Assume that a mutation affects the gene for each of the following eukaryotic RNA polymerases. Match each mutation with the possible effects from the list provided. More than one effect is possible for each mutation.

RNA Polymerase Mutation       Effect(s)
RNA pol I                                  _______________
RNA pol II                                 _______________
RNA pol III                                _______________
snRNA                                      _______________

Some tRNA is not synthesized.

Key Concepts

Eukaryotic RNA Polymerases

Eukaryotic cells contain three main types of RNA polymerases: RNA polymerase I (RNA pol I), RNA polymerase II (RNA pol II), and RNA polymerase III (RNA pol III). Each polymerase is responsible for transcribing different types of RNA; RNA pol I synthesizes rRNA, RNA pol II synthesizes mRNA and some snRNA, and RNA pol III synthesizes tRNA and other small RNAs. Understanding the specific functions of these polymerases is crucial for predicting the effects of mutations.

Mutations and Their Effects

Mutations are changes in the DNA sequence that can affect gene function. Depending on the type and location of the mutation, the effects can range from benign to detrimental, potentially leading to the loss of function of the encoded protein. In the context of RNA polymerases, mutations can disrupt the synthesis of specific RNA molecules, impacting cellular processes such as protein synthesis and gene regulation.

snRNA and tRNA Synthesis

Small nuclear RNA (snRNA) and transfer RNA (tRNA) are essential components of the cellular machinery. snRNA is involved in RNA splicing and processing, while tRNA is crucial for translating mRNA into proteins. A mutation affecting RNA pol II could lead to issues in snRNA synthesis, while a mutation in RNA pol III could result in insufficient tRNA production, both of which would disrupt normal cellular function.