A moderately repeated DNA sequence of wheat and rye genomes

Abstract

A 371 base pair segment (bordered by Hind III and Eco RI cutting sites) of wheat embryo nuclear DNA has been cloned and sequenced. It is AT-rich (68%), shares some sequence features with autonomously replicating sequence (ARS) elements, and occurs in approximately 7600 copies per haploid genome. When used as probe for blot hybridization to Hind III-digested wheat DNA, it gives an irregular series of hybridization bands. Essentially the same hybridization pattern was observed for rye DNA. It is concluded that this segment is distributed irregularly but, apparently, according to the same rule in both wheat and rye genomes.

A large DNA repeat of the dispersion pattern common to wheat and rye genomes

“…There are numerous short streches of 100~o identity within the wheat and rye repeated sequences, but the longest of them is only 13 nucleotides long. It differs markedly (40~/o homology) from the previously sequenced H371E repeat [2]. Some similarities may be, however, indicated.…”

“…Dispersed repeated sequences, such as copia-like elements, have been, however, successfully exploited in a large-scale characterization of plant genomes [ 5 ]. In a previous report [2], we identified a new, moderately repeated D N A sequence (371bp long). Not only was it common to wheat and rye nuclear DNAs, but it also seemed to be similarly distributed in both genomes.…”

“…The 1241 bp Hind III fragment of wheat embryo nuclear DNA was generated and cloned by a procedure similar to that used previously [2]. A transformant which hybridized efficiently to wheat and rye DNAs was selected.…”

“…It seemed, therefore, of interest to establish whether this moderately repeated sequence is arranged tandemly or scattered through the wheat genome. For this purpose, the genomic DNA was digested with Hind III and, after electrophoresis and blotting, probed with 32p-labelled H1241H under high-stringency conditions [2].…”