Related Experiment Video
Updated: Aug 8, 2026
06:55
Transfection of a Molecular Clone of Naegleria gruberi rDNA into N. gruberi Trophozoites
Published on: June 21, 2024
Euglena gracilis Chloroplast DNA Codes for Polyadenylated RNA
1Department of Microbiology, University of Illinois, Urbana, Illinois 61801.
Plant Physiology
|November 1, 1979
Summary
Polyadenylated RNA in Euglena gracilis is primarily cytoplasmic, not chloroplast-derived. This research clarifies the localization and nature of polyadenylated RNA in this organism.
Area of Science:
- Molecular Biology
- RNA Biology
- Euglena gracilis Research
Background:
- Polyadenylated RNA plays crucial roles in eukaryotic gene expression.
- The presence and function of polyadenylated RNA in chloroplasts are not fully understood.
- Euglena gracilis offers a unique model for studying chloroplast biology.
Purpose of the Study:
- To investigate the presence and characteristics of polyadenylated RNA in Euglena gracilis.
- To determine the proportion of polyadenylated RNA in total cellular RNA and its polyadenylic acid content.
- To ascertain the origin and potential function of polyadenylated RNA in chloroplasts versus cytoplasm.
Main Methods:
- Isolation and quantification of polyadenylated RNA from Euglena gracilis.
- In vitro labeling of polyadenylated RNA with iodine-125 ((125)I).
- Hybridization studies using labeled polyadenylated RNA and chloroplast DNA.
- Analysis of RNA from chloroplast and cytoplasmic polyribosomes.
Main Results:
- Polyadenylated RNA constituted 2.1% of total cellular RNA in Euglena gracilis, with 6.2% polyadenylic acid.
- Labeled polyadenylated RNA hybridized to 7.7% of chloroplast DNA, reduced to 2.8% with excess chloroplast ribosomal RNA (rRNA).
- Polyadenylic acid was virtually absent (<0.1%) in mature chloroplast mRNA, while 2.0% of cytoplasmic polyribosome RNA was polyadenylated and did not hybridize to chloroplast DNA.
Conclusions:
- The majority of polyadenylated RNA in Euglena gracilis is cytoplasmic, not associated with chloroplasts.
- Chloroplast mRNA in Euglena gracilis appears to be largely non-polyadenylated.
- This suggests distinct regulatory mechanisms for RNA processing and function in Euglena gracilis chloroplasts and cytoplasm.
Related Concept Videos
01:15Diversity of Protists I
Excavata is a diverse group of protists that includes both chemoorganotrophic and phototrophic species, with some thriving in anaerobic environments. Among the key groups within Excavata are diplomonads and parabasalids, which are flagellated protists that lack mitochondria and chloroplasts. These microorganisms typically inhabit anoxic environments, such as the intestines of animals, where they exist either symbiotically or as parasites, relying on fermentation for energy production. Some...
02:53Ribosomal RNA Synthesis
Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
00:58Eukaryotic 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...
All three eukaryotic RNAPs require specific transcription factors, of which the...
00:58Eukaryotic 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...
All three eukaryotic RNAPs require specific transcription factors, of which the...
01:25The Central Dogma
Overview
01:20The Central Dogma
The central dogma explains the flow of genetic information from DNA nucleotides to the amino acid sequence of proteins.
RNA is the Missing Link Between DNA and Proteins
In the early 1900s, scientists discovered that DNA stores all the information needed for cellular functions and that proteins perform most of these functions. However, the mechanisms of converting genetic information into functional proteins remained unknown for many years. Initially, it was believed that a single gene is...
RNA is the Missing Link Between DNA and Proteins
In the early 1900s, scientists discovered that DNA stores all the information needed for cellular functions and that proteins perform most of these functions. However, the mechanisms of converting genetic information into functional proteins remained unknown for many years. Initially, it was believed that a single gene is...