We examined the utility of 13 pharmaceuticals and personal care products (PPCPs) as molecular markers of sewage contamination in riverine, groundwater, and coastal environments. The PPCPs were crotamiton, ibuprofen, naproxen, ketoprofen, fenoprofen, mefenamic acid, thymol, triclosan, propyphenazone, carbamazepine, diethyltoluamide, ethenzamide, and caffeine. Measurements in 37 Japanese rivers showed positive correlations of riverine flux of crotamiton (r2 = 0.85), carbamazepine (r2 = 0.84), ibuprofen (r2 = 0.73), and mefenamic acid (r2 = 0.67) with the population in the catchments. In three surveys in the Tamagawa estuary, crotamiton, carbamazepine, and mefenamic acid behaved conservatively across seasons within a salinity range of 0.4-29 per thousand, suggesting their utility as molecular markers in coastal environments. Removal of ketoprofen and naproxen in the estuary was ascribed to photodegradation. Ibuprofen and thymol were removed from estuarine waters in summer by microbial degradation. Triclosan was removed by a combination of microbial degradation, photodegradation, and adsorption. These results were consistent with those of river water incubated for 8 d at 25 degrees C in the dark in order to examine the effects of biodegradation and photodegradation. Crotamiton was detected in groundwater from the Tokyo metropolitan area (12 out of 14 samples), suggesting wastewater leakage from decrepit sewers. Carbamazepine, ketoprofen, and ibuprofen (5/14), caffeine (4/14), and diethyltoluamide (3/14) were also detected in the groundwater, whereas the other carboxylic and phenolic PPCPs were not detected and were thought to be removed during their passage through soil. All the data demonstrated the utility of crotamiton and carbamazepine as conservative markers in freshwater and coastal environments. We recommend combining these conservative markers with labile PPCPs to detect inputs of poorly treated sewage.
The ubiquitin-proteasome system is essential for intracellular protein degradation, but an extracellular role of this system has not been known until now. We have previously reported that the proteasome is secreted into the surrounding seawater from sperm of the ascidian (Urochordata) Halocynthia roretzi on sperm activation, and that the sperm proteasome plays a key role in fertilization. Here, we show that a 70-kDa component (HrVC70) of the vitelline coat is the physiological substrate for the ubiquitin-proteasome system during fertilization of H. roretzi. A cDNA clone encoding the HrVC70 precursor (HrVC120) was isolated, and a homology search revealed that HrVC120 contains 13 epidermal growth factor-like repeats and a mammalian zona pellucida glycoprotein-homologous domain. HrVC70 functions as a sperm receptor. We demonstrate that HrVC70 is ubiquitinated both in vitro and in vivo. The immunocytochemical localization of multiubiquitin chains in the vitelline coat and the inhibitory effect of monoclonal antibodies against the multiubiquitin chains on fertilization strongly support the role of the ubiquitin-proteasome system in ascidian fertilization. Taken together, these results indicate that the ubiquitin-proteasome system is responsible for extracellular degradation of the sperm receptor HrVC70 and, consequently, for sperm penetration of the vitelline coat during fertilization.fertilization ͉ vitelline coat ͉ ubiquitin F ertilization is a key event in sexual reproduction, creating a new individual with novel genomic information. In animal reproduction, species-specific binding of sperm to the proteinaceous egg coat, called the vitelline coat in marine invertebrates or the zona pellucida in mammals, is particularly important for successful fertilization. Because the egg coat is a potential barrier to sperm-egg fusion, sperm must use a lytic agent (lysin) to penetrate it (1, 2). In mammals, it has long been believed that the sperm acrosomal trypsin-like protease acrosin is a zona lysin, which digests zona pellucida proteins to enable sperm to penetrate through the zona pellucida (3). However, recent studies by using acrosin-knockout mice revealed that acrosin is not essential for fertilization or sperm penetration through the zona pellucida (4). Rather, it is currently thought that acrosin is involved in the dispersal of acrosomal proteins during acrosome reaction (5) and that a sperm protease(s) other than acrosin is the actual zona-lysin in mammalian fertilization (6).Ascidians (Urochordata) occupy a phylogenetic position between invertebrates and segmented vertebrates. They are hermaphrodites that usually release sperm and eggs simultaneously during the spawning season. Several ascidians, including Ciona intestinalis (7) and Halocynthia roretzi (8), strictly prohibit selffertilization. Because self-nonself recognition in fertilization is accomplished by interaction between the sperm and vitelline coat (7,8), the sperm-lysin system seems to be triggered after the sperm recognizes the vitelline coat as nonself...
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