Fertilized Sea Urchin Eggs as a Model for Detecting Cell Division Inhibitors
Adorjan Aszalos in Modern Analysis of Antibiotics, 2020
Amphotericin B and nystatin are believed to act by binding to a sterol moiety, primarily ergosterol, present in the membrane of certain fungi. These polyene antibiotics, by virtue of their interaction with sterols, produce pores or channels in the membrane allowing leaking and loss of small molecules from intracellular pools. We are not sure if this is the mechanism of action of these drugs on the sea urchin. Similarly, haloprogin and pyrrolnitrin activity is not completely understood. 5-Fluorocytosine, which is converted to 5-fluorouracil, would not be expected to be active. Thus, the specificity of the fertilized sea urchin egg could be summarized as one in which DNA synthesis is not an absolute requirement for early cleavage. Drugs that block the first cleavage would be expected to act as steps affecting mRNA function forward to cytokinesis. Griseofulvin is a potent microtubule assembly inhibitor and would be expected to inhibit cell division by a mechanism similar to colchicine. The binding site for griseofulvin, however, is distinct from colchicine and the vinca alkaloids [62].
Role of Histones in Cell Differentiation
Gerald M. Kolodny in Eukaryotic Gene Regulation, 2018
There are no disagreements concerning the later stages of development. Most studies show that in different species — sea urchin,104,110,111Xenopus laevis,65,112Drosophila,113 etc. — no qualitative changes in the histone pattern could be detected usually after blastulation. Developmental changes in the relative content of different histone species which are often reported are most probably due to technical reasons. No changes in the histone pattern were observed during wheat germination in spite of the increasing template activity of the chromatin.114
Toxinology Emergencies
Anthony FT Brown, Michael D Cadogan in Emergency Medicine, 2020
Sea urchins and fire coral Relieve pain by immersion in warm water at 40–45°C without scalding or by using a local anaesthetic block, followed by exploration, irrigation and debridement as necessary, and give tetanus prophylaxis.Give an antibiotic such as doxycycline 100 mg orally b.d. for 5 days (not in children or pregnant patients), for deep or necrotic wounds.
Echinochrome Exhibits Antitumor Activity against Ehrlich Ascites Carcinoma in Swiss Albino Mice
Published in Nutrition and Cancer, 2021
Ayman Saber Mohamed
Although many synthetic anticancer substances are utilized in the treatment of malignancy, the side effects and the emergence of synthetic drug-resistant cancer cells limit their utilization (5). Certain chemotherapeutic agents as 5-Fluorouracil subject cells to oxidative stress, promoting adverse effects (6). Therefore, an examination of new anticancer agents from natural sources with fewer side effects has been strongly required. Marine creatures are a great source of biologically active natural products (7). There are many significant data on new anti-microbial agents from the sea urchin (Phylum Echinodermata, class Echinoidea), which give in an icebox on the bioactive compounds inside it (8). The sea urchin has several unique substances, such as quinonoid pigments named spinochromes (9). From these compounds, Echinochrome (Ech) is the darkest red pigment of sea urchin shells, spines and eggs (10). Ech is a water-insoluble substance that has antioxidant activity and is the active gradient in the Histochrome drug (11). It can improve mitochondrial function in the heart and therapeutic potential against the cardio-toxic agent (11,12). Also, many recent studies revealed the anti-oxidant and hypoglycemic activities of Ech (13–15). Thus, the present study aimed to assess the anticancer and antioxidant activities of Echinochrome against the Ehrlich ascites carcinoma tumor model in female Swiss albino mice.
Intraguild predation between Pristionchus pacificus and Caenorhabditis elegans: a complex interaction with the potential for aggressive behaviour
Published in Journal of Neurogenetics, 2020
Kathleen T. Quach, Sreekanth H. Chalasani
Other instances in which predator-prey interactions are not deemed aggressive concern the prey’s response. For example, herbivores that kill plant or algae in the process of grazing are not considered predators. Unlike engulfers and suspension/filter feeders, grazer-type herbivores can kill and feed in separate steps. For example, sea urchins can use its rasping teeth to incrementally carve away and feed on portions of kelp without necessarily killing it first (Harrold & Reed, 1985). In other words, sea urchins do not have to subjugate the kelp first to reap nutritional rewards. The kelp only dies when it receives a critical amount of damage, and once again, killing is a side effect of feeding, albeit delayed. Feeding without killing is possible when the prey is too large for engulfment and does not physically evade harm. Plants certainly can suffer from harm inflicted by herbivores and have accordingly evolved anti-herbivore defences, including chemical defences and tolerance to herbivory (Agrawal, 2011). However, these plant defences are largely passive or invisible to the herbivore, and therefore the predatory grazer lacks discernible cues for associating its own harmful actions with a correlated harm response from the prey. From an epistemological perspective, the predatory grazer cannot intend harm if it does not ‘know’ that its grazing is harmful to the prey. From an evolutionary perspective, the predatory grazer cannot intend harm if evolution did not select for it, particularly when the predator has no additional adaptive benefit from inflicting harm separately from feeding.
Comparative transcriptome analysis reveals the effects of different feeding times on the hepatopancreas of Chinese mitten crabs
Published in Chronobiology International, 2023
Yingkai Xu, Baoli Zhang, Changyue Yu, Ziwei Hung, Nan Hu, Yuqiao Cai, Yingdong Li
The feeding rhythm is a critical aspect of the aquaculture process, influencing a series of physiological functions in aquatic animals, including metabolism (del Pozo et al. 2013), behavior (Pradhan et al. 1989), immunity (Chen et al. 2022), and growth (Reis et al. 2021). Adjusting the feeding time can affect the feeding rhythms of aquatic organisms. For example, studies have shown that frequent meals throughout the daily cycle accelerate intestinal emptying and increase apparent digestibility in Senegal sole (Gilannejad et al. 2019). In addition, a change in the feeding time not only significantly affects the digestion and metabolism of aquatic organisms but also significantly influences the growth of sea urchins. Heflin and Watts (2016) used five different feeding times to feed sea urchins for 62 days and observed that weight gain in those fed continuously was significantly higher than that in animals fed every other day. Xu et al. (2022) observed that feeding time influences the composition of the intestinal flora of Chinese mitten crabs. In addition, to explore the effect of feeding rhythm on immunity regulation in crustaceans, Wang et al. altered the feeding strategy and proposed a strategy that could reduce Penaeus vannamei mortality under sub-lethal ammonia stress conditions, which improved their ammonia stress tolerance (Wang et al. 2022).