A protein-coding gene in a eukaryote has four exons and three introns in the following arrangement. Assuming that transcription begins at exon 1 and ends after exon 4, how many different proteins could be made by alternative splicing of the pre-mRNA from this gene?

Question

A protein-coding gene in a eukaryote has four exons and three introns in the following arrangement.  Assuming that transcription begins at exon 1 and ends after exon 4, how many different proteins could be made by alternative splicing of the pre-mRNA from this gene?

Quizplus · Accepted Answer

Alternative splicing allows for different combinations of exons to be included in the final mRNA, resulting in different protein isoforms being translated. In this case, there are four exons, meaning that there are potential combinations of 1, 2, 3, or all 4 exons that could be spliced together. Therefore, there are four possible alternatively spliced mRNA sequences, each encoding a different protein isoform.

A Protein-Coding Gene in a Eukaryote Has Four Exons and Three