Gdf15 Conditional Knockout mouse models

As the most divergent member of the TGF-beta superfamily, the mouse ortholog of human GDF15, Gdf15, produces a circulating hormone that signals not through canonical type II receptors but through GFRAL, a GDNF-receptor-family protein restricted to the area postrema and nucleus tractus solitarius, using RET as its signaling coreceptor. Transcription is driven by the integrated stress response through ATF4 and CHOP, and by p53, which is why plasma levels track mitochondrial disease, metformin exposure, and tumor burden, and why the ligand produces anorexia, nausea-like behavior, and cachexia. Germline nulls are viable, so straight knockouts remain informative, but tissue-restricted conditional deletion is needed to assign hepatic, placental, or tumor sources of the circulating pool. Alternatively, hepatocyte-directed overexpression or humanized knockins allow direct testing of blocking antibodies and long-acting agonists. No close paralog substitutes for this ligand, so single-locus loss is interpretable, and pairing it with Gfral alleles cleanly separates ligand supply from central reception.

Tissue restricted knockout of Gdf15 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.