caa a22 4500 465758886 CHVBK 20180323111855.0 cr unu---uuuuu 170327e19900201xx s 000 0 eng 10.1007/BF00312856 doi (NATIONALLICENCE)springer-10.1007/BF00312856 Subrepeat structure of the intergenic region in the ribosomal DNA of the oomycetous fungus Pythium ultimum [Elektronische Daten] [Glen Klassen, John Buchko] Summary: Restriction endonuclease site maps of the rDNA repeat in 14 isolates of the oomycetous fungus Pythium ultimum show that the intergenic region (IGR) includes two regions of heterogeneity. A region located about one kilobase downstream of the 3′ end of the large subunit rRNA gene contains a segment present in multiple versions differeing in size by as much as 0.9 kb. Each isolate shows a unique pattern of heterogeneity in this region. The other region of heterogeneity is located near the centre of the IGR and consists of segments which differ by integral multiples of 385 bp. Thus, the IGR in P. ultimum is dominated by an array of uniform subrepeats. The size of the repeat segment is identical in all isolates, but the number of subrepeats (6-12), and the relative abundance of each variant segment is highly polymorphic. Because no other fungus has been reported with this type or organization in its rDNA repeat, these findings support the idea that Oomycetes are phylogenetically distinct from other fungi. They also provide a new system for the study of the role of rDNA subrepeats in transcriptional regulation. Springer-Verlag, 1990 rDNA repeat nationallicence Pythium ultimum nationallicence Intergenic region heterogeneity nationallicence Subrepeat polymorphism nationallicence Klassen Glen Department of Microbiology, University of Manitoba, R3T 2N2, Winnipeg, Manitoba, Canada aut Buchko John Department of Microbiology, University of Manitoba, R3T 2N2, Winnipeg, Manitoba, Canada aut Current Genetics Springer-Verlag 17/2(1990-02-01), 125-127 0172-8083 17:2<125 1990 17 294 https://doi.org/10.1007/BF00312856 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00312856 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Klassen Glen Department of Microbiology, University of Manitoba, R3T 2N2, Winnipeg, Manitoba, Canada aut NATIONALLICENCE 700 1- Buchko John Department of Microbiology, University of Manitoba, R3T 2N2, Winnipeg, Manitoba, Canada aut NATIONALLICENCE 773 0- Current Genetics Springer-Verlag 17/2(1990-02-01), 125-127 0172-8083 17:2<125 1990 17 294 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer