W/ Sara Rubin & Wilson Gomarga in Len Zon’s lab, we also profiled thymi from zebrafish. Remarkably, zebrafish possess mimetic cells analogous to mammals despite >400M years of divergence. They also have fun fish-specific mimetics like gill ionocytes that regulate ion balance in aquatic life.

We defined new human mimetic cells, including ones mirroring kidney β-intercalated cells, cochlear hair cells, and DRG sensory neurons. We also discovered FEZF2+ neuroendocrine cells, which may mechanistically explain prior work from Takaba et al suggesting a role for Fezf2 in thymic tolerance.

Humans have an amazingly diverse mimetic cell repertoire with many similarities to mice. Interestingly, though, representation of certain mimetics varied widely between species: for instance, muscle mimetics expanded 25x in humans vs mice, whereas tuft mimetics contracted 25x.

With the help of wonderful collaborators @bostonchildrens.bsky.social (Meena Nathan, Pedro del Nido & team), we isolated mimetic cells from human thymi resected during cardiac corrective surgery and analyzed their composition/profiles using bulk and scRNA-seq.