The animated figure below shows formation of the lariat during mRNA splicing. Consider this figure as you answer the following question. A The animated figure shows the normal splicing process used to remove introns from eukaryotic mRNA. The XPC gene codes for aprotein that functions in DNA repair. This gene contains 16 exons with the first 5 shown in Figure A. Defects in splicing can lead tohuman disease. Individuals with xeroderma pigmentosum have high levels of skin cancer due to defects in the nucleotide excision DNArepair process because of nonfunctional XPC protein. DNA damage caused by exposure to the UV rays in sunlight is not repairedleading to mutations in critical genes that control the cell cycle leading to high rates of skin cancer. Several members of a particularfamily were found to have a mutation in intron 3 of the XPC DNA repair gene (Figure B). The mutation disrupted normal splicing leadingto skipping of exon 4 and little to no functional XPC protein in their cells.(A)(B)exon 1exon 1exon 2exon 3exon 2exon 4SPLICING4functional XPC proteinintron 3 mutationexon 3SPLICING35mRNAmRNAexon Sexon 5Choose one:O A. Mutation of exon junction siteO B. Mutation of lariat branch pointO C. Mutation of 5' splice siteO D. Mutation of 3' splice sitepre-mRNA transcriptpre-mRNA transcriptnonfunctional XPC proteinFigure A. The pre-mRNA transcript spanning the first 5 exons of the XPC gene is shown with introns (yellow) between the exons.Splicing removes the introns, generating the functional mRNAFigure B. The intron 3 mutation leads to skipping of exon 4 and nonfunctional XPC protein.Studying the gene further in vitro showed that the U2 snRNP did not bind to the mutated RNA from affected patients. Which of thefollowing mutations could explain the abnormal splicing of the mutated XPC gene?

Name: The animated figure below shows formation of the lariat during mRNA sp
Uploaded: 2024-03-20T06:42:41.000Z
Channel: Bartleby
Description: The animated figure below shows formation of the lariat during mRNA splicing. Consider this figure as you answer the following question. A The animated figure shows the normal splicing process used to remove introns from eukaryotic mRNA. The XPC gene