Biogenic Monoamines in Early Embryos of Sea Urchins

Abstract

Indolylalkylamine determination was performed on the eggs and embryos of six species of sea urchins, using several fluorometric techniques, including the fluorescence of a substance itself and the fluorescence of its condensation products after treatment with orthophthaldialdehyde and ninhydrin. The serotonin-like substance of sea urchin embryos as well as of adults was shown to consist of at least two components, of which the major one is tryptamine or its derivative with a substituting group at aminonitrogen. Further, serotonin was found to be present at all developmental stages investigated, although at much lower concentrations. The results of this study suggest a regulatory role of ''prenervous'' tryptamine in the early embryogenesis of the sea urchin.

Serotonin and its metabolism in basal deuterostomes: insights fromStrongylocentrotus purpuratusandXenoturbella bocki

“…Interestingly, when intact tissues from the radial nerves and gonads of the sea urchin were placed in extraction solution to observe the levels of indoleamine compounds, tryptamine was found to be a prominent native serotonin-like compound. These results are similar to those reported for sea urchin embryos (Manukhin et al, 1981). Tryptamine was detected in levels ranging from 0.6 to 2.4moll -1 in only half of the animals investigated (four trials total).…”

“…Such significant fluctuations in observed compound levels can be representative of the physiological state of an organism, such as hunger and satiation [similar to some 5-HT metabolites reported for predatory mollusks (Hatcher et al, 2008)]. Based on other reports that levels of tryptamine vary through the stages of sea urchin embryonic development (Manukhin et al, 1981), it is possible that adult animals have variable tryptamine levels based on their stage in the reproductive cycle, although the reproductive stage of these wildcaught animals was not determined. Interestingly, the measured tryptamine concentrations were higher in a set of animals shipped to us earlier in the year.…”

“…Although a significant body of research has focused on the detection of tryptamine and serotonin in sea urchin embryos (Buznikov et al, 2005;Manukhin et al, 1981;Morikawa et al, 2001;Renaud et al, 1983;Shmukler and Tosti, 2001), this marks one of the first studies of 5-HT catabolism in adult sea urchins. Our focus has been on elucidating the 5-HT-related pathways in several deuterostomes.…”

“…Specifically, its important positioning in the evolutionary tree, unusual nervous system organization, the essential role it plays in the investigation of fundamental developmental mechanisms and the availability of its genomic information (Burke et al, 2006). The distribution and levels of serotonin and serotonin-like compounds in the embryos of sea urchins have been reported previously (Buznikov et al, 2005;Manukhin et al, 1981;Morikawa et al, 2001;Renaud et al, 1983;Shmukler and Tosti, 2001). Surprisingly, however, little research has focused on the 5-HT pathways in adult sea urchins.…”

Serotonin Transporter Function Is an Early Step in Left-Right Patterning in Chick and Frog Embryos

“…Serotonin is widely distributed in both the animal and the plant kingdoms [Pennati et al, 2001], and occurs in mammalian [Shuey et al, 1990;Wu et al, 1999] and other vertebrate and invertebrate embryos [Manukhin et al, 1981;Emanuelsson et al, 1988]. Serotonin is synthesized by embryonic stem cells [Walther, 1999], and 5-HT is likely to play a role in egg maturation [Buznikov et al, 1993], mitogen-induced vascular remodeling [Fanburg and Lee, 1997], neural crest migration [Moiseiwitsch and Lauder, 1995], control of cleavage and cell division rates, patterning of cytoskeletal structures [Emanuelsson et al, 1988;Lee et al, 1991], blastomere adhesion, gastrulation movements [Hamalainen and Kohonen, 1989;Colas et al, 1999a, b], control of gap-junctional communication [Moore and Burt, 1995;Rorig and Sutor, 1996], craniofacial patterning [Lauder and Zimmerman, 1988;Shuey et al, 1992Shuey et al, , 1993, and the specifi cation of neuronal identity and connectivity in the developing nervous system [Lauder et al, 1981[Lauder et al, , 1983.…”