Question

What is an operon and what are the steps necessary to introduce it to human genome .how would you go about it where would you place it and what vector would you use ?

What are transpoons ? Where is it okay to find them ? And what are advantage and disadvantage to them

Answer 1

Operon is a cluster of coding sequences, which make up the group of coridnating genes and regulatory elements. An operon consists of two basic components: a regulatory elements , and protein coding sequences. The regulatory elements consists of promoter, inducer and enhancer elements.

If we want to introduce an operon in human genome, lot of modifications has to be carried out. The foremost thing we need is a promoter which works in eukaryotic system. Operons are present in the bacterial system and its promoters work in bacteria only. To make them work in human genome, we need human derived promters. We will need an enhnacer element which will help in inducing and increasing the expression of the promoter. The promoter should be kept under control of an inducer which will help to regulate the expression of the gene. The enhancer can be obtained from phage or virus genome. In order to transform the operon in genome, we need to use a vector which can deliver the components into human cell. A plasmid ,( bacterial artificial chromosome or pUC18) can be a good vector. We need to first engineed the enhancer and prmoter to the vector. The using the MCS of the plasmid, the gene of interst can be added onto the plasmid. Then this fusion plasmid is trnasformed into human cell either by gold nanoparticle or electroporation.
If we want to introduce it into the chromosomal DNA, then we can use homologous recombination to swap the operon with that of gene of interest. The flanking regions of the gene are added to the flanking areas of the operon. Then using recombinase enzyme which is introduced using another vector, the flanked regions can be swaped to introduce the operon into the chromosome.

Transposons are the DNA elements which can jump from one place in the genome to another. They are also called as Jumping genes. They occur in bacteria , in yeast and also in human genome. They make up to almost 50% of the human genom and nearly 90% of hte maize genome. Due to jumping and random nature of their insertion, they many a time cause deleterious mutations, may be silence an active gene or replace a gene, convert a gene into pseudogene...etc. However, on the positive side, the transposons, by virtue of jumping nature, they can create new mutations and thus can help in evolution. They also contribute to exon shuffling which results in diversitfied protein profile.