Question

1.Describe the various mechanisms involved in the regulation gene transcription.

•RNAi

•Epigenetics

•Regulatory elements

can u tell me plzz in brief

Answer 1

The first thing is that you have talked about gene regulation in this question, but it has not been talked about in prokaryotic or eukaryotic.

I am taking about eukaryotic gene regulation:

Regulating Gene Expression: In eukaryotes, the expression of biologically energetic proteins can be controlled at several points as follows:

a: This is an important point of the rule of eukaryotic gene expression. Here, numerous factors such as promoters and enhancers alter the capability of RNA polymerase to transcribe the mRNA, therefore controlling the expression of the gene.

b: Adjustments such as polyadenylation, splicing, and capping of the pre-mRNA transcript in eukaryotes can main to unlike levels and patterns of gene expression. For example, different splicing patterns for a similar gene will produce biologically different proteins following translation.

c: RNA Transport: Afterwards post-transcriptional processing, the mature mRNA necessity be transported from the nucleus to the cytosol so that it can be decoded into a protein. This step is an important fact of the regulation of gene expression in eukaryotes.

d: Stability of mRNA

Eukaryotic mRNA differs in their stability and some unstable transcripts usually have sequences that bind to microRNA and reduces the stability of mRNA, resulting in down-regulation of the corresponding proteins.

Epigenetics: More than 30 years have passed since DNA methylation is known to affect genetic expression. The adding of a methyl group to the cytosine improper does not modify the primary DNA sequence and is therefore measured to be an epigenetic modification. DNA made of 147 base-pair nucleotides contains histone proteins in the form of octamer.

Epigenetic processes regulate gene transcriptions by modulating the frequency, rate, or level of gene expression in a mitotically or meiotically heritable method that does not involve a modification in the DNA sequence. Molecular analysis shows epigenetic changes comprise covalent modifications, such as methylation and acetylation, to DNA and histones. RNA interference has been concerned at the beginning of some epigenetic changes, for example, transcriptional silencing of transposons. Proteins that bind to the modified DNA and histones are then responsible for suppressing transcription and for keeping the epigenetic modifications through cell division. Throughout differentiation, designs of gene expression are recognized by polycomb complexes PRC1 and PRC2. PRC2 methylates histones and DNA to produce the initial marks of repression: trimethylated lysine-27 on histone H3 (H3K27me3) and 5-methylcytosine in DNA. PRC2, through its component EZH2 or, in about complexes, EZH1 trimethylates lysine-27 of histone H3. The H3K27me3 produced by PRC2 is certain by the Polycomb subunit of PRC1. PRC1 ubiquitinates histone H2A and maintains repression.

Name of Regulatory elements

i. Repressors

ii. Specificity factors

iii. promoter

iv. Silencers

v. Lactose

vi. lacZ

vii. lacY

viii. lacA.