New Borrelidins from Onchidium sp. Associated Streptomyces olivaceus SCSIO LO13

Borrelidins M?O ( 1 – 3 ), along with four previously known family members ( 4 – 7 ), were isolated from marine pulmonated mollusks Onchidium sp. associated Streptomyces olivaceus SCSIO LO13. The structures of 1 – 3 were elucidated by extensive spectral analyses of HR‐ESI‐MS, 1D and 2D NMR data. In addition, the cytotoxic and antibacterial activities of 1 – 7 were evaluated enabling us to propose some tentative structure‐activity relationships (SARs), especially those involving modifications at C(22) and the moieties at C(7) and C(8) of the borrelidin scaffold.     

瘤背石磺交配规律的初步研究

雌雄同体动物的交配行为和机制具有多样性的特点。利用身型大小与交配之间的关系来推测雌雄同体动物的交配规律是一个重要的手段。瘤背石磺属雌雄同体动物,通过实验室研究观察及数理分析结果显示：瘤背石磺的求偶行为方式是2个或3个个体进行追逐,追逐具有随机性;其交配行为方式较复杂,既存在同型大小个体交配,也有异型大小个体交配,并且小个体更趋向于扮演雄性角色而大个体多扮演雌性角色。瘤背石磺在繁殖季节时会出现多次交配高峰期,在各交配高峰期时,交配形式具有差异,并且瘤背石磺具有发生互惠性交配的条件。     

瘤背石磺产卵前后生殖系统的组织学变化

瘤背石磺(Onchidium struma)是雌雄同体、异体交配的腹足纲贝类,其生殖系统较为复杂,通过解剖学和组织切片技术对成体瘤背石磺的生殖系统及产卵前后的组织学变化进行了系统的研究.结果表明:(1)雄性生殖系统主要南阴茎囊、阴茎、雄性附性腺、两性腺(早期主要产生精于)和储精囊等部分组成,而雌性生殖系统则由两性腺(后期主要产生卵子)、生殖细胞输送管、蛋白腺、黏液腺、受精囊和阴道等组成;(2)雄性生殖系统的组织学结构在产卵前后变化较小,但两性腺、卵蛋白腺和黏液腺的组织学在产卵前后变化显著;(3)产卵后的两性腺由于成熟卵子的排放,整体结构松散,部分腺泡中有少量未排出的成熟卵细胞和卵黄合成早期的卵母细胞;(4)产卵前的卵蛋白腺中含有许多强嗜碱性的小颗粒(组织学结构类似于卵鞘中的胚胎外周蛋白),产卵后腺体中的颗粒相对较大,且呈嗜酸性;(5)产卵前的黏液腺中存在嗜碱性区、嗜酸性区和混杂区三种区域,但是产卵前黏液腺以嗜酸性细胞为主,而产卵后的黏液腺中以嗜碱性细胞区域为主,且分泌管道中有一些嗜碱性物质.由此可见,卵蛋白腺的主要功能是分泌卵蛋白包裹受精卵形成卵外周蛋白层,而黏液腺则在产卵过程中分泌黏液物质形成卵鞘结构及链状的卵带.     

Hormonal control of egg-laying in the marine pulmonate,Onchidium verruculatum

Extirpation of the pleurovisceral ganglia (PV) blocked egg-laying whereas reimplantation of PV or injection of a PV homogenate into PV-less animals restored the egg-laying capacity of the marine pulomonate, O. verruculatum. Injection of PV homogenate induced egg-laying in intact, mature individuals within 15–45 minutes. Boiling of the homogenate for 15 minutes did not abolish its egg-laying efficacy. However, after incubation with trypsin, a PV homogenate lost its potency. Homogenates of PV from colchicinized animals could not induce egg-laying in intact Onchidium. Similarly, colchicinized animals did not respond to a PV ectract from intact Onchidium. It is hypothesized that egg-laying in O. verruculatum is under the control of a heat-stable, trypsin sensitive hormone secreted by the PV ganglia.     

瘤背石磺的生殖系统和性腺发育

2003年5~8月对瘤背石磺(Onchidium struma)的生殖系统结构和性腺发育进行了组织学研究。瘤背石磺生殖器包括两性腺、卵黄腺、蛋白腺。两性腺具有外管和内管,两管相连后通入蛋白腺,内管分支为收集管与腺泡相通。蛋白腺包括腺体部和分泌物两部分,中央为生殖输送管,蛋白腺具食指突和拇指突。性腺腺泡包括精子期腺泡、卵子期腺泡、精卵同泡和排空期腺泡4种类型。本文还对卵黄腺、受精囊、雄性交接器等结构进行了组织学观察,分析了精子和卵子的发育过程、运输路径。     

瘤背石磺的精子结构

用光学显微镜和透射电子显微镜技术研究了瘤背石磺精子的结构特点,分析了其生理生态适应性以及在肺螺亚纲系统演化中的意义。瘤背石磺的精子由头部、中段和末段组成。头部由奶嘴形的顶体和长圆筒状的细胞核构成。顶体包括顶体囊和顶体构架体两部分;两者的内含物都分布均匀,电子密度稍低于细胞核;顶体基部平整,与核前端之间有一空隙,内含物电子密度极低。细胞核由电子密度高的均匀颗粒物质组成,并出现核泡;核的后端有一"杯形"的凹陷,称为核后窝。中段结构复杂,主要包括一对位于核后窝内的中心粒、轴丝、质膜、线粒体及由线粒体衍生的糖原质螺旋体、基质层和类晶体层等。末段由"9 2"结构的轴丝及外包的质膜组成,无糖原质螺旋体和其它线粒体衍生物。比较瘤背石磺精子与肺螺亚纲其它物种的精子结构,我们认为该物种的精子属于"进化型",是一类在进化地位中比基眼目高等的动物。     

Regulation of ammonia (NH3-N) metabolism in the marine pulmonate,onchidium verruculatum. I. effects of a neuroendocrine centre on tissue ammonia levels

Effect of ganglionic extirpations and replacement on the ammonia levels in the blood and various tissues of the marine pulmonate, O. verruculatum was studied. Three hrs after extirpation of the pleurovisceral (PV) complex only and not any other ganglia, revealed a significant (P < 0.001) decline in the blood and foot ammonia levels and significant (P < 0.001) increment in the hepatopancreatic ammonia level. However, no change was observed in the mantle and nephridial ammonia levels. Replacement of the PV complex, either via implantation of intact ganglia or boiled and unboiled homogenate administration (1 gn/animal) into the ganglionectomised group, restored ammonia levels in the blood and foot and showed significant (P < 0.005) decrease in hepatopancreatic ammonia levels. The results are discussed in the light of hormonal regulation of the nitrogen metabolism.