Ret Conditional Knockout mouse models

Rearranged during transfection kinase, encoded by mouse Ret and orthologous to human RET, is a single-pass receptor tyrosine kinase with four cadherin-like domains and a calcium-binding cysteine-rich region that is activated by GDNF family ligands presented through GFRA1 to GFRA4 co-receptors, triggering phospholipase C gamma, RAS-ERK, and PI3K-AKT signaling essential for enteric neural crest colonization and kidney branching morphogenesis. The mutational logic is strikingly bidirectional: cysteine-rich domain substitutions such as C634R cause multiple endocrine neoplasia type 2A, activation loop M918T causes MEN2B with aggressive medullary thyroid carcinoma, CCDC6-RET and KIF5B-RET fusions drive papillary thyroid and lung adenocarcinoma, and loss-of-function alleles cause Hirschsprung disease. Germline nulls die perinatally with renal agenesis and intestinal aganglionosis, so conditional nulls suit developmental questions while precise hotspot or fusion knockins model tumorigenesis and selpercatinib or pralsetinib response, including resistance substitutions. Match allele to endpoint and use lineage-restricted Cre drivers for thyroid or pulmonary readouts.

Tissue restricted knockout of Ret keeps wild type function everywhere else. Breeding is often more robust, and the setup mirrors patient biology where mutations arise in a subset of cells.