DNA content of heterochromatin and euchromatin in tomato (Lycopersicon esculentum) pachytene chromosomes

Genome ◽  
1996 ◽  
Vol 39 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Daniel G. Peterson ◽  
Stephen M. Stack ◽  
H. James Price ◽  
J. Spencer Johnston
Keyword(s):  
Lycopersicon Esculentum ◽  
Synaptonemal Complex ◽  
Genome Size ◽  
Functional Genes ◽  
Tomato Genome ◽  
Chromosome Walking ◽  
The Family ◽  
Key Words Tomato ◽  
Effective Genome Size ◽  
Active Genes

Lycopersicon esculentum (tomato) has a small genome (2C = 1.90 pg of DNA) packaged in 2n = 2x = 24 small acrocentric to metacentric chromosomes. Like the chromosomes of other members of the family Solanaceae, tomato chromosomes have pericentromeric heterochromatin. To determine the fraction of the tomato genome found in euchromatin versus heterochromatin, we stained pachytene chromosomes from primary microsporocytes with Feulgen and analyzed them by densitometry and image analysis. In association with previously published synaptonemal complex karyotype data for tomato, our results indicate that 77% of the tomato microsporocyte genome is located in heterochromatin and 23% is found in euchromatin. If heterochromatin is assumed to contain few active genes, then the functional genes of the tomato must be concentrated in an effective genome of only 0.22 pg of DNA (1C = 0.95 pg × 0.23 = 0.22 pg). The physical segregation of euchromatin and heterochromatin in tomato chromosomes coupled with the small effective genome size suggests that tomato may be a more useful subject for chromosome walking and gene mapping studies than would be predicted based on its genome size alone. Key words : tomato, Lycopersicon esculentum, genome size, heterochromatin, euchromatin, pachytene chromosomes, synaptonemal complex.

scholarly journals GENOME SIZE DETERMINATION OF CUCUMBER (CUCUMIS SATIVUS), HONEYDEW (CUCUMIS MELO INODORUS) AND ROCK MELON (CUCUMIS MELO CANTALUPENSIS) VIA FLOW CYTOMETRY

2021 ◽  
Vol 5 (1) ◽  
pp. 14-16
Author(s):  
Raden Muhamad Imaduddin Yumni ◽  
Mohd Fauzihan Karim ◽  
Mohd Razik Midin
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Cucumis Melo ◽  
As Species ◽  
External Reference ◽  
The Family ◽  
Cucumis Species ◽  
Fcm Analysis ◽  
Interspecific And Intraspecific Variation

The family of Cucurbitaceae consists of species with economical and nutritional value. Morphologically, there are only few differences between Cucumis species. The interspecific and intraspecific variation in the genome size of the Cucumis species are not discovered yet. Due to this, this study aims to determine the genome size of C. sativus, C. melo inodorus and C. melo cantalupensis using flow cytometry (FCM) method. Nuclei suspension of selected Cucumis species were extracted using LBO1 lysis buffer by manual chopping technique and stained by propidium iodide priot to FCM analysis. Genome size of C. sativus, C. melo inodorus (Honeydew) and C. melo cantalupensis (Rockmelon) were determined by using Glycine max (Soybean) as an external reference standard (2C = 2.5 pg). This study found that the genome size of C. sativus, C. melo inodorus and C. melo cantalupensis estimated to be 2.83 pg, 3.00 pg and 3.47 pg respectively. The genome size data obtained from this study can be used in future genome studies as well as species characterization.

Chromosome pairing and potential for intergeneric recombination in some hypotetraploid somatic hybrids of Lycopersicon esculentum (+) Solanum tuberosum

Genome ◽  
1993 ◽  
Vol 36 (6) ◽  
pp. 1032-1041 ◽  
Author(s):  
J. H. de Jong ◽  
A. M. A. Wolters ◽  
J. M. Kok ◽  
H. Verhaar ◽  
J. van Eden
Keyword(s):  
Solanum Tuberosum ◽  
Lycopersicon Esculentum ◽  
Synaptonemal Complex ◽  
Chromosome Pairing ◽  
Somatic Hybrids ◽  
Cytogenetic Study ◽  
Unreduced Gametes ◽  
Root Tip ◽  
Prophase I ◽  
Metaphase I

Three somatic hybrids resulting from protoplast fusions of a diploid kanamycin-resistant line of tomato (Lycopersicon esculentum) and a dihaploid hygromycin-resistant transformant of a monohaploid potato (Solanum tuberosum) line were used for a cytogenetic study on chromosome pairing and meiotic recombination. Chromosome counts in root-tip meristem cells revealed two hypotetraploids with chromosome complements of 2n = 46 and one with 2n = 47. Electron microscope analyses of synaptonemal complex spreads of hypotonically burst protoplasts at mid prophase I showed abundant exchanges of pairing partners in multivalents involving as many as eight chromosomes. In the cells at late pachytene recombination nodules were found in multivalents on both sides of pairing partner exchanges, indicating recombination at both homologous and homoeologous sites. Light microscope observations of pollen mother cells at late diakinesis and metaphase I also revealed multivalents, though their occurrence in low frequencies betrays the reduction of multivalent number and complexity. Precocious separation of half bivalents at metaphase I and lagging of univalents at anaphase I were observed frequently. Bridges, which may result from an apparent inversion loop found in the synaptonemal complexes of a mid prophase I nucleus, were also quite common at anaphase I, though the expected accompanying fragments could be detected in only a few cells. Most striking were the high frequencies of first division restitution in preparations at metaphase II/anaphase II, giving rise to unreduced gametes. In spite of the expected high numbers of balanced haploid and diploid gametes, male fertility, as revealed by pollen staining, was found to be negligible.Key words: synaptonemal complex, recombination, chromosome pairing, somatic hybrid, Lycopersicon esculentum (+) Solanum tuberosum.

Genome size variation and endopolyploidy in the diverse succulent plant family Aizoaceae

2020 ◽  
Vol 194 (1) ◽  
pp. 47-68
Author(s):  
Robyn F Powell ◽  
Laura Pulido Suarez ◽  
Anthony R Magee ◽  
James S Boatwright ◽  
Maxim V Kapralov ◽  
...  
Keyword(s):  
Genome Size ◽  
Size Variation ◽  
Cape Floristic Region ◽  
Genome Size Variation ◽  
Rapid Radiation ◽  
Plant Family ◽  
Succulent Plant ◽  
The Family ◽  
The World ◽  
Plant Families

Abstract Aizoaceae are one of the most diverse succulent plant families in the world, with c. 2 400 species, and they are a major component of the Greater Cape Floristic Region of South Africa. Despite this diversity, genome size (GS) has only been recorded in three of the c. 144 genera of Aizoaceae. This study provides the first comprehensive assessment of GS in the family with 109 genera measured (76% of genera). GS (2C) is conserved in Aizoaceae, varying from 0.54 to 6.34 pg (0.53–6.20 Gbp), with a mean of 2.6 pg. No significant differences between GS and the ecological and environmental traits tested were recovered. Infrageneric GS was explored in the most diverse stoneplant genus, Conophytum, and was found to be extremely conserved [0.98–2.24 pg (1C)]. Furthermore, the extent of endoreduplication in Conophytum was determined across 46 species. Leaf and flower tissues of Conophytum are highly polysomatic and ploidy states of 2C–64C were typically observed across the genus, with some instances of 128C. The relatively conserved and small GS measured across Aizoaceae and in Conophytum is possibly linked to the recent and rapid radiation of the family.

The relationship between synaptonemal complex length and genome size in four vertebrate classes (Osteicthyes, Reptilia, Aves, Mammalia)

1994 ◽  
Vol 2 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Daniel G. Peterson ◽  
Stephen M. Stack ◽  
Joseph L. Healy ◽  
Bryon S. Donohoe ◽  
Lorinda K. Anderson
Keyword(s):  
Synaptonemal Complex ◽  
Genome Size ◽  
The Relationship ◽  
Complex Length

scholarly journals Medicinal Values of Tomato (Lycopersicon esculentum Mill. –Solanaceae)

2021 ◽  
Vol 9 (3) ◽  
pp. 166-168
Author(s):  
Pushpa Karna Mallick
Keyword(s):  
Antioxidant Activity ◽  
Lycopersicon Esculentum ◽  
Cell Damage ◽  
Soluble Sugars ◽  
Antioxidant Properties ◽  
Vitamin B1 ◽  
Flowering Plant ◽  
Mineral Salts ◽  
Blood Constituents ◽  
The Family

Lycopersicon esculentum is a flowering plant of the family Solanaceae. The common name for this plant is tomato. Tomatoes are a good source of lycopene which is a main pigment found in it and responsible for red colour. The lycopene provides antioxidant properties and helps to prevent cell damage. Tomatoes also prevent the adverse effects of lead in the blood constituents. Tomatoes are used in different ways such as raw or cooked, in many dishes, sauces, salads, pickles, puree, paste, juice, sun- dried and drink. Tomato fruits content ninety four percent water, citric acid, malic acid, soluble sugars, vitamin, vitamin B1, B2, vitamin A, and many mineral salts etc. High levels of lycopene which contain in tomatoes are used in facial cleanser. Flavonoids like flavonols which is present in tomatoes are rich in antioxidant activity and can help our body ward off every day toxins. Flavonoides such as flavonols present in tomatoes are rich in antioxidant activity and   can help our body ward off every day toxins Flavonoides directly associated with human dietary ingredients, play a great role in diseases prevention and shows versatile health benefits. Int. J. Appl. Sci. Biotechnol. Vol 9(3): 166-168.

Heterochromatin, the synaptonemal complex and crossing over

1984 ◽  
Vol 71 (1) ◽  
pp. 159-176 ◽  
Author(s):  
S.M. Stack
Keyword(s):  
Electron Microscopy ◽  
Lycopersicon Esculentum ◽  
Synaptonemal Complex ◽  
Electron Microscopic Examination ◽  
Differential Staining ◽  
Crossing Over ◽  
Mitotic Metaphase ◽  
Plantago Ovata ◽  
Electron Microscopic ◽  
Metaphase Chromosomes

A combined light- and electron-microscopic examination of chromosomes from two angiospermous plants, Plantago ovata and Lycopersicon esculentum, and a mammal, Mus musculus, was performed. From this investigation three observations have been made that may be relevant to the observed lack of crossing over in heterochromatin. (1) Differential staining indicates that heterochromatin represents a smaller fraction of the length of pachytene chromosomes than it represents in the length of mitotic metaphase chromosomes. Since the synaptonemal complex (SC) runs throughout the length of these pachytene chromosomes, it is under-represented in heterochromatin. Considering the evidence for a rough correlation between the length of SC and the amount of crossing over, this could result in less crossing over in heterochromatin than expected on the basis of its length in mitotic metaphase chromosomes. (2) Electron microscopy indicates that, unlike the SC in euchromatin, the SC in heterochromatin is densely ensheathed in highly compact chromatin. If crossing over occurs in the SC or even in the surrounding chromatin, the compaction of the chromatin may prevent the penetration of enzymes needed in recombination. (3) Finally, a difference in the structure of SCs in euchromatin versus heterochromatin was observed that could be associated with the lack of crossing over in heterochromatin.

GATA- and GACA-repeats are not evenly distributed throughout the tomato genome

Genome ◽  
1995 ◽  
Vol 38 (1) ◽  
pp. 84-90 ◽  
Author(s):  
P. Arens ◽  
P. Odinot ◽  
A. W. van Heusden ◽  
P. Lindhout ◽  
B. Vosman
Keyword(s):  
Lycopersicon Esculentum ◽  
Dna Fingerprinting ◽  
Tomato Genome ◽  
First Report ◽  
Mapping Experiment

This paper describes the distribution of highly polymorphic GATA- and GACA-containing DNA regions in tomato. To study the distribution of these polymorphic regions, a mapping experiment was done. The segregation of 32 GATA- and GACA-containing loci was analyzed in a F2 population from a cross between Lycopersicon esculentum and L. pennellii. From these loci, 28 could be mapped to 8 of the 12 tomato chromosomes. Both the GATA- and GACA-containing loci seem to cluster in the same chromosomal regions. To our knowledge, this is the first report on mapping of GATA- and GACA-containing loci in plants.Key words: mapping, microsatellites, Lycopersicon esculentum, RFLP, DNA-fingerprinting.

Complete meiotic pairing of crested newt chromosomes

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1105-1111 ◽  
Author(s):  
H. Wallace ◽  
B. M. N. Wallace
Keyword(s):  
Synaptonemal Complex ◽  
Genome Size ◽  
Chromosome Pairing ◽  
Meiotic Pairing ◽  
Homologous Chromosomes ◽  
Direct Observations ◽  
Crested Newt ◽  
The Individual ◽  
Complex Length ◽  
Complex Genome

The longest chromosome (number 1) of Trituturus cristatus carries a heteromorphic segment, a heterozygosity perpetuated by a balanced lethal system. The heteromorphic segment is regarded as achiasmate and has been claimed to be asynaptic. Direct observations of chromosome pairing in spermatocytes and oocytes yield some cases where all homologous chromosomes appear to be completely paired, but the individual bivalents could not be identified as pachytene is not particularly clear in this species. The long arms of bivalent 1 usually remain attached by a terminal chiasma in spermatocytes of T. c. cristatus but the corresponding chiasma is only rarely present in T. c. carnifex spermatocytes. Synaptonemal complexes have been measured in both spermatocytes and oocytes of T. c. cristatus. A karyotype constructed from these measurements matches the main features of somatic and lampbrush chromosome karyotypes, indicating that all chromosomes must be completely paired and proportionately represented as synaptonemal complex. The total length of synaptonemal complex is much the same in spermatocytes and oocytes and is similar to the length in spermatocytes of Xenopus laevis. These two amphibian examples supplement a recent survey of other vertebrate classes to reinforce its conclusion that synaptonemal complex length is not related to genome size in vertebrates.Key words: chromosome pairing, synaptonemal complex, genome size, amphibia.

scholarly journals Draft Genome Sequence of Tokyovirus , a Member of the Family Marseilleviridae Isolated from the Arakawa River of Tokyo, Japan

2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Masaharu Takemura
Keyword(s):  
Soil Sample ◽  
Family Member ◽  
Genome Size ◽  
Genome Sequence ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Dna Viruses ◽  
The Family

Members of the Marseilleviridae family are large DNA viruses with icosahedral particles that infect Acanthamoeba cells. This report presents a new Marseilleviridae family member discovered in a water/soil sample from a river in Tokyo, named Tokyovirus , with genome size of 370 to 380 kb.

scholarly journals Genome size variation and species diversity in salamanders

2016 ◽  
Author(s):  
John Herrick ◽  
Bianca Sclavi
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Genome Size ◽  
Geographical Area ◽  
Negative Relationship ◽  
Size Variation ◽  
Exact Nature ◽  
Genome Size Variation ◽  
The Family ◽  
C Value

AbstractSalamanders (Urodela) have among the largest vertebrate genomes, ranging in size from 10 to 120 pg. Although changes in genome size often occur randomly and in the absence of selection pressure, non-random patterns of genome size variation are evident among specific vertebrate lineages. Several reports suggest a relationship between species richness and genome size, but the exact nature of that relationship remains unclear both within and across different taxonomic groups. Here we report i) a negative relationship between haploid genome size (C-value) and species richness at the family taxonomic level in salamander clades; ii) a correlation of C-value and species richness with clade crown-age but not with diversification rates; iii) strong associations between C-value and either geographical area or climatic niche rate. Finally, we report a relationship between C-value diversity and species diversity at both the family and genus level clades in urodeles.

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