High impact information on hoxb1b

• We have used a morpholino-based knockdown approach to investigate the functions of a pair of zebrafish Hox gene duplicates, hoxb1a and hoxb1b, which are expressed during development of the hindbrain [1].
• When the posterior neural gene hoxb1b is expressed during gastrulation, it shows a strikingly complementary pattern to cyp26 [2].
• By contrast, zebrafish hoxb1b, like mouse Hoxa1, is required for proper segmental organization of rhombomere 4 and the posterior hindbrain [1].
• We show that exogenously applied retinoic acid causes the ectopic accumulation of Hoxa-1 message during gastrulation in the hypoblast in the head region [3].
• Ectopic expression of Hoxa-1 in the zebrafish alters the fate of the mandibular arch neural crest and phenocopies a retinoic acid-induced phenotype [3].

Biological context of hoxb1b

• In this study, we show that the phenotype induced by exogenous retinoic acid in the zebrafish can also be generated by the overexpression of Hoxa-1 following injection of synthetic RNA into the fertilised egg [3].
• Molecular evolution of duplicated ray finned fish HoxA clusters: increased synonymous substitution rate and asymmetrical co-divergence of coding and non-coding sequences [4].
• Comparison of the striped bass HoxA cluster paralog group 2 (PG2) genes to their orthologs and trans-orthologs shows that the striped bass hoxa2a gene expression pattern is similar to the overall expression pattern described for the hoxa2 genes in the lobe-finned fish lineage and for the hoxa2b gene from zebrafish [5].

Anatomical context of hoxb1b

• Zebrafish fgf3 is expressed in the correct place (dorsolateral margin) and at the correct time (late blastula to early gastrula stages), the same point that the most precocious posterior neural marker, hoxb1b, is first activated [6].

Other interactions of hoxb1b

• It effectively suppressed the anterior neural marker, otx2, but not the posterior marker, hoxb1b [6].
• The observed temporal and spatial distributions of zebrafish hoxa1a mRNA differ greatly from the expression patterns of zebrafish hoxb1a and hoxb1b paralagous genes [7].

References