FISH analysis of meiosis in Arabidopsis allopolyploids
FISH analysis of meiosis in Arabidopsis allopolyploids
复制标题
DOI：
10.1023/a:1022883709060
复制
发表时间：
2003-03-01
影响因子：
2.6
通讯作者：
Lysak, MA
中科院分区：
文献类型：
--
作者：
Comai, L;Tyagi, AP;Lysak, MA
虽然异源多倍体在自然界和农业中很常见，但对其起源、进化和基因组调控的了解有限。我们研究了人工合成的异源四倍体拟南芥和Arabidopsis arenosa以及天然异源四倍体拟南芥。为了阐明异源四倍体基因组的组成和行为，我们用来自A.和荧光原位杂交与着丝粒（CEN）探针特异性每个亲本基因组。我们记录了16 A的存在。arenosa和10 A. thaliana染色体上，并证明了两个不同的A. arenosa染色体与A. thaliana.虽然花粉母细胞中的染色体配对主要是同源的，但不同亲本来源的CEN在早期前期I合并，但在中期分解成适当的配对。此外，同源染色体的CEN在绒毡层细胞中不配对，并且通过大量独立的CEN证明了没有严格多线性的内多倍性。因此，拟南芥人工合成异源多倍体能够同源配对，早在三代后形成。这表明二倍体样配对不是调节配对的基因适应性突变的结果，也不是基因组结构重塑的结果：相反，很可能是父母提供了控制配对行为的基因，或者父母染色体的特征阻碍了同源配对。
Although allopolyploids are common in nature and in agriculture, knowledge of their origin, evolution and genomic regulation is limited. We study synthetic allotetraploids of Arabidopsis thaliana and Arabidopsis arenosa as well as the natural allotetraploid Arabidopsis suecica. To elucidate the composition and behavior of the allotetraploid genome, we used chromosome painting with probes from contiguous regions of chromosome 4 of A. thaliana and fluorescent in-situ hybridization with centromeric (CEN) probes specific for each parental genome. We documented the presence of 16 A. arenosa and 10 A. thaliana chromosomes and demonstrate that two different A. arenosa chromosomes are homeologous to chromosome 4 of A. thaliana. Although chromosome pairing in pollen mother cells was predominantly homologous, CENs of different parental origin coalesced at early prophase I, but resolved into proper pairs by metaphase. In addition, CENs of homologous chromosomes were not paired in tapetum cells and endopolyploidy without strict polyteny was evident by the large number of independent CENs. Thus, the Arabidopsis synthetic allopolyploids were capable of homologous pairing as early as three generations after their formation. This indicates that diploid-like pairing is not the result of adaptive mutations in genes that regulate pairing nor the result of structural remodeling of the genomes: rather, it is likely that either the parents provided genes controlling pairing behavior or that features of the parental chromosomes hinder homeologous pairing.