Chromosomal and genome-wide molecular changes associated with initial stages of allohexaploidization in wheat can be transit and incidental

Genome ◽  
2011 ◽  
Vol 54 (8) ◽  
pp. 692-699 ◽  
Author(s):  
Na Zhao ◽  
Liying Xu ◽  
Bo Zhu ◽  
Mingjiu Li ◽  
Huakun Zhang ◽  
...  
Keyword(s):  
Genomic Instability ◽  
Triticum Turgidum ◽  
Aegilops Tauschii ◽  
Tetraploid Wheat ◽  
Great Majority ◽  
Individual Plant ◽  
Single Individual ◽  
Genomic Changes ◽  
General Response ◽  
Allohexaploid Wheat

Genomic instability can be induced by nascent allopolyploidization in plants. However, most previous studies have not defined to what extent the allopolyploidy-induced rapid genomic instability represents a general response, and hence important to evolution, or merely incidental events occurring stochastically in a limited number of individuals. We report here that in a newly formed allohexaploid wheat line between tetraploid wheat Triticum turgidum subsp. durum (genome BBAA) and Aegilops tauschii (genome DD) a great majority of individual plants showed chromosomal stability and exhibited a genomic constitution similar to that of the present-day Triticum aestivum (genome BBAADD). In contrast, a single individual plant was identified at S2, which exhibited chromosomal instability in both number and structure based on multicolor genomic in situ hybridization (mc-GISH) analysis. Accordingly, this plant also manifested extensive changes at the molecular level including loss and gain of DNA segments and DNA methylation repatterning. Remarkably, the chromosomal and molecular instabilities that presumably occurred at S0 to S1 and (or) in the F1 hybrid were rapidly quenched by S2 and followed by stable transgenerational inheritance. Our results suggest that these stochastic and individual-specific rapid genomic changes, albeit interesting, probably have not played a major role in the speciation and evolution of common wheat, T. aestivum.

Development and discrimination of 12 double ditelosomics in tetraploid wheat cultivar DR147

Genome ◽  
2014 ◽  
Vol 57 (2) ◽  
pp. 89-95 ◽  
Author(s):  
Hao Li ◽  
Changyou Wang ◽  
Shulan Fu ◽  
Xiang Guo ◽  
Baoju Yang ◽  
...  
Keyword(s):  
Triticum Turgidum ◽  
Wheat Cultivar ◽  
Aegilops Tauschii ◽  
Tetraploid Wheat ◽  
Chromosome Complement ◽  
Phenotypic Characteristics ◽  
Wheat Evolution ◽  
Important Group ◽  
Entire Chromosome

As an important group in Triticum, tetraploid wheat plays a significant role in the research of wheat evolution. Several complete aneuploid sets of common wheat have provided valuable tools for genetic and breeding studies, while similar aneuploids of tetraploid wheat are still not well developed. Here, 12 double ditelosomics developed in Triticum turgidum L. var. durum cultivar DR147 (excluding dDT2B and dDT3A) were reported. Hybrids between DR147 and the original double-ditelosomic dDT2B of Langdon lost vigor and died prematurely after the three-leaf stage; therefore, the dDT2B line was not obtained. The cytogenetic behaviors and phenotypic characteristics of each line were detailedly described. To distinguish the entire chromosome complement of tetraploid wheat, the DR147 karyotype was established by fluorescence in situ hybridization (FISH), using the Aegilops tauschii clone pAsl and the barley clone pHvG38 as probes. FISH using a cereal-specific centromere repeat (6C6) probe suggested that all the lines possessed four telosomes, except for 4AS of double-ditelosomic dDT4A, which carried a small segment of the long arm. On the basis of the idiogram of DR147, these lines were successfully discriminated by FISH using the probes pAsl and pHvG38 and were then accurately designated.

scholarly journals Wheat, Rye, and Barley Genomes Can Associate during Meiosis in Newly Synthesized Trigeneric Hybrids

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 113
Author(s):  
María-Dolores Rey ◽  
Carmen Ramírez ◽  
Azahara C. Martín
Keyword(s):  
Chromosome Segregation ◽  
Genome Duplication ◽  
Triticum Turgidum ◽  
Aegilops Tauschii ◽  
Genomic In Situ Hybridization ◽  
Hordeum Chilense ◽  
Genomic Constitution ◽  
Chromosome Associations ◽  
High Level

Polyploidization, or whole genome duplication (WGD), has an important role in evolution and speciation. One of the biggest challenges faced by a new polyploid is meiosis, in particular, discriminating between multiple related chromosomes so that only homologs recombine to ensure regular chromosome segregation and fertility. Here, we report the production of two new hybrids formed by the genomes of species from three different genera: a hybrid between Aegilops tauschii (DD), Hordeum chilense (HchHch), and Secale cereale (RR) with the haploid genomic constitution HchDR (n = 7× = 21); and a hybrid between Triticum turgidum spp. durum (AABB), H. chilense, and S. cereale with the constitution ABHchR (n = 7× = 28). We used genomic in situ hybridization and immunolocalization of key meiotic proteins to establish the chromosome composition of the new hybrids and to study their meiotic behavior. Interestingly, there were multiple chromosome associations at metaphase I in both hybrids. A high level of crossover (CO) formation was observed in HchDR, which shows the possibility of meiotic recombination between the different genomes. We succeeded in the duplication of the ABHchR genome, and several amphiploids, AABBHchHchRR, were obtained and characterized. These results indicate that recombination between the genera of three economically important crops is possible.

scholarly journals Function and evolution of allelic variation of Sr13 conferring resistance to stem rust in tetraploid wheat ( Triticum turgidum L.)

2021 ◽  
Author(s):  
Baljeet K. Gill ◽  
Daryl L. Klindworth ◽  
Matthew N. Rouse ◽  
Jinglun Zhang ◽  
Qijun Zhang ◽  
...  
Keyword(s):  
Stem Rust ◽  
Triticum Turgidum ◽  
Allelic Variation ◽  
Tetraploid Wheat

scholarly journals The Independent Domestication of Timopheev’s Wheat: Insights from Haplotype Analysis of the Brittle rachis 1 (BTR1-A) Gene

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 338
Author(s):  
Moran Nave ◽  
Mihriban Taş ◽  
John Raupp ◽  
Vijay K. Tiwari ◽  
Hakan Ozkan ◽  
...  
Keyword(s):  
Promoter Region ◽  
Haplotype Analysis ◽  
Common Ancestor ◽  
Triticum Turgidum ◽  
Tetraploid Wheat ◽  
Wheat Species ◽  
Loss Of Function ◽  
Brittle Rachis ◽  
Gene Level ◽  
Large Panel

Triticum turgidum and T. timopheevii are two tetraploid wheat species sharing T. urartu as a common ancestor, and domesticated accessions from both of these allopolyploids exhibit nonbrittle rachis (i.e., nonshattering spikes). We previously described the loss-of-function mutations in the Brittle Rachis 1 genes BTR1-A and BTR1-B in the A and B subgenomes, respectively, that are responsible for this most visible domestication trait in T. turgidum. Resequencing of a large panel of wild and domesticated T. turgidum accessions subsequently led to the identification of the two progenitor haplotypes of the btr1-A and btr1-B domesticated alleles. Here, we extended the haplotype analysis to other T. turgidum subspecies and to the BTR1 homologues in the related T. timopheevii species. Our results showed that all the domesticated wheat subspecies within T. turgidum share common BTR1-A and BTR1-B haplotypes, confirming their common origin. In T. timopheevii, however, we identified a novel loss-of-function btr1-A allele underlying a partially brittle spike phenotype. This novel recessive allele appeared fixed within the pool of domesticated Timopheev’s wheat but was also carried by one wild timopheevii accession exhibiting partial brittleness. The promoter region for BTR1-B could not be amplified in any T. timopheevii accessions with any T. turgidum primer combination, exemplifying the gene-level distance between the two species. Altogether, our results support the concept of independent domestication processes for the two polyploid, wheat-related species.

Molecular characterization and chromosome-specific TRAP-marker development for Langdon durum D-genome disomic substitution lines

Genome ◽  
2006 ◽  
Vol 49 (12) ◽  
pp. 1545-1554 ◽  
Author(s):  
J. Li ◽  
D.L. Klindworth ◽  
F. Shireen ◽  
X. Cai ◽  
J. Hu ◽  
...  
Keyword(s):  
Triticum Turgidum ◽  
Tetraploid Wheat ◽  
Substitution Lines ◽  
Genome Chromosome ◽  
D Genome ◽  
Single Chromosome ◽  
B Genome ◽  
The Individual ◽  
Trap Marker

The aneuploid stocks of durum wheat ( Triticum turgidum L. subsp. durum (Desf.) Husnot) and common wheat ( T. aestivum L.) have been developed mainly in ‘Langdon’ (LDN) and ‘Chinese Spring’ (CS) cultivars, respectively. The LDN-CS D-genome chromosome disomic substitution (LDN-DS) lines, where a pair of CS D-genome chromosomes substitute for a corresponding homoeologous A- or B-genome chromosome pair of LDN, have been widely used to determine the chromosomal locations of genes in tetraploid wheat. The LDN-DS lines were originally developed by crossing CS nulli-tetrasomics with LDN, followed by 6 backcrosses with LDN. They have subsequently been improved with 5 additional backcrosses with LDN. The objectives of this study were to characterize a set of the 14 most recent LDN-DS lines and to develop chromosome-specific markers, using the newly developed TRAP (target region amplification polymorphism)-marker technique. A total of 307 polymorphic DNA fragments were amplified from LDN and CS, and 302 of them were assigned to individual chromosomes. Most of the markers (95.5%) were present on a single chromosome as chromosome-specific markers, but 4.5% of the markers mapped to 2 or more chromosomes. The number of markers per chromosome varied, from a low of 10 (chromosomes 1A and 6D) to a high of 24 (chromosome 3A). There was an average of 16.6, 16.6, and 15.9 markers per chromosome assigned to the A-, B-, and D-genome chromosomes, respectively, suggesting that TRAP markers were detected at a nearly equal frequency on the 3 genomes. A comparison of the source of the expressed sequence tags (ESTs), used to derive the fixed primers, with the chromosomal location of markers revealed that 15.5% of the TRAP markers were located on the same chromosomes as the ESTs used to generate the fixed primers. A fixed primer designed from an EST mapped on a chromosome or a homoeologous group amplified at least 1 fragment specific to that chromosome or group, suggesting that the fixed primers might generate markers from target regions. TRAP-marker analysis verified the retention of at least 13 pairs of A- or B-genome chromosomes from LDN and 1 pair of D-genome chromosomes from CS in each of the LDN-DS lines. The chromosome-specific markers developed in this study provide an identity for each of the chromosomes, and they will facilitate molecular and genetic characterization of the individual chromosomes, including genetic mapping and gene identification.

scholarly journals Reduced chromatin accessibility underlies gene expression differences in homologous chromosome arms of diploid Aegilops tauschii and hexaploid wheat

GigaScience ◽  
2020 ◽  
Vol 9 (6) ◽  
Author(s):  
Fu-Hao Lu ◽  
Neil McKenzie ◽  
Laura-Jayne Gardiner ◽  
Ming-Cheng Luo ◽  
Anthony Hall ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hexaploid Wheat ◽  
Aegilops Tauschii ◽  
Wheat Chromosome ◽  
Pilot Scale ◽  
Chromatin Accessibility ◽  
Diploid Progenitor ◽  
Genomic Changes ◽  
Chromosome Arm ◽  
Elevated Expression

Abstract Background Polyploidy is centrally important in the evolution and domestication of plants because it leads to major genomic changes, such as altered patterns of gene expression, which are thought to underlie the emergence of new traits. Despite the common occurrence of these globally altered patterns of gene expression in polyploids, the mechanisms involved are not well understood. Results Using a precisely defined framework of highly conserved syntenic genes on hexaploid wheat chromosome 3DL and its progenitor 3 L chromosome arm of diploid Aegilops tauschii, we show that 70% of these gene pairs exhibited proportionately reduced gene expression, in which expression in the hexaploid context of the 3DL genes was ∼40% of the levels observed in diploid Ae tauschii. Several genes showed elevated expression during the later stages of grain development in wheat compared with Ae tauschii. Gene sequence and methylation differences probably accounted for only a few cases of differences in gene expression. In contrast, chromosome-wide patterns of reduced chromatin accessibility of genes in the hexaploid chromosome arm compared with its diploid progenitor were correlated with both reduced gene expression and the imposition of new patterns of gene expression. Conclusions Our pilot-scale analyses show that chromatin compaction may orchestrate reduced gene expression levels in the hexaploid chromosome arm of wheat compared to its diploid progenitor chromosome arm.

A common ancestral glycoprotein (GP) 9 1828A>G (Asn45Ser) gene mutation occurring in European families from Australia and Northern Europe with Bernard-Soulier syndrome (BSS)

2005 ◽  
Vol 94 (09) ◽  
pp. 599-605 ◽  
Author(s):  
Marie-Christine Morel-Kopp ◽  
Jeannine M. Clemetson ◽  
Kenneth J. Clemetson ◽  
Riitta Kekomaki ◽  
Hartmut Kroll ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Haplotype Analysis ◽  
Great Majority ◽  
European Population ◽  
Single Individual ◽  
Adhesion Receptor ◽  
Northern European ◽  
Founder Event ◽  
Bernard Soulier Syndrome ◽  
Autosomal Recessive Manner

SummaryBernard-Soulier syndrome (BSS) is an extremely rare hereditary bleeding disorder, caused by mutations occurring in the Glycoprotein (GP) Ibα, GPIbβ and GP9 genes that encode for the corresponding subunits of platelet GPIb-V-IX adhesion receptor complex. BSS has been reported in many populations, mostly behaving in an autosomal-recessive manner. While the great majority of BSS mutations are unique to a single individual or family, the GP9 1828A>G Asn45Ser mutation, which we have identified in an undocumented Australian Caucasian, has already been reported in multiple unrelated Caucasian families from various Northern and Central European countries. Haplotype analysis of 19 BSS patients from 15 unrelated Northern European families (including 2 compound heterozygote siblings from a British family previously published, and 17 1828A>G Asn45Ser homozygotes), showed that 14 of these BSS patients from 11 of the 1828A>G Asn45Ser homozygote families share a common haplotype at the chromosomal region 3’ to the GP9 gene. Hence, the results suggest that the GP9 1828A>GAsn45Ser mutation in these families is ancient, and its frequent emergence in the European population is the result of a founder effect rather than recurrent mutational events. Association of the 1828A>G Asn45Ser mutation with variant haplotypes in 4 other Northern European BSS families raised the possibility of a second founder event, or rare recombinations in these families. Additional members from these ‘atypical’ lineages would need to be screened to resolve this question.

Sign in / Sign up

Export Citation Format

Share Document