Morphological Structure of Pineal Organ and Retina and Immunolocalization of Melatonin Receptor Mel1a in the Mudskipper Boleophthalmus pectinirostris

大弹涂鱼（Boleophthalmuspectinirostris）属于暖水广温广盐性的两栖鱼类，生活于潮间带的淤泥滩涂和红树林区，以底栖硅藻和有机碎屑为食，分布于中国、朝鲜、越南和日本，我国产于江苏、浙江、福建、台湾、广东和广西沿海滩涂，是我国东南沿海地区的名特优养殖品种。为了阐明大弹涂鱼的半月周期产卵机理，本文以大弹涂鱼为研究对象，运用组织细胞学方法观察了大弹涂鱼松果体和视网膜的形态结构；运用免疫组织化学方法研究了褪黑激素受体（Mel1a）在大弹涂鱼视网膜和脑上的分布情况；将大弹涂鱼暴露在不同的光照和潮汐环境下，研究了Mel1a在视网膜及脑上的分布差异。主要结果如下： 1、大弹涂鱼松果体...The mudskipper (Boleophthalmus pectinirostris) is amphibious fish adapting to a wide range of temperature and salinity, lives in the mudflats of intertidal zone and the mangrove forest. The fish lives on benthic diatoms and organic detritus. It is distributed throughout China, Korea, Vietnam, and Japan, and in China, it is mainly found in coastal mudflats of Jiangsu, Zhejiang, Fujian, Taiwan, Guan...学位：理学硕士院系专业：海洋与环境学院海洋学系_海洋生物学学号：2242008115149

Seasonal changes and differences of concentrations of sex steroid hormones in gonochoristic and hermaphroditic Bostrichthys sinensis

采用酶联免疫吸附法测定了野生中华乌塘鳢(bOSTrICHTHyS SInEnSIS)不同季节血清E2和11-kT含量的变化,并比较了生殖季节养殖雌雄同体与野生雌雄异体之间E2、11-kT和17α,20β-P三种性类固醇激素含量的差异.结果表明,野生雌鱼和雄鱼血清E2和11-kT的含量均具有明显的季节变化,其高低均依次为5>8>2>11月.在相同月份,雌鱼的E2含量显著高于雄鱼,而雄鱼的11-kT含量显著高于雌鱼.生殖高峰期,雌雄同体E2含量高于雌雄异体雄鱼,但低于雌雄异体雌鱼;雌雄同体11-kT和17α,20β-P含量均高于雌雄异体雌鱼和雄鱼;野生雌鱼和雄鱼血清17α,20β-P含量没有显著差异.性类固醇激素在中华乌塘鳢的生殖过程中起着重要作用,E2是野生中华乌塘鳢雌鱼的主要雌激素,而11-kT则是野生雄鱼的主要雄激素.The changes in the levels of serum 17β-estradiol(E2) and 11-keto-testosterone(11-KT) of wild Bostrichthys sinensis during different seasons were measured using enzyme-linked immunosorbent assay(ELISA).Differences in levels of three sex steroid hormones,E2,11-KT,and 17,20β-dihydroxypregn-4-en-3-one(17α,20β-P) were compared between hermaphroditic and gonochoristic Chinese black sleepers during the breeding seasons.The study found that the levels of serum E2 and 11-KT correlated with seasonal changes in both wild females and males.The levels of E2 and 11-KT peaked in May,declined sequentially in August,February,and November.In the same months,the levels of serum E2 in females(165.05±18.00 pg/cm3 in February,1 461.7±313.95 pg/cm3 in May,640.58±35.34 pg/cm3 in August,and 132.62±21.57 pg/cm3 in November) were significantly higher than those in males(40.87±8.16 pg/cm3 in February,70.33±11.08 pg/cm3 in May,56.44±8.46 pg/cm3 in August,and 27.59±7.66 pg/cm3 in November).The levels of 11-KT in males(40.37±8.44 pg/cm3 in February,318.89±15.02 pg/cm3 in May,44.12±2.01 pg/cm3 in August,and 31.41±2.87 pg/cm3 in November) were significantly higher than those in females(10.49±2.87 pg/cm3 in February,55.99±8.8 pg/cm3 in May,27.65±1.47 pg/cm3 in August and 9.18±2.39 pg/cm3 in November).The levels(398.02±248.19 pg/cm3) of serum E2 in the hermaphroditic Chinese black sleepers were higher than those in wild males(294.65±16.26 pg/cm3),but lower than those in wild females(1 461.7±313.95 pg/cm3) during the peak spawning seasons.The levels of serum 11-KT and 17α,20β-P in the hermaphroditic Chinese black sleepers were both higher than those in the gonochoristic females and males.There were no significant differences between the levels of serum 17α,20β-P of males and females.It can be inferred from this study that sex steroid hormones play important roles in the reproduction of Chinese black sleepers and that E2 is the main estrogen in wild females,while 11-KT is the main androgen in wild males.国家自然科学基金资助项目(40776080);福建省自然科学基金资助项目(2007J0068

Observation on Morphological Structure of Pineal Organ of Mudskipper(Boleophthalmus pectinirostris)

鱼类松果体是传达外界信息到体内的主要传感器之一,其分泌的褪黑激素与鱼类生殖活动密切相关.为了阐明大弹涂鱼松果体形态结构与其功能的关系,运用组织细胞学方法研究了大弹涂鱼松果体的形态结构.结果表明,大弹涂鱼松果体位于端脑和中脑之间,由松果体柄和终囊两部分组成,具有背囊结构.松果体柄细长,细胞排列紧密,柄中有空腔,开口与第三脑室相通;松果体终囊膨大成梨形,且有空腔,腔内有皱褶,终囊顶部表面有黑色素细胞;背囊位于终囊下方,形状不规则,其囊壁向囊腔内反复折叠,形成许多复杂、盘旋曲折的内褶,背囊内部可见血细胞.研究结果为将来揭示大弹涂鱼半月周期产卵的机制提供了基础资料.Pineal gland is a transducer that transmits environmental message to the brain in fishes.It produces melatonin to regulate fish spawning behaviors.In order to elucidate the relationship between the structure and functions of the pineal gland in the mudskipper(Boleophthalmus pectinirostris),the morphological structure of pineal organ of the mudskipper was studied using histocytology.Results showed that pineal organ of the mudskipper located between telencephalon and midbrain,was composed of pineal stalk and pineal vesicle,and had a dorsal sac.The pineal stalk was long and thin in shape,the cells arrangement was tight,and there was a cavum in the middle of the stalk.The opening of pineal organ was connected with the ventriculus tertius.Pineal vesicle was expanded as a pear in shape and had a cavum with rugas inside.The top surface of the vesicle was covered by melanophore.The dorsal sac lied under the pineal vesicle and was irregular in shape with a cavum.The inner wall of the sac cavum had many complicated,spiral and tortuous emboles.The blood cells were visible inside the dorsal sac.The data from the present study will be useful to future research on the mechanisms of spawning with semilunar periodicity in the mudskipper.国家自然科学基金项目(40976095);福建省科技计划重点项目(2008N0041