Related Experiment Video
Updated: May 12, 2026
08:13
RNA In situ Hybridization in Whole Mount Embryos and Cell Histology Adapted for Marine Elasmobranchs
Published on: April 12, 2013
Properties of sea urchin embryo messenger RNA containing and lacking poly(A)
Cell
|October 1, 1975
Summary
Messenger RNA (mRNA) with poly(A) tails ([+A]mRNA) and without ([ -A]mRNA) show similar turnover rates and unique DNA origins. However, [+A]mRNA is more frequently found on larger polysomes, suggesting higher ribosome loading.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Nonhistone messenger RNA (mRNA) exists in two main forms: polyadenylated ([+A]mRNA) and non-polyadenylated ([-A]mRNA).
- Understanding the distinct properties and functions of these mRNA populations is crucial for deciphering gene expression regulation.
Purpose of the Study:
- To characterize and compare the properties of [+A]mRNA and [-A]mRNA nonhistone species.
- To investigate the relationship between mRNA polyadenylation status, turnover rates, DNA origins, and polysome loading.
Main Methods:
- Analysis of mRNA turnover rates by monitoring entry and decay in the cytoplasm.
- Assessment of mRNA transcription origins using unique DNA sequence hybridization.
- Quantification of the ratio of [+A]mRNA to [-A]mRNA across different free polyribosome sizes.
Main Results:
- Both [+A]mRNA and [-A]mRNA exhibit comparable rates of cytoplasmic turnover.
- Each mRNA class is transcribed from unique DNA sequences, indicating distinct genetic origins.
- The proportion of [+A]mRNA relative to [-A]mRNA increases with larger polyribosome size.
- Despite similar average molecular weights, [+A]mRNA species are associated with higher ribosome densities on polysomes compared to [-A]mRNA.
Conclusions:
- Polyadenylation status does not significantly impact the turnover rate or DNA origin of nonhistone mRNAs.
- [+A]mRNA species demonstrate a tendency for greater ribosome occupancy on polysomes than [-A]mRNA species.
- These findings suggest differential translational efficiency or regulation based on the presence or absence of a poly(A) tail.
Related Concept Videos
01:23Types of RNA
Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
02:01pre-mRNA Processing
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 to it (7-Methyl guanosine). This 5’ cap helps the...
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 to it (7-Methyl guanosine). This 5’ cap helps the...
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,...
02:23RNA Editing
RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...
01:20Types of RNA
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in regulating gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA Performs Diverse...
RNA Performs Diverse...
01:35Pre-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 the cell...
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 the cell...