棕熊精子体外获能及异种穿卵的超微结构研究

对棕熊精子体外获能前后和异种穿卵的超微结构观察表明，棕熊精子全长７７μｍ，由头、颈和尾３部分组成，头部长７．３ｍ，宽２．５μｍ，主要由核、顶体及顶体后区组成；颈部由中心粒和９条纵行分节的节柱组成；尾部全长６８．２μｍ，其中中段长１３．２１ｍ，线粒体为６５－６８旋，主段中央为“９＋２”的微管结构，基外方被９条致密纤维和纤维鞘包裹。精子获能前群集成簇，运动缓慢；获能后精子呈超激活运动。获能的精子质膜膨     

牛精子体外获能前后超微结构的研究

应用透射电镜技术,对牛精子体外获能前后超微结构观察的结果表明,牛精子的超微结构相似于其他哺乳动物,但顶体较大;获能后精子发生了顶体反应.在顶体反应中,囊泡化有3种形式:(1)顶体外膜相互融合,形成囊泡;(2)顶体外膜内陷形成囊泡化;(3)顶体外膜和质膜融合形成囊泡.此外,对精子的结构特点和囊泡形成过程进行了讨论.     

猪体外受精中钙调控机理研究

本研究探讨了猪精子体外获能、卵母细胞成熟和受精过程中钙调控机制,并用X射线微分析仪,测定了钙的含量变化和分布状态.结果发现,猪精子获能后,质膜表面钙含量降低,而顶体内部钙升高,并诱发顶体反应,发生囊泡化;中段线粒体基质内的钙较获能前高;A类卵母细胞经体外成熟培养后,其质膜上钙含量升高,而B、C类卵母细胞钙变化却降低.卵子受精后,质膜上钙含量明显升高,分布状态也发生相应变化,受精后20h,质膜上的钙呈集团分布.     

昆明犬成熟精子超微结构的研究

应用透射电镜技术,对3头昆明犬精子的超微结构进行了观察。结果表明,昆明犬精子头部呈卵圆形,长约5.05μm,宽约0.91μm。颈部和尾部横切近圆形。颈部很短,长约0.92μm,直径为0.63μm。尾部中段长约15.02μm,直径约0.86μm;轴丝为9 2型。中段与主段套管式连接。终段轴丝为9×2 2形式。通过观察,没有发现昆明犬精子的独征。同时,冷冻对一些精子细胞膜和顶体造成损害,表现为细胞肿胀,头部和尾部主段、终段质膜变薄、皱褶、破损或丢失;顶体肿胀,顶体外膜囊泡化或不连续,个别出现顶体全脱;中段线粒体较完整,冷冻对昆明犬精子的损害并不十分严重。     

西藏獒犬精子的超微结构观察

应用透射电镜技术。对冷冻复温后西藏獒犬精子的超微结构进行了观察。结果表明．西藏獒犬精子头部呈卵圆形．长约4．62μm、宽约3.13μm、厚约0．66μm。颈部和尾部横切近圆形。颈部很短、长约0.88μm．直径为0．63μm。尾部中段长约7．9μm．直径约0.83μm;轴丝为9＋2型：线粒体螺旋42～49转。中段与主段套管式连接。终段轴丝为9×2＋2形式。同时．冷冻对一些精子细胞膜和顶体造成损害．表现为细胞肿胀．头部和尾部主段、终段质膜变薄、皱褶、玻损或丢失;顶体肿胀,顶体外膜囊泡化或不连续。个别出现顶体全脱;中段线粒体较完整．冷冻对西藏獒犬精子的损害并不严重。     

貉受精的细胞学和X射线微区分析研究

应用电子显微镜和Ｘ射线微分析技术，对貉受精过程和受精卵膜元素研究的结果表明，貉卵子的卵丘细胞具有吞噬和过滤功能；卵丘细胞间的精子顶体尚未发生囊泡化，而附着于透明带的精子发生了顶体反应，并以８０°角穿入透明带，在其穿入的前方打开一个通道，最后穿过。穿过透明带的精子以赤道段或顶体后区同卵膜融合，并激发皮质颗粒释放，接着穿入卵内，最终发育成雌、雄原核。原核期受精卵质膜上具有高含量的钙，并呈集团分布，它在皮质颗粒胞吐释放中起着重要作用。     

梅花鹿精子冷冻前后形态和超微结构的研究

采用光学显微镜和电子显微镜对冷冻前后的梅花鹿精子的形态和超显微结构进行了观察。结果表明：梅花鹿精子全长６１．６±２．７０μｍ,其中头长７．１９±０．４７μｍ,中段长１２．０８±０．７５μｍ。线粒体的螺旋数是６３．６８±４．６６旋,中段线粒体每个螺旋约由３～５个线粒体组成。梅花鹿精子超微结构有３个特点：一是头部的厚度为牛、羊、猪精子的１／２;二是在中环处的质膜未见反折现象,并且主段与中段的联接是以套管式镶嵌;三是末段以９＋２结构变成２０根（１２＋７＋１）单丝管形式排列。冷冻处理可使梅花鹿精子顶体膨胀,顶体内容物丢失,顶体内发生空泡,顶体外膜自身囊泡化,线粒体发生断裂和丢失,末段纤维束因质膜丢失而分散成扫帚状。冷冻后的梅花鹿精子畸形率极显著增高（Ｐ＜０．０１）,冷冻解冻是致使梅花鹿精子顶体完整率和活力降低的主要原因。     

第三讲母猪生殖生理

第三节受精、妊娠与分娩一、受精(一)配子的运行1.射精部位在交配过程中,公猪将精液直接射到母猪子宫或子宫颈中。母猪的子宫颈没有阴道部,使得精液能顺利射入子宫内。2.精子获能精子在受精前必须在雌性生殖道内经历一段时间,并发生一系列生理性、机能性变化,才具有与卵母细胞受精的能力,这种现象称精子获能。公猪精子获能需要3～6小时。3.受精部位在输卵管上1/3的壶腹部受精。4.顶体反应精子获能之后,在穿越透明带前后,精子顶体开始膨大,精子质膜和顶体外膜开始融合,使精子顶体形成许多泡状结构,通过空泡间隙释放出透明质酸酶、放射冠穿透…     

肝素和钙离子载体诱导猪射出精子体外获能的研究

本文采用肝素和钙离子载体诱导猪射出精子体外获能,根据对去透明带仓鼠卵的穿透情况评价获能效果,并用台盼兰·姬姆萨染色观察精子的死活及顶体状态。结果表明,未经获能处理的猪精子不能穿透仓鼠卵,肝素和I-A均能诱导猪精子体外获能并引起顶体反应。经获能处理的精子,在授精后2小时穿透卵子,4小时开始形成雄原核,6小时形成发育良好的雄原核。肝素处理以100μg效果最好,穿透率达77.8%,有原核卵百分率达47.2%;I-A处理以0.3uM为宜,穿透率达66.7%,有原核卵百分率达42.4%。咖啡因与肝素和I-A具有协同作用,能提高精子的穿透能力。有顶体反应的活精子百分率与穿透率呈强正相关(肝素组:r=0.97,P<0.01;I-A组:r=0.94,P<0.01)。     

兔精液冷冻复温后超微结构变化和低渗膨胀实验

实验从精子超微结构的变化对冷冻解冻精子的损伤进行研究。结果表明冷冻复温后兔的一些精子不同程度出现了质膜膨胀、变薄、皱褶及损伤；顶体肿胀、顶体外膜、内膜囊泡化或不连续，及顶体完全脱落；部分精子中段质膜破损。线粒体裸露、断裂、电子密度降低或部分丢失；少数主段末段质膜破损，抽丝断裂、散开。实验验证HOST（hypoosmotic swelling test)适合于兔精子膜功能活性检测。     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.

     

Scrapie in goats in Cyprus

Ovine scrapie was first recorded in Cyprus in 1985. Subsequently four dairy goats kept in two mixed flocks with affected sheep developed characteristic clinical signs similar to those seen in sheep. Fifteen goats from the two flocks were examined histologically and neurological lesions consistent with a diagnosis of scrapie were found in the four animals and in three others which had subsequently developed early neurological signs. These lesions were similar to those of naturally-affected sheep although neuronal degeneration and vacuolation were more severe in some cases.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.