Elevation of the vitelline coat of eggs of the ascidian, Halocynthia roretzi, was induced by 12-O-tetradecanoylphorbol-13-acetate or phorbol-12, 13-didecanoate, but not by their 4-epimers. After elevation of the vitelline coat in this way, eggs were unable to undergo cleavage on addition of sperm. This elevation of the vitelline coat by phorbol esters was inhibited by specific inhibitors of trypsin-like enzyme, calmodulin, phospholipase A , and protein kinase C. In association with elevation of the vitelline coat, a trypsin-like enzyme was released from the eggs. The properties of this enzyme were similar to those of the enzyme released by calcium ionophore, which also induced elevation of the vitelline coat, suggesting that similar exocytosis of intracellular granules occurred in both cases. Calmodulin, possibly involved in the elevation process, was isolated from eggs and characterized.

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1440-169X.1989.00543.xDOI Listing

Publication Analysis

Top Keywords

elevation vitelline
24
vitelline coat
24
coat eggs
12
eggs ascidian
8
ascidian halocynthia
8
halocynthia roretzi
8
trypsin-like enzyme
8
enzyme released
8
elevation
7
vitelline
6

Similar Publications

Prostatic adenocarcinoma is characterized by elevated phosphatidylcholine metabolism. F-choline positron emission tomography/computed tomography (PET/CT) is widely used for patients with biochemical recurrence and a prostate-specific antigen threshold above 2 ng/mL. We report a case of a patient with high-risk prostatic adenocarcinoma undergoing F-choline PET/CT for biochemical recurrence.

View Article and Find Full Text PDF

Negligible additive effect of environmental concentrations of fragmented polyethylene terephthalate microplastics on the growth and reproductive performance of Java medaka exposed to 17β-estradiol and bisphenol A.

Aquat Toxicol

September 2024

Department of Marine Science, College of Natural Sciences, Incheon National University, Incheon 22012, Republic of Korea; Research Institute of Basic Sciences, Incheon National University, Incheon 22012, Republic of Korea; Yellow Sea Research Institute, Incheon 22012, Republic of Korea. Electronic address:

To investigate whether environmental concentrations of fragmented polyethylene terephthalate (PET) microplastics (MPs) have additional or combined effects on endocrine-disrupting activity, Java medaka (Oryzias javanicus) were exposed to 17β-estradiol (E2; 5, 10, 50, and 100 ng L), bisphenol A (BPA; 5, 10, 50, and 100 µg L), and E2 and BPA combined with PET MPs (1 and 100 particles L) for 200 days. The growth parameters, such as body length and weight, were significantly decreased by the highest concentrations of E2 and BPA. A significant reduction in egg production was observed in female fish exposed to BPA, with an additive toxic effect of PET MPs.

View Article and Find Full Text PDF

Exploring the endocrine disrupting potential of a complex mixture of PAHs in the estrogen pathway in Oreochromis niloticus hepatocytes.

Aquat Toxicol

August 2024

Laboratório de Toxicologia Celular, Departamento de Biologia Celular, Universidade Federal do Paraná, CEP 81.531-980, Curitiba, PR, Brazil. Electronic address:

Article Synopsis
  • - This study explored the toxic effects and potential endocrine disruption of a mixture of polycyclic aromatic hydrocarbons (PAHs) on the liver cells of Nile tilapia, focusing on their impact on the estrogen pathway.
  • - Although the PAH mixture had minimal effects on cell metabolism and adhesion, it significantly increased gene expression related to estrogen, particularly vitellogenin and estrogen receptor 2, indicating potential endocrine disruption.
  • - The study also revealed changes in oxidative stress markers and altered efflux activity, suggesting that the PAH mixture affects both the estrogen pathway and oxidative stress responses in the hepatocytes of O. niloticus.
View Article and Find Full Text PDF

The water accommodated fraction (WAF) of spilled crude oil is a severe threat to the health of marine fish. This study was conducted to investigate the effects of short-term embryonic exposure to the WAF on the ovarian development and reproductive capability of F0 adult female marine medaka (Oryzias melastigma). Following embryonic exposure to the WAF with nominal total petroleum hydrocarbon concentrations of 0.

View Article and Find Full Text PDF

Long-term exposure of metamifop affects sex differentiation and reproductive system of zebrafish (Danio rerio).

Aquat Toxicol

August 2024

Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China. Electronic address:

The extensive use of herbicide metamifop (MET) in rice fields for weeds control will inevitably lead to its entering into water environments and threaten the aquatic organisms. Previous researches have demonstrated that sublethal exposure of MET significantly affected zebrafish development. Yet the long-term toxicological impacts of MET on aquatic life remains unknown.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!