Question

A researcher discovers a novel mouse gene called "SPIT." She shows that SPIT mRNA is expressed in the developing salivary glands of the mouse embryo. She wants to learn what the role of SPIT might be in salivary gland development, and decides to create a SPIT "knockout" mouse that is missing both normal alleles of the SPIT gene to find out what happens in its absence. What type of experiment is this?

a: Gain-of-function
b: Loss-of-function

Answer 1

A researcher creating a SPIT "knockout" mouse for studying gene function in salivary gland development is conducting a loss-of-function experiment, which falls under reverse genetics methodology.

Step-by-step explanation:

The experiment in which a researcher creates a SPIT "knockout" mouse to understand the role of the SPIT gene in salivary gland development is a loss-of-function experiment. This method is associated with the field of reverse genetics, where the function of a gene is determined by observing the effects of its absence. Gene targeting, which includes mutating or deleting genes, helps to reveal gene function by analyzing the resulting phenotypic changes. By creating a SPIT knockout mouse, the researcher can identify what developmental processes or structures are affected without the SPIT gene, thus determining its role in salivary gland development.