Experimental Institute of Cereal Crops, Bergamo Section, Via Stezzano 24, I-24100, Bergamo, Italy.
Theor Appl Genet. 1990 Dec;80(6):769-75. doi: 10.1007/BF00224190.
To provide an insight into the molecular basis of heterosis, we investigated gene expression in primary root tips of a heterotic maize hybrid (B73 × Mo17) and its parental lines (B73 and Mo17). This analysis was carried out (i) by differential plaque hybridization of a recombinant cDNA library made to poly(A) RNA isolated from B73 × Mo17 primary root tips, and (ii) by comparing with two-dimensional gel electrophoresis proteins synthesized in vitro in the rabbit reticulocyte system by poly(A) RNA isolated, at different stages of development, from the three genotypes. The results showed that there are sets of proteins and mRNAs that are differentially synthesized and expressed in the F1 primary root tips in comparison to the parental lines. Moreover, results from the survey of 21 major in-vitrosynthesized polypeptide variants, from mRNAs of primary root tips of the parental lines and their F1 hybrid, indicated that in seven instances hybrid proteins translated in vitro were more abundant or possibly new. In most of the remaining cases, hybrid spots were similar in intensity to the same protein produced by one of the two parental lines.
为了深入了解杂种优势的分子基础，我们研究了杂种玉米杂交种（B73×Mo17）及其亲本系（B73 和 Mo17）的初生根尖中的基因表达。这项分析是通过对从 B73×Mo17 初生根尖分离的 poly(A) RNA 构建的 cDNA 文库进行差异斑点杂交进行的，（ii）通过比较在不同发育阶段从三种基因型分离的 poly(A) RNA 在兔网织红细胞系统中体外合成的蛋白质的二维凝胶电泳来进行。结果表明，与亲本系相比，F1 初生根尖中有一组蛋白质和 mRNAs 是差异合成和表达的。此外，对来自亲本系及其 F1 杂种的初生根尖的 mRNA 体外合成的 21 种主要多肽变体的调查结果表明，在七种情况下，体外翻译的杂种蛋白更丰富或可能是新的。在其余大多数情况下，杂交斑点的强度与两个亲本系之一产生的相同蛋白质相似。
