What is Britton and Davidson model of regulation?
The Britten–Davidson model, also known as the gene-battery model, is a hypothesis for the regulation of protein synthesis in eukaryotes. The activator RNA then binds with a nearby receptor site, which stimulates the synthesis of mRNA at the structural gene.
Are battery of genes?
Together the set of producer genes, which is activated based on the activity of a specific sensor gene and its associated downstream regulators (i.e., the integrator gene and activator RNA), is defined as ‘battery’ of ‘genes’ (Table 1). Cellular signalling pathways and gene expression regulation.
How gene expression is regulated in eukaryotes?
Gene expression in eukaryotic cells is regulated by repressors as well as by transcriptional activators. Like their prokaryotic counterparts, eukaryotic repressors bind to specific DNA sequences and inhibit transcription. Other repressors compete with activators for binding to specific regulatory sequences.
What do you mean by regulation of gene expression describe the mechanism of gene regulation with the help of lac operon?
Regulation of the lac Operon The activity of the promoter that controls the expression of the lac operon is regulated by two different proteins. One of the proteins prevents the RNA polymerase from transcribing (negative control), the other enhances the binding of RNA polymerase to the promoter (positive control).
How do steroid hormones control gene expression?
The mechanism of action of steroid hormones involves their interaction with tissue-specific binding sites, and results in a precise modulation of gene expression. Both high-affinity receptors and secondary binding sites exist for steroid hormones in target tissues.
What is a gene battery?
Gene batteries are sets of coregulated genes with common cis-regulatory elements that define the differentiated state of a cell. The nature of gene batteries for individual neuronal cellular subtypes and their linked cis-regulatory elements is poorly defined.
What is the lac operon in E coli a classic example of?
The lac operon is a classic example an inducible operon. When lactose is present in the cell, it is converted to allolactose. Allolactose acts as an inducer, binding to the repressor and preventing the repressor from binding to the operator. This allows transcription of the structural genes.
What is lac operon explain with diagram?
The lactose or lac operon of Escherichia coli is a cluster of three structural genes encoding proteins involved in lactose metabolism and the sites on the DNA involved in the regulation of the operon. It was Jacob and Monod in 1961 who proposed the operon model for the regulation of transcription. …