Cannabinoids reduce fertility of sea urchin sperm

1987 ◽  
Vol 65 (2) ◽  
pp. 130-136 ◽  
Author(s):  
Herbert Schuel ◽  
Regina Schuel ◽  
Arthur M. Zimmerman ◽  
Selma Zimmerman

Cannabinoids are potent pharmacological substances derived from marihuana. The effects of Δ9-tetrahydrocannabinol (THC), cannabinol (CBN), and cannabidiol (CBD) on fertilization in the sea urchin Strongylocentrotus purpuratus were investigated. Insemination of THC-treated eggs (5–400 μM) with excess sperm did not result in polyspermic fertilization. At minimal sperm densities, THC (0.1–10 μM) inhibited fertilization in a dose-dependent manner. Pretreatment of eggs with THC did not reduce their receptivity to sperm. Pretreatment of sperm with THC reduced their fertilizing capacity. The concentration of THC required to reduce sperm fertility by 50% was 1.1 ± 1.1 μM. The fertilizing capacity of THC-treated sperm depended on concentration of sperm and duration of pretreatment. The fertility of sperm at minimal densities was reduced by 50% at 129.3 ± 43 s treatment with 10 μM THC. The adverse effect of THC on sperm fertility was reversible. CBN and CBD at comparable concentrations (0.1–10 μM) inhibited fertilization in a manner similar to THC. First division was not delayed in zygotes that were fertilized with sperm pretreated with 10 μM THC. These studies show that cannabinoids directly affect the process of fertilization in sea urchins by reducing the fertilizing capacity of sperm.

Zygote ◽  
1999 ◽  
Vol 8 (S1) ◽  
pp. S20-S21 ◽  
Author(s):  
Blanca-Estela Galindo ◽  
Takuya Nishigaki ◽  
Esmeralda Rodríguez ◽  
Daniel Sánchez ◽  
Camen Beltrán ◽  
...  

We are studying the regulation of ion transport in sperm physiology. Sperm ion permeability is modulated by components from the outer layer of the egg which, depending on the species, regulate sperm motility, Chemotaxis and the acrosome reaction (AR). This reaction is required for sperm to fertilise the egg in many species from sea urchins to man (Darszon et al., 1999).Speract, a decapeptide from the external layer of Strongylocentrotus purpuratus sea urchin eggs, influences sperm respiration, motility and possibly the AR. Signal transduction starts when speract binds to a protein of 77 kDa closely coupled to sperm guanylyl cyclase (Garbers, 1989). Our recent receptor binding experiments using fluorescent-labelled speract (fluorescein and rhodamine) have allowed estimates of the association (kon 2.4 × 107 M−1s−1) and dissociation rate constants (koff 1.3 × 10−4 s−1). Furthermore, studies with fluorescent speract analogues indicate that the receptor undergoes conformational changes that depend on intracellular pH (pHi). The overall results are consistent with the possibility that speract may induce in sea urchin sperm a hyperactivated-like flagellar movement inside the jelly coat to accelerate sperm penetration through this layer.


Cells ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 63 ◽  
Author(s):  
Nunzia Limatola ◽  
Filip Vasilev ◽  
Luigia Santella ◽  
Jong Tai Chun

While alkaloids often exert unique pharmacological effects on animal cells, exposure of sea urchin eggs to nicotine causes polyspermy at fertilization in a dose-dependent manner. Here, we studied molecular mechanisms underlying the phenomenon. Although nicotine is an agonist of ionotropic acetylcholine receptors, we found that nicotine-induced polyspermy was neither mimicked by acetylcholine and carbachol nor inhibited by specific antagonists of nicotinic acetylcholine receptors. Unlike acetylcholine and carbachol, nicotine uniquely induced drastic rearrangement of egg cortical microfilaments in a dose-dependent way. Such cytoskeletal changes appeared to render the eggs more receptive to sperm, as judged by the significant alleviation of polyspermy by latrunculin-A and mycalolide-B. In addition, our fluorimetric assay provided the first evidence that nicotine directly accelerates polymerization kinetics of G-actin and attenuates depolymerization of preassembled F-actin. Furthermore, nicotine inhibited cofilin-induced disassembly of F-actin. Unexpectedly, our results suggest that effects of nicotine can also be mediated in some non-cholinergic pathways.


1977 ◽  
Vol 73 (1) ◽  
pp. 182-192 ◽  
Author(s):  
K Ogawa ◽  
D J Asai ◽  
C J Brokaw

Effects of an antiserum against native dynein 1 from sperm flagella of the sea urchin Strongylocentrotus purpuratus were compared with effects of an antiserum previously obtained against an ATPase-active tryptic fragment (fragment 1A) of dynein 1 from sperm flagella of the sea urchin, Anthocidaris crassispina. Both antisera precipitate dynein 1 and do not precipitate dynein 2. Only the fragment 1A antiserum precipitates fragment 1A and produces a measurable inhibition of dynein 1 ATPase activity. Both antisera inhibit the movement and the movement-coupled ATP dephosphorylation of reactivated spermatozoa. The inhibition of movement by the antiserum against dynein 1 is much less than by the antiserum against fragment 1A, suggesting that a specific interference with the active ATPase site may be required for effective inhibition of movement. Both antisera reduce the bend angle as well as the beat frequency of reactivated S. purpuratus spermatozoa, suggesting that the bend angle may depend on the activity of the dynein arms which generate active sliding.


2014 ◽  
Author(s):  
Matthew C Foster ◽  
Jarrett E Byrnes ◽  
Daniel C Reed

Consumer growth and reproductive capacity are direct functions of diet. Strongylocentrotid sea urchins, the dominant herbivores in California kelp forests, strongly prefer giant kelp (Macrocystis pyrifera), but are highly catholic in their ability to consume other species. The biomass of Macrocystis fluctuates greatly in space and time and the extent to which urchins can use alternate species of algae or a mixed diet of multiple algal species to maintain fitness when giant kelp is unavailable is unknown. We experimentally examined the effects of single and mixed species diets on consumption, growth and gonad weight in the purple sea urchin Strongylocentrotus purpuratus. Urchins were fed single species diets consisting of one of four common species of macroalgae (the kelps Macrocystis pyrifera and Pterygophora californica, and the red algae Chondracanthus corymbiferus and Rhodymenia californica (hereafter referred to by genus) or a mixed diet containing all four species ad libitum over a 13-week period in a controlled laboratory setting. Urchins fed Chondracanthus, Macrocystis and a mixed diet showed the highest growth (in terms of test diameter, wet weight and jaw length) and gonad weight while urchins fed Pterygophora and Rhodymenia showed the lowest. Urchins consumed their preferred food, Macrocystis at the highest rate when offered a mixture, but consumed Chondracanthus or Macrocystis at similar rates when the two algae were offered alone. The differences in urchin feeding behavior and growth observed between these diet types suggest the relative availability of the algae tested here could affect urchin populations and their interactions with the algal assemblage. The fact that the performance of urchins fed Chondracanthus was similar or higher than those fed the preferred Macrocystis suggests purple sea urchins could sustain growth and reproduction during times of low Macrocystis abundance as is common following large wave events.


2020 ◽  
Author(s):  
Stefania Mariano ◽  
Elisa Panzarini ◽  
Maria Dias Inverno ◽  
Nikolaos Voulvoulis ◽  
Luciana Dini

Abstract BackgroundSilver nanoparticles (AgNPs) are one of the most widely used nanomaterials in consumer products. When discharged into the aquatic environment AgNPs can cause toxicity to aquatic biota, through mechanisms that are still under debate, thus rendering the NPs effects evaluation a necessary step. Different aquatic organism models, i.e. microalgae, mussels, Daphnia magna, sea urchins and Danio rerio, etc. have been largely exploited for NPs toxicity assessment. On the other hand, alternative biological microorganisms abundantly present in nature, i.e. microalgae, are nowadays exploited as a potential sink for removal of toxic substances from the environment. Indeed, the green microalgae Chlorella vulgaris is one of the most used microorganisms for waste treatment.ResultsWith the aim to verify the possible involvement of C. vulgaris not only as a model microorganism of NPs toxicity but also for the protection toward NPs pollution, we used these microalgae to measure the AgNPs biotoxicity and bioaccumulation. In particular, to exclude any toxicity derived by Ag+ ions release, green chemistry synthesised and Glucose coated AgNPs (AgNPs-G) were used. C. vulgaris actively internalised AgNPs-G whose amount increases in a time and dose-dependent manner. The internalised NPs, found inside large vacuoles, were not released back into the medium, even after 1 week, and did not undergo biotransformation since AgNPs-G maintained their crystalline nature. Biotoxicity of AgNPs-G causes an exposure time and AgNPs-G dose-dependent growth reduction and a decrease in chlorophyll-a amount.ConclusionsThese results confirm C. vulgaris as a biomonitoring organism and also suggest it as a bioaccumulating microalgae for possible use in the environment protection.


Zygote ◽  
2021 ◽  
pp. 1-12
Author(s):  
Arlet Loza-Huerta ◽  
Hiram Pacheco-Castillo ◽  
Alberto Darszon ◽  
Carmen Beltrán

Summary Fertilization, a crucial event for species preservation, in sea urchins, as in many other organisms, requires sperm motility regulation. In Strongylocentrotus purpuratus sea urchins, speract, a sperm chemoattractant component released to seawater from the outer egg layer, attracts sperm after binding to its receptor in the sperm flagellum. Previous experiments performed in demembranated sperm indicated that motility regulation in these cells involved protein phosphorylation mainly due to the cAMP-dependent protein kinase (PKA). However, little information is known about the involvement of protein kinase C (PKC) in this process. In this work, using intact S. purpuratus sea urchin sperm, we show that: (i) the levels of both phosphorylated PKA (PKA substrates) and PKC (PKC substrates) substrates change between immotile, motile and speract-stimulated sperm, and (ii) the non-competitive PKA (H89) and PKC (chelerythrine) inhibitors diminish the circular velocity of sperm and alter the phosphorylation levels of PKA substrates and PKC substrates, while the competitive inhibitors Rp-cAMP and bisindolylmaleimide (BIM) do not. Altogether, our results show that both PKA and PKC participate in sperm motility regulation through a crosstalk in the signalling pathway. These results contribute to a better understanding of the mechanisms that govern motility in sea urchin sperm.


2019 ◽  
Vol 7 (2) ◽  
pp. 35 ◽  
Author(s):  
Joseph Hakim ◽  
Julie Schram ◽  
Aaron Galloway ◽  
Casey Morrow ◽  
Michael Crowley ◽  
...  

The sea urchin Strongylocentrotus purpuratus (order Camarodonta, family Strongylocentrotidae) can be found dominating low intertidal pool biomass on the southern coast of Oregon, USA. In this case study, three adult sea urchins were collected from their shared intertidal pool, and the bacteriome of their pharynx, gut tissue, and gut digesta, including their tide pool water and algae, was determined using targeted high-throughput sequencing (HTS) of the 16S rRNA genes and bioinformatics tools. Overall, the gut tissue demonstrated Arcobacter and Sulfurimonas (Epsilonproteobacteria) to be abundant, whereas the gut digesta was dominated by Psychromonas (Gammaproteobacteria), Propionigenium (Fusobacteria), and Flavobacteriales (Bacteroidetes). Alpha and beta diversity analyses indicated low species richness and distinct microbial communities comprising the gut tissue and digesta, while the pharynx tissue had higher richness, more closely resembling the water microbiota. Predicted functional profiles showed Kyoto Encyclopedia of Genes and Genomes (KEGG) Level-2 categories of energy metabolism, membrane transport, cell motility, and signal transduction in the gut tissue, and the gut digesta represented amino acid, carbohydrate, vitamin and cofactor metabolisms, and replication and repair. Co-occurrence network analysis showed the potential relationships and key taxa, such as the highly abundant Arcobacter and Propionigenium, influencing population patterns and taxonomic organization between the gut tissue and digesta. These results demonstrate a trend of microbial community integration, allocation, predicted metabolic roles, and taxonomic co-occurrence patterns in the S. purpuratus gut ecosystem.


Reproduction ◽  
2004 ◽  
Vol 127 (2) ◽  
pp. 141-149 ◽  
Author(s):  
Anna T Neill ◽  
Victor D Vacquier

Sea urchins have long been a model system for the study of fertilization. Much has been learned about how sea urchin sperm locate and fertilize the egg. Sperm and eggs are spawned simultaneously into the surrounding seawater. Sperm signaling pathways lead to downstream events that ensure fertilization. Upon spawning, sperm must acquire motility and then they must swim towards or respond to the egg in some way. Finally, they must undergo a terminal exocytotic event known as the acrosome reaction that allows the sperm to bind to the vitelline layer of the egg and then to fuse with the egg plasma membrane. Motility is stimulated by exposure to seawater, while later events are orchestrated by factors from the egg. The sperm signaling pathways are exquisitely tuned to bring the sperm to the egg, bind, and fuse the two cells as quickly as possible.


2014 ◽  
Author(s):  
Matthew C Foster ◽  
Jarrett E Byrnes ◽  
Daniel C Reed

Consumer growth and reproductive capacity are direct functions of diet. Strongylocentrotid sea urchins, the dominant herbivores in California kelp forests, strongly prefer giant kelp (Macrocystis pyrifera), but are highly catholic in their ability to consume other species. The biomass of Macrocystis fluctuates greatly in space and time and the extent to which urchins can use alternate species of algae or a mixed diet of multiple algal species to maintain fitness when giant kelp is unavailable is unknown. We experimentally examined the effects of single and mixed species diets on consumption, growth and gonad weight in the purple sea urchin Strongylocentrotus purpuratus. Urchins were fed single species diets consisting of one of four common species of macroalgae (the kelps Macrocystis pyrifera and Pterygophora californica, and the red algae Chondracanthus corymbiferus and Rhodymenia californica (hereafter referred to by genus) or a mixed diet containing all four species ad libitum over a 13-week period in a controlled laboratory setting. Urchins fed Chondracanthus, Macrocystis and a mixed diet showed the highest growth (in terms of test diameter, wet weight and jaw length) and gonad weight while urchins fed Pterygophora and Rhodymenia showed the lowest. Urchins consumed their preferred food, Macrocystis at the highest rate when offered a mixture, but consumed Chondracanthus or Macrocystis at similar rates when the two algae were offered alone. The differences in urchin feeding behavior and growth observed between these diet types suggest the relative availability of the algae tested here could affect urchin populations and their interactions with the algal assemblage. The fact that the performance of urchins fed Chondracanthus was similar or higher than those fed the preferred Macrocystis suggests purple sea urchins could sustain growth and reproduction during times of low Macrocystis abundance as is common following large wave events.


Zygote ◽  
2015 ◽  
Vol 24 (3) ◽  
pp. 371-377 ◽  
Author(s):  
Jing Liang ◽  
Heghush Aleksanyan ◽  
Stan Metzenberg ◽  
Steven B. Oppenheimer

SummaryThe sea urchin embryo is recognized as a model system to reveal developmental mechanisms involved in human health and disease. In Part I of this series, six carbohydrates were tested for their effects on gastrulation in embryos of the sea urchin Lytechinus pictus. Only l-rhamnose caused dramatic increases in the numbers of unattached archenterons and exogastrulated archenterons in living, swimming embryos. It was found that at 30 h post-fertilization the l-rhamnose had an unusual inverse dose-dependent effect, with low concentrations (1–3 mM) interfering with development and higher concentrations (30 mM) having little to no effect on normal development. In this study, embryos were examined for inhibition of archenteron development after treatment with α-l-rhamnosidase, an endoglycosidase that removes terminal l-rhamnose sugars from glycans. It was observed that the enzyme had profound effects on gastrulation, an effect that could be suppressed by addition of l-rhamnose as a competitive inhibitor. The involvement of l-rhamnose-containing glycans in sea urchin gastrulation was unexpected, since there are no characterized biosynthetic pathways for rhamnose utilization in animals. It is possible there exists a novel l-rhamnose-containing glycan in sea urchins, or that the enzyme and sugar interfere with the function of rhamnose-binding lectins, which are components of the innate immune system in many vertebrate and invertebrate species.


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