Kamstra S A, Kuipers A G, De Jeu M J, Ramanna M S, Jacobsen E
Department of Plant Breeding, Graduate School of Experimental Plant Sciences, Wageningen Agricultural University, The Netherlands.
Genome. 1997 Oct;40(5):652-8. doi: 10.1139/g97-086.
Fluorescence in situ hybridization (FISH) was used to localise two species-specific repetitive DNA sequences, A001-I and D32-13, and two highly conserved 25S and 5S rDNA sequences on the metaphase chromosomes of two species of Alstroemeria. The Chilean species, Alstroemeria aurea (2n = 16), has abundant constitutive heterochromatin, whereas the Brazilian species, Alstroemeria inodora, has hardly any heterochromatin. The A. aurea specific A001-I probe hybridized specifically to the C-band regions on all chromosomes. The FISH patterns on A. inodora chromosomes using species-specific probe D32-13 resembled the C-banding pattern and the A001-I pattern on A. aurea chromosomes. There were notable differences in number and distribution of rDNA sites between the two species. The 25S rDNA probe revealed 16 sites in A. aurea that closely colocalised with A001-I sites and 12 in A. inodora that were predominantly detected in the centromeric regions. FISH karyotypes of the two Alstroemeria species were constructed accordingly, enabling full identification of all individual chromosomes. These FISH karyotypes will be useful for monitoring the chromosomes of both Alstroemeria species in hybrids and backcross derivatives.
荧光原位杂交（FISH）被用于在两种六出花属植物的中期染色体上定位两个物种特异性重复DNA序列A001-I和D32-13，以及两个高度保守的25S和5S核糖体DNA序列。智利物种六出花（2n = 16）具有丰富的组成型异染色质，而巴西物种无香六出花几乎没有任何异染色质。六出花特异的A001-I探针特异性地与所有染色体上的C带区域杂交。使用物种特异性探针D32-13对无香六出花染色体进行FISH分析的结果与六出花染色体上的C带模式和A001-I模式相似。这两个物种的核糖体DNA位点在数量和分布上存在显著差异。25S核糖体DNA探针在六出花中揭示了16个位点，这些位点与A001-I位点紧密共定位，在无香六出花中揭示了12个位点，主要在着丝粒区域检测到。据此构建了两种六出花属植物的FISH核型，从而能够完全鉴定所有单条染色体。这些FISH核型将有助于监测杂种和回交后代中两种六出花属植物的染色体情况。
