Metamorphosis gene families in Pancrustacea

Reviewing the fly reference genes behind a convergent-evolution result

AI Gene Review · projects/PANCRUSTACEA_METAMORPHOSIS · 2026

Bottom line

  • Metamorphosis arose four times in Pancrustacea; a 2026 preprint finds each origin recruited different gene families converging on the same functions.
  • We reviewed every GO annotation on the 8 Drosophila reference genes the paper names: 183 rows plus 4 NEW.
  • 108 accepted, 24 modified, 1 removed. Propagated receptor terms on adhesion molecules and a ligand-less orphan NR were corrected; bare protein binding resolved to named partners.

Four independent origins

Why review the fly genes

  • Almost all functional knowledge for these families comes from Drosophila.
  • Any GO transfer to crustacean orthologues will start from these annotations.
  • Copy number, pleiotropy, rewiring and co-option mean fly function should not be assumed to transfer. So the fly annotations need to be right and focused first.
  • Named genes: kni, hairy (TFs) · klg, trn, caps, kek1 (adhesion/receptor) · krz, insc (signalling, asymmetric division)

Results across 8 genes

Gene Rows ACCEPT Non-core MODIFY REMOVE Other
kni 29 17 3 8 1
hairy 45 28 6 9 0 1 over, 1 undecided
klg 20 12 5 2 0 1 NEW
trn 7 2 3 1 0 1 NEW
caps 13 5 6 0 0 2 NEW
kek1 22 19 1 0 0 2 undecided
krz 21 8 12 1 0
insc 30 17 10 3 0

Receptor terms that did not fit

What a review row looks like

knirps: nucleus accepted; the IBA "nuclear receptor activity" modified to a DNA-binding repressor term, with the propagation failure recorded.

Other corrections

  • hairy: every protein binding IPI resolved via WITH/FROM to STUbL ligase, Groucho/CtBP corepressor, or TF binding (Ultrabithorax); membrane organization flagged as over-annotation.
  • knirps: protein binding IPIs → GO:0001222 transcription corepressor binding.
  • insc: establishment of mitotic spindle localization → orientation; two miscited references flagged.
  • krz: GPCR-binding adaptor core accepted; MAPK/Toll/Hedgehog/Notch attenuation kept non-core.

Status and next steps

  • ✅ 8/8 reference genes reviewed and validated.
  • ⬜ An ecdysteroid-biosynthesis-regulation module (not started).
  • ⬜ Optional: deadpan (dpn), mentioned but not an expanding family.
  • Open question: do fly imaginal-disc terms over-attribute insect-specific roles to crustacean orthologues?

Read more: projects/PANCRUSTACEA_METAMORPHOSIS.md · genes/DROME/<gene>/