Genome organization of Brassica napus and Lesquerella fendleri and analysis of their somatic hybrids using genomic in situ hybridization

Genome ◽  
1998 ◽  
Vol 41 (5) ◽  
pp. 691-701 ◽  
Author(s):  
Marina Skarzhinskaya ◽  
Jan Fahleson ◽  
Kristina Glimelius ◽  
Armand Mouras
Keyword(s):  
In Situ Hybridization ◽  
Brassica Napus ◽  
Somatic Hybrids ◽  
Chromosome Translocation ◽  
Genomic In Situ Hybridization ◽  
Lesquerella Fendleri ◽  
Hybrid Plants ◽  
Transformed Root Cultures ◽  
Asymmetric Fusion

Construction of Brassica napus (2n = 38) and Lesquerella fendleri (2n = 12) karyotypes revealed that B. napus contains 10 pairs of metacentric, 5 pairs of submetacentric, and 4 pairs of subtelocentric chromosomes, while L. fendleri contains 6 pairs of metacentric chromosomes that are, on average, 1.5 times longer than those of B. napus. By analysing the karyotypes and performing genomic in situ hybridization (GISH), the chromosome complements of somatic hybrids produced between Brassica napus (+) Lesquerella fendleri were studied. Protoplasts fused with no pretreatment, symmetric fusions, resulted in hybrids containing L. fendleri chromosomes in numbers varying from 2 chromosomes to 2 chromosome complements. In the asymmetric fusion experiments, in which L. fendleri protoplasts were irradiated before fusion, plants with from 38 to more than 76 chromosomes were obtained. In the hybrids with 38 chromosomes, the presence of L. fendleri chromosomes was not detected by GISH analysis, even though L. fendleri DNA was revealed by Southern blotting. Intra- and inter-genomic recombinations were observed in hybrids from both symmetric and asymmetric fusions. The rearrangements were more prevalent in plants resulting from asymmetric fusions. Modifications of the phenotype and reduced fertility of the hybrid plants were correlated with increased dosages of the L. fendleri genome. At least one genome complement of L. fendleri was required to express its morphological features.Key words: Agrobacterium rhizogenes transformed root cultures, Brassica napus, Lesquerella fendleri, somatic hybrids, chromosome translocation.

Cytological characterization of potato - Solanum etuberosum somatic hybrids and their backcross progenies by genomic in situ hybridization

Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 987-992 ◽  
Author(s):  
F Dong ◽  
R G Novy ◽  
J P Helgeson ◽  
J Jiang
Keyword(s):  
In Situ Hybridization ◽  
Dna Marker ◽  
Somatic Hybrids ◽  
Molecular Cytogenetics ◽  
Genomic In Situ Hybridization ◽  
Preferential Pairing ◽  
Potato Germplasm ◽  
Solanum Etuberosum

Four somatic hybrids derived from a diploid wild species Solanum etuberosum and a diploid tuber-bearing Solanum clone 463-4, together with five BC1 and three BC2 plants, were analyzed by genomic in situ hybridization (GISH). None of the four somatic hybrids had the expected chromosome constitutions, i.e., 24 chromosomes from each fusion parent. Either one chromosome from S. etuberosum or one from the potato parent 463-4 was lost in the hybrids. Three BC1 plants had exactly one set of S. etuberosum chromosomes. The other two BC1 plants either had one extra or one fewer S. etuberosum chromosome, possibly because their somatic hybrid parents had an extra or had lost one S. etuberosum chromosome. The presence of one set, or close to one set, of S. etuberosum chromosomes in all BC1 plants suggests a preferential pairing and segregation of the S. etuberosum chromosomes in the somatic hybrids. Two of the three BC2 plants had 52 chromosomes, deviating significantly from the expected chromosome number of 48. These results suggest poor pairing between S. etuberosum and S. tuberosum chromosomes in the BC1 plants. The present study demonstrates the importance of combining GISH and DNA marker analysis for a thorough characterization of potato germplasm containing chromosomes from different species.Key words: potato germplasm, Solanum etuberosum, molecular cytogenetics.

Genomic in situ hybridization in plants with small genomes is feasible and elucidates the chromosomal parentage in interspecific Arabidopsis hybrids

Genome ◽  
2004 ◽  
Vol 47 (5) ◽  
pp. 954-960 ◽  
Author(s):  
Hoda B.M Ali ◽  
Martin A Lysak ◽  
Ingo Schubert
Keyword(s):  
In Situ Hybridization ◽  
Genomic In Situ Hybridization ◽  
Closely Related Species ◽  
Meiotic Chromosomes ◽  
Hybrid Plants ◽  
Synthetic Hybrids ◽  
High Concentrations ◽  
Arabidopsis Suecica ◽  
Allotetraploid Species

Genomic in situ hybridization (GISH) is a useful tool to analyse natural polyploids, hybrid plants, and their backcross progenies as to their origin, genomic composition, and intergenomic rearrangements. However, in angiosperms with very small genomes (<0.6 pg/1 C), often only heterochromatic regions were found to be labeled. We have modified the GISH technique to label entire mitotic and meiotic chromosomes of Arabidopsis thaliana (2n = 10) and closely related species with very small genomes by using high concentrations of DNA (7.5–15 µg per probe per slide) or 5 µg of probe and long hybridization times (>60 h). According to our GISH data, Cardaminopsis carpatica (2n = 16) is most likely the diploid ancestor of the autotetraploid Arabidopsis arenosa (2n = 32). Furthermore, within the allotetraploid species Arabidopsis suecica (2n = 26), it was possible to elucidate the origin of chromosomes contributed by the parental species A. thaliana and A. arenosa for a specimen with 2n = 26 or a deviating chromosome number.Key words: genomic in situ hybridization (GISH), Arabidopsis, Brassicaceae, allopolyploids, synthetic hybrids.

Behaviour of Sinapis alba chromosomes in a Brassica napus background revealed by genomic in-situ hybridization

2005 ◽  
Vol 13 (8) ◽  
pp. 819-826 ◽  
Author(s):  
Y. P. Wang ◽  
X. X. Zhao ◽  
K. Sonntag ◽  
P. Wehling ◽  
R. J. Snowdon
Keyword(s):  
In Situ Hybridization ◽  
Brassica Napus ◽  
Sinapis Alba ◽  
Genomic In Situ Hybridization

Molecular cytogenetic analysis of wheat–barley hybrids using genomic in situ hybridization and barley microsatellite markers

Genome ◽  
2003 ◽  
Vol 46 (2) ◽  
pp. 314-322 ◽  
Author(s):  
L Malysheva ◽  
T Sjakste ◽  
F Matzk ◽  
M Röder ◽  
M Ganal
Keyword(s):  
Molecular Markers ◽  
In Situ Hybridization ◽  
Microsatellite Markers ◽  
Genetic Material ◽  
Introgressive Hybridization ◽  
Intergeneric Hybrids ◽  
Genomic In Situ Hybridization ◽  
Genome Constitution ◽  
Hybrid Plants

In the present investigation, genomic in situ hybridization (GISH) and barley microsatellite markers were used to analyse the genome constitution of wheat–barley hybrids from two backcross generations (BC1 and BC2). Two BC1 plants carried 3 and 6 barley chromosomes, respectively, according to GISH data. Additional chromosomal fragments were detected using microsatellites. Five BC2 plants possessed complete barley chromosomes or chromosome segments and six BC2 plants did not preserve barley genetic material. Molecular markers revealed segments of the barley genome with the size of one marker only, which probably resulted from recombination between wheat and barley chromosomes. The screening of backcrossed populations from intergeneric hybrids could be effectively conducted using both genomic in situ hybridization and molecular microsatellite markers. GISH images presented a general overview of the genome constitution of the hybrid plants, while microsatellite analysis revealed the genetic identity of the alien chromosomes and chromosomal segments introgressed. These methods were complementary and provided comprehensive information about the genomic constitution of the plants produced.Key words: wheat–barley hybrids, introgressive hybridization, recombination, molecular markers, genomic in situ hybridization (GISH).

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