Leino M, Teixeira R, Landgren M, Glimelius K
Department of Plant Biology, Box 7080, Swedish University for Agricultural Sciences, 750 07 Uppsala, Sweden.
Theor Appl Genet. 2003 May;106(7):1156-63. doi: 10.1007/s00122-002-1167-y. Epub 2002 Dec 13.
Numerous Brassica napus (+) Arabidopsis thaliana somatic hybrids were screened for male sterility and aberrant flower phenotypes. Nine hybrids were selected and backcrossed recurrently to B. napus. The resulting lines displayed stable maternal inheritance of flower phenotypes. Nuclear and organellar genomes were characterized molecularly using RFLP analysis. No DNA from A. thaliana was found in the nuclear genome after six back-crosses, whilst the mitochondrial genomes contained rearranged DNA from both A. thaliana and B. napus. Each line tested had a unique RFLP pattern of the mitochondrial DNA (mtDNA) that remained unchanged between the BC(3) and BC(6) generation. The plastid genomes consisted of B. napus DNA. Five lines of the BC(5) generation were subjected to more comprehensive investigations of growth, morphology and fertility. On the basis of these investigations, the five CMS lines could be assigned to two groups, one represented by three lines displaying reduced vegetative development, complete male sterility, and homeotic conversions of stamens into feminized structures. The second group, represented by the other two lines, were not completely male-sterile but still displayed severely affected flower morphologies. These two lines did not display any reduction in vegetative development. For both groups only stamens and petals suffered from the morphological and functional aberrations, while the sepals and pistils displayed normal morphology. All plants were fully female-fertile. Different rearrangements of the mitochondrial genome disturbed nuclear-mitochondrial interactions and led to various types of aberrant growth and flower development. The existence of numerous CMS lines with different mitochondrial patterns involving a species with a sequenced genome offers new opportunities to investigate the genetic regulation of CMS and its associated developmental perturbations.
对众多甘蓝型油菜（+）拟南芥体细胞杂种进行了雄性不育和异常花表型筛选。选择了9个杂种，并与甘蓝型油菜反复回交。所得品系表现出花表型的稳定母系遗传。使用RFLP分析对核基因组和细胞器基因组进行了分子表征。经过六次回交后，在核基因组中未发现拟南芥的DNA，而线粒体基因组包含来自拟南芥和甘蓝型油菜的重排DNA。每个测试品系的线粒体DNA（mtDNA）都有独特的RFLP模式，在BC(3)和BC(6)代之间保持不变。质体基因组由甘蓝型油菜DNA组成。对BC(5)代的五个品系进行了更全面的生长、形态和育性研究。基于这些研究，这五个细胞质雄性不育（CMS）品系可分为两组，一组由三个品系代表，表现为营养发育减少、完全雄性不育，以及雄蕊向雌性化结构的同源异型转化。另一组由另外两个品系代表，它们并非完全雄性不育，但仍表现出严重受影响的花形态。这两个品系的营养发育没有任何减少。对于两组而言，只有雄蕊和花瓣出现形态和功能异常，而萼片和雌蕊表现出正常形态。所有植株雌性育性完全正常。线粒体基因组的不同重排扰乱了核 - 线粒体相互作用，导致了各种类型的异常生长和花发育。存在众多具有不同线粒体模式的CMS品系，涉及一个基因组已测序的物种，这为研究CMS的遗传调控及其相关的发育扰动提供了新的机会。
