Related Experiment Video
Updated: Aug 6, 2026
09:37
An Integrated Approach for Microprotein Identification and Sequence Analysis
Published on: July 12, 2022
Diversity in isochore structure among cold-blooded vertebrates based on GC content of coding and non-coding sequences
Gloria G Fortes1, Carmen Bouza, Paulino Martínez
1Departamento de Genética, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain.
Genetica
|August 10, 2006
Summary
Genomic analysis reveals that cold-blooded vertebrates, including fish, amphibians, and reptiles, exhibit GC-rich coding sequences (CDS). Introns are GC-poorer than their corresponding CDS, with significant positive correlations observed between GC3 and intron GC content.
Area of Science:
- Genomics
- Comparative Genomics
- Bioinformatics
Background:
- Vertebrate genomes exhibit diverse compositional structures.
- Understanding genome composition is crucial for evolutionary and functional insights.
- Previous studies have explored nucleotide distributions in various species.
Purpose of the Study:
- To analyze the compositional structure of coding and non-coding regions in cold-blooded vertebrate genomes.
- To investigate the relationship between GC content in coding sequences (CDS) and introns.
- To compare genomic compositional patterns across fish, amphibians, and reptiles.
Main Methods:
- Analysis of genetic sequences, including coding (exons) and non-coding (introns) regions.
- Calculation of nucleotide distributions, specifically GC content at the third codon position (GC3).
- Examination of the correlation between GC content of CDS and their corresponding introns (GCI) in fish, amphibians, and reptiles.
Main Results:
- GC3-rich coding sequences were identified in fish, amphibians, and reptiles.
- High diversity in compositional patterns was observed among different orders within these vertebrate groups.
- Significant positive correlations were confirmed between GC3 and GCI.
- Introns were found to be poorer in GC than their corresponding CDS, with a larger difference than observed in the human genome.
Conclusions:
- Cold-blooded vertebrates display distinct genomic compositional patterns, characterized by GC-rich coding sequences.
- The observed GC richness in coding sequences, compared to introns, may help reconcile discrepancies between sequence analysis and ultracentrifugation studies.
- Further research with more extensive sequence data is needed for definitive conclusions.
Related Concept Videos
02:51Multi-species Conserved Sequences
Next-generation sequencing technologies have created large genomic databases of a variety of animals and plants. Ever since the human genome project was completed, scientists studied the genome of primates, mammals, and other phylogenetically distant living beings. Such large-scale studies have provided new insights into the evolutionary relationship between organisms.
Although the genome of each species varies greatly from each other, a few sequences are highly conserved. Such conserved DNA...
Although the genome of each species varies greatly from each other, a few sequences are highly conserved. Such conserved DNA...
02:02Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...
02:02Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...
00:58Genomic DNA in Eukaryotes
Eukaryotes have large genomes compared to prokaryotes. To fit their genomes into a cell, eukaryotic DNA is packaged extraordinarily tightly inside the nucleus. To achieve this, DNA is tightly wound around proteins called histones, which are packaged into nucleosomes that are joined by linker DNA and coil into chromatin fibers. Additional fibrous proteins further compact the chromatin, which is recognizable as chromosomes during certain phases of cell division.
01:28Prokaryotic Gene Structure and Organization
Prokaryotic genomes exhibit a streamlined organization of coding and non-coding regions essential for gene expression and protein synthesis. While coding regions contain the genetic instructions for proteins or functional RNAs, non-coding regions regulate the precise transcription and translation of these genes.Coding Regions: Proteins and RNAsThe primary coding regions, known as structural genes, include sequences transcribed into messenger RNA (mRNA) and ultimately translated into...
02:54Evolutionary Relationships through Genome Comparisons
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...