A fundamental question in developmental neurobiology is how a common neurotransmitter is specified in different neuronal types?. We describe cell-specific regulation of the serotonergic phenotype by the C. elegans POU-transcription factor UNC-86. We show that unc-86 regulates particular aspects of the terminal neuronal identity in four classes of serotonergic neurons, but that the development of the ADF serotonergic neurons is regulated by an UNC-86-independent program. In the NSM neurons, the role of unc-86 is confined in late differentiation; the neurons are generated but do not express genes necessary for serotonergic neurotransmission. unc-86-null mutations affect the expression in NSM of tph-1, which encodes the serotonin synthetic enzyme tryptophan hydroxylase, and cat-1, which encodes a vesicular transporter that loads serotonin into synaptic vesicles, suggesting that unc-86 coordinately regulates serotonin synthesis and packaging. However, unc-86-null mutations do not impair the ability of NSM to reuptake serotonin released from the ADF serotonergic chemosensory neurons and this serotonin reuptake is sensitive to the serotonin reuptake block drugs imipramine and fluoxetine, demonstrating that serotonin synthesis and reuptake is regulated by distinct factors. The NSM neurons in unc-86-null mutants also display abnormal neurite outgrowth, suggesting a role of unc-86 in regulating this process as well.
The C. elegans POU-domain transcription factor UNC-86 regulates the tph-1 tryptophan hydroxylase gene and neurite outgrowth in specific serotonergic neurons
Ji Ying Sze, Shenyuan Zhang, Jie Li, Gary Ruvkun; The C. elegans POU-domain transcription factor UNC-86 regulates the tph-1 tryptophan hydroxylase gene and neurite outgrowth in specific serotonergic neurons. Development 15 August 2002; 129 (16): 3901–3911. doi: https://doi.org/10.1242/dev.129.16.3901
Download citation file:
Sign in
Client Account
Sign in via your institution
Sign in via ShibbolethAdvertisement
Cited by
Interviews with Biologists @ 100 conference speakers

Explore our interviews with keynote speakers from the Biologists @ 100 conference, hosted to celebrate our publisher’s 100th anniversary, where we discuss climate change and biodiversity with Hans-Otto Pörtner and Jane Francis, health and disease with Charles Swanton and emerging technologies with Manu Prakash and Jennifer Lippincott-Schwartz.
Call for papers – Lifelong Development: the Maintenance, Regeneration and Plasticity of Tissues

Development invites you to submit your latest research to our upcoming special issue – Lifelong Development: the Maintenance, Regeneration and Plasticity of Tissues. This issue will be coordinated by Guest Editors Meritxell Huch (Max Planck Institute of Molecular Cell Biology and Genetics, Germany) and Mansi Srivastava (Harvard University and Museum of Comparative Zoology, USA), working alongside our team of academic Editors. Submit your articles by 15 May 2025.
A case for broadening our view of mechanism in developmental biology

In this Perspective, B. Duygu Özpolat and colleagues survey researchers on their views on what it takes to infer mechanism in developmental biology. They examine what factors shape our idea of what we mean by ‘mechanism’ and suggest a path forward that embraces a broad outlook on the diversity of studies that advance knowledge in our field.
In preprints
Did you know that Development publishes perspectives on recent preprints? These articles help our readers navigate the ever-growing preprint literature. Together with our preprint highlights service, preLights, these perspectives help our readers navigate the ever-growing preprint literature. We welcome proposals for ‘In preprints’ articles, so please do get in touch if you’d like to contribute.
How to build a community site for developmental biologists

Our community site, the Node, has been serving the developmental and stem cell biology community for 15 years. In this post, our Community Manager, Joyce Yu, shares how the Node was born and describes how to build a community site from scratch.