共查询到20条相似文献,搜索用时 31 毫秒
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本研究旨在对比值性状QTL采用贝叶斯定位方法进行探讨。将两个具有正态分布的普通数量性状之比定义为比值性状。由于此类性状不服从正态分布,因此在遗传分析上不同于普通性状。利用构成比值性状的两个组分性状的线性结合,我们提出了定位比值性状数量性状位点(QTL)的最大似然法。在此基础上,进一步探索比值性状的贝叶斯定位策略。首先采用贝叶斯压缩方法估计两个组分性状的QTL参数,然后利用两个组分性状的群体均值和QTL遗传效应,产生一个关于比值性状QTL遗传效应的后验样本,通过对这个后验样本的统计分析,来推断比值性状的QTL。模拟研究表明:新方法表现出比似然法更高的QTL检测效力。 相似文献
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《黑龙江畜牧兽医》2015,(7)
为了分析不同标记密度对标记辅助导入一个数量性状基因座(QTL)有利等位基因效率的影响,试验采用两阶段选择策略,前景选择是利用与导入QTL紧密连锁的两侧标记进行间接选择,并将标记辅助最佳线性无偏预测(MBLUP)用于背景选择。结果表明:在回交阶段,不同标记间图距对导入QTL有利等位基因的频率和前景性状的遗传进展影响很小;而在横交阶段,缩小标记间图距可以提高导入QTL有利等位基因的频率和前景性状的遗传进展,但当标记间图距由10 cm缩小到2 cm时,导入QTL有利等位基因频率的变化幅度很小。背景QTL有利等位基因的频率和背景性状的遗传进展在不同标记密度之间基本没有差异,说明当标记间图距小于10 cm时标记辅助导入效率比较高,而且将MBLUP应用于背景选择是可行的。 相似文献
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四倍体紫花苜蓿是重要的豆科牧草之一,由于其复杂的遗传背景与二倍体作物相比遗传作图与重要性状数量性状位点(quantitative trait locus,QTL)定位研究相对滞后。然而,二倍体苜蓿的相关研究起步较早,已经建立了高密度遗传图谱和物理图谱,这些研究为四倍体苜蓿遗传作图与QTL定位奠定了基础。随着第三代分子标记与测序技术的快速发展,极大地促进了四倍体苜蓿的高密度遗传图谱构建与QTL定位研究,并借助分子标记辅助育种技术对提高苜蓿选育效率,加速育种进程具有重要意义。本文对苜蓿遗传图谱构建与QTL定位研究及发展趋势进行了总结,并对苜蓿关联作图与全基因组选择的研究进展及应用前景加以概述,旨在为读者就相关研究领域有较全面的了解。 相似文献
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利用广义线性方法定位家畜抗性等级性状的QTL 总被引:1,自引:1,他引:1
在广义线性模型的框架内模拟研究了家畜抗性等级性状的QTL定位方法,QTL参数的估计采用最大似然方法,比较了阈模型方法与一般线性方法的QTL定位效率,并对影响等级性状QTL定位效率的主要因素(QTL效应、性状的遗传力)进行了模拟研究。试验为多个家系的女儿设计,资源群体大小为500头。结果表明:在QTL位置参数估计及检验功效方面,阈模型方法具有一定的优势,对抗性等级性状QTL定位的功效也高于线性方法。另外,性状遗传力和QTL效应的大小对QTL定位的准确度也有直接的影响,随着性状遗传力QTL效应的增大,2种方法QTL定位的效率均有不同程度的提高。 相似文献
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Hanna F 《Journal of Feline Medicine and Surgery》2005,7(5):275-287
Multiple myelomas are uncommon neoplasms of the bone marrow of cats [Weber NA, Tebeau CS (1998) An unusual presentation of multiple myeloma in two cats. Journal of the American Animal Hospital Association34 (6), 477-483]. Nine cats diagnosed with multiple myelomas were retrospectively identified over a 16-year period (1986-2002). Cats with multiple myelomas were older than 7 years (mean age 11.7 years); six males and three females were affected (2.1), but no breed predisposition was evident. Treatment of multiple myelomas consisted of supportive management in the nine cats and anti-neoplastic therapy in eight cats. Supportive treatment consisted of maintaining hydration, renal function and antimicrobial therapy even when there was no sign of infection. Anti-neoplastic therapy with melphalan and prednisolone was carried out in eight cats. Three failed to respond to treatment and five responded to treatment, but the response was only partial and temporary in one cat. The five cats that responded were improved clinically and had reduced serum protein levels. Five out of eight cats (63%) responded to chemotherapy, and it appeared to be complete in four cats and partial in one cat. Survival time in those cats was 15, 4, 17 and 24 months. 相似文献
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Résumé— Des épithéliomas spinocellulaires se sont développés à partir de kystes folliculaires multiples chez un chien croisé berger Catalan de 6 ans. Le chien est mort après un suivi de 29 mois. Des métastases ont été trouvées dans les poumons et au niveau des métacarpiens 1 et 2 de la patte antérieure gauche. [Multiple squamous cell carcinomas arising from multiple cutaneous follicular cysts in a dog (Épithéliomas spinocel-lalaires multiples se développant à partir de kystes folliculaires multiples chez un chien).
Resumen— Un perro Pastor Catalan desarrolló carcinomas de células planas a partir de multiples quistes foliculares. El perro murió a los 29 meses del seguimiento. Se detectaron carcinomas de células escamosas metástaticos en los pulmones y en los metacarpos I y II de la extremidad izquierda. [Multiple squamous cell carcinomas arising from multiple cutaneous follicular cysts in a dog. (Múltiples carcinomas de células planas surgidos a partir de multiples quised foliculares cutáneo en un perro).
Abstract— Squamous cell carcinomas developed in multiple follicular cysts in a 6-year-old Catalan shepherd cross dog. The dog died after a 29-month follow-up period. Metastatic squamous cell carcinoma was detected in the lungs and metacarpal bones 1 and 2 of the left front paw. 相似文献
Resumen— Un perro Pastor Catalan desarrolló carcinomas de células planas a partir de multiples quistes foliculares. El perro murió a los 29 meses del seguimiento. Se detectaron carcinomas de células escamosas metástaticos en los pulmones y en los metacarpos I y II de la extremidad izquierda. [Multiple squamous cell carcinomas arising from multiple cutaneous follicular cysts in a dog. (Múltiples carcinomas de células planas surgidos a partir de multiples quised foliculares cutáneo en un perro).
Abstract— Squamous cell carcinomas developed in multiple follicular cysts in a 6-year-old Catalan shepherd cross dog. The dog died after a 29-month follow-up period. Metastatic squamous cell carcinoma was detected in the lungs and metacarpal bones 1 and 2 of the left front paw. 相似文献
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Multiple Myeloma in a Dog 总被引:1,自引:0,他引:1
PAUL PENNOCK LENNART JÖNSSON † STEN-ERIK OLSSON ‡ 《The Journal of small animal practice》1966,7(5):343-349
Abstract— Multiple myeloma, a rare tumour of the hemopoietic system, is reported in a 10-yr-old female Poodle. Clinical signs included anemia, weakness, cachexia and pain when the dog was forced to move. Radiographs revealed demineralization of the skeleton; circular radiolucent foci were evident, especially in the long bones, and the sixth thoracic vertebra was compressed. Numerous cells of the plasma cell type were evident in bone marrow smears. Blood electrophoresis revealed hypergammaglobulinemia. Bence-Jones proteinuria was not detected. The animal was destroyed and the clinical diagnosis confirmed at necropsy. Plasma cells were found in the bone marrow, liver, spleen and kidney. The bones were porous and numerous old fractures of the ribs and vertebrae were found. Résumé— Un mytlome multiple, rare tumeur du systtme hématopoiésique est observée chez une caniche femelle de 10 am. Les signes cliniques incluent l'anémie, la faiblesse, la cachexie et des douleurs lorsque la chienne était obligée de faire des mouvements. Des radiographies ont révélé la déminéralisation du squelette; des foyers circulaires translucides aux Rayons X sont évidents, spécialement dans les os longs, et la sixième vertèbre toraxique est compressée. De nombreuses cellules du type des cellules à plasma étaient évidentes dans les macules de moelle. L'électrophorèse du sang a révélé de I'hypergammaglobulinémie. La présence Bence-Jones de protéine dans l'urine n'a pas été détectée. L'animal a été détruit et le diagnostic clinique confirméà la nécropsie. Dies cellules de plasma ont été trouvées dans la moelle, le foie, la rate et les reins. Les os étaient poreux et de nombreuses vieilles fractures des cbtes et des vertèbres ont été trouvtes. Zusammenfassuug—Berichterstattung über das Auftreten von multiplex Myelom, ein seltener Tumor im hämopoietischen System einer zehnjährigen Pundelhündin. Klinische Anzeichen umfassen Anämie, Schwäche, Kachexie und Schmerzen, wenn der Hund zur Bewegung gezwungen wurde. Radiogramme zeigten Demineralisierung des Skelettes; kreisförmige radiotransparente Herde traten besonders in den langen Knochen klar hervor und der sechste Brustwirbel war kompressed. Zahl-reiche Zellen der Plasmakategorie wurden in Knochenmarkabstrichen augenscheinlich. Blut-Elektrophoresis brachte Hyper-Gammaglobulinamie zum Vorschein. Bence-Jones Albuminurie wurde nicht gefunden. Das Tier wurde vernichtet und die klinische Diagnose bei der Obduktion bestätigt. Im Knochenmark, der Leber, der Milz und in den Nieren wurden Plasmazellen festgestellt. Die Knochen waren porös und zahlreiche alte Rippen-und Rückenwirbelbrüche zeigten sich. 相似文献
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McDonnell JJ Kalbko K Keating JH Sato AF Faissler D 《Journal of the American Animal Hospital Association》2007,43(4):201-208
Three dogs with seizures were diagnosed with multiple intracranial meningiomas. Two of the three dogs were golden retrievers, and ages ranged from 9 to 11 years. Treatment consisted of surgery and radiation (n=2) or chemotherapy (n=1). In all three cases, the masses were two distinct tumors as determined by imaging, surgery, or necropsy. In two dogs, the meningiomas had the same histological pattern, while in one dog the histological subtypes were different. 相似文献
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Epulides account for 0-7.8% of tumors in surveys of feline oral neoplasms. A review of the literature revealed no reports of multiple epulides in cats. Multiple, concurrent epulides were diagnosed microscopically in 13 cats. Fibromatous and ossifying epulides were diagnosed in 11 of 13 cats and fibromatous epulides were diagnosed in 2 of 13 cats. Microscopically, these epulides were nonencapsulated, well-vascularized, infiltrative, highly cellular neoplasms that expanded the gingiva and were composed of haphazardly arranged, spindle-shaped to stellate cells amid a dense, collagenous stroma. Osseous foci were a feature in the fibromatous and ossifying epulides. The mitotic rate was low and there was marked hyperplasia of the overlying gingiva with a prominent downgrowth of epithelial cords. These tumors recurred in 8 of 13 cats following surgical excision. While uncommon, multiple epulides in cats have a high incidence of recurrence but do not appear to have metastatic potential. 相似文献
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