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1.
Hepatocyte growth factor/scatter factor (HGF/SF) is a pleiotropic cytokine that plays a crucial role in the embryonic and postnatal development of various organs including the mammary gland. We cloned bovine HGF and its c-Met receptor cDNAs, and examined their expression during mammary gland development in dairy cows. The 2.5-kbp HGF cDNA clone contained a 2190 bp open reading frame coding a 730 amino acid protein, while the 4.8-kbp c-Met cDNA clone contained a 4152 bp open reading frame coding a 1384 amino acid protein. The bovine HGF and c-Met sequences exhibited more than 87% identity with those of other mammals. RT-PCR analysis revealed ubiquitous expression of both HGF and c-Met mRNAs in various bovine tissues tested. HGF mRNA was detected only in the inactive stage of bovine mammary gland development and not in the developing, lactating, and involuting stages, while c-Met mRNA was detected in the inactive and involuting stages. Immunohistochemical analysis demonstrated that the c-Met protein was found on mammary epithelial cells in the inactive, developing, and involuting stages, and on myoepithelial cells in all stages. These results suggest pivotal roles of HGF and c-Met in the development of bovine mammary gland.  相似文献   

2.
This study was conducted to investigate the developmental capacity of domestic cat-bovine reconstructed embryos via interspecies somatic cell nuclear transfer (iSCNT) and to observe the mitochondrial DNA (mtDNA) content of the iSCNT embryos. The iSCNT embryos were generated using mixed-breed domestic cat fibroblasts as donor cells and enucleated bovine oocytes as the recipient cytoplasm. When the developmental capacities of iSCNT embryos and parthenogenic bovine embryos were compared, there was no difference (P>0.05) in the rates of cleavage and development to the 8-cell stage (86.6 vs. 84.0% and 32.2 vs. 36.2%, respectively). However, in contrast to development of parthenogenic embryos to the morula and blastocyst stages, no iSCNT embryos (0/202) developed beyond the 8-cell stage. For mtDNA analysis, iSCNT embryos at the 1-cell, 2-cell, 4-cell and 8-cell stages were randomly selected. Both cat and bovine mtDNA quantification analysis were performed using quantitative PCR. The levels of both cat and bovine mtDNA in cat-bovine iSCNT embryos varied at each stage of development. The cat mtDNA concentration in the iSCNT embryos was stable from the 1-cell to 8-cell stages. The bovine mtDNA in the iSCNT embryos at the 8-cell stage was significantly lower than that at the 4-cell stage (P<0.05). No difference in the proportions of cat mtDNA in the iSCNT embryos was found in any of the observed developmental stages (1- through 8-cell stages). In conclusion, bovine cytoplasm supports domestic cat nucleus development through the 8-cell stage. The mtDNA genotype of domestic cat-bovine iSCNT embryos illustrates persistence of heteroplasmy, and the reduction in mtDNA content might reflect a developmental block at the 8-cell stage.  相似文献   

3.
牛肺疫是比较常见的一种牛接触性传染病症,严重危害着牛机体。随着近些年国内畜牧业的迅猛发展,牛养殖场规模与数量随之不断扩大,我国养殖业呈现繁荣发展局面。然而,牛养殖期间也会突发各种疫病,带给畜牧生产巨大的经济损失。所以,有效的牛肺疫诊断防控措施对我国养殖业的发展极具重要意义。  相似文献   

4.
旨在分离纯化牛天然肺泡表面活性蛋白A(SP-A)和分析其抗菌活性,首先通过共价交联法制备出可特异吸附SP-A的麦芽糖-Sepharose(MS)胶粒,然后用MS胶粒从牛肺泡洗出液中吸附牛SP-A,从而得到牛SP-A.SDS-PAGE和Western blot检测表明,牛SP-A单体的相对分子质量为30 ku,二聚体为6...  相似文献   

5.
应用mRNA差异显示技术,对两个发育阶段(16月龄和5岁龄)蒙古牛臀肌组织差异表达的基因进行研究,从分子水平分析影响不同发育阶段蒙古牛肉品质的遗传机制。经mRNA差异筛选获得6条差异表达的EST片段,与GenBank中序列进行相似性比对后发现,其中一条序列S1与牛的丝切蛋白2(cofilin 2, CFL2)基因高度同源(相似性99%),确认S1就是牛的CFL2基因;另外5条S2-S6在数据库中未发现同源序列,确定为新的EST片段。 采用相对定量PCR方法对差异表达基因CFL2进行真实性鉴定和差异表达量检测,结果显示,CFL2基因在5岁龄蒙古牛肌肉组织中的表达量是16月龄的3.8倍。过量的丝切蛋白2可以抑制单体型肌动蛋白的聚合及1型优质肌纤维的累积,其高表达可能导致了蒙古牛肉质性状的下降。  相似文献   

6.
7.
In this study, we investigated the ultrastructural changes during the prenatal differentiation of oviductal epithelium in 16 bovine embryos and fetuses from CRL of 18.0 cm to a CRL of 94.0 cm. Ciliated and secretory cells of bovine uterine tube, a derivative of the Müllerian duct, differentiate to distinct development stages in the prenatal period. The typical cellular pattern, which is generally characteristic for the adult bovine oviduct, is also obtained during fetal life. In the early stages (CRL 18.0/20.4 cm), the bovine oviductal epithelium appears mostly undifferentiated. The epithelial cells show only a few mitochondria, some cisternae of rough endoplasmic reticulum (rER) and a small Golgi-complex. Most of the cytoplasm is filled with a large amount of glycogen, which decreases during later development. Interspersed between the undifferentiated epithelial cells, a few cells undergoing ciliogenesis can be observed. Ciliogenesis increased significantly during the later prenatal developmental stages. At a CRL of 55.0 cm, ciliated cells appear fully differentiated with mature cells covering their luminal surface. Formation of cilia usually use the acentriolar pathway. Fibrous granules occurred initially in association with the Golgi-apparatus and r(ER) in the supranuclear cytoplasm. Fibrous granules later fuse with deuterosomes and give rise to procentrioles, which are translocated to the luminal plasma membrane. There they become arranged in a line just beneath the apical cell membrane and further differentiate to basal bodies from which the formation of cilia and striated rootlets take place. Clear signs of differentiation of secretory cells were first seen in our material in fetuses with a CRL of 51.0 cm and 64.0 cm. These cells contain a well developed rER and Golgi-apparatus with dilated cisterns. In the supranuclear cytoplasm, the number of secretory granules continuously increases during later development and the cells adapt to the morphology of mature secretory cells at the CRL 94.0 cm.  相似文献   

8.
为了解内蒙古呼和浩特部分地区牛病毒性腹泻病毒(Bovine viral diarrhea virus,BVDV)的流行情况,本研究采用RTPCR技术从采集自内蒙古某屠宰场的32份牛肺脏样品中检测出两株BVDV,命名为BVDV-HT1704、BVDV-HT1723株。通过在MDBK细胞上传代、免疫荧光试验、5’-UTR基因序列测定及分子进化分析对检测出BVDV阳性的肺脏组织进行鉴定。结果显示:在MDBK细胞中盲传10代后没有病变产生;经IFA检测,在病毒感染的细胞浆内产生特异性荧光;序列同源性和系统进化分析表明该毒株属于BVDV-Ⅱa型,且两株分离株属于单一的分支。本研究首次在我国正常牛肺脏组织中分离到BVDV,为了解BVDV在内蒙古自治区的流行情况及地理分布提供依据,并为相关疫苗的研发奠定了基础。  相似文献   

9.
This study was carried out to determine whether culture media reconstructed with bovine enucleated oocytes and the expression pattern of Oct-4 could support dedifferentiaton of monkey fibroblasts in interspecies cloned monkey embryos. In this study, monkey and bovine skin fibroblasts were used as donor cells for reconstruction with bovine enucleated oocytes. The reconstructed monkey interspecies somatic cell nuclear transfer (iSCNT) embryos were then cultured under six different culture conditions with modifications of the embryo culture media and normal bovine and monkey specifications. The Oct-4 expression patterns of the embryos were examined at the two-cell to blastocyst stages using immunocytochemistry. The monkey iSCNT embryos showed similar cleavage rates to those of bovine SCNT and bovine parthenogenetic activation (PA). However, the monkey iSCNT embryos were not able to develop beyond the 16-cell stage under any of the culture conditions. In monkey and bovine SCNT embryos, Oct-4 could be detected from the two-cell to blastocyst stage, and in bovine PA embryos, Oct-4 was detectable from the morula to blastocyst stage. These results suggested that bovine ooplasm could support dedifferentiation of monkey somatic cell nuclei but could not support embryo development to either the compact morula or blastocyst stage. In conclusion, we found that the culture conditions that tend to enhance monkey iSCNT embryo development and the expression pattern of Oct-4 in cloned embryos (monkey iSCNT and bovine SCNT) are different than in bovine PA embryos.  相似文献   

10.
A seroepizootiologic study of bovine respiratory syncytial virus in a beef herd was conducted from February 1983 through March 1984. During the study period, 3 separate respiratory tract disease epizootics were recognized in calves after they had been split into 3 groups. Bovine respiratory syncytial virus infection was diagnosed in each epizootic on the basis of serologic evidence, postmortem findings, and immunofluorescent examination of lung tissue. Additionally, there was serologic evidence for involvement of bovine adenovirus type 3 in the epizootics in 2 of the groups of calves, but not in the 3rd. In 2 groups of calves, respiratory tract disease occurred in 2 stages, with the 1st stage being mild followed by apparent recovery. The 2nd stage, which was associated with a change to colder weather, was clinically more severe, with death loss occurring.  相似文献   

11.
V(D)J recombination, or immunoglobulin gene rearrangement is a developmentally regulated, cell type specific, site directed recombination event that brings either immunoglobulin or T-cell receptor gene segments together to form mature, expressible Ig or TCT genes. This DNA recombination is directed by the recombinational signal sequences or RSS elements present adjacent to Ig and TCR gene segments. The RSS element is composed of a conserved nonamer element and a conserved heptamer element separated by a conserved length spacer region. In this report, we examine the expression of DNA binding proteins that interact with the RSS element in the bovine fetal thymus using EMSA assays. Our data indicates that the nonamer portion of the RSS element is the primary site of recognition for RSS binding proteins expressed in the bovine fetal thymus. We also show that these proteins are expressed from early stages of bovine fetal development through to full term development.  相似文献   

12.
从牛肺提取精品肝素钠工艺的研究   总被引:1,自引:0,他引:1  
本文报道了酶解盐解,D-254树脂吸附,沉淀剂YNB99-1去蛋白和H2O2氧化制取牛肺精品肝素钠的工艺,结果显示,精品效价150USPu/mg,质量符合出口标准,产率比传统工艺提高22.6%,下脚料一肺渣可用以制取饲料蛋白。  相似文献   

13.
This study represents a continuation of part 1 of a study of the development of the bovine stomach. Material and methods are more fully described in part i of the study. In this part 2 of the study further developmental stages and morphometric analysis is presented.  相似文献   

14.
Intrauterine developmental stages of the gastric compartments of the caprine ( Capra hircus )
A chronological and systematic scheme for intrauterine development stages of the composed stomach of caprine is proposed. Twenty one embryos (1.69 cm to 5.90 cm S. C.) and 16 fetuses (5.90 to 35 cm S. C.) for studying morphogenesis, histogenesis and relationships of gastric compartments were used. Six developmental stages were conventionally determined from the most relevant anatomical and histological characteristics.
The first four stages are characterized by appearance of the different compartments, their morphological modifications and progressive positional changes until their semi-final form and relations.
The two last stages are characterized by histological differentiation of both the reticulum wall and abomasum mucosa. They can also be recognized by observing the volume relationships between rumen and abomasum. Comparative aspects with bovine and ovine intrauterine development are commented together with considerations concerning the unitary origin of the stomach compartments.  相似文献   

15.
Cultures of macrophages initiated from peripheral blood monocytes and organ cultures of tracheal rings were tested for their susceptibility to bovine viruses. With several notable exceptions, viruses cytopathogenic for bovine embryonic lung cultures were cytopathogenic for macrophages. Although cowpox virus replicated in macrophages, pseudocowpox did not, and although pseudorabies virus replicated within macrophages, infectious bovine rhinotracheitis and DN-599 herpesviruses did not. Bluetongue virus established an interesting relationship with macrophages. Whereas bluetongue virus was initially cytopathogenic for macrophages, it lost its cytopathogenicity on repeated passage, although it was capable of continued replication in macrophages. When subsequently passaged onto bovine embryonic lung cultures, it regained its cytopathogenicity. Parainfluenza-3, bovine viral diarrhea, and infectious bovine rhinotracheitis viruses readily destroyed ciliary activity in tracheal-ring cultures, as contrasted with the inability of bovine respiratory syncytial virus to destroy ciliary activity, even though bovine respiratory syncytial virus was able to replicate within ciliated epithelial cells of tracheal rings.  相似文献   

16.
17.
Studying gene expression during the early embryonic stages of in vitro culture is essential and of special interest, not only to gain insights in embryo development but also to find candidate genes that can be used as markers to assess embryo quality. Using differential display RT‐PCR expression of AMPD3 coding for AMP deaminase 3 was found in bovine blastocysts cultured in vitro only under 2% but not under 5 and 20% oxygen tensions. Mapping of this gene to bovine chromosome 15 confirmed its identity. The differential expression of bovine AMPD3 was confirmed by RT‐PCR with specific primers.  相似文献   

18.
Using light microscopic immunohistochemistry, neuron-specific enolase (NSE)-positive endocrine cells were quantitatively analyzed in the sheep lung during different stages of development from the canalicular stages to adulthood. In all stages, NSE-positive endocrine cells were usually located in the bronchi and bronchioles as solitary cells, although a few NSE-positive cell clusters, the so-called neuroepithelial bodies, were found in some places. The number of NSE-positive endocrine cells decreased with advanced stages of gestation. In the late alveolar stage, the number of NSE-positive endocrine cells reached its bottom during the fetal period. There was a gradual upturn after birth. The overall pattern of growth and differentiation of the endocrine cells is most likely species-related and depends on the state of airway development; the number of the endocrine cells of almost all animals, excluding the sheep, in relation to the size of the lung reaches a peak in the late fetal and early neonatal periods and decreases shortly thereafter. NSE-positive endocrine cells were also predominantly located in the large airways during the early stage of development (canalicular stage), and were found more frequently in the small peripheral airways towards the term. These results show the number of NSE-positive endocrine cells in the sheep to be different from that seen in other species.  相似文献   

19.
Scrapie and bovine spongiform encephalopathy (BSE) are major global concerns and the emergence of variant Creutzfeldt-Jakob disease (vCJD) has caused turmoil for blood transfusion services and hospitals worldwide. Recent reports of iatrogenic CJD (iCJD) cases following blood transfusions from Transmissible Spongiform Encephalopathies (TSE)-infected donors have fuelled this concern. Major diagnostic tests for BSE and scrapie are conducted post-mortem from animals in late stages of the disease. Although the lymphoreticular system is involved in the earlier pathogenesis of some forms of sheep scrapie and vCJD, which presents great opportunity for diagnostic development, other TSE diseases (some strains of scrapie, sporadic CJD (sCJD) and bovine BSE) do not present such a diagnostic opportunity. Thus, there is an urgent need for pre-mortem tests that differentiate between healthy and diseased individuals at early stages of illness, in accessible samples such as blood and urine using less invasive procedures. This review reports on the current state of progress in the development and use of prion and non-prion biomarkers in the diagnosis of TSE diseases. Some of these efforts have concentrated on improving the sensitivity of PrPSc detection to allow in vivo diagnosis at low abundances of PrPSc whilst others have sought to identify non-prion protein biomarkers of TSE disease, many of which are still at early stages of development. In this review we comment upon the limitations of prion based tests and review current research on the development of tests for TSE that rely on non-prion disease markers in body fluids that may allow preclinical disease diagnosis.  相似文献   

20.
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