Mosaic hoxb4a neuronal pleiotropism in zebrafish caudal hindbrain.
To better understand how individual genes and experience influence behavior, the role of a single homeotic unit, hoxb4a, was comprehensively analyzed in vivo by clonal and retrograde fluorescent labeling of caudal hindbrain neurons in a zebrafish enhancer-trap YFP line. A quantitative spatiotemporal neuronal atlas showed hoxb4a activity to be highly variable and mosaic in rhombomere 7-8 reticular, motoneuronal and precerebellar nuclei with expression decreasing differentially in all subgroups through juvenile stages. The extensive Hox mosaicism and widespread pleiotropism demonstrate that the same transcriptional protein plays a role in the development of circuits that drive behaviors from autonomic through motor function including cerebellar regulation. We propose that the continuous presence of hoxb4a positive neurons may provide a developmental plasticity for behavior-specific circuits to accommodate experience- and growth-related changes. Hence, the ubiquitous hoxb4a pleitropism and modularity likely offer an adaptable transcriptional element for circuit modification during both growth and evolution.
Ma
Leung-Hang
LH
Department of Physiology and Neuroscience, New York University Medical Center, New York, New York, United States of America.
Punnamoottil
Beena
B
Rinkwitz
Silke
S
Baker
Robert
R
D000818:Animals; D001369:Axons; D019521:Body Patterning; D005456:Fluorescent Dyes / Q000494:pharmacology; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000378:metabolism*; D017403:In Situ Hybridization; D018613:Microscopy, Confocal; D009474:Neurons / Q000378:metabolism; D012249:Rhombencephalon / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism / Q000473:pathology; D014158:Transcription, Genetic; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000378:metabolism*
D005456:Fluorescent Dyes; D018398:Homeodomain Proteins; C514262:Hoxb4a protein, zebrafish; D029961:Zebrafish Proteins