abi1b notes

Setup and provenance

• Fetched with just fetch-gene on A0A286YAJ7 (TrEMBL, RefSeq XP_005171233.1, "isoform X1",
  507 aa; secondary accession A0A8M2BIW1); 8 GOA rows (5 IBA, 3 IEA), none with a PMID.
  ZFIN ZDB-GENE-060929-1182, Ensembl ENSDARG00000062991, chromosome 2.
• Deep research unavailable: Edison returned 402 Payment Required and the OpenAI key is
  invalid. Literature searched by hand via Europe PMC (same searches as abi1a; see
  genes/DANRE/abi1a/abi1a-notes.md).
• DANRE_DUPLICATION batch 3 (random draw 7, seed 20260928); paralog abi1a.

Zebrafish literature

No study of abi1b function. The only mention with a claim is a speculation, in a paper that
knocked down the paralog abi1a
PMID:32368696.
It was not tested.

Mammalian ABI1

See abi1a notes. Core points: WAVE-complex assembly subunit
PMID:15048123;
mouse knockout lethal at mid-gestation with heart and brain defects
PMID:21482783.

Own analyses

Shared pair analysis in genes/DANRE/abi1a/abi1a-bioinformatics/ (RESULTS.md).
- abi1b is 77.5% identical to human ABI1 (abi1a 81.6%); WAVE-binding N-terminus 91.9%,
coiled coil 100%, SH3 91.7% identical to human; divergence sits in the disordered linker.
- 13-residue N-terminal extension in the predicted isoform X1 (not verified by cDNA here).
- Not significantly faster-evolving than abi1a (gar relative-rate test).
- abi1b is the maternal/cleavage-stage copy (peak 28 TPM at 128-cell), 3-7 TPM after
gastrulation; Bgee calls limited to early embryo, retina, brain, ovary, bone.

Curation decisions

Same actions as abi1a for all 8 family-level rows (the protein and the IBA nodes are shared).
No NEW terms.