Genomic constitution and intergenomic translocations in the Elymus dahuricus complex revealed by multicolor GISH

Genome ◽  
2017 ◽  
Vol 60 (6) ◽  
pp. 510-517 ◽  
Author(s):  
Cairong Yang ◽  
Haiqin Zhang ◽  
Weihuan Chen ◽  
Houyang Kang ◽  
Yi Wang ◽  
...  

Multicolor genomic in situ hybridization was used to investigate the genomic constitution and intergenomic translocations in the Elymus dahuricus complex. The genomic constitution of species of the E. dahuricus complex was confirmed as StYH. H/Y and H/St intergenomic translocations were identified in the present study, with 7H and 1Y chromosomes involved in reciprocal translocations for all the accessions investigated in the complex. We propose that the translocations in the E. dahuricus complex are species-specific, associated with allopolyploidy, and may serve as important structural alterations for allopolyploid stability. Furthermore, they may help to restore fertility and nucleocytoplasmic compatibility in a newly formed polyploid and facilitate the successful establishment of E. dahuricus as a stable species. It was found that more chromosomes were involved in translocations and more types of intergenomic translocations were observed in the high altitude (4150 m) population Y 2228 than in populations from relatively lower altitudes (2600–3800 m). We speculate that more complicated genomic changes were associated with escalating altitudes in the Tibetan Plateau. These genomic changes contribute to promote the genetic variability and enable the newly formed allopolyploids to adapt to more changeable and harsher environments during the evolution of a polyploid species, thus facilitating their rapid and successful establishment in nature.

Genome ◽  
1995 ◽  
Vol 38 (5) ◽  
pp. 976-981 ◽  
Author(s):  
Ekatherina D. Badaeva ◽  
Jiming Jiang ◽  
Bikram S. Gill

Triticum araraticum Jakubz. (2n = 4x = 28, AtAtGG), a wild progenitor of the polyploid cultivated wheat T. timopheevii, shows extensive chromosome translocation polymorphism in natural populations from the Middle East and Transcaucasia. From an extensive survey, eight intergenomic translocation types were observed and their breakpoints analyzed by genomic in situ hybridization. The previously reported species-specific 6At–1G–4G cyclic translocation was found in all accessions studied. In four translocation types, the breakpoints were in interstitial regions of chromosomes and the other four arose via centric–breakage–fusion. A model is presented on the mechanism of origin and the adaptive significance of translocations with centromeric and noncentromeric breakpoints.Key words: intraspecific diversity, intergenomic translocations, Triticum araraticum.


2019 ◽  
Author(s):  
Jisue Moon ◽  
Carter Abney ◽  
Dmitriy Dolzhnikov ◽  
James M. Kurley ◽  
Kevin A. Beyer ◽  
...  

The local structure of dilute CrCl<sub>3</sub> in a molten MgCl<sub>2</sub>:KCl salt was investigated by <i>in situ</i> x-ray absorption spectroscopy (XAS) at temperatures from room temperature to 800<sup>o</sup>C. This constitutes the first experiment where dilute Cr speciation is explored in a molten chloride salt, ostensibly due to the compounding challenges arising from a low Cr concentration in a matrix of heavy absorbers at extreme temperatures. CrCl<sub>3</sub> was confirmed to be the stable species between 200 and 500<sup>o</sup>C, while mobility of metal ions at higher temperature (>700<sup>o</sup>C) prevented confirmation of the local structure.


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 113
Author(s):  
María-Dolores Rey ◽  
Carmen Ramírez ◽  
Azahara C. Martín

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.


Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 706-713 ◽  
Author(s):  
Concha Linares ◽  
Antonio Serna ◽  
Araceli Fominaya

A repetitive sequence, pAs17, was isolated from Avena strigosa (As genome) and characterized. The insert was 646 bp in length and showed 54% AT content. Databank searches revealed its high homology to the long terminal repeat (LTR) sequences of the specific family of Ty1-copia retrotransposons represented by WIS2-1A and Bare. It was also found to be 70% identical to the LTR domain of the WIS2-1A retroelement of wheat and 67% identical to the Bare-1 retroelement of barley. Southern hybridizations of pAs17 to diploid (A or C genomes), tetraploid (AC genomes), and hexaploid (ACD genomes) oat species revealed that it was absent in the C diploid species. Slot-blot analysis suggested that both diploid and tetraploid oat species contained 1.3 × 104 copies, indicating that they are a component of the A-genome chromosomes. The hexaploid species contained 2.4 × 104 copies, indicating that they are a component of both A- and D-genome chromosomes. This was confirmed by fluorescent in situ hybridization analyses using pAs17, two ribosomal sequences, and a C-genome specific sequence as probes. Further, the chromosomes involved in three C-A and three C-D intergenomic translocations in Avena murphyi (AC genomes) and Avena sativa cv. Extra Klock (ACD genomes), respectively, were identified. Based on its physical distribution and Southern hybridization patterns, a parental retrotransposon represented by pAs17 appears to have been active at least once during the evolution of the A genome in species of the Avena genus.Key words: chromosomal organization, in situ hybridization, intergenomic translocations, LTR sequence, oats.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 250
Author(s):  
Rebecca E O’Connor ◽  
Lucas G Kiazim ◽  
Claudia C Rathje ◽  
Rebecca L Jennings ◽  
Darren K Griffin

With demand rising, pigs are the world’s leading source of meat protein; however significant economic loss and environmental damage can be incurred if boars used for artificial insemination (AI) are hypoprolific (sub-fertile). Growing evidence suggests that semen analysis is an unreliable tool for diagnosing hypoprolificacy, with litter size and farrowing rate being more applicable. Once such data are available, however, any affected boar will have been in service for some time, with significant financial and environmental losses incurred. Reciprocal translocations (RTs) are the leading cause of porcine hypoprolificacy, reportedly present in 0.47% of AI boars. Traditional standard karyotyping, however, relies on animal specific expertise and does not detect more subtle (cryptic) translocations. Previously, we reported development of a multiple hybridisation fluorescence in situ hybridisation (FISH) strategy; here, we report on its use in 1641 AI boars. A total of 15 different RTs were identified in 69 boars, with four further animals XX/XY chimeric. Therefore, 4.5% had a chromosome abnormality (4.2% with an RT), a 0.88% incidence. Revisiting cases with both karyotype and FISH information, we reanalysed captured images, asking whether the translocation was detectable by karyotyping alone. The results suggest that chromosome translocations in boars may be significantly under-reported, thereby highlighting the need for pre-emptive screening by this method before a boar enters a breeding programme.


Genome ◽  
2010 ◽  
Vol 53 (10) ◽  
pp. 769-777 ◽  
Author(s):  
Melanie Mehes-Smith ◽  
Paul Michael ◽  
Kabwe Nkongolo

Genome organization in the family Pinaceae is complex and largely unknown. The main purpose of the present study was to develop and physically map species-diagnostic and species-specific molecular markers in pine and spruce. Five RAPD (random amplified polymorphic DNA) and one ISSR (inter-simple sequence repeat) species-diagnostic or species-specific markers for Picea mariana , Picea rubens , Pinus strobus , or Pinus monticola were identified, cloned, and sequenced. In situ hybridization of these sequences to spruce and pine chromosomes showed the sequences to be present in high copy number and evenly distributed throughout the genome. The analysis of centromeric and telomeric regions revealed the absence of significant clustering of species-diagnostic and species-specific sequences in all the chromosomes of the four species studied. Both RAPD and ISSR markers showed similar patterns.


2013 ◽  
Vol 72 (1) ◽  
pp. 1-133 ◽  
Author(s):  
Višnja Besendorfer ◽  
Jelena Mlinarec

Abstract Satellite DNAis a genomic component present in virtually all eukaryotic organisms. The turnover of highly repetitive satellite DNAis an important element in genome organization and evolution in plants. Here we study the presence, physical distribution and abundance of the satellite DNAfamily AhTR1 in Anemone. Twenty-two Anemone accessions were analyzed by PCR to assess the presence of AhTR1, while fluorescence in situ hybridization and Southern hybridization were used to determine the abundance and genomic distribution of AhTR1. The AhTR1 repeat unit was PCR-amplified only in eight phylogenetically related European Anemone taxa of the Anemone section. FISH signal with AhTR1 probe was visible only in A. hortensis and A. pavonina, showing localization of AhTR1 in the regions of interstitial heterochromatin in both species. The absence of a FISH signal in the six other taxa as well as weak signal after Southern hybridization suggest that in these species AhTR1 family appears as relict sequences. Thus, the data presented here support the »library hypothesis« for AhTR1 satellite evolution in Anemone. Similar species-specific satellite DNAprofiles in A. hortensis and A. pavonina support the treatment of A. hortensis and A. pavonina as one species, i.e. A. hortensis s.l.


Development ◽  
1993 ◽  
Vol 119 (1) ◽  
pp. 41-48 ◽  
Author(s):  
J.M. Brown ◽  
S.E. Wedden ◽  
G.H. Millburn ◽  
L.G. Robson ◽  
R.E. Hill ◽  
...  

Mouse mesenchyme was grafted into chick embryos to investigate the control of mesenchymal expression of Msx-1 in the developing limb and face. In situ hybridization, using species-specific probes, allows a comparison between Msx-1 expression in the graft and the host tissue. The results show that Msx-1 expression in both limb-to-limb and face-to-face grafts corresponds closely with the level of Msx-1 expression in the surrounding chick mesenchyme. Cells in grafts that end up within the host domain of Msx-1 express the gene irrespective of whether they were from normally expressing, or non-expressing, regions. Therefore Msx-1 expression in both the developing limb and the developing face appears to be position-dependent. Mesenchyme from each of the three major facial primordia behaved in the same way when grafted to the chick maxillary primordium. Reciprocal grafts between face and limb gave a different result: Msx-1 expression was activated when facial mesenchyme was grafted to the limb but not when limb mesenchyme was grafted to the face. This suggests either that there are quantitative or qualitative differences in two local signalling systems or that additional factors determine the responsiveness of the mesenchyme cells.


2010 ◽  
Vol 58 (3) ◽  
pp. 195-202 ◽  
Author(s):  
I. Molnár ◽  
M. Molnár-Láng

The multicolour genomic in situ hybridization (mcGISH) method was improved in order to visualize the U b and M b genomes of Aegilops biuncialis Vis. (2n=4x=28, U b U b M b M b ). Hybridization probes prepared from the diploid U and M genome donors, Ae. umbellulata and Ae. comosa , resulted in clear hybridization signals on the U and M chromosomes in Ae. biuncialis . The random primed labelling method made it possible to decrease the blocking ratio to 1:30. McGISH allowed the simultaneous discrimination of individual Ae. biuncialis genomes and wheat chromosomes in γ-irradiated Triticum aestivum-Ae. biuncialis amphiploids (2n=70; AABBDDU b U b M b M b ). Dicentric chromosomes, terminal and interstitial translocations and centric fusions were detected in the irradiated generation. The irradiation-induced wheat- Ae. biuncialis intergenomic translocations will facilitate the successful introgression of useful agronomic traits into bread wheat.


Author(s):  
Audrey Denvir ◽  
Jeannine Cavender-Bares ◽  
Antonio González-Rodríguez

Gardens and horticulturists play an increasingly important role in plant conservation, both in situ and ex situ. Integrated research and conservation of species intends to work across fields to connect science to conservation practice by engaging actors from different sectors, including gardens. The case of integrated conservation of Quercus brandegeei, a microendemic oak species in Baja California Sur, Mexico, is presented as an example of a collaboration between gardens and academic researchers to create a species-specific conservation plan that incorporates horticultural knowledge.


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