3510 Nucleic Acids Research, Vol. 20, No. 13
Nucleotide sequence of genes for a 5.8S and 25S rRNA from rape seed (Brassica napus) Satoru Okumura and Hiroaki Shimada* Mitsui Plant Biotechnology Research Institute, Sengen 2-1-6, Tsukuba 305, Japan DDBJ accession
Submitted June 11, 1992 A cluster of cytoplasmic ribosomal RNA genes has been isolated from a Brassica napus (cultivar Bridger) genomic library. The genomic library used in this work was purchased from Clontech Inc. (Palo Alto, CA). Genes for a 5.8S and 25S rRNA were sequenced as well as the intragenic spacer. Nucleotide sequence was determined by the dideoxy method (1). The regions corresponding rRNAs were identified by comparison with the equivalent genes of Arabidopsis thaliana (2). Sizes of the 5.8S and 25S rRNA genes were 164 bp and 3378 bp, respectively. An analysis of the possible stem-loop structures led to a putative secondary structure of the 5.8S rDNA with the 5' portion of the 25S rDNA (Figure 1), which is similar to that predicted for Iwodes scapulars (3). The 5.8S rRNA gene of B.napus maintains 99.4% homology with the corresponding gene of Arabidopsis thaliana (2) (only one base is different), 96.3% with that of tomato (4) and 94.4% with that of rice (5), respectively. The 25S rRNA gene of B. napus exhibits 96.1% homology with the corresponding gene of Arabidopsis (2), 91.8% with that of tomato (6) and 88.0% with that of rice (7), respectively. The intragenic spacer between the 5.8S and 25S rDNA of B.napus retains 78.8% homology with its counterpart in Arabidopsis (2), a Brassicaceae, but no significant homology with those of tomato (4) and rice (7), respectively. The extent of ribosomal sequence conservation between these plants is consistent with evolutionary relationships proposed on the basis of morphological features.
REFERENCES 1. Sanger,F., Nicklen,A. and Coulson,A.R. (1977) Proc. Natl. Acad. Sci. USA 74, 5463-5468. 2. Unfried,I. and Gruendler,P. (1990) Nucleic Acids Res. 18, 4011. 3. Wesson,D.M. and Collins,F.H. (1992) Nucleic Acids Res. 20, 1139. 4. Kiss,T., Kis,M., Abel,S. and Solymosy,F. (1988) Nucleic Acids Res. 16, 7179. 5. Takaiwa,F., Oono,K. and Sugiura,M. (1985) Plant Mol. Biol. 4, 355-364. 6. Kiss,T., Kis,M. and Solymosy,F. (1989) Nucleic Acids Res. 17, 796. 7. Takaiwa,F., Oono,K., lida,Y. and Sugiura,M. (1985) Gene 37, 255 -259.
*
To whom
correspondence should be addressed
A GA A A G-C U-G A-U G A AU C-G C G AA G G U-G G U U C A-U AUA C-G A-U C-G U-A C U-A C G-U G-U C-G C
u c U u C-G C-G G-C A C A G C A C-G
U-A
C-G
AU-A U-A A-U G-C GC C A A C G G
c
G
U
GC
C C
C
CA
C-G
CGUGAACCAUGAGUCUUGM
5.8 S
T
A C-G C-G C-G G-C C_G C-G
Dl 0840
no.
25 S
G-C
A
U
U-G
A
GU
C-G U-A
u c u c A G C A
G-C
C-G C-G U-A G-C G-C G-C
AAA
G U
5,
Ak
C
U-A
G C
G
5'
AC A
31
Figure 1. Possible secondary structure of the 5.8S rRNA. G-C, A-U and G-T pairs predicted are indicated by bars. The 3' portion of the 5.8S is predicted to be bound with the 5' end of the 25S rRNA.
Nucleotide sequence of genes for a 5.8S and 25S rRNA from rape seed (Brassica napus) Satoru Okumura and Hiroaki Shimada* Mitsui Plant Biotechnology Research Institute, Sengen 2-1-6, Tsukuba 305, Japan DDBJ accession
Submitted June 11, 1992 A cluster of cytoplasmic ribosomal RNA genes has been isolated from a Brassica napus (cultivar Bridger) genomic library. The genomic library used in this work was purchased from Clontech Inc. (Palo Alto, CA). Genes for a 5.8S and 25S rRNA were sequenced as well as the intragenic spacer. Nucleotide sequence was determined by the dideoxy method (1). The regions corresponding rRNAs were identified by comparison with the equivalent genes of Arabidopsis thaliana (2). Sizes of the 5.8S and 25S rRNA genes were 164 bp and 3378 bp, respectively. An analysis of the possible stem-loop structures led to a putative secondary structure of the 5.8S rDNA with the 5' portion of the 25S rDNA (Figure 1), which is similar to that predicted for Iwodes scapulars (3). The 5.8S rRNA gene of B.napus maintains 99.4% homology with the corresponding gene of Arabidopsis thaliana (2) (only one base is different), 96.3% with that of tomato (4) and 94.4% with that of rice (5), respectively. The 25S rRNA gene of B. napus exhibits 96.1% homology with the corresponding gene of Arabidopsis (2), 91.8% with that of tomato (6) and 88.0% with that of rice (7), respectively. The intragenic spacer between the 5.8S and 25S rDNA of B.napus retains 78.8% homology with its counterpart in Arabidopsis (2), a Brassicaceae, but no significant homology with those of tomato (4) and rice (7), respectively. The extent of ribosomal sequence conservation between these plants is consistent with evolutionary relationships proposed on the basis of morphological features.
REFERENCES 1. Sanger,F., Nicklen,A. and Coulson,A.R. (1977) Proc. Natl. Acad. Sci. USA 74, 5463-5468. 2. Unfried,I. and Gruendler,P. (1990) Nucleic Acids Res. 18, 4011. 3. Wesson,D.M. and Collins,F.H. (1992) Nucleic Acids Res. 20, 1139. 4. Kiss,T., Kis,M., Abel,S. and Solymosy,F. (1988) Nucleic Acids Res. 16, 7179. 5. Takaiwa,F., Oono,K. and Sugiura,M. (1985) Plant Mol. Biol. 4, 355-364. 6. Kiss,T., Kis,M. and Solymosy,F. (1989) Nucleic Acids Res. 17, 796. 7. Takaiwa,F., Oono,K., lida,Y. and Sugiura,M. (1985) Gene 37, 255 -259.
*
To whom
correspondence should be addressed
A GA A A G-C U-G A-U G A AU C-G C G AA G G U-G G U U C A-U AUA C-G A-U C-G U-A C U-A C G-U G-U C-G C
u c U u C-G C-G G-C A C A G C A C-G
U-A
C-G
AU-A U-A A-U G-C GC C A A C G G
c
G
U
GC
C C
C
CA
C-G
CGUGAACCAUGAGUCUUGM
5.8 S
T
A C-G C-G C-G G-C C_G C-G
Dl 0840
no.
25 S
G-C
A
U
U-G
A
GU
C-G U-A
u c u c A G C A
G-C
C-G C-G U-A G-C G-C G-C
AAA
G U
5,
Ak
C
U-A
G C
G
5'
AC A
31
Figure 1. Possible secondary structure of the 5.8S rRNA. G-C, A-U and G-T pairs predicted are indicated by bars. The 3' portion of the 5.8S is predicted to be bound with the 5' end of the 25S rRNA.
