Amphidiploid Brassica juncea contains conserved progenitor genomes

Genome ◽  
2000 ◽  
Vol 43 (4) ◽  
pp. 679-688 ◽  
Author(s):  
T Axelsson ◽  
C M Bowman ◽  
A G Sharpe ◽  
D J Lydiate ◽  
U Lagercrantz
Keyword(s):  
Genome Evolution ◽  
Fragment Length Polymorphism ◽  
Rapid Change ◽  
Linkage Maps ◽  
Diploid Progenitor ◽  
B Genome ◽  
Disomic Inheritance ◽  
Polyploid Formation ◽  
A Genome ◽  
Restriction Fragment Length

To perform a detailed study of genome evolution in the natural Brassica amphidiploid B. juncea, we have constructed two linkage maps based on RFLP (restriction fragment length polymorphism) markers; one generated from a cross between a resynthesized B. juncea (a chromosome doubled interspecific B. rapa × B. nigra hybrid) and a natural B. juncea cultivar, the other from a cross between two B. juncea cultivars. By using a common cultivar in both crosses, the two maps could be unambiguously integrated. All loci exhibited disomic inheritance of parental alleles in the natural × resynthesized cross, showing that B. rapa chromosomes paired exclusively with their A-genome homologues in B. juncea and that B. nigra chromosomes likewise paired with their B-genome homologues. The maps derived from the two crosses were also perfectly collinear. Furthermore, these maps were collinear with maps of the diploid progenitor species (B. nigra and B. rapa) produced using the same set of RFLP probes. These data indicate that the genome of B. juncea has remained essentially unchanged since polyploid formation. Our observations appear to refute the suggestion that the formation of polyploid genomes is accompanied by rapid change in genome structure.Key words: RFLP, comparative mapping, Brassica rapa, Brassica nigra, genome evolution.

Mapping genes for resistance to Leptosphaeria maculans in Brassica juncea

Genome ◽  
2006 ◽  
Vol 49 (1) ◽  
pp. 30-41 ◽  
Author(s):  
J A Christianson ◽  
S R Rimmer ◽  
A G Good ◽  
D J Lydiate
Keyword(s):  
Linkage Group ◽  
Brassica Juncea ◽  
Fragment Length Polymorphism ◽  
Leptosphaeria Maculans ◽  
Recessive Gene ◽  
Brassica Species ◽  
Blackleg Disease ◽  
Recessive Resistance ◽  
B Genome ◽  
Restriction Fragment Length

Blackleg disease of crucifers, caused by the fungus Leptosphaeria maculans, is a major concern to oilseed rape producers worldwide. Brassica species containing the B genome have high levels of resistance to blackleg. Brassica juncea F2 and first-backcross (B1) populations segregating for resistance to a PG2 isolate of L. maculans were created. Segregation for resistance to L. maculans in these populations suggested that resistance was controlled by two independent genes, one dominant and one recessive in nature. A map of the B. juncea genome was constructed using segregation in the F2 population of a combination of restriction fragment length polymorphism (RFLP) and microsatel lite markers. The B. juncea map consisted of 325 loci and was aligned with previous maps of the Brassica A and B genomes. The gene controlling dominant resistance to L. maculans was positioned on linkage group J13 based on segregation for resistance in the F2 population. This position was confirmed in the B1 population in which the resistance gene was definitively mapped in the interval flanked by pN199RV and sB31143F. The provisional location of the recessive gene controlling resistance to L. maculans on linkage group J18 was identified using a subset of informative F2 individuals.Key words: blackleg, B genome, phoma, recessive resistance.

scholarly journals Inheritance of Race-Specific Resistance to Xanthomonas campestris pv. campestris in Brassica Genomes

2002 ◽  
Vol 92 (10) ◽  
pp. 1134-1141 ◽  
Author(s):  
J. G. Vicente ◽  
J. D. Taylor ◽  
A. G. Sharpe ◽  
I. A. P. Parkin ◽  
D. J. Lydiate ◽  
...  
Keyword(s):  
Doubled Haploid ◽  
Xanthomonas Campestris ◽  
Fragment Length Polymorphism ◽  
Specific Resistance ◽  
Doubled Haploid Line ◽  
B Genome ◽  
Brassica Spp ◽  
A Genome ◽  
Race 4 ◽  
Xanthomonas Campestris Pv Campestris

The inheritance of resistance to three Xanthomonas campestris pv. campestris races was studied in crosses between resistant and susceptible lines of Brassica oleracea (C genome), B. carinata (BC genome), and B. napus (AC genome). Resistance to race 3 in the B. oleracea doubled haploid line BOH 85c and in PI 436606 was controlled by a single dominant locus (Xca3). Resistance to races 1 and 3 in the B. oleracea line Badger Inbred-16 was quantitative and recessive. Strong resistance to races 1 and 4 was controlled by a single dominant locus (Xca1) in the B. carinata line PI 199947. This resistance probably originates from the B genome. Resistance to race 4 in three B. napus lines, cv. Cobra, the rapid cycling line CrGC5, and the doubled haploid line N-o-1, was controlled by a single dominant locus (Xca4). A set of doubled haploid lines, selected from a population used previously to develop a restriction fragment length polymorphism map, was used to map this locus. Xca4 was positioned on linkage group N5 of the B. napus A genome, indicating that this resistance originated from B. rapa. Xca4 is the first major locus to be mapped that controls race-specific resistance to X. campestris pv. campestris in Brassica spp.

Restriction fragment length polymorphism based phylogenetic analysis of Avena L.

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1279-1284 ◽  
Author(s):  
Rita Alicchio ◽  
Lina Aranci ◽  
Lucia Conte
Keyword(s):  
Fragment Length Polymorphism ◽  
Phylogenetic Analyses ◽  
Diploid Species ◽  
The Other ◽  
Molecular Approach ◽  
Polyploid Species ◽  
Species Relationships ◽  
Biochemical Traits ◽  
A Genome ◽  
Restriction Fragment Length

We report a molecular approach to the study of the phylogenetic relationships of Avena diploid and polyploid species based on RFLP detected with three cDNA probes of nuclear genes belonging to multigenic families (low pI α-amylase, avenin, and globulin). All the probes were highly informative in the detection of polymorphism between oat species. Associations between species were determined from cluster (UPGMA) analysis based on distance values calculated from RFLP data separately for each of the two levels of ploidy. Results were in general agreement with morphology based phylogenetic analyses, confirming the large differentiation among A and C genomes in the evolution of diploid species and the genetic homogeneity among A. brevis, A. strigosa, and A. nuda and the recently discovered A. atlantica. A certain divergence was observed between two endemic species (A. canariensis and A. damascena) and the other diploid species with the A genome. The analysis of tetraploid species relationships confirms the differentiation of the barbata complex (A. wiestii, A. barbata, A. abyssinica, and A. vaviloviana) from the maroccana–murphyi–agadiriana group, which, despite some similarities in morphological and biochemical traits, seems to have accumulated deep genetic differences along its evolutionary pathway.Key words: Avena genomes, genetic distance, ploidy, RFLP, multigenic families.

scholarly journals Quantum Theory on Genome Evolution

2015 ◽  
Author(s):  
LiaoFu Luo
Keyword(s):  
Quantum Theory ◽  
Genome Evolution ◽  
Large Scale ◽  
Rapid Change ◽  
Classical Equation ◽  
Evolutionary Equation ◽  
Quantum Evolution ◽  
Time Dimension ◽  
Quantum Equation ◽  
A Genome

AbstractA model of genome evolution is proposed. Based on several general assumptions the evolutionary theory of a genome is formulated. Both the deterministic classical equation and the stochastic quantum equation are proposed. The classical equation is written in a form of of second-order differential equations on nucleotide frequencies varying in time. It is proved that the evolutionary equation can be put in a form of the least action principle and the latter can be used for obtaining the quantum generalization of the evolutionary law. The wave equation and uncertainty relation for the quantum evolution are deduced logically. Two fundamental constants of time dimension, the quantization constant and the evolutionary inertia, are introduced for characterizing the genome evolution. During speciation the large-scale rapid change of nucleotide frequency makes the evolutionary inertia of the dynamical variables of the genome largely decreasing or losing. That leads to the occurrence of quantum phase of the evolution. The observed smooth/sudden evolution is interpreted by the alternating occurrence of the classical and quantum phases. In this theory the probability of new-species formation is calculable from the first-principle. To deep the discussions we consider avian genome evolution as an example. More concrete forms on the assumed potential in fundamental equations, namely the diversity and the environmental potential, are introduced. Through the numerical calculations we found that the existing experimental data on avian macroevolution are consistent with our theory. Particularly, the law of the rapid post-Cretaceous radiation of neoavian birds can be understood in the quantum theory. Finally, the present work shows the quantum law may be more general than thought, since it plays key roles not only in atomic physics, but also in genome evolution.

Segregation of molecular markers supports an allotetraploid structure for Medicago sativa × Medicago papillosa interspecific hybrid

Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 574-578 ◽  
Author(s):  
T. J. McCoy ◽  
C. S. Echt ◽  
L. C. Mancino
Keyword(s):  
Restriction Fragment Length Polymorphism ◽  
Medicago Sativa ◽  
Restriction Fragment ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Rflp Markers ◽  
Disomic Inheritance ◽  
Species Specific ◽  
Restriction Fragment Length

Cytogenetic analysis has indicated there is little genomic affinity between the genomes of Medicago sativa L. and Medicago papillosa Boiss. The objective of this study was to determine whether disomic segregation of alleles at isozyme and restriction fragment length polymorphism (RFLP) loci occurs in F1 hybrids of M. sativa × M. papillosa. We examined segregation of alleles at seven isozyme loci and 13 RFLP loci. Of the 20 loci analyzed, 11 exhibited a disomic pattern of inheritance, indicative of strict species-specific chromosome pairing in the M. sativa × M. papillosa hybrids. The other nine loci generally followed disomic inheritance, with exceptions. The results provide significant evidence in support of the concept that M. sativa × M. papillosa hybrids are basically allotetraploids with limited genomic affinity between the genomes. This report also represents the first documentation of the utility of RFLP markers in genetic analysis of alfalfa, a species with an essentially nonexistent genetic map.Key words: isozymes, genomic affinity, alfalfa, introgression, restriction fragment length polymorphism.

An RFLP-based linkage map of oats based on a cross between two diploid taxa (Avena atlantica × A. hirtula)

Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 765-771 ◽  
Author(s):  
L. S. O'Donoughue ◽  
Z. Wang ◽  
M. Röder ◽  
B. Kneen ◽  
M. Leggett ◽  
...  
Keyword(s):  
Restriction Fragment Length Polymorphism ◽  
Restriction Fragment ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Rflp Markers ◽  
Linkage Groups ◽  
Marker Selection ◽  
A Genome ◽  
Restriction Fragment Length

A restriction fragment length polymorphism (RFLP) map for the A genome of Avena has been developed using F3 families from the cross A. atlantica × A. hirtula. The main source of markers were an oat cDNA and a barley cDNA library. A total of 194 RFLP markers was used, 192 of which were mapped or assigned to linkage groups. Seven main linkage groups, presumably corresponding to the seven chromosomes of the haploid genome, were identified. The linkage groups varied in size from 30 to 118 cM for a total map length of 614 cM. This map provides a tool for the interpretation of genome organization in Avena and for marker selection in the development of a map of hexaploid oats.Key words: restriction fragment length polymorphism, Avena, mapping.

Variation in the Promoter Region of the β Fibrinogen Gene Is Associated with Plasma Fibrinogen Levels in Smokers and Non-Smokers

1991 ◽  
Vol 65 (05) ◽  
pp. 487-490 ◽  
Author(s):  
A E Thomas ◽  
F R Green ◽  
C H Kelleher ◽  
H C Wilkes ◽  
P J Brennan ◽  
...  
Keyword(s):  
Heart Disease ◽  
Promoter Region ◽  
Fragment Length Polymorphism ◽  
Fibrinogen Level ◽  
Plasma Fibrinogen ◽  
Plasma Fibrinogen Level ◽  
Healthy Men ◽  
History Of ◽  
General Practices ◽  
Restriction Fragment Length

SummaryWe investigated the association between fibrinogen levels and a HaeIII restriction fragment length polymorphism located at −453 bp from the start of transcription of the β fibrinogen gene. 292 healthy men aged 45 to 69 years, recruited from general practices throughout Britain, were studied. None had a history of ischaemic heart disease. 41.1% (120) were smokers and fibrinogen levels were higher in this group. The frequency of the noncutting allele (designated H2) was 0.19 and was the same in smokers and non-smokers. The H2 allele was associated with elevated levels of fibrinogen in both smokers and non-smokers and the effect of genotype was similar in both groups. After smoking, HaeIII genotype was the strongest predictor of fibrinogen levels and explained 3.1% of the variance in fibrinogen levels. These results confirm earlier studies that variation at the fibrinogen locus contributes to the between-individual differences in plasma fibrinogen level.

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