Pcyt1b, encoding CTP:phosphocholine cytidylyltransferase β (CCTβ), is a key gene in the Kennedy pathway, which is crucial for phosphatidylcholine (PtdCho) biosynthesis [2,3]. PtdCho is essential for cell membrane structure and various cellular functions, making Pcyt1b's role in this pathway of great biological importance. Mouse models have been valuable for studying its functions.

In mouse studies, gonadal dysfunction in the CCTβ2 knockout mouse indicates a role for this protein in ovary maturation and sperm production [2]. Also, p53 drives the Kennedy pathway via Pcyt1B. Loss of p53 leads to dysregulation of choline metabolism as cells lacking p53 fail to respond to choline depletion, resulting in hepatic steatosis and tumorigenesis, and these effects could be reversed by enforcing Pcyt1B expression [1].

In conclusion, Pcyt1b is vital for phosphatidylcholine biosynthesis through the Kennedy pathway. Studies using gene knockout mouse models have revealed its role in processes like gonadal function and in preventing hepatic steatosis and tumorigenesis associated with choline metabolism dysregulation. These findings contribute to understanding the biological functions of Pcyt1b and its implications in disease, especially in liver-related diseases and tumorigenesis.