FIND ARTICLE

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1
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Mobile genetic elements have been identified in all studied so far animal species , fungi , and Protozoa . They form a significant component of plant genomes . They are subject to intensive processes of amplification , and then are inserted in new places. Mobile devices are commonly divided into two large classes . The first is the retrotransposons , created with the participation of RNA and reverse transcriptase ; This second class of DNA transposons , in which the process of creating new copies and their movement is mediated by DNA and transposase . The first of these include, among others devoid of LTR ( non - LTR ) retrotransposons type of SINE (short dispersed nuclear elements ) . They are small , non-autonomous DNA sequences , devoid of open reading frames (ORFs ) , which do not themselves have the ability to encode proteins necessary retropozycji use for this purpose proteins encoded by elements such as lines (long diffuse nuclear elements ), also assigned to the same class. SINE have characteristic structural elements , such as the presence of A and B boxes of RNA polymerase internal promoter III of Part t -RNA - related , variable-length region of t -RNA niepokrewny and short , rich in dA 3 'region . In plants, all SINE , unlike the analogous sequences of the genomes of animal derived from tRNA genes . They are also less abundant plants and the number of copies of the elements of the family is usually a few hundred to a few thousand in the haploid genome (compared to 104-106 animals ) . Currently , the isolated genomes examined over 80 families SINE and p- SINE1 sequence was the first of this type are described in plants. It was identified in the intron of the gene of Oryza sativa Waxy . Further SINE elements found among other Gramineae (Zea mays , Aegilops umbellulata , Triticum aestivum ) , and also in dicotyledonous species : in Brassicaceae ( Arabidopsis thaliana , Brassica napus , Brassica oleracea ) , Solanaceae ( Nicotiana tabacum , Capsicum annuum , Lycopersicon esculentum ) , Fabaceae ( Medicago truncatula and Lotus japonicus , Glycine max ) . They are usually distributed in the genomes , rarely present in heterochromatin , regions przycentromerowych showing preference for regions rich in genes. Abundance and diversity of repeated elements makes that they are grouped in a family of characteristics , and a high level of polymorphism SINE makes families established within numerous subfamilies . That feature makes SINE sequences useful markers used , among others, in the classification of varieties of plant species in the phylogeny.

The Editorial Board
Andrzej Łukaszyk - przewodniczący, Zofia Bielańska-Osuchowska, Szczepan Biliński, Mieczysław Chorąży, Aleksander Koj, Włodzimierz Korochoda, Leszek Kuźnicki, Aleksandra Stojałowska, Lech Wojtczak

Editorial address:
Katedra i Zakład Histologii i Embriologii Uniwersytetu Medycznego w Poznaniu, ul. Święcickiego 6, 60-781 Poznań, tel. +48 61 8546453, fax. +48 61 8546440, email: mnowicki@ump.edu.pl

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