title: Activity of the En/Spm-like transposons in meiosis as a base for chromosome repatterning in a small, isolated, peripheral population of Aegilops speltoides Tausch.
abstract: Chromosomal repatterning is considered to be one of the main mechanisms for plant genome evolution. Here, we report the first cytogenetic evidence for the involvement of En/Spm transposons in ongoing chromosomal repatterning leading to the rise of new fertile genomic forms in a small, isolated, peripheral plant population. Cytogenetical screening of original individual plants of Aegilops speltoides Tausch. with different phenotypes revealed a wide spectrum of chromosomal abnormalities including extra chromosomes, chromosomal rearrangements, and variability in chromosomal position/number of 45S and 5S rDNA sites. Cytogenetic analysis of the dynamics of En/Spm transposons in meiosis indicates that: (i) this type of transposon is active during male gametogenesis; (ii) separately or in conjunction with rDNA they form clusters in the hot spots of large chromosomal rearrangements; (iii) appearance of at least part of the mobile rDNA sites in genome of Ae. speltoides are connected with meiotic activity of En/Spm transposons. PCR screening for the site-selected transposon insertions confirm the presence of combined fragments that consist partly of the sequence of En/Spm transposon and partly of 5S rDNA sequence.
authors.affiliation: Institute of Evolution, University of Haifa, Mt. Carmel, Haifa 31905, Israel. raskina@research.haifa.ac.il
authors.forename: Olga
authors.initials: O
authors.lastname: Raskina
authors.forename: Alexander
authors.initials: A
authors.lastname: Belyayev
authors.forename: Eviatar
authors.initials: E
authors.lastname: Nevo
mesh_terms: D002875:Chromosomes / Q000235:genetics; D004251:DNA Transposable Elements; D004275:DNA, Ribosomal; D015321:Gene Rearrangement; D008540:Meiosis / Q000235:genetics*; D006109:Poaceae / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D004275:DNA, Ribosomal