Non-coordinate regulation of 5S rRNA genes and the gene encoding the 5S rRNA-binding ribosomal protein homolog in Neurospora crassa

2000 ◽  
Vol 263 (6) ◽  
pp. 987-994 ◽  
Author(s):  
I. de la Serna ◽  
T. P. Cujec ◽  
Y. Shi ◽  
B. M. Tyler
1985 ◽  
Vol 82 (7) ◽  
pp. 2067-2071 ◽  
Author(s):  
R. L. Metzenberg ◽  
J. N. Stevens ◽  
E. U. Selker ◽  
E. Morzycka-Wroblewska

Author(s):  
Hoda B. M. Ali ◽  
Samira A. Osman

Abstract Background Fluorescence In Situ Hybridization (FISH) played an essential role to locate the ribosomal RNA genes on the chromosomes that offered a new tool to study the chromosome structure and evolution in plant. The 45S and 5S rRNA genes are independent and localized at one or more loci per the chromosome complement, their positions along chromosomes offer useful markers for chromosome discriminations. In the current study FISH has been performed to locate 45S and 5S rRNA genes on the chromosomes of nine Lathyrus species belong to five different sections, all have chromosome number 2n=14, Lathyrus gorgoni Parl, Lathyrus hirsutus L., Lathyrus amphicarpos L., Lathyrus odoratus L., Lathyrus sphaericus Retz, Lathyrus incospicuus L, Lathyrus paranensis Burkart, Lathyrus nissolia L., and Lathyrus articulates L. Results The revealed loci of 45S and 5S rDNA by FISH on metaphase chromosomes of the examined species were as follow: all of the studied species have one 45S rDNA locus and one 5S rDNA locus except L. odoratus L., L. amphicarpos L. and L. sphaericus Retz L. have two loci of 5S rDNA. Three out of the nine examined species have the loci of 45S and 5S rRNA genes on the opposite arms of the same chromosome (L. nissolia L., L. amphicarpos L., and L. incospicuus L.), while L. hirsutus L. has both loci on the same chromosome arm. The other five species showed the loci of the two types of rDNA on different chromosomes. Conclusion The detected 5S and 45S rDNA loci in Lathyrus could be used as chromosomal markers to discriminate the chromosome pairs of the examined species. FISH could discriminate only one chromosome pair out of the seven pairs in three species, in L. hirsutus L., L. nissolia L. and L. incospicuus L., and two chromosome pairs in five species, in L. paranensis Burkart, L. odoratus L., L. amphicarpos L., L. gorgoni Parl. and L. articulatus L., while it could discriminate three chromosome pairs in L. sphaericus Retz. these results could contribute into the physical genome mapping of Lathyrus species and the evolution of rDNA patterns by FISH in the coming studies in future.


1987 ◽  
Vol 11 (6-7) ◽  
pp. 571-573 ◽  
Author(s):  
S?awomir Bartoszewski ◽  
Piotr Borsuk ◽  
Izabela Kern ◽  
Ewa Bartnik

Gene ◽  
1994 ◽  
Vol 142 (2) ◽  
pp. 291-295 ◽  
Author(s):  
Charlotte Hallenberg ◽  
Jens <SNM> Nederby Nielsen ◽  
Sune Frederiksen
Keyword(s):  
5S Rrna ◽  

1989 ◽  
Vol 9 (10) ◽  
pp. 4416-4421
Author(s):  
W S Grayburn ◽  
E U Selker

5S rRNA genes of Neurospora crassa are generally dispersed in the genome and are unmethylated. The xi-eta region of Oak Ridge strains represents an informative exception. Most of the cytosines in this region, which consists of a diverged tandem duplication of a 0.8-kilobase-pair segment including a 5S rRNA gene, appear to be methylated (E. U. Selker and J. N. Stevens, Proc. Natl. Acad. Sci. USA 82:8114-8118, 1985). Previous work demonstrated that the xi-eta region functions as a portable signal for de novo DNA methylation (E. U. Selker and J. N. Stevens, Mol. Cell. Biol. 7:1032-1038, 1987; E. U. Selker, B. C. Jensen, and G. A. Richardson, Science 238:48-53, 1987). To identify the structural basis of this property, we have isolated and characterized an unmethylated allele of the xi-eta region from N. crassa Abbott 4. The Abbott 4 allele includes a single 5S rRNA gene, theta, which is different from all previously identified Neurospora 5S rRNA genes. Sequence analysis suggests that the xi-eta region arose from the theta region by duplication of a 794-base-pair segment followed by 267 G.C to A.T mutations in the duplicated DNA. The distribution of these mutations is not random. We propose that the RIP process of N. crassa (E. U. Selker, E. B. Cambareri, B. C. Jensen, and K. R. Haack, Cell 51:741-752, 1987; E. U. Selker, and P. W. Garrett, Proc. Natl. Acad. Sci. USA 85:6870-6874, 1988; E. B. Cambareri, B. C. Jensen, E. Schabtach, and E. U. Selker, Science 244:1571-1575, 1989) is responsible for the numerous transition mutations and DNA methylation in the xi-eta region. A long homopurine-homopyrimidine stretch immediately following the duplicated segment is 9 base pairs longer in the Oak Ridge allele than in the Abbott 4 allele. Triplex DNA, known to occur in homopurine-homopyrimidine sequences, may have mediated the tandem duplication.


1993 ◽  
Vol 13 (5) ◽  
pp. 2835-2845
Author(s):  
M Deshmukh ◽  
Y F Tsay ◽  
A G Paulovich ◽  
J L Woolford

Ribosomal protein L1 from Saccharomyces cerevisiae binds 5S rRNA and can be released from intact 60S ribosomal subunits as an L1-5S ribonucleoprotein (RNP) particle. To understand the nature of the interaction between L1 and 5S rRNA and to assess the role of L1 in ribosome assembly and function, we cloned the RPL1 gene encoding L1. We have shown that RPL1 is an essential single-copy gene. A conditional null mutant in which the only copy of RPL1 is under control of the repressible GAL1 promoter was constructed. Depletion of L1 causes instability of newly synthesized 5S rRNA in vivo. Cells depleted of L1 no longer assemble 60S ribosomal subunits, indicating that L1 is required for assembly of stable 60S ribosomal subunits but not 40S ribosomal subunits. An L1-5S RNP particle not associated with ribosomal particles was detected by coimmunoprecipitation of L1 and 5S rRNA. This pool of L1-5S RNP remained stable even upon cessation of 60S ribosomal subunit assembly by depletion of another ribosomal protein, L16. Preliminary results suggest that transcription of RPL1 is not autogenously regulated by L1.


2010 ◽  
Vol 21 (2) ◽  
pp. 254-265 ◽  
Author(s):  
Osamu Iwasaki ◽  
Atsunari Tanaka ◽  
Hideki Tanizawa ◽  
Shiv I.S. Grewal ◽  
Ken-ichi Noma

The eukaryotic genome is a complex three-dimensional entity residing in the nucleus. We present evidence that Pol III–transcribed genes such as tRNA and 5S rRNA genes can localize to centromeres and contribute to a global genome organization. Furthermore, we find that ectopic insertion of Pol III genes into a non-Pol III gene locus results in the centromeric localization of the locus. We show that the centromeric localization of Pol III genes is mediated by condensin, which interacts with the Pol III transcription machinery, and that transcription levels of the Pol III genes are negatively correlated with the centromeric localization of Pol III genes. This centromeric localization of Pol III genes initially observed in interphase becomes prominent during mitosis, when chromosomes are condensed. Remarkably, defective mitotic chromosome condensation by a condensin mutation, cut3-477, which reduces the centromeric localization of Pol III genes, is suppressed by a mutation in the sfc3 gene encoding the Pol III transcription factor TFIIIC subunit, sfc3-1. The sfc3-1 mutation promotes the centromeric localization of Pol III genes. Our study suggests there are functional links between the process of the centromeric localization of dispersed Pol III genes, their transcription, and the assembly of condensed mitotic chromosomes.


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