【摘要】 采用组织学及生物化学的方法,研究了瘤背石磺(Onchidium struma)不同发育时期两性囊的组织结构及其氨基酸组成的变化。瘤背石磺的性腺发育可分为四个时期:增殖期、生长期、成熟期、休止期或耗尽期。增殖期生殖系统开始形成,生殖上皮分裂增生原始生殖细胞;生长期两性囊中生殖原细胞增殖分化迅速,囊泡内出现雌雄两类生殖细胞;成熟期两性囊囊泡中有的充满了主体(受体)的卵母细胞,有的充满了客体(授体)的前精子,有的同时分布着卵母细胞和前精子;休止期生殖系统萎缩,两性囊体积变小,囊泡内仅残留少量生殖细胞。不同发育期瘤背石磺各组织中除牛磺酸及半胱氨酸外共检出氨基酸有16种,其中均以Glu含量最高,Val含量最低,必需氨基酸中以Met含量最高,半必需氨基酸中以Arg含量最高。不同组织中氨基酸总量、必需氨基酸总量不同,但总体上看随着性腺的发育过程,各组织中氨基酸总量大体呈"高-低-高"的变化趋势,单个必需氨基酸含量与必需氨基酸总量的比值(A/E)在各不同发育阶段基本趋于一致。更多还原

【Abstract】 Onchidium struma is a kind of protandrous hermaphrodite marine pulmonate that reproduces by allogamy and oviparity.It contains many kinds of amino acids and trace elements,high protein and low fat contents,and also has significantly edible and medicinal value.Researches on the histological structure and the dynamic changes of amino acids content of Onchidium struma in different development stages will make some contribution to further researches of the reproduction physiology of Onchidium struma,and provide some technical assistance for the artificial cultivation of Onchidium struma.So the histological structure of the hermaphroditic and the amino acids content of Onchidium struma in different development stages had been studied by histological and biochemical methods in our study.The results indicated that the reproductive cycle of Onchidium struma can be divided into four stages: proliferating stage,growing stage,maturing stage and degeneration stage(resting stage).The whole reproductive system started to develop during the proliferating stage and the primordial germ cell began to proliferate.The primordial germ cell proliferated observably and started to differentiate during growing stage.The ovotestis vesica was full of presperm or oocyte or both of them during the ovotestis maturing stage.The vitelline gland was pink and the volume became the largest.The whole reproductive system especially the vitelline gland degenerated obviously during the degeneration stage.Our research suggested that the vitelline gland possibly had the ability of providing nutrients for the development of the sperm and ova.The annual reproduction cycle of the marine pulmonate indicated that ovotestis proliferation mainly appeared from March to April,and the ovotestis growing stage from April to May,the maturing stage from May to August,and the degeneration stage(resting stage) from August to September.But each development stage had no evident boundary.The maturing stage and degeneration stage often overlapped.And Onchidium struma possibly ovulateed more than one time each year,the first time often occured in middle of June and the last time in the middle of August.Sixteen kinds of amino acids(AA) except Tau and Cystine of Onchidium struma were analyzed in different development stages.Among these amino acids,the content of Glu was the highest,and the Val was the lowest.The content of Met was the highest among the essential amino acids(EAA),and among the semi-essential amino acids(SEAA) the content of Arg was the highest.The total content of AA,EAA were not the same in different tissues in different development stages,but there was little difference among the ratios of single EAA content to total EAA content(A/E) in different development stages.The content of total AA has a trend of "high-low-high" with the development of the ovotestis.更多还原