Effect of dopamine on early larvae of sea urchins, Mesocentrotus nudus and Strongylocentrotus intermedius

Abstract

Larvae of many echinoids are known to be phenotypically plastic and capable of changing the growth rate of their post-oral arms depending on the microalgae concentration in their habitat. As literature data show, developing larvae use chemosensation to detect algae in the environment and "adjust" the rate of growth of their post-oral arms through dopamine signaling. According to our results, dopamine has a significant effect on the post-oral arm growth in early larvae of two sea urchin species, Mesocentrotus nudus and Strongylocentrotus intermedius. The dopamine effect depends on concentration: the higher the dopamine concentration in the water, the shorter the post-oral arms. We suggest that the pattern of response to variation in dopamine concentration, manifested by early larvae of both species, is similar to that observed at different concentrations of microalgae.

The dopamine effect on sea urchin larvae depends on their age

“…purpuratus larvae (Adams et al, 2011). Considered together, our results confirm the assumption that dopaminergic neurons are involved in the regulation of post‐oral arms development in sea urchin larvae (Adams et al, 2011; Chen & Adams, 2022; Kalachev, 2020; Rivera Vázquez et al, 2017).…”

“…The effect of dopamine was dose‐depended and was more evident at higher concentrations, irrespective of the developmental stage exposed to dopamine. It should be noted that in previous studies, sea urchin embryos and larvae were treated with quinpirole, an agonist of dopamine (Adams et al, 2011; Chen & Adams, 2022), or dopamine (Kalachev, 2020) for a long time, while in the present study, the dopamine treatment was limited to 4 h. In the study of Kalachev (2020) and in the present one, the 24 hpf S . intermedius embryos that had been treated with 1.5 μM solution of dopamine developed into larvae with shorter post‐oral arms.…”

“…Another example where dopamine signaling induces phenotypic changes in animals is echinoplutei (Adams et al, 2011; Chen & Adams, 2022; Kalachev, 2020; Rivera Vázquez et al, 2017). According to Adams et al (2011), pharmacological activation of a dopamine type‐D 2 receptor in late gastrula of a sea urchin species, Strongylocentrotus purpuratus , with quinpirole, a dopamine agonist, decreases the growth rate of the larval post‐oral arms and, hence, mimics the phenotype of larvae developed with abundant food available.…”

“…Similar results on the role of dopamine were reported for early four‐armed plutei of the sea urchins Mesocentrotus nudus and S . intermedius (Kalachev, 2020) and six‐armed plutei of sand dollar, Dendraster excentricus (Rivera Vázquez et al, 2017). Although these studies provided valuable data on the role of dopamine signaling in the development of plastic phenotype in larval sea urchins, it is still unclear how the effect of dopamine depends on the developmental stage exposed to it.…”

“…Although these studies provided valuable data on the role of dopamine signaling in the development of plastic phenotype in larval sea urchins, it is still unclear how the effect of dopamine depends on the developmental stage exposed to it. In most studies (Adams et al, 2011; Chen & Adams, 2022; Kalachev, 2020), quinpirole or dopamine were added into the culture medium at the gastrula stage when no neurons had formed yet. However, gastrulae of many sea urchin species are known to have dopamine receptor(s) that are important for normal embryonic development (Buznikov et al, 1999; Carginale et al, 1995; Katow et al, 2010).…”