Related Experiment Video
Updated: Aug 14, 2026
11:42
Sample Preparation and Analysis of RNASeq-based Gene Expression Data from Zebrafish
Published on: October 27, 2017
Qa-region class I gene expression: identification of a second class I gene, Q9, encoding a Qa-2 polypeptide
M J Soloski1, L Hood, I Stroynowski
1Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Summary
Quantitative variation in mouse Qa-2 antigen expression is linked to gene dosage and allele-specific differences. These factors influence cell-surface expression levels, explaining strain-specific variations in Qa-2 antigen.
Area of Science:
- Immunogenetics
- Molecular immunology
- Histocompatibility antigens
Background:
- Tissue-specific class I antigen Qa-2 exhibits quantitative variation across mouse strains.
- The class I gene Q7 encodes a protein product biochemically similar to the lymphocyte-bound Qa-2 molecule.
Purpose of the Study:
- To identify additional class I genes in the Qa-2 subregion.
- To investigate the molecular basis for quantitative variation in Qa-2 antigen expression.
Main Methods:
- Gene transfection into cell lines.
- Biochemical analysis of encoded polypeptides.
- Quantitative assessment of cell-surface antigen expression.
Main Results:
- A second Qa-2 subregion class I gene, Q9, was identified in H-2b mice, encoding a polypeptide similar to Q7 and Qa-2.
- Allelic forms of the Q7 gene from different mouse strains (C57BL/10 and BALB/C) resulted in quantitative differences in cell-surface expression.
Conclusions:
- Gene dosage and allele-specific variations in cell-surface expression contribute to strain-specific differences in Qa-2 antigen levels.
- The Q7 and Q9 genes are implicated in the regulation of Qa-2 expression.
Related Concept Videos
01:58Cell Specific Gene Expression
Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with...
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...
02:32Exon 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...
02:11Reporter Genes
Reporter genes are a type of protein-coding gene that are often tagged to a gene of interest. Once inside a target cell, reporter genes usually produce visually identifiable characteristics like fluorescence and luminescence when expressed along with the gene of interest. Thus, reporter genes “report” the presence or absence of genes of interest in an organism, determine the gene expression pattern, or track the physical location of a DNA segment or protein in the cell.
Commonly used reporter...
Commonly used reporter...
02:24Ribosome Profiling
Ribosome profiling or ribo-sequencing is a deep sequencing technique that produces a snapshot of active translation in a cell. It selectively sequences the mRNAs protected by ribosomes to get an insight into a cell’s translation landscape at any given point in time.
Applications of ribosome profiling
Ribosome profiling has many applications, including in vivo monitoring of translation inside a particular organ or tissue type and quantifying new protein synthesis levels.
The technique helps...
Applications of ribosome profiling
Ribosome profiling has many applications, including in vivo monitoring of translation inside a particular organ or tissue type and quantifying new protein synthesis levels.
The technique helps...
01:28Gene Regulation in Microbial Communities: Quorum Sensing
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...