TY - JOUR
T1 - Proneural gene requirement for hair cell differentiation in the zebrafish lateral line
AU - Sarrazin, Andres F.
AU - Villablanca, Eduardo J.
AU - Nuñez, Viviana A.
AU - Sandoval, Pablo C.
AU - Ghysen, Alain
AU - Allende, Miguel L.
N1 - Funding Information:
We thank Catalina Lafourcade and Florencio Espinoza for expert technical assistance and Christine Dambly-Chaudière and David Raible for critical comments on the manuscript. We thank the following for their kind gifts of probes and reagents and help with various protocols: Christine Dambly-Chaudière, Robert Cornell, Vladimir Korzh, Ajay Chitnis, Ariel Reyes, Julio Amigo, Dora Sapede and Fabien Soubiran. This work was supported by grants from ICM (P02-050), FONDECYT (1031003), ICGEB (CRP/CHI03-03c) to MA and ECOS/CONICYT (C03B01) to MA and AG, and by a fellowship from the Universidad de Chile (PG/UCH0012/2003) to AS.
PY - 2006/7/15
Y1 - 2006/7/15
N2 - The lateral line system comprises an array of mechanosensory organs, the neuromasts, distributed over the body surface. Each neuromast consists of a patch of mechanosensory hair cells surrounded by support cells. We show that, in the zebrafish, two proneural genes are essential for differentiation of the hair cells, neuroD (nrd) and atonal homolog 1 (ath1). Gene knockdown experiments demonstrate that loss of function of either gene, but not of the related proneural gene neurogenin1 (ngn1), abrogate the appearance of hair cell markers. This is in contrast to other sensory systems, such as the neurons of the lateral line ganglion, where nrd is regulated by ngn1 and not by ath1. Overexpression of ath1 can induce nrd, and the phenotype produced by loss of ath1 function can be partially rescued by injection of nrd mRNA. This supports the conclusion that the activation of nrd probably requires ath1 in the hair cell lineage, whereas in sensory neurons nrd activation requires ngn1. We propose that the emergence of two atonal homologs, ath1 and ngn1, allowed the cellular segregation of mechanoreception and signal transmission that were originally performed by a single cell type as found in insects.
AB - The lateral line system comprises an array of mechanosensory organs, the neuromasts, distributed over the body surface. Each neuromast consists of a patch of mechanosensory hair cells surrounded by support cells. We show that, in the zebrafish, two proneural genes are essential for differentiation of the hair cells, neuroD (nrd) and atonal homolog 1 (ath1). Gene knockdown experiments demonstrate that loss of function of either gene, but not of the related proneural gene neurogenin1 (ngn1), abrogate the appearance of hair cell markers. This is in contrast to other sensory systems, such as the neurons of the lateral line ganglion, where nrd is regulated by ngn1 and not by ath1. Overexpression of ath1 can induce nrd, and the phenotype produced by loss of ath1 function can be partially rescued by injection of nrd mRNA. This supports the conclusion that the activation of nrd probably requires ath1 in the hair cell lineage, whereas in sensory neurons nrd activation requires ngn1. We propose that the emergence of two atonal homologs, ath1 and ngn1, allowed the cellular segregation of mechanoreception and signal transmission that were originally performed by a single cell type as found in insects.
KW - Atonal homolog
KW - Hair cells
KW - Lateral line
KW - NeuroD
KW - Neuromasts
KW - Proneural genes
KW - bHLH
UR - http://www.scopus.com/inward/record.url?scp=33745225586&partnerID=8YFLogxK
U2 - 10.1016/j.ydbio.2006.03.037
DO - 10.1016/j.ydbio.2006.03.037
M3 - Article
C2 - 16678150
AN - SCOPUS:33745225586
VL - 295
SP - 534
EP - 545
JO - Developmental Biology
JF - Developmental Biology
SN - 0012-1606
IS - 2
ER -