Related Experiment Video
Updated: Jul 23, 2026
08:51
Identification of Mouse and Human Antibody Repertoires by Next-Generation Sequencing
Published on: March 15, 2019
Polymorphisms of the human IFNG gene noncoding regions.
J H Bream1, M Carrington, S O'Toole
1Laboratory of Experimental Immunology, National Cancer Institute, Frederick, Maryland 21702-1201, USA.
Immunogenetics
|February 9, 2000
Summary
Researchers found the human Interferon gamma (IFN-gamma) gene promoter is invariant. However, they identified polymorphisms in introns and the 3' untranslated region (UTR), with one 3'UTR variant showing altered DNA-binding abilities, impacting HIV-1 research.
Area of Science:
- Immunology
- Genetics
- Virology
Background:
- Interferon gamma (IFN-gamma) is crucial for Th1 cell development and cellular immunity against intracellular pathogens like HIV-1.
- Genetic variations in the IFNG gene could influence immune responses and disease progression.
Purpose of the Study:
- To identify polymorphisms in the human IFNG gene and assess their functional impact.
- To investigate the association of IFNG gene variants with HIV-1 infection and AIDS progression.
Main Methods:
- Screening of genomic DNA from HIV-infected and healthy donors for IFNG gene polymorphisms using single-stranded conformational polymorphism.
- Electrophoretic mobility shift assays (EMSA) to evaluate DNA-binding abilities of identified variants.
- Cox proportional hazards model to analyze the association of a CA-repeat microsatellite with AIDS progression.
Main Results:
- The proximal promoter region (-777 to transcription start) of the IFNG gene was found to be invariant.
- Polymorphisms were identified in the first intron (poly-T tract insertion), third intron (three single base pair substitutions), and the 3' untranslated region (UTR).
- A 3'UTR variant demonstrated altered DNA-binding complex formation compared to the wild-type sequence, suggesting potential functional significance. No association was found between IFNG alleles and HIV-1 infection or AIDS progression.
Conclusions:
- The human IFNG gene possesses an invariant proximal promoter but contains multiple intronic variants and a potentially functional 3'UTR polymorphism.
- These genetic variations, particularly in the 3'UTR, may influence gene regulation and cellular responses, although no direct link to HIV-1 infection or AIDS progression was established in this study.
Related Concept Videos
02:28Leaky Scanning
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...
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...
02:32Exon Recombination
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Exon shuffling follows “splice frame rules.” Each exon has three reading...
02:26Comparing Copy Number Variations and SNPs
Sequencing of the human genome has opened up several best-kept secrets of the genome. Scientists have identified thousands of genome variations that exist within a population. These variations can be a single nucleotide or a larger chromosomal variation.
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
01:05Single Nucleotide Polymorphisms-SNPs
A single nucleotide polymorphism or SNP is a single nucleotide variation at a specific genomic position in a large population. It is the most prevalent type of sequence variation found in the human genome. Point mutations that occur in more than 1% of the population qualify as SNPs. These are present once every 1000 nucleotides on an average in the human genome. Replacement of a purine with another purine (A/G) or a pyrimidine with another pyrimidine (C/T) is known as a transition. In contrast,...
01:27Principles of Pharmacogenetics: Types of Genetic Variants
The human genome is over 99.9% identical between individuals, yet genetic differences exist at millions of bases. The human genome contains approximately 3 million variant positions per individual, many of which are heterozygous, contributing to genetic diversity and individual traits. Genetic variations include single-nucleotide polymorphisms (SNPs), insertions, deletions, and copy number variations (CNVs).SNPs, the most common variation, involve single-base changes in DNA. These can be...