Genome analysis of Elytrigia pycnantha and Thinopyrum junceiforme and of their putative natural hybrid using the GISH technique

Genome ◽  
2001 ◽  
Vol 44 (4) ◽  
pp. 708-715 ◽  
Author(s):  
Aïcha Refoufi ◽  
Joseph Jahier ◽  
Marie-Andrée Esnault

Genomic in situ hybridization (GISH), using genomic DNA probes from Thinopyrum elongatum (Host) D.R. Dewey (E genome, 2n = 14), Th. bessarabicum (Savul. & Rayss) A. Löve (J genome, 2n = 14), Pseudoroegneria stipifolia (Czern. ex Nevski) Löve (S genome, 2n = 14), and Agropyron cristatum (L.) Gaertner (P genome, 2n = 14), was used to characterize the genome constitution of the polyploid species Elytrigia pycnantha (2n = 6x = 42) and Thinopyrum junceiforme (2n = 4x = 28) and of one hybrid population (2n = 5x = 35). GISH results indicated that E. pycnantha contains S, E, and P genomes; the first of these was closely related to the S genome of Ps. stipifolia, the second was closely related to to the E genome of Th. elongatum, and the third was specifically related to A. cristatum. The E and P genomes included 2 and 10 chromosomes, respectively, with S genome DNA sequences in the centromeric region. GISH analysis of Th. junceiforme showed the presence of two sets of the E genome, except for fewer than 10 chromosomes for which the telomeric regions were not identified. Based on these results, the genome formula SSPSPSESES is proposed for E. pycnantha and that of EEEE is proposed for Th. junceiforme. The genomic constitution of the pentaploid hybrid comprised one S genome (seven chromosomes), one P genome (seven chromosomes), and three E genomes (21 chromosomes). The E and P genomes both included mosaic chromosomes (chromosomes 1 and 5, respectively) with the centromere region closely related to S-genome DNA. On the basis of these data, the genome formula SPSESEE is suggested for this hybrid and it is also suggested that the two species E. pycnantha and Th. junceiforme are the parents of the pentaploid hybrid.Key words: GISH, Elytrigia pycnantha, Thinopyrum junceiforme, pentaploid hybrid, P genome.

Author(s):  
Barbara Trask ◽  
Susan Allen ◽  
Anne Bergmann ◽  
Mari Christensen ◽  
Anne Fertitta ◽  
...  

Using fluorescence in situ hybridization (FISH), the positions of DNA sequences can be discretely marked with a fluorescent spot. The efficiency of marking DNA sequences of the size cloned in cosmids is 90-95%, and the fluorescent spots produced after FISH are ≈0.3 μm in diameter. Sites of two sequences can be distinguished using two-color FISH. Different reporter molecules, such as biotin or digoxigenin, are incorporated into DNA sequence probes by nick translation. These reporter molecules are labeled after hybridization with different fluorochromes, e.g., FITC and Texas Red. The development of dual band pass filters (Chromatechnology) allows these fluorochromes to be photographed simultaneously without registration shift.


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 ◽  
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.


Genetics ◽  
1986 ◽  
Vol 113 (4) ◽  
pp. 1077-1091
Author(s):  
John H Gillespie

ABSTRACT A statistical analysis of DNA sequences from four nuclear loci and five mitochondrial loci from different orders of mammals is described. A major aim of the study is to describe the variation in the rate of molecular evolution of proteins and DNA. A measure of rate variability is the statistic R, the ratio of the variance in the number of substitutions to the mean number. For proteins, R is found to be in the range 0.16 < R < 35.55, thus extending in both directions the values seen in previous studies. An analysis of codons shows that there is a highly significant excess of double substitutions in the first and second positions, but not in the second and third or first and third positions. The analysis of the dynamics of nucleotide evolution showed that the ergodic Markov chain models that are the basis of most published formulas for correcting for multiple substitutions are incompatible with the data. A bootstrap procedure was used to show that the evolution of the individual nucleotides, even the third positions, show the same variation in rates as seen in the proteins. It is argued that protein and silent DNA evolution are uncoupled, with the evolution at both levels showing patterns that are better explained by the action of natural selection than by neutrality. This conclusion is based primarily on a comparison of the nuclear and mitochondrial results.


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.


2011 ◽  
Vol 30 (9) ◽  
pp. 1779-1786 ◽  
Author(s):  
Kun Yang ◽  
Hecui Zhang ◽  
Richard Converse ◽  
Yong Wang ◽  
Xiaoying Rong ◽  
...  

1982 ◽  
Vol 20 ◽  
Author(s):  
P.P. Vaishnava ◽  
P.A. Montano

ABSTRACTIn situ 57Fe Mössbauer spectra are reported for the first-, higher-stage ferric chloride, and a mixed ferric chloride-potassium chloride intercalated graphite catalysts under reduction and Fischer-Tropsch reaction conditions. The mass spectroscopic measurements reveal a different catalytic selectivity for the three catalysts. The first two catalysts predominantly possess a higher selectivity for methane, whereas the third catalyst has higher selectivity for the formation of propane. The differences are attributed to geometrical effects in the catalytic sites of the intercalated compounds.


Parasitology ◽  
1999 ◽  
Vol 119 (3) ◽  
pp. 315-321 ◽  
Author(s):  
A. IMASE ◽  
T. KUMAGAI ◽  
H. OHMAE ◽  
Y. IRIE ◽  
Y. IWAMURA

Localization of the type 2 Alu sequence (B2), a highly repetitive DNA sequence in the mouse genome, was examined by in situ polymerase chain reaction (in situ PCR) in schistosomes. The signals to the B2 sequence were detected in the cytoplasm of the tegumental membrane and in the nuclei of the mesenchymal, testicular, ovarian and vitelline cells of 8- week Schistosoma japonicum. In contrast, it was difficult to detect any signals of this sequence in 8-week S. mansoni, whereas in 24-week male S. mansoni the signals were observed in the cytoplasm of the tegumental tubercles and in the nuclei of the mesenchymal and testicular cells. On the other hand, in 24-week female S. mansoni the signals were found in the nuclei of the mesenchymal, ovarian and vitelline cells but not found in the tegument. On the contrary, no hybridization band of the B2 sequence was detected in the amplified DNA of 3-week schistosomula of either species. These observations proved that the host DNA sequences existed in restricted schistosome cells and were accumulated in the schistosome body during their development.


Genes ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 517 ◽  
Author(s):  
Daniel García-Souto ◽  
Sandra Alonso-Rubido ◽  
Diana Costa ◽  
José Eirín-López ◽  
Emilio Rolán-Álvarez ◽  
...  

Periwinkles of the family Littorinidae (Children, 1834) are common members of seashore littoral communities worldwide. Although the family is composed of more than 200 species belonging to 18 genera, chromosome numbers have been described in only eleven of them. A molecular cytogenetic analysis of nine periwinkle species, the rough periwinkles Littorina arcana, L. saxatilis, and L. compressa, the flat periwinkles L. obtusata and L. fabalis, the common periwinkle L. littorea, the mangrove periwinkle Littoraria angulifera, the beaded periwinkle Cenchritis muricatus, and the small periwinkle Melarhaphe neritoides was performed. All species showed diploid chromosome numbers of 2n = 34, and karyotypes were mostly composed of metacentric and submetacentric chromosome pairs. None of the periwinkle species showed chromosomal differences between male and female specimens. The chromosomal mapping of major and minor rDNA and H3 histone gene clusters by fluorescent in situ hybridization demonstrated that the patterns of distribution of these DNA sequences were conserved among closely related species and differed among less related ones. All signals occupied separated loci on different chromosome pairs without any evidence of co-localization in any of the species.


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