Genome size, heterochromatin organisation, and ribosomal gene mapping in four species of Ribes

2003 ◽  
Vol 81 (11) ◽  
pp. 1049-1057 ◽  
Author(s):  
Joëlle Chiche ◽  
Spencer C Brown ◽  
Jean-Claude Leclerc ◽  
Sonja Siljak-Yakovlev
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Nuclear Dna ◽  
5S Rdna ◽  
Ribosomal Gene ◽  
Fluorochrome Banding ◽  
Genome Organisation ◽  
Satellite Chromosome ◽  
26S Rdna

Four wild Ribes species (Ribes alpinum L., Ribes petraeum Wulf., Ribes rubrum L., and Ribes uva- crispa L.; all 2n = 2x = 16) were surveyed for their chromosome and genome organisation. Their genome size was assessed using flow cytometry. Ribes alpinum had 5.3% more nuclear DNA than did the three other species, whose average was 2C = 1.91 pg with 40.4% GC. In addition, GC- and AT-rich heterochromatin and rDNA (18S–5.8S–26S and 5S) patterns were studied using fluorochrome banding and double-target fluorescence in situ hybridization (FISH), respectively. Only GC-rich heterochromatin was detected, co-localizing with 18S–26S rDNA. Fluorochrome banding and FISH patterns revealed marked differences between species. Ribes alpinum and R. uva-crispa differed from R. rubrum and R. petraeum by the number of 18S–26S sites and the localization of 5S rDNA. Ribes alpinum and R. uva-crispa were differentiated by the number of 5S sites. Ribes rubrum and R. petraeum also differed by the number of 5S sites and by the size of the GC-rich band on the satellite chromosome pair. These results should contribute to a better understanding of phylogenetic relationships among these species.Key words: Ribes, flow cytometry, fluorochrome banding, FISH, rDNA, NORs.

Detection of a variable number of 18S-5.8S-26S and 5S ribosomal DNA loci by fluorescent in situ hybridization in diploid and tetraploid Arachis species

Genome ◽  
1999 ◽  
Vol 42 (1) ◽  
pp. 52-59 ◽  
Author(s):  
S N Raina ◽  
Y Mukai
Keyword(s):  
In Situ Hybridization ◽  
5S Rdna ◽  
Gene Families ◽  
Ribosomal Gene ◽  
Rrna Genes ◽  
Tetraploid Species ◽  
Arachis Species ◽  
26S Rdna ◽  
Rdna Loci

In order to obtain new information on the genome organization of Arachis ribosomal DNA, more particularly among A. hypogaea and its close relatives, the distribution of the 18S-5.8S-26S and 5S ribosomal RNA gene families on the chromosomes of 21 diploid and tetraploid Arachis species, selected from six of nine taxonomic sections, was analyzed by in situ hybridization with pTa71 (18S-5.8S-26S rDNA) and pTa794 (5S rDNA) clones. Two major 18S-5.8S-26S rDNA loci with intense signals were found in the nucleolus organizer regions (NOR) of each of the diploid and tetraploid species. In addition to extended signals at major NORs, two to six medium and (or) minute-sized signals were also observed. Variability in the number, size, and location of 18S-5.8S-26S sites could generally distinguish species within the same genome as well as between species with different genomes. The use of double fluorescence in situ hybridization enabled us to locate the positions of 5S rRNA genes in relation to the chromosomal location of 18S-5.8S-26S rRNA genes in Arachis chromosomes which were difficult to karyotype. Two or four 5S rDNA loci and 18S-5.8S-26S rDNA loci were generally located on different chromosomes. The tandemly repeated 5S rDNA sites were diagnostic for T and C genomes. In one species, each of B and Am genomes, the two ribosomal gene families were observed to occur at the same locus. Barring A. ipaensis and A. valida, all the diploid species had characteristic centromeric bands in all the 20 chromosomes. In tetraploid species A. hypogaea and A. monticola only 20 out of 40 chromosomes showed centromeric bands. Comparative studies of distribution of the two ribosomal gene families, and occurrence of centromeric bands in only 20 chromosomes of the tetraploid species suggests that A. villosa and A. ipaensis are the diploid progenitors of A. hypogaea and A. monticola. This study excludes A. batizocoi as the B genome donor species for A. hypogaea and A. monticola.Key words: Arachis species, 5S rRNA, 18S-5.8S-26S rRNA, in situ hybridization, evolution.

Genome size, fluorochrome banding, and karyotype evolution in some Hypochoeris species

Genome ◽  
1995 ◽  
Vol 38 (4) ◽  
pp. 689-695 ◽  
Author(s):  
M. Cerbah ◽  
J. Coulaud ◽  
B. Godelle ◽  
S. Siljak-Yakovlev
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Nucleolar Organizer ◽  
Phylogenetic Position ◽  
Nucleolar Organizer Regions ◽  
Fluorochrome Banding ◽  
South American

Four South American and two European species of Hypochoeris (Asteraceae) were studied using fluorochrome banding, and genome size was determined by flow cytometry, in order to obtain information about microevolution in this genus and about its primary origin. Fluorochrome banding patterns showed GC-rich repeated sequences, particularly around the nucleolar organizer regions. Few differences appeared among the South American species. Nevertheless, determination of nuclear DNA content and base composition revealed significant differences among these species. The phylogenetic position of Hypochoeris robertia, which has the smallest DNA content, is discussed with regard to chromosome evolution in this genus.Key words: Hypochoeris, Asteraceae, fluorochromes, flow cytometry, nucleolar organizer regions, microevolution.

First estimates of genome size in ribbon worms (phylum Nemertea) using flow cytometry and Feulgen image analysis densitometry

2014 ◽  
Vol 92 (10) ◽  
pp. 847-851 ◽  
Author(s):  
Kelly L. Mulligan ◽  
Terra C. Hiebert ◽  
Nicholas W. Jeffery ◽  
T. Ryan Gregory
Keyword(s):  
Flow Cytometry ◽  
Image Analysis ◽  
Body Size ◽  
Genome Size ◽  
Positive Relationship ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Size Estimation ◽  
Size Diversity ◽  
Size Estimates

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.

The use of double fluorescence in situ hybridization to physically map the positions of 5S rDNA genes in relation to the chromosomal location of 18S–5.8S–26S rDNA and a C genome specific DNA sequence in the genus Avena

Genome ◽  
1996 ◽  
Vol 39 (3) ◽  
pp. 535-542 ◽  
Author(s):  
Concha Linares ◽  
Juan González ◽  
Esther Ferrer ◽  
Araceli Fominaya
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequence ◽  
Diploid Species ◽  
5S Rdna ◽  
Rdna Genes ◽  
26S Rdna ◽  
A Genome ◽  
Rdna Loci ◽  
C Genome

A physical map of the locations of the 5S rDNA genes and their relative positions with respect to 18S–5.8S–26S rDNA genes and a C genome specific repetitive DNA sequence was produced for the chromosomes of diploid, tetraploid, and hexaploid oat species using in situ hybridization. The A genome diploid species showed two pairs of rDNA loci and two pairs of 5S loci located on both arms of one pair of satellited chromosomes. The C genome diploid species showed two major pairs and one minor pair of rDNA loci. One pair of subtelocentric chromosomes carried rDNA and 5S loci physically separated on the long arm. The tetraploid species (AACC genomes) arising from these diploid ancestors showed two pairs of rDNA loci and three pairs of 5S loci. Two pairs of rDNA loci and 2 pairs of 5S loci were arranged as in the A genome diploid species. The third pair of 5S loci was located on one pair of A–C translocated chromosomes using simultaneous in situ hybridization with 5S rDNA genes and a C genome specific repetitive DNA sequence. The hexaploid species (AACCDD genomes) showed three pairs of rDNA loci and six pairs of 5S loci. One pair of 5S loci was located on each of two pairs of C–A/D translocated chromosomes. Comparative studies of the physical arrangement of rDNA and 5S loci in polyploid oats and the putative A and C genome progenitor species suggests that A genome diploid species could be the donor of both A and D genomes of polyploid oats. Key words : oats, 5S rDNA genes, 18S–5.8S–26S rDNA genes, C genome specific repetitive DNA sequence, in situ hybridization, genome evolution.

The genome sizes of Hordeum species show considerable variation

Genome ◽  
1996 ◽  
Vol 39 (4) ◽  
pp. 730-735 ◽  
Author(s):  
Juha Kankanpää ◽  
Alan H. Schulman ◽  
Leena Mannonen
Keyword(s):  
Flow Cytometry ◽  
Hordeum Vulgare ◽  
Genome Size ◽  
Nuclear Dna ◽  
Size Variation ◽  
Nuclear Dna Content ◽  
Meiotic Pairing ◽  
Genome Size Variation ◽  
Dapi Staining ◽  
Hordeum Vulgare Ssp

Hordeum, distributed worldwide in temperate zones, is the second largest genus in the tribe Triticeae and includes diploid, tetraploid, and hexaploid species. We determined, by DAPI staining and flow cytometry, the nuclear DNA content for 35 accessions of the genus Hordeum, from a total of 19 species, including specimens of 2 cultivars and 2 landraces of Hordeum vulgare ssp. vulgare as well as samples of 12 Hordeum vulgare ssp. spontaneum populations. Genome sizes ranged from 5.69 to 9.41 pg for the G1 nuclei of the diploids, and from 13.13 to 18.36 pg for those of the tetraploids. This constitutes a 1.7-fold variation for the diploids, contrasting with a 4% variation previously reported. For H. vulgare ssp. vulgare (barley), the accessions examined differed by 18%. These variations in genome size cannot be correlated with meiotic pairing groups (I, H, X, Y) or with proposed phylogenetic relationships within the genus. Genome size variation between barley accessions cannot be related to status as cultivated or wild, or to climatic or geological gradients. We suggest these data may indicate rapid but sporadic changes in genome size within the genus. Key words : barley, Hordeum, Triticeae, genome size, flow cytometry.

Nuclear DNA content of the whitefly Bemisia tabaci (Aleyrodidae: Hemiptera) estimated by flow cytometry

2005 ◽  
Vol 95 (4) ◽  
pp. 309-312 ◽  
Author(s):  
J.K. Brown ◽  
G.M. Lambert ◽  
M. Ghanim ◽  
H. Czosnek ◽  
D.W. Galbraith
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Bemisia Tabaci ◽  
Dna Content ◽  
Blood Cells ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Chromosome Counting ◽  
Male And Female ◽  
Haploid Genome Size

AbstractThe nuclear DNA content of the whitefly Bemisia tabaci (Gennnadius) was estimated using flow cytometry. Male and female nuclei were stained with propidium iodide and their DNA content was estimated using chicken red blood cells and Arabidopsis thaliana L. (Brassicaceae) as external standards. The estimated nuclear DNA content of male and female B. tabaci was 1.04 and 2.06 pg, respectively. These results corroborated previous reports based on chromosome counting, which showed that B. tabaci males are haploid and females are diploid. Conversion between DNA content and genome size (1 pg DNA = 980 Mbp) indicate that the haploid genome size of B. tabaci is 1020 Mbp, which is approximately five times the size of the genome of the fruitfly Drosophila melanogaster Meigen. These results provide an important baseline that will facilitate genomics-based research for the B. tabaci complex.

scholarly journals Genome Sizes in Hepatica Mill: (Ranunculaceae) Show a Loss of DNA, Not a Gain, in Polyploids

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
B. J. M. Zonneveld
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Dna Content ◽  
Close Relationships ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Dna Contents ◽  
Asiatic Species ◽  
Nuclear Dna Contents ◽  
Allotetraploid Species

Genome size (C-value) was applied anew to investigate the relationships within the genus Hepatica (Ranunculaceae). More than 50 samples representing all species (except H. falconeri), from wild and cultivated material, were investigated. Species of Hepatica turn out to be diploid (), tetraploid ( ), and a possible pentaploid. The somatic nuclear DNA contents (2C-value), as measured by flow cytometry with propidium iodide, were shown to range from 33 to 80 pg. The Asiatic and American species, often considered subspecies of H. nobilis, could be clearly distinguished from European H. nobilis. DNA content confirmed the close relationships in the Asiatic species, and these are here considered as subspecies of H. asiatica. Parents for the allotetraploid species could be suggested based on their nuclear DNA content. Contrary to the increase in genome size suggested earlier for Hepatica, a significant (6%–14%) loss of nuclear DNA in the natural allopolyploids was found.

scholarly journals Evolution of Genome Size in Duckweeds (Lemnaceae)

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Wenqin Wang ◽  
Randall A. Kerstetter ◽  
Todd P. Michael
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Propidium Iodide ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Continuous Increase ◽  
Spirodela Polyrhiza ◽  
Wolffia Arrhiza ◽  
Basic Reference

To extensively estimate the DNA content and to provide a basic reference for duckweed genome sequence research, the nuclear DNA content for 115 different accessions of 23 duckweed species was measured by flow cytometry (FCM) stained with propidium iodide as DNA stain. The 1C-value of DNA content in duckweed family varied nearly thirteen-fold, ranging from 150 megabases (Mbp) in Spirodela polyrhiza to 1,881 Mbp in Wolffia arrhiza. There is a continuous increase of DNA content in Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia that parallels a morphological reduction in size. There is a significant intraspecific variation in the genus Lemna. However, no such variation was found in other studied species with multiple accessions of genera Spirodela, Landoltia, Wolffiella, and Wolffia.

scholarly journals Ο προσδιορισμός των γενετικών σχέσεων μεταξύ ποικιλιών σιταριού με τη χρήση μορφολογικών, μοριακών και κυτταρογενετικών δεικτών

2007 ◽  
Author(s):  
Kamal Abdellatif
Keyword(s):  
5S Rdna ◽  
26S Rdna

Τριάντα εννέα μορφολογικά χαρακτηριστικά, 11 ζευγάρια SSR εκκινητών, εννέα ISSR εκκινητών και in situ υβριδισμοί χρησιμοποιήθηκαν προκειμένου να μελετηθεί η γενετική παραλλακτικότητα και οι σχέσεις μεταξύ 45 καταχωρήσεων σιταριού με διαφορετική γεωγραφική προέλευση (Ελλάδα, Αίγυπτος, Κύπρος και Ιταλία). Ένα υψηλό ποσοστό της φαινοτυπικής πλαστικότητας οφείλεται σε ποσοτικά μορφολογικά χαρακτηριστικά. Οι καταχωρήσεις σιταριού που έχουν διαφορετικό επίπεδο πλοειδίας ομαδοποιήθηκαν ξεχωριστά με όλους τους τύπους δεικτών (μορφολογικά χαρακτηριστικά και μοριακοί δείκτες SSR και ISSR), αλλά δεν ομαδοποιήθηκαν με βάση τη γεωγραφική προέλευση. Πολύ υψηλές τιμές συσχετισμού βρέθηκαν μεταξύ μερικών μορφολογικών χαρακτηριστικών που κυμάνθηκαν από 0,73 έως 0,95. Εννέα ποιοτικά μορφολογικά χαρακτηριστικά και ένα ποσοτικό ξεχώρισαν τις καταχωρήσεις σκληρού σιταριού, από τις καταχωρήσεις μαλακού σιταριού που χαρακτηρίστηκαν από τέσσερα ποιοτικά και δύο ποσοτικά χαρακτηριστικά. Οι τιμές συσχέτισης μεταξύ των μορφολογικών και μοριακών μήτρων ομοιότητας κυμάνθηκαν σε ικανοποιητικά επίπεδα (r=0,54 μεταξύ των μορφολογικών χαρακτηριστικών και SSR, ενώ r=0,57 μεταξύ μορφολογικών και ISSR), ενώ ήταν πολύ υψηλές μεταξύ των δύο τύπων μοριακών δεικτών (r=0,85). Όλες οι τετραπλοειδείς καταχωρήσεις σιταριού που χρησιμοποιήθηκαν για τον in situ υβριδισμό έχουν τέσσερις περιοχές για το 5S rDNA και 12 περιοχές 18S-5.8S-26S. Οι εξαπλοειδείς καταχωρήσεις έχουν έξι 5S rDNA περιοχές και 16 περιοχές 18S-5.8S-26S rDNA.

Chromatin characterization by banding techniques, in situ hybridization, and nuclear DNA content in Cicer L. (Leguminosae)

Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 258-265 ◽  
Author(s):  
I. Galasso ◽  
D. Pignone ◽  
M. Frediani ◽  
M. Maggiani ◽  
R. Cremonini
Keyword(s):  
In Situ Hybridization ◽  
Dna Content ◽  
Nuclear Dna ◽  
Hybrid Sterility ◽  
Nuclear Dna Content ◽  
5S Rdna ◽  
Rrna Genes ◽  
Evolutionary Pathway ◽  
C Banding

The karyotypes of three accessions, one each from three annual species of the genus Cicer, namely Cicer arietinum, Cicer reticulation, and Cicer echinospermum, were examined and compared using C-banding, the fluorochromes chromomycin A3, DAPI, and Hoechst 33258, in situ hybridization of the 18S–5.8S–25S and 5S rDNA sequences, and silver staining. The nuclear DNA content of the three species and the amount of heterochromatin were also determined. The results suggest an evolutionary pathway in which C. reticulatum is the ancestral species from which both C. arietinum and C. echinospermum are derived with the loss of one pair of satellites; subsequently, C. echinospermum further differentiated by the accumulation of chromosomal rearrangement(s) that gave rise to a hybrid sterility barrier. Key words : Cicer, C-banding, fluorochromes, Ag staining, rRNA genes.

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