What happens during rna splicing m?

Answer 1

Gene splicing means cutting of gene in fragments and rejoining them according to need There are two phenomenon by which gene splicing occur one is natural i.e. post transcriptional modification and other is artifically or by chemical agent used generally in recombinant technology

POST TRANSCRIPTIONAL MODIFICATION: Gene splicing is a post-transcriptional modification in which a single gene can code for multiple proteins. Gene Splicing is done in eukaryotes, prior to mRNA translation, by the differential inclusion or exclusion of regions of pre-mRNA. Gene splicing is an important source of protein diversity. During a typical gene splicing event, the pre-mRNA transcribed from one gene can lead to different mature mRNA molecules that generate multiple functional proteins. Thus, gene splicing enables a single gene to increase its coding capacity, allowing the synthesis of protein isoforms that are structurally and functionally distinct. Gene splicing is observed in high proportion of genes. In human cells, about 40-60% of the genes are known to exhibit alternative splicing.

Gene Splicing Mechanism

There are several types of common gene splicing events. These are the events that can simultaneously occur in the genes after the mRNA is formed from the transcription step of the central dogma of molecular Biology.

Exon Skipping: This is the most common known gene splicing mechanism in which exon(s) are included or excluded from the final gene transcript leading to extended or shortened mRNA variants. The exons are the coding regions of a gene and are responsible for producing proteins that are utilized in various cell types for a number of functions.

Intron Retention: An event in which an intron is retained in the final transcript. In humans 2-5 % of the genes have been reported to retain introns. The gene splicing mechanism retains the non-coding (junk) portions of the gene and leads to a demornity in the protein structure and functionality.

Alternative 3' splice site and 5' splice site: Alternative gene splicing includes joining of different 5' and 3' splice site. In this kind of gene splicing, two or more alternative 5' splice site compete for joining to two or more alternate 3' splice site.

A gene-sized fragment of DNA is isolated from another organism. The bases of the fragment are spliced (joined) to the bases of the molecule by using a chemical called ligase.

Answer 2

Enzymes cut introns out of an mRNA strand. <--- Gradpoint/NovaNet

Answer 3

Enzymes cut introns out of an mRNA strand.