Effects of BPA and DES on longchin goby (Chasmichthys dolichognathus) in vitro during the oocyte maturation

This study was performed in order to assess whether bisphenol (BPA) and diethylstilbestrol (DES) had agonistic or antagonistic effects on oocyte maturation using marine fish. We tested the effects of these chemicals on in vitro maturation, germinal vesicle breakdown (GVBD), assay using oocytes from the longchin goby, Chasmichthys dolichognathus. During the maturation process, low concentrations of BPA and DES triggered GVBD depending on the stage of oocyte development; BPA at 0.044 nM and DES at 0.037, 0.37, and 3.73 nM induced GVBD in 0.82-0.88 mm diameter oocytes (germinal vesicle located near the center of oocytes). In 0.76-0.80 mm diameter oocytes (fully vitellogenic oocytes), BPA induced GVBD at relatively higher concentrations (4.38, 43.8, and 438 nM). In 0.86-0.90 mm diameter oocytes, BPA and DES had no observable effect on GVBD at the concentrations tested. Oocytes with diameters between 0.82 and 0.88 mm appeared to be more sensitive to these chemicals. Moreover, our results showed that BPA and DES did not inhibit GVBD.     

Reproductive life history stages sensitive to oil and naphthalene in Atlantic croaker

The reproductive effects of chronic exposure to water-soluble fractions (WSF) of diesel fuel oil and naphthalene in female Atlantic croaker during critical periods of their reproductive life history were investigated. Fish were repeatedly exposed to WSF of oil (2.5 or 5%) or naphthalene (0.5 or 1.0 ppm) for 5 or 8 weeks. Both pollutants blocked sexual maturation in some fish and impaired ovarian recrudescence in others. The majority of the oocytes in exposed fish were undeveloped and widespread oocyte atresia was evident at higher concentrations of these polycyclic aromatic hydrocarbons (PAH). The disruption of ovarian growth and oocyte development in croaker after PAH exposure was associated with alterations in reproductive endocrine function at multiple sites on the hypothalamus-pituitarygonadal axis. A third period of increased sensitivity to xenobiotics was observed during final oocyte maturation.     

香鱼(Plecoglossus altivelis)排卵后卵内油球、酶活、丙二醛及受精率、孵化率的变化

以香鱼卵母细胞为研究对象,采用观察卵内油球、有关酶的活力、以及卵的受精率和孵化率等变化的方法,研究了香鱼卵母细胞长时效演化的相关机理,结果表明,随着香鱼卵在腹腔内保存时间的延长,卵内油球从0h的油球直径≤10μm,且均匀分布,逐渐融合增大,至108h增大到120μm,油球数仅有5—6个。同时,SOD、POD的活力及MDA含量均呈先升后降的变化趋势,最大峰值分别出现在60h、36h和24h。随着油球和酶活的变化,卵子质量逐渐下降,表现为受精率和孵化率的降低:排卵后24h、48h、72h、96h的受精率分别为94.37%、88.19%、50.20%、10.83%,孵化率分别为85.78%、68.14%、25.54%、0.53%。     

Using oocyte size to assess seasonal ovarian development in Solea solea (L.)

Maximum oocyte size was used to assess seasonal ovarian development in sole. Fish age, especially the adolescent period, appeared to affect the start of vitellogenin-dependent oocyte development in the annual reproductive cycle and the subsequent oocyte growth rate. The majority of oocyte growth occurred between September and March. Several other aspects of ovarian development were also age-dependent, including the increase in ovary condition factor (ovary weight/fish length³) and the size of oocytes commencing nuclear migration. Evidence is presented that in the recruiting year class of sole abortive maturation occurs where oocytes develop yolk but spawning does not take place. The implications of this study on the estimation of female spawning stock biomass are discussed.     

Agonistic effect of imidazole and triazole fungicides on in vitro oocyte maturation in rainbow trout (Oncorhynchus mykiss)

The purpose of the present study was to assess the in vitro effect of some imidazole (prochloraz, imazalil) and triazole (epoxiconazole) agricultural fungicides on gonadotropin-induced oocyte maturation in rainbow trout. Results show that prochloraz, epoxiconazole and imazalil strongly potentiated the induction of oocyte maturation by gonadotropin in a dose-dependent manner. Furthermore, 10(-5) M prochloraz and epoxiconazole alone induced oocyte maturation. The mRNA biosynthesis inhibitor, actinomycin d, completely inhibited oocyte maturation induced by fungicides, suggesting that the gonadotropin-like effect of these chemicals is at least dependent on de novo gene expression.     

Agonistic effect of imidazole and triazole fungicides on in vitro oocyte maturation in rainbow trout (Oncorhynchus mykiss)

The purpose of the present study was to assess the in vitro effect of some imidazole (prochloraz, imazalil) and triazole (epoxiconazole) agricultural fungicides on gonadotropin-induced oocyte maturation in rainbow trout. Results show that prochloraz, epoxiconazole and imazalil strongly potentiated the induction of oocyte maturation by gonadotropin in a dose-dependent manner. Furthermore, 10⁻⁵ M prochloraz and epoxiconazole alone induced oocyte maturation. The mRNA biosynthesis inhibitor, actinomycin , completely inhibited oocyte maturation induced by fungicides, suggesting that the gonadotropin-like effect of these chemicals is at least dependent on de novo gene expression.     

促性腺激素释放素类似物（GnRH—A）对文昌鱼卵细胞成熟及产卵的诱发

在繁殖季节，给正在成熟的文昌鱼体腔注射ＧｎＲＨ－Ａ，结果表明，注射激素后３６ｈ时，有５０％文昌鱼产卵，未产动物成熟卵母细胞达９５．５％。而对照组无任何动物产卵，成熟卵母细胞为５５％，我们由引首次直接证实文昌鱼脊椎动物一样，ＧｎＲＨ－Ａ是调控其卵母细胞成熟和产卵的重要激素。     

Pentachlorophenol and 3,4-dichloroaniline as models for photochemical reactions in seawater

Pentachlorophenol (PCP) and 3,4-dichloroaniline (DCA) were used as models to examine photochemical reactions in seawater.The photolysis of PCP in seawater differed in both rate and product distribution from that in distilled water; rates were slower in seawater due to the photonucleophilic interaction of PCP with chloride ions, demonstrated by the formation of ³⁶Cl-labeled PCP in irradiated PCP solutions containing Na³⁶Cl. DCA showed no rate change and gave identical products in both systems. Both PCP and DCA yielded greater amounts of photoreduction products in seawater than in distilled water, and tetrachloromuconic acid was isolated and identified as a new and unstable PCP photoproduct resulting from ringfission. This study demonstrates the operation of photooxidation, photonucleophilic substitution, and photoreduction reactions which differ in detail between seawater and distilled water and suggests that photochemical reactions can be a major factor in the breakdown of organic pollutants and other chemicals in the marine environment.     

Induced Maturation and Spawning by Sex Pheromones in Female Mudskipper (Boleophthalmus pectinirostris)

1 IntroductionMudskipper ( Boleophthalmus pectinirostris ) inhabits muddy burrow in the intertidal mudflats of the temperature zone, feeding mainly on benthic diatoms and adapting to a wide range of salinity[1~3]. Although it is small in size, the mudskipper is delicious, nutritious and has a high market value. Fish farmers in Southeastern Mainland China are eager to culture this species. However, at present the natural resource of the fish has been decreasing or disappearing in some area…     

Antibacterial substance from mucus of a scleractinian coral, Symphyllia gigantea

Coral mucus covers the surface of coral and contains antibacterial substances as a first line of defense. Coral mucus not only enables the coral itself to resist disease, but also provides antibacterial agents for people. We collected mucus from a scleractinian coral (Symphyllia gigantea) at Sta. Sanya (China), then extracted the antibacterial substances using 10% glacial acetic acid with the help of antiprotease inhibitors, and tested the antibacterial activity by a terrestrial bacterium (Staphylococcus aureus) and a marine bacterium (Vibrio anguillarum). The result showed that, there were antibacterial agents in the mucus, and their antibacterial activities were lost by treatment of the sample at 90 ℃ water for 10 min.     

卵形鲳鲹早期卵子发生显微及超微结构的研究

本文研究了卵形鲳鲹早期卵子发生的显微与超微结构特点。研究结果表明在1～2龄鱼卵巢中卵原细胞进入首次成熟分裂前期的结构特点，3～4龄鱼才开始进入小生长期，文中讨论了此鱼性腺成熟的年龄以及如何加速性腺发育，为人工繁殖提供科学依据。     

中华绒螯蟹卵巢发育周期的组织学细胞学观察

于1989－1990年，用组织切片技术，结合外观特征，在光镜水平对浙北地区的中华绒螯蟹卵巢发育周期进行组织学、细胞学观察，并对从卵原细胞增殖到卵母细胞生长、卵子成熟及卵巢退化、重新发生等进行系统观察研究。研究表明，中华绒螯蟹可以观察到第一次成熟分裂中期相为成熟卵的标志，并以此标志将卵子发生分成四期、卵巢发育分成VII期。结果还表明，中华绒螯蟹雌蟹的成熟时间因所处的地理纬度不同而有所差异，浙北地区雌蟹促产怀卵的最佳时间是3月份并延至4月上旬；卵子必须借助海水及交配活动刺激才能达到成熟；因故无法产卵或一直生活在淡水中的成熟雌蟹其整个卵巢即退化，退化卵巢亦能重新发生，新生卵子的形态、发育时序与首次等待青春期蜕壳的蟹一致；孵后母蟹不仅能继续蜕壳生长，其卵巢也能重新发生，新生卵子的形态、发育时序如前一致；但在卵巢结构上彼此又有明显的区别。     

氨海水与5-羟色胺对栉孔扇贝解剖卵的体外促熟作用

研究氨海水与5-羟色胺(5-HT)对栉孔扇贝解剖获得卵母细胞的促熟作用。通过体外浸泡的方法处理栉孔扇贝卵母细胞使其成熟,并完成人工受精。结果表明一定浓度的氨海水可显著促使栉孔扇贝卵母细胞生发泡破裂,但经过氨处理的卵母细胞受精率却不高;5-羟色胺不能诱导栉孔扇贝卵母细胞生发泡破裂,但可有效地使已经发生生发泡破裂的卵母细胞进一步成熟。先用氨海水处理然后用5-羟色胺处理可以得到最佳诱导效果,受精率可达(40.02±2.73)%。     

激素在诱导鲻鱼卵母细胞成熟中的作用机制

本文报道了在注射促性腺激素和促黄体素释放素类似物诱导鲻鱼卵母细胞成熟过程中,其胞质中高尔基体、油球数量和核的形态均发生显著变化,并据此分析了这两种激素在诱导鲻鱼卵母细胞成熟中的作用机理。     

Reproductive biology of horse mackerel Trachurus capensis and Trachurus trecae in Namibia and Angola

Harvest control measures for Namibia and Angola are defined using reference points for spawning biomass, which requires knowledge of spawning potential and dynamics of fishery stocks. The reproductive biology of two species of horse mackerel, Trachurus capensis and Trachurus trecae, in these waters was investigated for spawning distribution in time and space. Samples were collected during two scientific cruises conducted in February and July/August 2007 off the coast of Namibia and Angola. A total of 396 fish ovaries was examined to determine the spawning dynamics of the two species. The ovaries were histologically analysed and their oocyte distributions mapped. The length (TL)–weight relationships of the two species differed significantly. The observed development of oocyte recruitment and absence of a hiatus in the oocyte distribution indicated that these species are indeterminate spawners. Analyses of the data from the NatMIRC database (2001–2004) indicated annual changes in gonadosomatic index (GSI) for T. capensis at different latitudes, but these changes were small. GSI also fluctuated between years and areas, but there were no clear spatial or temporal trends, with averages ≤4.0% at all stations. The GSI of both species was not indicative of the histologically determined development of gonad maturity. Oocyte maturation for T. capensis indicated that smaller and younger fish spawn first. Batch fecundity (F) for T. trecae was best described by F = 4 986 TL (cm) – 99 645 (r ² = 0.83). This study provided the first analyses of oocyte development in time and space for the two species in the region.     

Ca2+，Mg2+，K+及胰蛋白酶和胰蛋白酶抑制剂对中国对虾卵子激活的影响

对虾成熟卵子的激活都是由海水引起的,海水的刺激引起成熟的卵母细胞发生皮层反应,完成减数分裂,这一过程同有无精子的作用无关(Clark et al.,1977,1980; Lynn et al.,1991; Pillai et al.,1987)。在对锐脊单肢虾(Sicyonia ingentis)的卵子激活研究中发现,其成熟卵子无论受精与否在接触海水以后均具有相同的激活过程,受精卵和未受精卵的皮层反应及减数分裂的恢复没有区别,而海水中刺激卵子发生皮层反应直接因子是Mg2+而不是Ca2+。在无Mg2+人工海水中,锐脊单肢虾的卵子不能激活;而在无Ca2+人工海水中,卵子则可正常激活(Pillai et al.,1987; Lindsay et al.,1992a)。Mg2+对锯额长臂虾(Palaemon serratus)卵子减数分裂的形响的研究表明,锯额长臂虾卵子减数分裂的恢复必须有Mg2+参与,而Ca2+则是非必须的;胞外Mg2+可以诱导卵子的皮层反应,并使卵膜外的微绒毛消失;胞外Mg2+的增加可使卵子内部游离Ca2+浓度发生变化,从而诱导卵子的激活(Goudeau et al.,1986,1991,1996)。 根据前人的报道,胰蛋白酶和胰蛋白抑制剂对对虾精子的顶体反应、卵子的激活都具有明显的影响(Lynn et al.,1987; Griffin et al.,1990; Lindsay et al.,1992b; Chen et al.,1994)。Lynn等(1987)报道褐对虾(Penaeus aztecus)的卵胶前体(jelly procusor)含有约70%-75%的蛋白质及25%-30%的多糖,胰蛋白酶对于人工分离的卵胶前体具有明显的降解作用,胰蛋白酶抑制剂可以抑制卵子在海水中的激活,Griffin等(1990)的研究发现,锐脊单肢虾的卵子内含有类胰蛋白酶的物质,解剖性成熟雌虾获得的卵子置入海水摇匀,上清液-卵水(egg water)可以诱导取自雌虾纳精囊内的精子发生顶体反应,胰蛋白酶也可以诱导对虾精子的顶体反应,而胰蛋白酶抑制剂则完全可以抑制对虾精子在人工海水中发生顶体反应时顶体丝的形成。Lindsay等(1992b)的研究也得出了类似的结果,并对卵水和胰蛋白酶不同浓度及不同作用时间下对对虾精子顶体反应的诱导作用进行比较研究。Chen等(1994)对锐脊单肢虾精子的提取物进行生化分析发现,精子内部也有类胰蛋白酶的物质,并通过免疫电镜技术将其进行定位,精子的提取物可以降解分离的卵黄膜。 激光扫描共聚焦显微镜(Laser scanning confocal microscope)在海洋动物的受精及发育生物学的研究中已有一些报道(Sardet et al.,1992; Stricker et al.,1992; Shen et al.,1993; Jaffe, et al.,1994; Malinda, et al.,1994)。而在对虾的受精及发育生物学方面应用还比较少,只有锐脊单肢虾的卵子激活及早期发育的研究上有一些报道(Hertzler et al., 1992, 1994: Lindsay et al.,1992a)。 海水中的离子成分是影响卵子激活的关键因子,而胰蛋白酶和胰蛋白酶抑制剂对对虾受精也有着很大影响,这两方面的工作在国内、外中国对虾的受精生物学研究中均未见报道。 作者对上述两类理化因子对中国对虾卵子激活的影响进行研究,并使用激光扫描共聚焦显微镜对中国对虾卵子受胰蛋白酶和胰蛋白酶抑制剂的作用而发生的形态变化进行研究,初步分析了造成异常卵裂的原因。     

南非紫菜多糖抗衰老作用的研究

研究了南非紫菜(Porphyra capensis)多糖(PCP)对自然衰老小鼠抗氧化活性及免疫器官的影响。将PCP 以三个剂量(50、100、200 (mg/(kg)?d）)腹腔注射给药, 连续给药20 d, 可以显著提高衰老小鼠的脾脏和胸腺指数, 提高衰老小鼠SOD 和GSH-Px 的活力及总抗氧化能力, 在高剂量时降低衰老动物的MDA 的含量。PCP 能够提高衰老小鼠的免疫机能和机体的抗氧化能力, 是一种比较理想的抗衰老保健产品。     

Critical evaluation of an intercalibration exercise undertaken in the framework of the MED POL biomonitoring program.

The results of an intercalibration exercise among the laboratories participating in the MED POL program for monitoring biological effects of pollutants along the Mediterranean coasts are presented. Three established biomarkers, i.e. lysosomal membrane stability, metallothionein concentration and ethoxyresorufin-O-deethylase (EROD) activity, were intercalibrated. The stability of lysosomal membranes in mussels (Mytilus galloprovincialis Lam.) was assessed with a cytochemical method. The four participating laboratories were able to discriminate between control animals (membrane labilization times ranging from 21 to 35 min) and Cu-exposed animals (40 micrograms/l Cu for 3 days) (labilization times ranging from 4.5 to 7.4 min). The metallothionein concentration was evaluated in digestive gland homogenates of control mussels and of animals exposed to 200 micrograms/l Cd for 7 days. The eight participating laboratories were able to discriminate between controls and treated samples using a spectrophotometric method. The EROD activity was evaluated by 11 laboratories. All laboratories were able to discriminate between liver microsomal preparations obtained from control and from benzo-a-pyrene exposed fish (Dicentrarchus labrax), with values ranging from 0.5 to 15.88 pmol/min/mg protein in controls and from 5.41 to 165.13 pmol/min/mg protein in treated animals. Using S9 fractions, it was possible to correctly identify control and treated fish, with a variation similar to that found using microsomal fractions, albeit with an inevitable difference in specific activity. As a corollary, all laboratories involved produced comparable data and were able to identify pollutant-induced stress syndromes in sentinel organisms. Thus, intercalibration enables the use of biomarkers in large biomonitoring programs.     

Interference by atrazine and bisphenol-A with progestin binding to the ovarian progestin membrane receptor and induction of oocyte maturation in Atlantic croaker

Recent studies have shown that several environmental chemicals which disrupt classical genomic steroid actions can also interfere with nongenomic steroid actions initiated at the cell surface. The effects of bisphenol-A and atrazine on the nongenomic actions of a progestin, 17,20 beta,21-trihydroxy-4-pregnen-3-one (20 beta-S), on oocyte maturation (OM) were investigated an in vitro Atlantic croaker (Micropogonias undulatus) oocyte bioassay. Treatment of croaker follicle-enclosed oocytes with either bisphenol-A or atrazine blocked OM in response to 20 beta-S in a concentration-dependent manner at 10-25 microM (2.2-5.7 ppm) and higher concentrations. These compounds were also effective competitors at concentrations of 10(-6)-10(-5)M of [3H]-20 beta-S binding to the ovarian progestin membrane receptor that mediates the OM response to 20 beta-S. The results suggest that diverse classes of environmental chemicals can disrupt nongenomic progestin actions via receptor-mediated mechanisms.     

Reproduction of the giant jellyfish, <Emphasis Type="Italic">Nemopilema nomurai</Emphasis> (Scyphozoa: Rhizostomeae), in 2006–2008 as peripherally-transported populations

This study investigated the sexual maturation process, release of spermatozoa or eggs and oocyte diameter of the rhizostomid medusae Nemopilema nomurai using samples collected from August 2006 to June 2008 from the waters around Korea and Japan, including peripheral areas outside the species’ usual habitat. Immature medusae were observed from June to October only in the western sector of the study area. The onset of spermatozoa and egg release occurred in September and October, respectively, and peaked in December and January. Medusae migrated eastward from source areas with the Tsushima Warm Current, where they formed gametes and spawned. Peak position and maximum oocyte diameter increased as the gonads developed according to the size-frequency distribution of oocytes. No fertilized eggs or embryos were found in the gonads. The correlation was analyzed with bell diameter, maximum oocyte diameter, sampling date, surface water temperature and gonad color to estimate which environmental factors and maturation indices were related to the maturation stage of females. Maturation stage correlated well with maximum oocyte diameter, which correlated negatively with surface water temperature. There was no significant correlation between bell diameter and maturation stage. Therefore, bell diameter was inappropriate for determining maturation index. Sex could not be distinguished clearly by gonad color. However, light pink gonads were more prevalent in males and various deep colors such as orange and brown were more frequent in female medusae.