I. Phantom: a multiplex CRISPR-Cas9 gRNA toolkit for efficient generation of fully unpigmented F0 zebrafish

A multiplex CRISPR-Cas9 gRNA toolkit simultaneously targeting three major zebrafish pigment types generates fully unpigmented “phantom” F0 larvae with low mortality.

• Why it matters: Late-stage zebrafish imaging is hindered by multiple pigments, and PTU only blocks melanin while affecting development; stacking recessive pigment mutations is also laborious.
• What they did: The study optimized a multiplex CRISPR-Cas9 gRNA set to target three major pigment types at once, aiming to minimize mortality while producing the new phantom phenotype.
• The result: Phantom zebrafish show complete absence of visible pigmentation in F0 larvae yet retain survival to adulthood and the ability to reproduce, enabling improved late-stage imaging.