Maternal Contribution of katnb1 Is Essential for Zebrafish Gastrulation

(A) Katanin p80 protein and gene structure is highly conserved between humans and zebrafish.

(B) TALENs targeting the genomic region surrounding the zebrafish katnb1 exon 6-intron 6 boundary create a series of mutant alleles. Reference sequence (top). Blue box, TALEN recognition sites; dash, deleted base pairs; red letters, inserted base pairs.

(C) Mutant alleles are predicted to alter protein structure by deletion of amino acids or early truncation of katanin p80 protein.

(D) Progeny of mutant females show a wide spectrum of phenotypes, ranging from early embryonic lethality and anencephaly to microcephaly.

(E) Maternal effect of katnb1 is observed in crosses of mutant females, compared with progeny arising from heterozygous carriers. Embryos developed normally until 70% epiboly.

See also Table S2 and Figure S3.

Sequences and characterization of zebrafish katnb1 mutant alleles.

(A) Multiple sequence alignment of the human, mouse and zebrafish Katnb1, showing a high level of conservation of the protein sequence between the species.

(B) Summary of identified TALEN-induced mutations in zebrafish katnb1. Genomic region surrounding the exon 6 - intron 6 boundary in zebrafish is highlighted. TALEN recognition sites are marked with blue boxes; exonic sequence (capital letters); intronic sequence (lowercase). Wild-type sequence is listed above and the sequences of identified alleles are detailed below; deleted base pairs (red dashes); inserted base pairs (red letters). The effect on the genomic sequence is summarized to the right of each sequence: - deletion; + insertion; presence (+) or absence (Δ) of the splice site; allele names; frequency of the allele in 288 fish analyzed.