Related Experiment Video

Updated: Mar 6, 2026

Artificial RNA Polymerase II Elongation Complexes for Dissecting Co-transcriptional RNA Processing Events
10:59

Artificial RNA Polymerase II Elongation Complexes for Dissecting Co-transcriptional RNA Processing Events

Published on: May 13, 2019

10.2K

Sequence complexity of poly(A) RNA fromPhysarum polycephalum

Annette Baeckmann1, Helmut W Sauer1

  • 1Zoologisches Institut der Universität, Röntgenring 10, D-8700, Würzburg, Germany.

Wilhelm Roux'S Archives of Developmental Biology
|March 18, 2017
PubMed

Insights

Physarum poly(A) RNA analysis reveals similar polypeptide patterns across cell cycle phases and starvation. Gene expression changes significantly, with substantial RNA sequence reduction during starvation.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Polyadenylated (poly(A)) RNA plays a crucial role in gene expression regulation.
  • Understanding mRNA sequence dynamics during different cellular states is vital for comprehending cellular processes.

Purpose of the Study:

  • To investigate the complexity and changes in mRNA populations during the cell cycle (S and G2 phases) and starvation in Physarum macroplasmodia.
  • To quantify the proportion of the genome transcribed and the abundance of specific RNA species under different conditions.

Main Methods:

  • In vitro translation and fluorography to analyze polypeptide patterns from poly(A) RNA.
  • DNA reassociation kinetics (Cot) for isolating single-copy DNA.
  • Saturation hybridization of labeled DNA with poly(A) RNA.
  • Homologous and heterologous cDNA/poly(A) RNA hybridization reactions (Rot) to assess transcriptional complexity and sequence overlap.

Main Results:

  • Similar polypeptide patterns were observed from poly(A) RNA of S, G2, and starved Physarum macroplasmodia.
  • 23% of the genome is transcribed during growth and 17% during starvation, based on DNA/poly(A) RNA hybridization.
  • 22-28% of the genome is transcribed during growth and 12% during starvation, with 50-80 RNA species present at ~1,000 copies/nucleus.
  • Up to 25,000 RNA species (1-5 copies/nucleus) during growth and ~15,000 during starvation were estimated.
  • RNA sequences in S and G2 phases are similar, with higher abundance in G2. About 25% of growth-related RNA sequences are undetectable during starvation.

Conclusions:

  • Physarum exhibits significant modulation of gene expression between growth and starvation states.
  • While overall polypeptide patterns remain similar, substantial changes occur in the abundance and diversity of mRNA sequences.
  • Cell cycle progression involves dynamic regulation of RNA populations, with distinct differences observed between growth and starvation conditions.
Keywords:
DevelopmentPhysarumRNASequence complexity

More Related Videos

Author Spotlight: Exploring the Frontier of mRNA Research with Poly A Tail Analysis Techniques08:16

Author Spotlight: Exploring the Frontier of mRNA Research with Poly A Tail Analysis Techniques

Published on: January 12, 2024

1.5K
An Oligonucleotide-based Tandem RNA Isolation Procedure to Recover Eukaryotic mRNA-Protein Complexes09:45

An Oligonucleotide-based Tandem RNA Isolation Procedure to Recover Eukaryotic mRNA-Protein Complexes

Published on: August 18, 2018

11.7K

Related Concept Videos

Eukaryotic RNA Polymerases00:58

Eukaryotic RNA Polymerases

RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
27.4K
Eukaryotic RNA Polymerases00:58

Eukaryotic RNA Polymerases

9.7K
Bacterial RNA Polymerase00:43

Bacterial RNA Polymerase

Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
33.2K
Pre-mRNA Processing: Modification of pre-mRNA Ends01:35

Pre-mRNA Processing: Modification of pre-mRNA Ends

In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
16.2K
piRNA - Piwi-interacting RNAs02:57

piRNA - Piwi-interacting RNAs

PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
7.8K
RNA Structure01:19

RNA Structure

The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three...
8.0K