Related Experiment Video
Updated: Jul 31, 2026
11:13
Using Mouse Oocytes to Assess Human Gene Function During Meiosis I
Published on: April 10, 2018
Non-coordinate expression of closely linked mouse casein genes
S George1, A Springbett, A J Clark
1Department of Veterinary Biochemistry, College of Veterinary and Animal Sciences, Mannuthy, Trichur, India. sisilamma@yahoo.com
Indian Journal of Biochemistry & Biophysics
|May 7, 2002
Summary
Mouse casein gene expression varies significantly during pregnancy and lactation. The epsilon casein gene is uniquely expressed only during lactation, unlike other casein genes.
Area of Science:
- Genetics
- Molecular Biology
- Biochemistry
Background:
- The five mouse casein genes (alpha, beta, gamma, epsilon, kappa) are located in close proximity on a 250 kb DNA fragment.
- Understanding the differential expression of these genes is crucial for comprehending milk production regulation.
Purpose of the Study:
- To analyze the expression levels of five mouse casein genes in the mammary gland during different reproductive stages (virgin, pregnant, lactating).
- To investigate the coordinated or non-coordinated expression patterns of these closely located genes.
Main Methods:
- Northern blot analysis was employed to quantify mRNA levels of the five casein genes.
- Expression was analyzed in mammary glands of mice at virgin, pregnant, and lactating stages.
Main Results:
- Alpha, beta, and gamma casein genes are expressed during both pregnancy and lactation, with varying mRNA levels by lactation onset.
- Epsilon casein gene expression is restricted to the lactation period.
- Kappa casein gene expression increases from mid-pregnancy but at a slower rate, reaching ~60% by day one of lactation.
Conclusions:
- Mouse casein genes exhibit a non-coordinate expression profile, particularly evident with the lactation-specific epsilon casein gene.
- Gene proximity does not guarantee coordinated expression, suggesting complex regulatory mechanisms control casein gene expression during mammary gland development and function.
Related Concept Videos
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
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...
02:51Multi-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...
02:11Reporter 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...
01:09Epistasis Analysis
Although Mendel chose seven unrelated traits in peas to study gene segregation, most traits involve multiple gene interactions that create a spectrum of phenotypes. When the interaction of various genes or alleles at different locations influences a phenotype, this is called epistasis. Epistasis often involves one gene masking or interfering with the expression of another (antagonistic epistasis). Epistasis often occurs when different genes are part of the same biochemical pathway. The...