Related Experiment Video
Updated: Aug 7, 2026

Expression of Fluorescent Proteins in Branchiostoma lanceolatum by mRNA Injection into Unfertilized Oocytes
Published on: January 12, 2015
The Mnx homeobox gene class defined by HB9, MNR2 and amphioxus AmphiMnx
D E Ferrier1, N M Brooke, G Panopoulou
1School of Animal and Microbial Sciences, The University of Reading, Whiteknights, PO Box 228, Reading, RG6 6AJ, UK.
Abstract:
The HB9 homeobox gene has been cloned from several vertebrates and is implicated in motor neuron differentiation. In the chick, a related gene, MNR2, acts upstream of HB9 in this process. Here we report an amphioxus homologue of these genes and show that it diverged before the gene duplication yielding HB9 and MNR2. AmphiMnx RNA is detected in two irregular punctate stripes along the developing neural tube, comparable to the distribution of 'dorsal compartment' motor neurons, and also in dorsal endoderm and posterior mesoderm. We propose a new homeobox class, Mnx, to include AmphiMnx, HB9, MNR2 and their Drosophila and echinoderm orthologues; we suggest that vertebrate HB9 is renamed Mnx1 and MNR2 be renamed Mnx2.
Related Concept Videos
Position-effect Variegation
Euchromatin
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...
Master Transcription Regulators
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Hedgehog Signaling Pathway
Heterochromatin
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...

