scholarly journals Genome size in Humulus lupulus L. and H. japonicus Siebold and Zucc. (Cannabaceae)

2011 ◽  
Vol 75 (3) ◽  
pp. 207-214 ◽  
Author(s):  
Aleksander Grabowska-Joachimiak ◽  
Elwira Śliwińska ◽  
Magdalena Piguła ◽  
Urszula Skomra ◽  
Andrzej J. Joachimiak

We analysed chromosome lengths, karyotype structure, and nuclear DNA content (flow cytometry) in diploid (2n=20) and triploid (2n=30) European <em>H. lupulus</em> var. <em>lupulus</em>, American <em>H. lupulus</em> var. <em>neomexicanus</em> (2n=20) and Japanese ornamental hop, <em>H. japonicus</em> (F/2n=16; M/2n=17). Diploid female representatives of <em>H. lupulus</em> var. <em>lupulus</em> and <em>H. l.</em> var. <em>neomexicanus</em> differed in total length of the basal chromosome set (23.16 µm and 25.99 µm, respectively) and nuclear 2C DNA amount (5.598 pg and 6.064 pg) but showed similar karyotype structure. No deviation from the additivity, both in chromosome length and 2C DNA amount was evidenced in triploid monoecious <em>H. lupulus</em> (2n=30, XXY). <em>H. japonicus</em> showed different karyotype structure, smaller basal chromosome set (F/18.04 µm, M/20.66 µm) and lower nuclear DNA amount (F/3.208 pg and M/3.522 pg). There are first evaluations of nuclear genome size in diploid, not commercial representative of European <em>H. lupulus</em> var. <em>lupulus</em> and American <em>H. lupulus</em> var. <em>neomexicanus</em> and first attempt to determine the absolute male and female genome size in two Humulus species.


Genome ◽  
2007 ◽  
Vol 50 (11) ◽  
pp. 1029-1037 ◽  
Author(s):  
T. Eilam ◽  
Y. Anikster ◽  
E. Millet ◽  
J. Manisterski ◽  
O. Sagi-Assif ◽  
...  

One of the intriguing issues concerning the dynamics of plant genomes is the occurrence of intraspecific variation in nuclear DNA amount. The aim of this work was to assess the ranges of intraspecific, interspecific, and intergeneric variation in nuclear DNA content of diploid species of the tribe Triticeae (Poaceae) and to examine the relation between life form or habitat and genome size. Altogether, 438 plants representing 272 lines that belong to 22 species were analyzed. Nuclear DNA content was estimated by flow cytometry. Very small intraspecific variation in DNA amount was found between lines of Triticeae diploid species collected from different habitats or between different morphs. In contrast to the constancy in nuclear DNA amount at the intraspecific level, there are significant differences in genome size between the various diploid species. Within the genus Aegilops , the 1C DNA amount ranged from 4.84 pg in A. caudata to 7.52 pg in A. sharonensis; among genera, the 1C DNA amount ranged from 4.18 pg in Heteranthelium piliferum to 9.45 pg in Secale montanum . No evidence was found for a smaller genome size in annual, self-pollinating species relative to perennial, cross-pollinating ones. Diploids that grow in the southern part of the group’s distribution have larger genomes than those growing in other parts of the distribution. The contrast between the low variation at the intraspecific level and the high variation at the interspecific one suggests that changes in genome size originated in close temporal proximity to the speciation event, i.e., before, during, or immediately after it. The possible effects of sudden changes in genome size on speciation processes are discussed.



Genome ◽  
2010 ◽  
Vol 53 (12) ◽  
pp. 1066-1082 ◽  
Author(s):  
David Zaitlin ◽  
Andrew J. Pierce

The Gesneriaceae (Lamiales) is a family of flowering plants comprising >3000 species of mainly tropical origin, the most familiar of which is the cultivated African violet ( Saintpaulia spp.). Species of Gesneriaceae are poorly represented in the lists of taxa sampled for genome size estimation; measurements are available for three species of Ramonda and one each of Haberlea , Saintpaulia, and Streptocarpus , all species of Old World origin. We report here nuclear genome size estimates for 10 species of Sinningia , a neotropical genus largely restricted to Brazil. Flow cytometry of leaf cell nuclei showed that holoploid genome size in Sinningia is very small (approximately two times the size of the Arabidopsis genome), and is small compared to the other six species of Gesneriaceae with genome size estimates. We also documented intraspecific genome size variation of 21%–26% within a group of wild Sinningia speciosa (Lodd.) Hiern collections. In addition, we analyzed 1210 genome survey sequences from S. speciosa to characterize basic features of the nuclear genome such as guanine–cytosine content, types of repetitive elements, numbers of protein-coding sequences, and sequences unique to S. speciosa. We included several other angiosperm species as genome size standards, one of which was the snapdragon ( Antirrhinum majus L.; Veronicaceae, Lamiales). Multiple measurements on three accessions indicated that the genome size of A. majus is ∼633 × 106 base pairs, which is approximately 40% of the previously published estimate.



Genome ◽  
2005 ◽  
Vol 48 (3) ◽  
pp. 511-520 ◽  
Author(s):  
A Ricroch ◽  
R Yockteng ◽  
S C Brown ◽  
S Nadot

Allium L. (Alliaceae), a genus of major economic importance, exhibits a great diversity in various morphological characters and particularly in life form, with bulbs and rhizomes. Allium species show variation in several cytogenetic characters such as basic chromosome number, ploidy level, and genome size. The purpose of the present investigation was to study the evolution of nuclear DNA amount, GC content, and life form. A phylogenetic approach was used on a sample of 30 Allium species, including major vegetable crops and their wild allies, belonging to the 3 major subgenera Allium, Amerallium, and Rhizirideum and 14 sections. A phylogeny was constructed using internal transcribed spacer (ITS) sequences of 43 accessions representing 30 species, and the nuclear DNA amount and the GC content of 24 Allium species were investigated by flow cytometry. For the first time, the nuclear DNA content of Allium cyaneum and Allium vavilovii was measured, and the GC content of 16 species was measured. We addressed the following questions: (i) Is the variation in nuclear DNA amount and GC content linked to the evolutionary history of these edible Allium species and their wild relatives? (ii) How did life form (rhizome or bulb) evolve in edible Allium? Our results revealed significant interspecific variation in the nuclear DNA amount as well as in the GC content. No correlation was found between the GC content and the nuclear DNA amount. The reconstruction of nuclear DNA amount on the phylogeny showed a tendency towards a decrease in genome size within the genus. The reconstruction of life form history showed that rhizomes evolved in the subgenus Rhizirideum from an ancestral bulbous life form and were subsequently lost at least twice independently in this subgenus.Key words: Allium, nuclear DNA amount, GC content, flow cytometry, internal transcribed spacer (ITS), phylogeny, life form.



1994 ◽  
Vol 119 (6) ◽  
pp. 1312-1316 ◽  
Author(s):  
W. Vance Baird ◽  
Agnes S. Estager ◽  
John K. Wells

Using laser flow cytometry, nuclear DNA amounts were estimated for 12 Prunus species, representing three subgenera [Prunophora (Prunus), Amygdalus, and Cerasus (Lithocerasus)], two interspecific hybrids, four cultivars, and a synthetic polyploid series of peach consisting of haploids, diploids, triploids, and tetraploids (periclinal cytochimeras). Peach nuclear DNA content ranged from 0.30 pg for the haploid nuclei to 1.23 pg for the tetraploid nuclei. The diploid genome of peach is relatively small and was estimated to be 0.60±0.03 pg (or 5.8×108 nucleotide base pairs). The polyploid series represented the expected arithmetic progression, as genome size positively correlated with ploidy level (i.e., DNA content was proportional to chromosome number). The DNA content for the 12 diploid species and two interspecific diploid hybrids ranged from 0.57 to 0.79 pg. Genome size estimates were verified independently by Southern blot analysis, using restriction fragment length polymorphism clones as gene-copy equivalents. Thus, a relatively small and stable nuclear genome typifies the Prunus species investigated, consistent with their low, basic chromosome number (× = 8).



Database ◽  
2019 ◽  
Vol 2019 ◽  
Author(s):  
Daniel Vitales ◽  
Pol Fernández ◽  
Teresa Garnatje ◽  
Sònia Garcia

Abstract The Genome Size in Asteraceae Database (GSAD, http://www.asteraceaegenomesize.com) has been recently updated, with data from papers published or in press until July 2018. This constitutes the third release of GSAD, currently containing 4350 data entries for 1496 species, which represent a growth of 22.52% in the number of species with available genome size data compared with the previous release, and a growth of 57.72% in terms of entries. Approximately 6% of Asteraceae species are covered in terms of known genome sizes. The number of source papers included in this release (198) means a 48.87% increase with respect to release 2.0. The significant data increase was exploited to study the genome size evolution in the family from a phylogenetic perspective. Our results suggest that the role of chromosome number in genome size diversity within Asteraceae is basically associated to polyploidy, while dysploidy would only cause minor variation in the DNA amount along the family. Among diploid taxa, we found that the evolution of genome size shows a strong phylogenetic signal. However, this trait does not seem to evolve evenly across the phylogeny, but there could be significant scale and clade-dependent patterns. Our analyses indicate that the phylogenetic signal is stronger at low taxonomic levels, with certain tribes standing out as hotspots of autocorrelation between genome size and phylogeny. Finally, we also observe meaningful associations among nuclear DNA content on Asteraceae species and other phenotypical and ecological traits (i.e. plant habit and invasion ability). Overall, this study emphasizes the need to continue generating and analysing genome size data in order to puzzle out the evolution of this parameter and its many biological correlates.



Genome ◽  
2001 ◽  
Vol 44 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Montserrat Torrell ◽  
Joan Vallès

Genome size was estimated by flow cytometry in 24 populations belonging to 22 Artemisia taxa (21 species, 1 with two subspecies), which represent the distinct subgenera, life forms, basic chromosome numbers, and ploidy levels in the genus. 2C nuclear DNA content values range from 3.5 to 25.65 pg, which represents a more than sevenfold variation. DNA content per haploid genome ranges from 1.75 to 5.76 pg. DNA amount is very well correlated with karyotype length and ploidy level. Some variations in genome size have systematic and evolutionary implications, whereas others are linked to ecological selection pressures.Key words: Artemisia, Asteraceae, flow cytometry, genome size, nuclear DNA amount variation, systematics, evolution, ecology.



Genome ◽  
2004 ◽  
Vol 47 (2) ◽  
pp. 246-256 ◽  
Author(s):  
Elzbieta Kuta ◽  
Borut Bohanec ◽  
Ewa Dubas ◽  
Liliana Vizintin ◽  
Leslaw Przywara

Chromosomes and nuclear DNA amount were analyzed in leaf tissues of Luzula nivea, Luzula luzuloides, and Luzula multiflora. Intra- and interspecific karyological variability was stated. Chromosome numbers in diploids ranged 2n = 8-24 in L. nivea and L. luzuloides and 2n = 12-84 in hexaploid L. multiflora. Karyological variability resulted mainly from chromosome fission (agmatoploidy) and aneusomaty; chromosome fusion (symploidy) and polyploidy were also involved. Flow cytometric determination of nuclear genome size using propidium iodide staining gave values of 1.584 pg in L. luzuloides, 1.566 pg in L. nivea, and 3.034 pg in L. multiflora. Variability in relative nuclear genome size within species was measured by 4',6-diamidino-2-phenylindole staining. In contrast with previous reports, variability was fairly small and ranged from 1.796 to 1.864 pg in L. luzuloides, from 1.783 to 1.847 pg and from 1.737 to 1.808 pg in two populations (S and F) of L. nivea, respectively, and from 3.125 to 3.271 pg in L. multiflora. An intraplant (interleaf) genome size variation was also observed and its possible causes are discussed.Key words: Luzula, holokinetic chromosomes, agmatoploidy, symploidy, polyploidy, nuclear DNA amount, intraplant genome size variability, flow cytometry.



Genome ◽  
1991 ◽  
Vol 34 (5) ◽  
pp. 763-768 ◽  
Author(s):  
Sangeeta Srivastava ◽  
U. C. Lavania

In 23 species of Papaver L., 2C nuclear DNA amounts range from 4.64 pg in Papaver persicum (2n = 14) to 22.43 pg in Papaver orientale (2n = 42), revealing a fivefold variation within the genus. However, such variation is limited to only twofold among the species that have the same chromosome number (2n = 14). The distribution of DNA is discontinuously spread over six groups in the genus. A strong positive correlation exists between nuclear DNA content and metaphase chromosome length. Viewed in the context of evolutionary divergence, it is revealed that DNA reduction has taken place in conjunction with speciation. This is achieved by equal reduction to each chromosome independent of chromosome size, as apparent from the estimated DNA values for individual chromosomes within the complements. The diminution in DNA amount with evolutionary specialisation appears to be a genomic strategy to dispense with the less important DNA associated with heterochromatic segments. The uniform distribution of such dispensible DNA throughout the complement is probably nucleotypically conducive to allow the genomic loss to be adaptationally operative, lest it affects the very survival of the evolving species.Key words: Papaver, evolution, DNA content, DNA systematics.



2014 ◽  
Vol 92 (10) ◽  
pp. 847-851 ◽  
Author(s):  
Kelly L. Mulligan ◽  
Terra C. Hiebert ◽  
Nicholas W. Jeffery ◽  
T. Ryan Gregory

Ribbon worms (phylum Nemertea) are among several animal groups that have been overlooked in past studies of genome-size diversity. Here, we report genome-size estimates for eight species of nemerteans, including representatives of the major lineages in the phylum. Genome sizes in these species ranged more than fivefold, and there was some indication of a positive relationship with body size. Somatic endopolyploidy also appears to be common in these animals. Importantly, this study demonstrates that both of the most common methods of genome-size estimation (flow cytometry and Feulgen image analysis densitometry) can be used to assess genome size in ribbon worms, thereby facilitating additional efforts to investigate patterns of variability in nuclear DNA content in this phylum.



2021 ◽  
Vol 41 (3) ◽  
Author(s):  
Emilly Schutt ◽  
Maria Hołyńska ◽  
Grace A Wyngaard

Abstract Genome size is a fundamental property of organisms that impacts their molecular evolution and life histories. The hypothesis that somatic genome sizes in copepods in the order Cyclopoida are small and evolutionary constrained relative to those in the order Calanoida was proposed 15 years ago. Since then, the number of estimates has almost doubled and the taxon sampling has broadened. Here we add 14 new estimates from eight genera of freshwater cyclopoids that vary from 0.2 to 6.6 pg of DNA per nucleus in the soma; all except one are 2.0 pg DNA per nucleus or smaller. This new sample adds to the pattern of genome size in copepods and is remarkably similar to the distribution on which the original hypothesis was based, as well as those of subsequently published estimates. Embryonic chromatin diminution, during which large portions of DNA are excised from the presomatic cell lineage, is reported in Paracyclops affinis (G.O. Sars, 1863). This diminution results in a somatic genome that is one half the size of the germline genome. When the sizes of the germline genomes carried in presomatic cells of cyclopoid species that possess chromatin diminution are considered, the prediminuted germline genome sizes of cyclopoid embryos overlap with the distribution of calanoid somatic genome sizes, supporting the hypothesis that chromatin diminution has functioned as a mechanism to constrain somatic nuclear DNA content in cyclopoid copepods. Geographically based variation in genome size among populations is also reviewed.



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