Mice that are homozygous for the targeted null mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. When combined with the mutations Tyro3tm1Grl (Stock No. 007937) and Mertktm1Grl (Stock No. 011122), mice exhibit a lymphoproliferative disorder, autoimmunity, increased apoptosis in multiple tissues, blindness, abnormal spermatogenesis and reduced fertility (in females) or infertility (in males).
The TAM receptors (Tyro3, Axl, and Mertk) are a family of receptor tyrosine kinases whose ligands (Gas6 and Protein S) bind to phosphatidylserine on the surface of apoptotic cells and enveloped viruses. Axl is highly expressed by key cellular targets of ZIKA virus (ZIKV) - including human radial glial cells, astrocytes, endothelial cells and microglia in developing human cortex, and by progenitor cells in developing retina (Nowakowski et al. 2016 Cell Stem Cell 18:591), as well as in subtypes of trophoblasts (Tabata et al. 2016 Cell Host Microb. 20:155). Research in 2017 identifies a dual role of Axl during ZIKV infection of human glial cells (astrocytes and microglia) - promoting viral entry and modulating innate immune responses - and suggests Axl inhibition may represent a potential target for antiviral therapies (Meertens et al. 2017 Cell Rep. 18:324).
