F,G) Immunocytochemistry of DIV4 primary hippocampal neurons from wild type, Ttll1-/- and Ttll7‑/- mice. Microtubules in Ttll1-/- cells have reduced levels of polyE signal, indicative of lower α-tubulin polyglutamylation (F), Ttll7‑/- neurons are specifically reduced in β‑monoE reactivity, indicating the lack of β‑tubulin glutamylation (G). 