Balancing genetic diversity, genetic merit and population viability in conservation programmes     

N. Piyasatian  B. P. Kinghorn 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2003,120(3):137-149

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鸡球虫病的免疫控制   总被引：9，自引：0，他引：9  

Shirley M.W  蔡建平  谢明权 《中国家禽》2003,25(7):33-35

球虫一旦感染鸡并在其体内定居,就处于宿主免疫系统的监测下并设法建立寄生生活。球虫在鸡体内最长可持续生存14天,且几乎都位于宿主肠壁深层的细胞内,并完全依赖于宿主营养,最多可进行4代生长、增殖(无性生殖)的过程。鸡在感染后数小时即对球虫产生反应,大约4天即可产生特异性的保护性免疫反应,且足以限制再感染。免疫反应强度与许多因素有关,如感染剂量及感染虫种的特性等,但通常一次摄入少量卵囊即足以诱导能充分抵御再感染的免疫反应。虽然认为免疫接种是控制鸡球虫病的实用方法已有50多年,但在化学治疗的鼎盛时代,疫苗使用常被忽略,仅…  相似文献   

Immunodiscrimination Between Native and Recombinant Somatotropin: a Possible Pathway?     

Guidi  A.  Iannone  G.  Castigliego  L.  Gianfaldoni  D. 《Veterinary research communications》2004,28(1):193-196

Veterinary Research Communications -  相似文献   

Identification of Cytokeratins in Bovine Sperm Outer Dense Fibre Fractions     

E Hinsch  JG Boehm  S Groeger  F Mueller-Schloesser  K-D Hinsch 《Reproduction in domestic animals》2003,38(2):155-160

Outer dense fibres (ODF) are important substructures of mammalian sperm tails that are involved in the regulation of sperm motility. In this study, we investigated the identity of several sodium dodecyl sulphate (SDS)‐insoluble ODF proteins. Bovine ODF were purified by separating sperm heads and tails using ultrasound and Percoll^® density gradient centrifugation. Sperm flagella were treated with the detergent cetyltrimethylammonium bromide (CTAB). CTAB‐insoluble material, which reportedly represents the ODF fraction, was collected, and electron microscopy confirmed a highly purified ODF fraction. We found after solubilization of this fraction with SDS that high amounts of insoluble material were retained after centrifugation. SDS‐insoluble material was collected and quantitatively dissolved in 8 M urea. SDS‐gel electrophoresis in the presence of urea revealed polypeptides with apparent molecular masses of approximately 25, 43, and 50 kDa. Subsequent immunoblotting with anti‐cytokeratin antibodies detected two urea‐soluble, SDS‐insoluble proteins with apparent molecular masses of 45 and 66 kDa. The 45‐kDa protein was identified as cytokeratin 19. An antibody reacting with a palette of cytokeratins (CK 1–18 and CK 20), KL1, was the only antibody that reacted with the 66‐kDa polypeptide. We conclude that sperm ODF fractions contain at least one each of type I and type II intermediate filaments. As keratins and intermediate filaments are described as rope‐like structures, we suggest that these intermediate filaments play an important structural or tension‐bearing role in sperm flagella.  相似文献   

Analysis of In vitro Fertilizing Capacity to Evaluate the Freezing Procedures of Boar Semen and to Predict the Subsequent Fertility     

E Sellés  J Gadea  R Romar  C Matás  S Ruiz 《Reproduction in domestic animals》2003,38(1):66-72

A porcine in vitro fertilization (IVF) system and seminal quality parameters of frozen–thawed boar semen were used to assess the effectiveness of two different thawing rates of frozen boar semen, and to address the question of whether differences between fertility of ejaculates could be predicted in a limited field trial. In the first experiment, two thawing procedures were analysed (37°C, 30 s; 50°C, 12 s) and no differences in sperm quality were found. However, when the procedure was 50°C, 12 s the IVF results showed a higher number of sperm per penetrated oocyte and a near 10 points higher rate of pronuclear formation. In the second experiment, the fertility results obtained in the limited field trial show to be efficient enough for application in a commercial use, especially for three of the employed boars (fertility ≥80%). In this limited study, the conventional seminal parameters are not accurate enough to discriminate good and bad boars in relation to fertility. On the contrary, parameters of in vitro penetrability are more precise to predict subsequent fertilities. As conclusion, the IVF fertilization system seems to be a good tool to evaluate the quality of frozen–thawed boar semen previous to its commercial way, to verify the bank semen storage quality and a good way to assay new sperm freezing procedures, as it is the more precise evaluating method in estimating the potential fertilizing ability.  相似文献   

THE SIZE OF STREPTOCOCCUS BACTERIO-PHAGES AS DETERMINED BY X-RAY INACTIVATION     

Exner FM  Luria SE 《Science (New York, N.Y.)》1941,94(2443):394-395

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Über die Winterfestigkeit des BlutlausparasitenAphelinus mali Hald. im niederelbischen Obstbaugebiet     

W. Speyer 《Journal of pest science》1942,18(2):19-21

Ohne Zusammenfassung  相似文献   

Panther Creek coal-basin     

Ashburner CA 《Science (New York, N.Y.)》1883,1(14):394-395

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Molluscan rock-boring     

Wadsworth ME 《Science (New York, N.Y.)》1883,1(15):422

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Sin Herbarium zu verfaufen     

A. Maher 《European Journal of Forest Research》1869,13(1):280

Ohne Zusammenfassung  相似文献