Variation in Chiasma Frequency Among Eight Accessions of Arabidopsis thaliana

Abstract Natural variation in meiotic recombination frequency in Arabidopsis thaliana has been assessed by analyzing chiasma frequency variation among a range of geographically and ecologically diverse accessions. Fifty pollen mother cells at metaphase I of meiosis were analyzed from each of eight accessions and fluorescence in situ hybridization was applied to enable identification of all 10 chromosome arms. There was no significant variation in mean chiasma frequency between plants within accessions, but there was significant variation between accessions. Further analysis confirmed this finding and identified two particular accessions, Cvi and Ler, as having chiasma frequencies significantly lower than those of the other accessions. The analysis also revealed that the pattern of chiasma distribution between arms and among chromosomes is not consistent over accessions. Further detailed analyses were conducted on each individual chromosome (1-5) in turn, revealing that chromosome 4, one of the acrocentric chromosomes, is the least variable while the other acrocentric chromosome (2) is the most variable. These findings indicate the existence of recombination regulatory elements in Arabidopsis and we conclude that it may be possible in the future to identify these elements and determine their mode of action. The practical implications of such developments are considerable.

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Assignment of the mouse desmin gene to chromosome 1 band C3

Genetics Research ◽

10.1017/s0016672300025337 ◽

1990 ◽

Vol 55 (2) ◽

pp. 101-105 ◽

Cited By ~ 11

Author(s):

Zhenlin Li ◽

Marie-Geneviève Mattei ◽

Jean-François Mattei ◽

Denise Paulin

Keyword(s):

Human Chromosome ◽

Gene Cluster ◽

Intermediate Filament ◽

Chromosomal Localization ◽

Chromosome 1 ◽

Chromosome 2 ◽

Gene Coding ◽

Partial Homology ◽

Conserved Gene

SummaryThe chromosomal localization of the mouse gene coding for desmin, one of the muscle-specific intermediate filament subunits, was determined by in situ hybridization using a specific 3H-labelled DNA probe. There is only one copy of the desmin gene and it is located on chromosome 1 in the band C3. This result adds an eleventh locus to a conserved gene cluster and confirms the partial homology that exists between the long arm of human chromosome 2 and chromosome 1 of the mouse.

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Adaptative Evolution of Metallothionein 3 in the Cd/Zn Hyperaccumulator Thlaspi caerulescens

Zeitschrift für Naturforschung C ◽

10.1515/znc-2005-3-407 ◽

2005 ◽

Vol 60 (3-4) ◽

pp. 224-228 ◽

Cited By ~ 5

Author(s):

Nancy H. Roosens ◽

Catherine Bernard ◽

Raphael Leplae ◽

Nathalie Verbruggen

Keyword(s):

Functional Analysis ◽

Arabidopsis Thaliana ◽

Local Adaptation ◽

Expression Analysis ◽

Significant Variation ◽

Binding Capacity ◽

Thlaspi Caerulescens ◽

The Other ◽

Functional Screening ◽

High Identity

Abstract A functional screening in yeast allowed to identify various cDNAs from the Cd/Zn hyperaccumulator Thlaspi caerulescens. TcMT3 displayed high identity with its closest homologue in Arabidopsis thaliana but variation in its Cys residues. Functional analysis in yeast supported a higher binding capacity for Cu, but not for Cd or Zn, of TcMT3 compared to AtMT3. Expression analysis in plants indicated that metallothionein 3 (MT3) like all the other T. caerulescens genes from the screen studied is overexpressed in all studied populations of T. caerulescens compared to A. thaliana. TcMT3 was induced by Cu, but not by Cd. Moreover significant variation in expression within T. caerulescens populations that have contrasting tolerance and accumulation capacities indicated a possible local adaptation of MT3.

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Drosophila melanogaster homologs of the raf oncogene

Molecular and Cellular Biology ◽

10.1128/mcb.7.6.2134-2140.1987 ◽

1987 ◽

Vol 7 (6) ◽

pp. 2134-2140

Author(s):

G E Mark ◽

R J MacIntyre ◽

M E Digan ◽

L Ambrosio ◽

N Perrimon

Keyword(s):

Drosophila Melanogaster ◽

In Situ Hybridization ◽

Steady State ◽

Kinase Domain ◽

Early Embryogenesis ◽

The Other ◽

Chromosome 2 ◽

Related Gene ◽

Steady State Levels

A murine v-raf probe, representing the kinase domain, was used to identify two unique loci in Drosophila melanogaster DNA. The most closely related to v-raf was mapped by in situ hybridization to position 2F5-6 (Draf-1) on the X chromosome, whereas the other raf-related gene (Draf-2) was found at position 43A2-5 on chromosome 2. The nucleotide and amino acid homologies of Draf-1 to the kinase domain of v-raf are 61 and 65%, respectively. The large amount of a 3.2-kilobase Draf-1 transcript detected in eggs as a maternal message decreases during embryonic development, and significant steady-state levels are observed throughout the remainder of morphogenesis. We speculate that the Draf-1 locus plays an important role in early embryogenesis.

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Nucleolus-associated telomere clustering and pairing precede meiotic chromosome synapsis in Arabidopsis thaliana

Journal of Cell Science ◽

10.1242/jcs.114.23.4207 ◽

2001 ◽

Vol 114 (23) ◽

pp. 4207-4217 ◽

Cited By ~ 2

Author(s):

Susan J. Armstrong ◽

F. Christopher H. Franklin ◽

Gareth H. Jones

Keyword(s):

Arabidopsis Thaliana ◽

Meiotic Chromosome ◽

In Situ Hybridisation ◽

Embryo Sac ◽

Early Prophase ◽

Homologous Chromosomes ◽

Chromosome Synapsis ◽

Mother Cells ◽

Telomere Signal

The intranuclear arrangements of centromeres and telomeres during meiotic interphase and early prophase I of meiosis in Arabidopsis thaliana were analysed by fluorescent in situ hybridisation to spread pollen mother cells and embryo-sac mother cells. Meiocyte identification, staging and progression were established by spreading and sectioning techniques, including various staining procedures and bromodeoxyuridine labeling of replicating DNA. Centromere regions of Arabidopsis are unpaired, widely dispersed and peripherally located in nuclei during meiotic interphase, and they remain unpaired and unassociated throughout leptotene. Eventually they associate pairwise during zygotene, as part of the nucleus-wide synapsis of homologous chromosomes. Telomeres, by contrast, show a persistent association with the nucleolus throughout meiotic interphase. Variation in telomere signal number indicates that telomeres undergo pairing during this interval, preceding the onset of general chromosome synapsis. During leptotene the paired telomeres lose their association with the nucleolus and become widely dispersed. As the chromosomes synapse during zygotene, the telomeres reveal a loose clustering within one hemisphere, which may represent a degenerate or relic bouquet configuration. We propose that in Arabidopsis the classical leptotene/zygotene bouquet is absent and is replaced functionally by nucleolus-associated telomere clustering.

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Physical mapping of four sites of 5S rDNA sequences and one site of the α-amylase-2 gene in barley (Hordeum vulgare)

Genome ◽

10.1139/g93-071 ◽

1993 ◽

Vol 36 (3) ◽

pp. 517-523 ◽

Cited By ~ 101

Author(s):

I. J. Leitch ◽

J. S. Heslop-Harrison

Keyword(s):

In Situ Hybridization ◽

Hordeum Vulgare ◽

Physical Mapping ◽

5S Rdna ◽

Chromosome 1 ◽

Chromosome 2 ◽

Hordeum Vulgare L ◽

Rdna Sequences ◽

5S Rdna Sequence

The 5S rDNA sequences have been mapped on four pairs of barley (Hordeum vulgare L.) chromosomes using in situ hybridization and barley monotelotrisomic lines. The 5S rDNA sequences are located, genetically and physically, on the short arm of chromosome 1 (7I) and the long arms of chromosomes 2 (2I) and 3 (3I). The 5S rDNA sequence is also located on the physically long arm of chromosome 4 (4I). Only one site on chromosome 2(2I) has previously been reported. The characteristic locations of the 5S rDNA sequences make them useful as molecular markers to identify each barley chromosome. The physical position of the low-copy α-amylase-2 gene was determined using in situ hybridization; the location of this gene on the long arm of chromosome 1 (7I) was confirmed by reprobing the same preparation with the 5S rDNA probe. The results show that there is a discrepancy between the physical and genetic position of the α-amylase-2 gene.Key words: genetic mapping, physical mapping, barley, mapping, 5S DNA, α-amylase, in situ hybridization.

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A comparative analysis of the karyotypes of three dolphins – Tursiops truncatus Montagu, 1821, Tursiops australis Charlton-Robb et al., 2011, and Grampus griseus Cuvier, 1812

Comparative Cytogenetics ◽

10.3897/compcytogen.v15.i1.60398 ◽

2021 ◽

Vol 15 (1) ◽

pp. 53-63

Author(s):

Ross Brookwell ◽

Kimberly Finlayson ◽

Jason P. van de Merwe

Keyword(s):

Comparative Analysis ◽

Tursiops Truncatus ◽

Diploid Number ◽

Chromosome Morphology ◽

The Other ◽

Chromosome 1 ◽

Chromosome 2 ◽

Potential Significance ◽

Grampus Griseus ◽

Taxonomic Studies

The aim of this study is to produce G-banded karyotypes of three dolphin species, Tursiops truncatus Montagu, 1821, Tursiops australisCharlton-Robb et al., 2011, and Grampus griseus Cuvier, 1812, and to determine if any differences between the species can be observed. Monolayer skin cultures were established and processed for chromosome study by trypsin banding. The results indicate that the three species here investigated have the same diploid number (2n = 44) and very similar gross chromosome morphology, however G-banding allows distinction between each species. Chromosome 1 in G. griseus is significantly different from the other 2 species, and chromosome 2 in T. australis is subtly different from the other 2 species. This result is of potential significance in taxonomic studies, and can provide an unequivocal answer in the assessment of suspected hybrids between these species.

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Murine chromosomal regions correlated with longevity.

Genetics ◽

10.1093/genetics/118.4.693 ◽

1988 ◽

Vol 118 (4) ◽

pp. 693-704

Author(s):

R Gelman ◽

A Watson ◽

R Bronson ◽

E Yunis

Keyword(s):

Proportional Hazards ◽

Proportional Hazards Model ◽

The Other ◽

Chromosome 7 ◽

Chromosome 1 ◽

Chromosome 2 ◽

Hazards Model ◽

Single Room ◽

Single Region ◽

Different Strains

Abstract In this longevity analysis of 360 BXD recombinant inbred female mice (20 different strains), 2 strains had very significantly shorter survival and 1 strain had very significantly longer survival than the other 17 strains; 4 other strains had less significant lengthening of survival compared to the other 13 strains in a proportional hazards model of survival. Mean survival on the shortest lived strain was 479 days; on the longest lived strain the mean survival was almost double (904 days). Ranges of survival within strain were very large (averaging 642 days), and strain accounted for only 29% of the variation in survival, showing that there are important environmental and/or special developmental effects on longevity even in this colony housed in a single room. Each strain had been typed for markers of 141 regions on 15 chromosomes; 101 of these markers had distinguishable distributions on the 20 strains. The two shortest lived strains had the same alleles for 63% of the markers. The single region most significantly correlated with survival (marked by P450, Coh, Xmmv-35 on chromosome 7) divided the mice into two groups with survival medians which differed by 153 days (755 days for mice with a B genotype; 602 days for mice with a D genotype). Evaluated individually, 44% of the genetic markers (including some markers on 11 of 15 chromosomes with any markers typed) were found to be significantly correlated with survival (P less than 0.05) although one would only expect 5% of the markers to be significant by chance. While studies of many markers should adjust for the multiple comparisons problem, one interpretation of these crude P values is that any experiment with only one of these "significant" markers typed would be likely to conclude that the marker was a significant predictor of survival. Two types of multiple regression models were used to examine the correlation with survival of groups of genes. When a proportional hazards model for survival was done in terms of genotype regions, a six genetic region model best correlated with survival: that marked by P450, Coh, Xmmv-35 on chromosome 7 (B allele lives longer), Ly-24 on chromosome 2 (B allele lives longer), beta 2M and H-3 on chromosome 2 (D allele lives longer) Lamb-2 on chromosome 1 (D allele lives longer), Ltw-4 on chromosome 1 (B allele lives longer), and the Igh area of chromosome 12 (Igh-Sa4, Igh-Sa2, Igh-Bgl, Igh-Nbp, Igh-Npid, Igh-Gte, Odc-8, and Ox-1; D allele lives longer).(ABSTRACT TRUNCATED AT 400 WORDS)

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Genetically controlled desynapsis in diploid Critesion violaceum and its hybrids with autotetraploid Psathyrostachys juncea

Canadian Journal of Genetics and Cytology ◽

10.1139/g84-085 ◽

1984 ◽

Vol 26 (5) ◽

pp. 532-537 ◽

Cited By ~ 4

Author(s):

Richard R-C. Wang

Keyword(s):

Chromosome Pairing ◽

Chiasma Frequency ◽

Intergeneric Hybrid ◽

Dosage Effect ◽

The Other ◽

Pollen Mother Cells ◽

Psathyrostachys Juncea ◽

Self Pollination ◽

Meiotic Irregularities ◽

Mother Cells

Segregation for chiasma frequency was observed in the progeny of a diploid (2n = 14) Critesion violaceum strain following self-pollination. One S1 plant had normal metaphase pairing with an average of 0.43I + 6.78II, giving a high chiasma frequency, 12.03 per cell. The other S1 plant averaged 7.89I + 3.08II and a low chiasma frequency, 3.47 per cell. Examination of pollen mother cells at early prophases revealed that chromosome pairing was not totally prevented. It was concluded that desynapsis was responsible for the meiotic irregularities observed in the variant progeny. The same phenomena were observed in F1 hybrids of the cross between diploid C. violaceum and an induced autotetraploid (2n = 28), Psathyrostachys juncea. The normal F1 hybrid had a chiasma frequency of 12.81, but the desynaptic hybrid had a chiasma frequency of 6.94. A dosage effect of the desynaptic gene, which was probably recessive, was suggested. The implications and significance of this discovery are discussed.Key words: asynapsis, chiasma, meiosis, intergeneric hybrid.

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Synaptic mutants in potato, Solanum tuberosum L. II. Concurrent reduction of chiasma frequencies in male and female meiosis of ds-1 (desynapsis) mutants

Genome ◽

10.1139/g89-553 ◽

1989 ◽

Vol 32 (6) ◽

pp. 1054-1062 ◽

Cited By ~ 13

Author(s):

E. Jongedijk ◽

M. S. Ramanna

Keyword(s):

Chiasma Frequency ◽

Solanum Tuberosum L ◽

Chiasma Formation ◽

Male Meiosis ◽

Frequency Variation ◽

Female Meiosis ◽

Male And Female ◽

A Cell ◽

The Mean ◽

Mother Cells

Chiasma frequencies in pollen mother cells and megaspore mother cells from both normal and desynaptic (ds-1ds-1) diploid potato clones were estimated on the basis of chiasmate chromosome arm association in metaphase I. In desynaptic mutants both the mean chiasma and bivalent frequencies per cell and the mean chiasma frequency per bivalent proved to be significantly lower. Despite significant differences in within-cell chiasma frequency variation among and particularly between normal and desynaptic clones, no clear effects of the ds-1 gene on the distribution of chiasmata over chromosomes in a cell were detected. The distribution of chiasmata over chromosomes appeared to be more or less random in both normal and desynaptic plants, which suggests that the ds-1 gene similarly affects chiasma frequencies in all chromosomes. Genetic data reported in the literature indicate that the ds-1 gene affects both the overall chiasma frequency and the chiasma distribution along individual chromosomes rather than chiasma maintenance. Sex differences in chiasma formation were not observed among normal plants or among desynaptic mutants, which indicates that chiasma formation in male and female meiosis of potato is governed by a single control system that is similarly expressed in both sexes.Key words: Solanum, desynapsis, chiasma frequency, male meiosis, female meiosis.

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