+1 Recommend
1 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Serotonin is required for pharyngeal arch morphogenesis in zebrafish

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          Serotonin (5-HT) is not only a neurotransmitter but also a mediator of developmental processes in vertebrates. In this study, we analyzed the importance of 5-HT during zebrafish development. The expression patterns of three zebrafish tryptophan hydroxylase isoforms (Tph1A, Tph1B, Tph2), the rate-limiting enzymes in 5-HT synthesis, were analyzed and compared to the appearance and distribution of 5-HT. 5-HT was found in the raphe nuclei correlating with tph2 expression and in the pineal gland correlating with tph1a and tph2 expressions. Tph2-deficient fish generated with antisense morpholino oligonucleotides exhibited morphogenesis defects during pharyngeal arch development. The correct specification of neural crest (NC) cells was not affected in tph2 morphants as shown by the expression of early markers, but the survival and differentiation of pharyngeal arch progenitor cells were impaired. An organizing role of 5-HT in pharyngeal arch morphogenesis was suggested by a highly regular pattern of 5-HT positive cells in this tissue. Moreover, the 5-HT2B receptor was expressed in the pharyngeal arches and its pharmacological inhibition also induced defects in pharyngeal arch morphogenesis. These results support an important role of Tph2-derived serotonin as a morphogenetic factor in the development of NC-derived tissues.

          Related collections

          Most cited references 59

          • Record: found
          • Abstract: found
          • Article: not found

          Stages of embryonic development of the zebrafish.

          We describe a series of stages for development of the embryo of the zebrafish, Danio (Brachydanio) rerio. We define seven broad periods of embryogenesis--the zygote, cleavage, blastula, gastrula, segmentation, pharyngula, and hatching periods. These divisions highlight the changing spectrum of major developmental processes that occur during the first 3 days after fertilization, and we review some of what is known about morphogenesis and other significant events that occur during each of the periods. Stages subdivide the periods. Stages are named, not numbered as in most other series, providing for flexibility and continued evolution of the staging series as we learn more about development in this species. The stages, and their names, are based on morphological features, generally readily identified by examination of the live embryo with the dissecting stereomicroscope. The descriptions also fully utilize the optical transparancy of the live embryo, which provides for visibility of even very deep structures when the embryo is examined with the compound microscope and Nomarski interference contrast illumination. Photomicrographs and composite camera lucida line drawings characterize the stages pictorially. Other figures chart the development of distinctive characters used as staging aid signposts.
            • Record: found
            • Abstract: found
            • Article: not found

            A gene regulatory network orchestrates neural crest formation.

            The neural crest is a multipotent, migratory cell population that is unique to vertebrate embryos and gives rise to many derivatives, ranging from the peripheral nervous system to the craniofacial skeleton and pigment cells. A multimodule gene regulatory network mediates the complex process of neural crest formation, which involves the early induction and maintenance of the precursor pool, emigration of the neural crest progenitors from the neural tube via an epithelial to mesenchymal transition, migration of progenitor cells along distinct pathways and overt differentiation into diverse cell types. Here, we review our current understanding of these processes and discuss the molecular players that are involved in the neural crest gene regulatory network.
              • Record: found
              • Abstract: found
              • Article: not found

              A transient placental source of serotonin for the fetal forebrain

              Serotonin (5-hydroxytryptamine; 5-HT) is thought to regulate neurodevelopmental processes through maternal-fetal interactions that have long-term mental health implications. Dogma states that beyond fetal 5-HT neurons, there are significant maternal contributions to fetal 5-HT during pregnancy 1,2 , but this has not been tested empirically. To examine putative central and peripheral sources of embryonic brain 5-HT, we used the Pet-1−/− mice in which most dorsal raphe (DR) neurons lack 5-HT 3 . Measures of 5-HT revealed previously unknown differences in accumulation between the fore- and hindbrain during early and late fetal stages, through an exogenous source of 5-HT. We show that this source is not of maternal origin. Using additional genetic strategies, a new technology for studying placental biology ex vivo, and direct manipulation of placental neosynthesis, we investigated the nature of this exogenous source and uncovered a placental 5-HT synthetic pathway from a maternal tryptophan precursor, in both mice and humans. This study reveals a new, direct role for placental metabolic pathways in modulating fetal brain development and implicates novel maternal-placental-fetal interactions that could underlie the pronounced impact of 5-HT on long-lasting mental health outcomes.

                Author and article information

                (View ORCID Profile)
                ScienceOpen Research
                22 December 2014
                : 0 (ID: 501d70cc-221a-444f-a69e-b74f39809599 )
                : 0
                : 1-9
                [1 ]Max-Delbrück-Center for Molecular Medicine (MDC), Berlin, Germany
                Author notes
                [* ]Corresponding author's e-mail address: sbashammakh@
                © 2014 S. Bashammakh et al.

                This work has been published open access under Creative Commons Attribution License CC BY 4.0 , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Conditions, terms of use and publishing policy can be found at .

                Figures: 4, Tables: 0, References: 54, Pages: 9
                Original article

                Life sciences

                serotonin, zebrafish, pharyngeal arches, neural crest cells


                Comment on this article