Question

A bacterial cell was transformed with a recombinant DNA molecule that was generated using a human gene. However, the transformed cells did not produce the desired protein. Reasons could be:

Answer 1

Human gene may have intron which bacteria cannot process:

Eukaryotic genes do not function properly when transferred into bacterial cells because introns (non-coding sequences) are present in the eukaryotic genes. However, bacterial genes do not have introns.

In eukaryotes, after transcription of the DNA strand into a RNA molecule, the intron sequences are spliced off to form functional mRNA molecules that can be translated into a polypeptide chain. Prokaryotes do not possess the machinery for splicing of introns. Hence, when a bacterial cell is transformed with recombinant DNA, which is generated using a human gene containing introns, the gene of interest is not expressed into desired functional proteins.

Amino acid codons for humans and bacteria are different:

Genetic code is universal. Almost all the codons are the same in humans and bacteria. Hence, this is not the possible option.

Human protein is formed but degraded by bacteria:

This is not an appropriate reason as the question states that the transformed bacteria did not produce the protein.