (2) ◽  
pp. 39 ◽  
Author(s):  
Neiva Izabel PIEROZZI ◽  
Thalita C. BORGHI ◽  
Maria Bernadete SILVAROLLA
Keyword(s):  
Chromosome Pair ◽  
Secondary Constriction ◽  
Karyological Study ◽  
Karyotype Asymmetry ◽  
Centromeric Position ◽  
Karyotype Formula ◽  
Orcein Staining ◽  
Nor Band ◽  
Chromosome Characterization

Chromosome characterization were carried out in Coffea kapakata A. Chev (Bridson), C. racemosa Lour., C. salvatrix Swynn. & Philipson and in Psilanthus travancorensis (Wight & Arn.) J.-F. Leroy (2n=22) by employing the conventional acetic orcein technique as well as by C- and NOR-banding aiming further comparative studies. Although C. canephora and C. dewevrei have already been studied and depict a C-band karyotype, they have also been included for further comparisons, since NOR-banding and some other morphometric data have not been obtained yet. However, there were observed some differences among the species regarding chromosomal morphometry. The karyotype formula obtained was 3m+6sm+2sms for C. salvatrix and P. travancorensis, 1M +2m + 6sm + 2sms for C. kapakata and 2M +1m + 6sm + 2sms for C. racemosa. All species displayed a moderate karyotype asymmetry and according to Stebbins system, C. canephora, C. dewevrei, C. kapakata and C. racemosa were classified as 3B while C. salvatrix and P. travancorensis were classified as 2A. Among the four indices used to assess karyotype asymmetry, Paszko AI index along with Stebbins were best suited to individualize the species. C-bands were preferentially situated at a pericentromeric/centromeric position. Two pairs of chromosomes, with secondary constriction and satellite segments, were observed in all the species following acetic orcein staining. C. racemosa and C. salvatrix showed NOR-band in both pairs, while only one chromosome pair carrying NOR-band was seen in C. canephora, C. dewevrei, C. kapakata and P. travancorensis. Data on chromosome morphometry, asymmetry indices and NOR-banding were suitable for the characterization of the species.

Polytene chromosomes of Simulium (Psaroniocompsa) daltanhani (Diptera: Simuliidae) from Central Amazonia, Brazil

Zootaxa ◽  
2008 ◽  
Vol 1676 (1) ◽  
pp. 57 ◽  
Author(s):  
NEUSA HAMADA ◽  
ELENY DA SILVA PEREIRA ◽  
PETER H. ADLER
Keyword(s):  
Banding Pattern ◽  
Polytene Chromosomes ◽  
Nucleolar Organizer ◽  
Species Group ◽  
Chromosomal Complement ◽  
Central Amazonia ◽  
Similar Banding Pattern ◽  
Chromosome I

Last-instar larvae of Simulium (Psaroniocompsa) daltanhani Hamada and Adler from a stream in Central Amazonia were analyzed cytologically by mapping their polytene chromosomes. Simulium daltanhani has the nucleolar organizer in the short arm of chromosome I, heterogametic females, and an absence of autosomal polymorphisms. The chromosomes carry multiple rearrangements relative to other analyzed members of the S. quadrifidum species group in the subgenus Psaroniocompsa. One-third of the chromosomal complement is rearranged relative to the sequence of S. ulyssesi, the species with the most similar banding pattern among studied members of the S. quadrifidum group.

scholarly journals PAIRING COMPETITION BETWEEN IDENTICAL AND HOMOLOGOUS CHROMOSOMES IN RYE AND GRASSHOPPERS

Genetics ◽  
1983 ◽  
Vol 104 (4) ◽  
pp. 677-684
Author(s):  
J L Santos ◽  
J Orellana ◽  
R Giraldez
Keyword(s):  
Secale Cereale ◽  
Banding Pattern ◽  
Chromosome Pair ◽  
Meiotic Pairing ◽  
Homologous Pairing ◽  
Eyprepocnemis Plorans ◽  
Homologous Chromosomes ◽  
Random Pairing ◽  
Structural Differences ◽  
Telomeric Heterochromatin

ABSTRACT Meiotic pairing preferences between identical and homologous but not identical chromosomes were analyzed in spontaneous tetraploid/diploid chimeras of three male grasshoppers (Eyprepocnemis plorans) whose chromosome pair 11 were heterozygous for C-banding pattern and in four induced tetraploid/diploid chimaeral rye plants (Secale cereale) heterozygous for telomeric heterochromatin C-bands in chromosomes 1R and 2R. In the grasshoppers, a preference for identical over homologous pairing was observed, whereas in rye both a preference for homologous rather than identical pairing and random pairing between the four chromosomes of the set was found. From the results in rye, it can be deduced that pairing preferences do not depend exclusively on the similarities between chromosomes involved. It is suggested that genotypic or cryptic structural differences between the homologous chromosomes of each pair analyzed might be responsible for the pairing preferences found. This hypothesis can also explain the results obtained in grasshoppers, although the possibility of premeiotic association cannot be excluded in this material.

GENETIC VARIATION IN REACTION TO SCLEROTINIA STEM ROT IN Brassica SPECIES

1989 ◽  
Vol 69 (1) ◽  
pp. 229-232 ◽  
Author(s):  
F. S. SEDUN ◽  
G. SEGUIN-SWARTZ ◽  
G. F. W. RAKOW
Keyword(s):  
Genetic Variation ◽  
Sclerotinia Sclerotiorum ◽  
Brassica Campestris ◽  
Brassica Species ◽  
Stem Rot ◽  
Stem Tissue ◽  
Sclerotinia Stem Rot ◽  
Selection Technique ◽  
Resistance Selection ◽  
Stem Lesion

Twenty-five cultivars and strains representing five Brassica species were tested under controlled conditions for their reaction to infection by Sclerotinia sclerotiorum, the causal agent of sclerotinia stem rot. Using the rate of stem lesion expansion as an indicator of the resistance of stem tissue to the pathogen, significant differences were present between species and among cultivars/strains within species. Although S0 parent-S1 progeny heritability of stem lesion expansion was low, S0 plants of Brassica campestris and B. juncea with increased sclerotinia stem rot resistance could be selected.Key words: Brassica, Sclerotinia sclerotiorum, stem rot resistance, selection technique

Analysis of present status, production constraints and future research strategies in Oilseed Brassica species

2018 ◽  
Vol 3 (02) ◽  
pp. 227-232
Author(s):  
Mahak Kumar Singh ◽  
Amit Tomar
Keyword(s):  
Brassica Campestris ◽  
Indian Mustard ◽  
Brassica Species ◽  
Future Research ◽  
Indigenous Species ◽  
Research Strategies ◽  
Brassica Napus L ◽  
Ethiopian Mustard ◽  
Black Mustard ◽  
Brown Sarson

Rapeseed-mustard crops in India comprise traditionally grown indigenous species, namely toria (Brassica campestris L. var. toria), brown sarson (Brassica campestris L. var. brown sarson), yellow sarson (Brassica campestris L. var. yellow sarson), Indian mustard (Brassica juncea L. Czern and Coss.), black mustard (Brassica nigra) and taramira (Eruca sativa/ vesicaria Mill.), which have been grown since about 3,500 BC along with non-traditional species like gobhi sarson (Brassica napus L.) and Ethiopian mustard or karan rai (Brassica carinata A. Braun).

scholarly journals Mitotic chromosomes fold by condensin-dependent helical winding of chromatin loop arrays

2017 ◽  
Author(s):  
Johan H. Gibcus ◽  
Kumiko Samejima ◽  
Anton Goloborodko ◽  
Itaru Samejima ◽  
Natalia Naumova ◽  
...  
Keyword(s):  
Mitotic Chromosome ◽  
Conformation Analysis ◽  
Interphase Chromatin ◽  
Mitotic Chromosomes ◽  
Metaphase Chromosomes ◽  
Late Prophase ◽  
Nested Loops ◽  
Helical Winding ◽  
Progressive Growth ◽  
Helical Turn

AbstractDuring mitosis, chromosomes fold into compacted rod shaped structures. We combined imaging and Hi-C of synchronous DT40 cell cultures with polymer simulations to determine how interphase chromosomes are converted into compressed arrays of loops characteristic of mitotic chromosomes. We found that the interphase organization is disassembled within minutes of prophase entry and by late prophase chromosomes are already folded as arrays of consecutive loops. During prometaphase, this array reorganizes to form a helical arrangement of nested loops. Polymer simulations reveal that Hi-C data are inconsistent with solenoidal coiling of the entire chromatid, but instead suggest a centrally located helically twisted axis from which consecutive loops emanate as in a spiral staircase. Chromosomes subsequently shorten through progressive helical winding, with the numbers of loops per turn increasing so that the size of a helical turn grows from around 3 Mb (~40 loops) to ~12 Mb (~150 loops) in fully condensed metaphase chromosomes. Condensin is essential to disassemble the interphase chromatin conformation. Analysis of mutants revealed differing roles for condensin I and II during these processes. Either condensin can mediate formation of loop arrays. However, condensin II was required for helical winding during prometaphase, whereas condensin I modulated the size and arrangement of loops inside the helical turns. These observations identify a mitotic chromosome morphogenesis pathway in which folding of linear loop arrays produces long thin chromosomes during prophase that then shorten by progressive growth of loops and helical winding during prometaphase.One Sentence SummaryMitotic chromosome morphogenesis occurs through condensin-mediated disassembly of the interphase conformation and formation of extended prophase loop arrays that then shorten by loop growth and condensin-dependent helical winding.

scholarly journals Variants of Tribulus species – a scientific study through DNA RAPD – molecular characterization

2014 ◽  
Vol 2 (04) ◽  
pp. 15-19
Author(s):  
Bhavesh Patil ◽  
Bhupesh Patel ◽  
Harisha C. R. ◽  
Neha Parmar ◽  
Ashwini Save
Keyword(s):  
Molecular Characterization ◽  
Banding Pattern ◽  
Morphological Difference ◽  
Scientific Study ◽  
Tribulus Terrestris ◽  
Three Samples ◽  
Similar Banding Pattern ◽  
Cardiac Disorders ◽  
Method Analysis ◽  
Rapd Method

Gokshura a well-known drug in Ayurveda which is extensively used in many disease conditions like dysuria, asthma, diabetes, cough, oedema, cardiac disorders etc. Tribulus terrestris (Family – Zygophyllaceae) is an official source of Gokshura as per API. Five species of genus Tribulus are found throughout India with a slight morphological difference. In this study, three different species of Tribulus genus from different regions were subjected for molecular characterization by RAPD method. Analysis showed that three different samples gave clearly similar banding pattern with each of the random primers used and 80% similarity between the three samples were observed when the results were subjected to band scoring and analysis with clustering. Even through the micromorpholgical observations showed differentiating characters in mature carpels and intrastaminal glands of the selected species.

scholarly journals Splicing conservation signals in plant long non-coding RNAs

2019 ◽  
Author(s):  
Jose Antonio Corona-Gomez ◽  
Irving Jair Garcia-Lopez ◽  
Peter F. Stadler ◽  
Selene L. Fernandez-Valverde
Keyword(s):  
Gene Activation ◽  
Sequence Divergence ◽  
Brassica Species ◽  
Conclusive Evidence ◽  
Stabilizing Selection ◽  
Evolutionary Patterns ◽  
Protein Coding ◽  
Computational Workflow ◽  
Non Coding Rnas ◽  
Or Gene

AbstractLong non-coding RNAs (lncRNAs) have recently emerged as prominent regulators of gene expression in eukaryotes. LncRNAs often drive the modification and maintenance of gene activation or gene silencing states via chromatin conformation rearrangements. In plants, lncRNAs have been shown to participate in gene regulation, and are essential to processes such as vernalization and photomorphogenesis. Despite their prominent functions only over a dozen lncRNAs have been experimentally and functionally characterized.Similar to its animal counterparts, the rates of sequence divergence are much higher in plant lncRNAs than in protein coding mRNAs, making it difficult to identify lncRNA conservation using traditional sequence comparison methods. Beyond this, little is known about the evolutionary patterns of lncRNAs in plants. Here, we characterized the splicing conservation of lncRNAs in Brassicaceae. We generated a whole-genome alignment of 16 Brassica species and used it to identify synthenic lncRNA orthologues. Using a scoring system trained on transcriptomes from A. thaliana and B. oleracea, we identified splice sites across the whole alignment and measured their conservation. Our analysis revealed that 17.9% (112/627) of all intergenic lncRNAs display splicing conservation in at least one exon, an estimate that is substantially higher to previous estimates of lncRNA conservation in this group. Our findings agree with similar studies in vertebrates, demonstrating that splicing conservation can be evidence of stabilizing selection. We provide conclusive evidence for the existence of evolutionary deeply conserved lncRNAs in plants and describe a generally applicable computational workflow to identify functional lncRNAs in plants.

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