Mouse quaking is caused by a recessive dysmyelination mutation (qk), which appears to in...

Mouse quaking is caused by a recessive dysmyelination mutation (qk), which appears to involve defects in alternative splicing of an evolutionarily conserved signal transduction protein. Homozygotes (qk/qk) suffer tremors during exertion. Mature mice may experience seizures and remain motionless for many seconds. Below is a figure that describes the splicing patterns in various genotypes of quaking and normal mice. Portions of brain MAG (myelin-associated glycoprotein) RNA (in-cluding exons 11, 12, and 13) from young (14-day) and adult (2-month) mice are represented. The relative concentration of each RNA is indicated in the gel diagram below. (Figure and data are modified from Wu, J., et al. 2002. Proc. Natl. Acad. Sci. 99: 4233-4238.)

Given this information, describe the alternative splicing pat-terns with regards to exons included/excluded as a function of age and genotype.