Zebrafish homologue irx1a is required for the differentiation of serotonergic neurons.
Serotonergic (5HT) neurons produce neurotransmitter serotonin, which modulates various neuronal circuits. The specification and differentiation of 5HT neurons require both extrinsic signals such as Shh and Fgf, as well as intrinsic transcription factors such as nkx2.2, mash1, phox2b, Gata2, and pet1. In this study, we show that iroquois homeodomain factor irx1a, but not irx1b, is expressed in the 5HT neurons. Knockdown of irx1a by antisense morpholino nucleotides reveals that it is a critical determinant for the differentiation of 5HT neurons in the hindbrain. However, irx1a morphants do not show a reduction of the progenitors of 5HT neurons. Hence, irx1a is not required for the initial specification but it is required for the complete differentiation of 5HT neurons.
Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong.
Chi Wa
CW
Cheng
Carol Hiu Mei
CH
Yan
Siu Wah
SW
Choy
Michelle Nga Yu
MN
Hui
Chi-Chung
CC
Hui
Shuk Han
SH
Cheng
D000165:Acridine Orange / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis; D015509:Developmental Biology / Q000379:methods; D005456:Fluorescent Dyes / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins / Q000378:metabolism / Q000502:physiology*; D017403:In Situ Hybridization; D008954:Models, Biological; D009474:Neurons / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology*; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000378:metabolism / Q000502:physiology*
D005456:Fluorescent Dyes; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins; D018377:Neurotransmitter Agents; D014157:Transcription Factors; D029961:Zebrafish Proteins; C501593:irx1a protein, zebrafish; C000715630:nkx2.2b protein, zebrafish; D012701:Serotonin; D000165:Acridine Orange