Final answer:
The gene involved is the Ac gene, also known as the activator gene, in the Ac/Ds system. This system influences mosaicism in maize kernels, leading to the alteration in SCC and AK.
Step-by-step explanation:
The gene involved in the alteration in SCC (supplementary color cells) and AK (aleurone kernels) is the Ac gene, also known as the activator gene. The Ac/Ds system, consisting of the Ac gene and the Ds (Dissociator) gene, influences mosaicism in maize kernels.
In maize kernels, when some aleurone layer cells experience chromosome breakage at the Ds locus, the C' allele is inactivated. This leads to the creation of brown pigment spots or streaks in the kernel, surrounded by cells with an active C' allele.
McClintock's research revealed that the Ds gene is prone to unstable mutations and causes chromosomal instability in corn kernel color genetics.