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71.
The aim of this study was to determine the changes in the mRNA expression of Toll-like receptors (TLRs) in hen ovarian follicles during follicular growth and in response to lipopolysaccharide (LPS). White follicles and the fifth largest to largest follicles (WF and F(5)-F(1), respectively) were collected from laying hens. To examine the effects of LPS, the laying hens were treated intravenously with LPS (1 mg/kg BW) 0, 3, 6, 12 and 24 h before examination. Expressions of TLRs and IL-1beta in the theca and granulosa layers were examined by semi-quantitative RT-PCR. Immunocytochemistry was performed to identify immunoreactive TLR-4. The theca layer expressed TLR-2, TLR-4, TLR-5 and TLR-7, whereas the granulosa layer expressed only TLR-4 and TLR-5. The expression of TLR-4 and TLR-5 in the theca layer increased significantly during follicular growth. In the granulosa layer, the expression of TLR-5 increased, but that of TLR-4 was unchanged. Expression of TLR-4 increased significantly during the period of 6 to 12 h of LPS treatment in the theca layer and during the period of 12 to 24 h in the granulosa layer of F(3). Immunoreaction products for TLR-4 were observed in theca interna and granulosa layers of WF and F(5)-F(1), with the greater amount observed in the theca interna. LPS treatment significantly increased expression of IL-1beta in the theca layer after 3 h and in the granulosa layer during the period of 12 to 24 h. These results suggest that TLRs are expressed in ovarian follicles and that TLR-4 and TLR-5 expression increase with the growth of follicles. Enhanced expression of TLR-4 and IL-1beta by LPS in the theca and granulosa layers suggests possible roles of TLR in recognition of microorganisms.  相似文献   
72.
The pathogenicities of RacL11 and Kentucky D strains of equine herpesvirus 1 in the hamster infection model are different from those of Ab4p and the Japanese isolates. Virus genome restriction fragment length polymorphism analysis and sequence comparison of an intergenic region, glycoproteins and tegument genes showed higher conservation but with some strain-specific differences. These results indicate that point nucleotide differences in RacL11 and Kentucky D might be responsible for their pathogenicity in rodent models.  相似文献   
73.
The incidence of canine rabies has been widely reported in Brazil, and new rabies virus (RV) variants, genetically similar to canine RV, have recently been isolated from foxes. In order to derive the epidemiological characteristics of Brazilian Carnivora RV, Brazilian RVs isolated from dogs, cats, and foxes were genetically analyzed. Brazilian Carnivora RV isolates were divided into 2 main lineages. The predominant lineage was found in dogs and cats, which included the Argentinean and Bolivian Carnivora RV isolates, and was extensively distributed throughout Brazil and surrounding countries. The other lineage consisted of three sublineages containing Brazilian dog and fox RV isolates, with the dog sublineages located on an internal branch of 2 fox sublineages, suggesting that RV transmission events might have occurred between foxes and dogs in the past. These results suggest that contact between dogs and wildlife has the potential to generate new rabies variants and that it is important to control RV infection cycles in both dogs and wildlife to prevent spread of rabies infection.  相似文献   
74.
The nucleotide sequences of 18S rDNA and internal transcribed spacer (ITS) regions were used for studying the relationships of Trypanosoma evansi isolate from a buffalo. The sequences were analyzed and compared to 18S rDNA and the ITS regions of the other Trypanosoma spp. Maximum likelihood phylogenetic trees were constructed using Leishmania major as the outgroup. The tree of 18S rDNA indicated that T. evansi (buffalo B18) isolate was closely related to those of Taiwan and T. brucei stock. The ITS tree showed the genetic diversity among 32 clones of T. evansi (B18) within a single host. This data will be useful for epidemiological and dynamic studies for designing the rational control programs of the disease.  相似文献   
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Background:Cotton fiber quality and seed composition play vital roles in the economics of cotton production systems and the cottonseed meal industry.This research aimed to examine the effects of different irrigation levels and planting geometries on fiber quality and seed composition of cotton(Gossypium hirsutum L.).We conducted a 2-year study in 2018 and 2019 in a warm,humid area in the Southeast United States on Dundee silt loam soil.There were three irrigation treatments in the study.The treatments included irrigating every furrow,or full irrigation(FI),every alternate furrow,or half irrigation(HI),and no irrigation,or rain-fed(RF).Planting geometries were on ridges spaced 102 cm apart and either a single-row(SR)or twin-rows(TR).Results:The results of high-volume instrument(HVI),advanced fiber information systems(AFIS)and near-infrared reflectance spectroscopy(NIRS)showed that irrigation and planting treatments played a significant role in fiber quality and seed composition.Across irrigation treatments,significant differences were seen in fiber properties,including fineness,maturity ratio,micronaire,neps,short fiber,strength,uniformity,upper half mean length(UHML),upper quartile length by weight(UQLw),and yellowness(+b).Irrigation and planting geometry(PG)had a significant effect on micronaire,strength,and UHML while their interaction was significant only for micronaire.The micronaire was negatively affected by irrigation as FI-SR,FI-TR,HI-SR,and HI-TR recorded 11%~12%lower over the RF-SR and TR treatments.The PG played a minor role in determining fiber quality traits like micronaire and nep count.Irrigation treatments produced significantly lower(3%~4%)protein content than rain-fed,while oil content increased significantly(6%~10%).Conclusions:The study results indicate a potential for improving cotton fiber and seed qualities by managing irrigation and planting geometries in cotton production systems in the Mississippi(MS)Delta region.The HI-TR system appears promising for lint and seed quality.  相似文献   
78.
Somaclonal variation in tissue culture is a common phenomenon induced by various external or internal environmental conditions,resulting in heritable or non-heritable alterations in gene expression. One crucial mechanism involved in plant growth and development is epigenetic regulation. A highly dynamic epigenome can respond to environmental changes by regulating gene expression. DNA methylation is one of these epigenetic modifications that can alter gene expression in tissue-cultured pineapple ...  相似文献   
79.
Neoparamoeba pemaquidensis is an ubiquitous amphizoic marine protozoan and has been implicated as the causative agent for several diseases in marine organisms, most notably amoebic gill disease (AGD) in Atlantic salmon. Despite several reports on the pathology of AGD, relatively little is known about the protozoan and its relationship to host cells. In this study, an in vitro approach using monolayers of a rainbow trout gill cell line (RTgill-W1, ATCC CRL-2523) was used to rapidly grow large numbers of N. pemaquidensis (ATCC 50172) and investigate cell-pathogen interactions. Established cell lines derived from other tissues of rainbow trout and other fish species were also evaluated for amoeba growth support. The amoebae showed preference and highest yield when grown with RTgill-W1 over nine other tested fish cell lines. Amoeba yields could reach as high as 5 x 10(5) cells mL(-1) within 3 days of growth on the gill cell monolayers. The amoebae caused visible focal lesions in RTgill-W1 monolayers within 24 h of exposure and rapidly proliferated and spread with cytopathic effects destroying the neighbouring pavement-like cells within 48-72 h after initial exposure in media above 700 mOsm kg(-1). Disruption of the integrity of the gill cell monolayers could be noted within 30 min of exposure to the amoeba suspensions by changes in transepithelial resistance (TER) compared with control cell monolayers maintained in the exposure media. This was significantly different by 2 h (P < 0.05) compared with control cells and remained significantly different (P < 0.01) for the remaining 72 h that the TER was monitored. The RTgill-W1 cell line is thus a convenient model for growing N. pemaquidensis and for studying host-pathogen interactions in AGD.  相似文献   
80.
The amyloid-like fibrillation of soy β-conglycinin subunits (α, α', and β) upon heating (0-20 h) at 85 °C and pH 2.0 was characterized using dynamic light scattering, circular dichroism (CD), binding to amyloid dyes (Thioflavin T and Congo red), and atomic force microscopy. The fibrillation of all three subunits was accompanied by progressive polypeptide hydrolysis. The hydrolysis behaviors, fibrillation kinetics, and morphologies of amyloid-like fibrils considerably varied among α, α', and β subunits. Faster hydrolysis rates and special fragments were observed for the α and α' subunits compared to the β subunit. However, the order of the fibrillation rate and capacity to form β-sheets was α' > β > α, as evidenced by CD and Thioflavin T data. Moreover, sequential growth of twisted screw-structure fibrils, leading to macroscopic fibrils with distinct morphological characteristics, was observed for β-conglycinin and individual subunits. The different fibrillation kinetics and morphologies of α, α', and β subunits appear to be associated with the differences in the amino acid composition and typical sequence of peptides. Besides, the disruption of ordered structure of fibrils occurred upon further heating (6-20 h) due to extensive hydrolysis. These results would suggest that all subunits are involved in the fibrillation of β-conglycinin, following multiple steps including polypeptide hydrolysis, assembly to amyloid structure, and growth into macroscopic fibrils with a fibril shaving process.  相似文献   
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