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排序方式: 共有86条查询结果,搜索用时 12 毫秒
1.
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
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SR Cho SA Ock JG Yoo B Mohana kumar SY Choe GJ Rho 《Reproduction in domestic animals》2005,40(2):171-176
The present study was designed to examine the effects of cell-cycle synchronization protocols, such as confluent, roscovitine treatment and serum starvation, in bovine foetal fibroblasts on synchronization accuracy at G0/G1, viability, apoptosis, necrosis and ploidy for use as a nuclei donor. The cells in 5-10 passages were randomly allocated into three treated groups. Cells were cultured either in Dulbecco's modified Eagle's medium (DMEM) + 10% foetal bovine serum (FBS) until 90% confluent (group 1, confluent), in DMEM + 10% FBS + 30 microM roscovitine for 12 h (group 2, roscovitine), or in DMEM + 0.5% FBS for 5 days (group 3, serum starvation). Most of the cells (>80%) in all groups were arrested at the G0/G1 stage. Although the rates did not differ, cells in group 1 showed an increased cell population arrested at the G0/G1 phase. Significantly (p < 0.05) higher rates of apoptosis occurred in group 3 than in group 1 and 2 (10% vs 6% and 6%, respectively). No differences in chromosomal abnormality were observed among groups. However, by increasing the number of cell culture passages up to 15, significantly (p < 0.05) higher chromosomal abnormality was observed than in 5 and 10 passages (39% vs 28% and 23%, respectively) in group 1. The results clearly indicated that bovine foetal fibroblasts could be effectively synchronized at G0/G1 stages by all the three different treatments, confluent, roscovitine and serum starvation. However, cells in confluent showed reduced apoptosis and necrosis when they underwent 5-10 passages, exhibiting increased percentage of cells with stable chromosome diversity. Hence, cells in confluent merit further studies before they could be used as nuclear donors. 相似文献
4.
Theileria orientalis (also known historically as T. sergenti and T. buffeli) is responsible for benign or non-transforming theileriosis, and exerts its major effect through erythrocyte destruction. The life cycle of T. orientalis is essentially similar to that of other Theileria species, except that the schizonts do not induce transformation and fatal lymphoproliferation. The pathogenesis of anaemia as a result of infection is not clearly established and may be multifaceted. Clinical signs of weakness, reluctance to walk and abortion are early but non-specific indications of disease, particularly if accompanied by a history of cattle being moved. Physical examination may reveal pallor (pale eyes, vaginal mucosa), pyrexia, and elevated heart and respiratory rates. T. orientalis is an economically important parasite of cattle in New Zealand, Australia and Japan, especially where naïve animals are introduced into an endemic area or in animals under stress. Increased awareness of the risks posed by the parasite is required to enable management practices to be implemented to minimise its impact. 相似文献
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Two humic acids, extracted from widely different soils, have been fractionated with respect to molecular weight by means of gel chromatography. The resulting fractions were assayed for total nitrogen, amino acid nitrogen, phosphorus and sulphur. Nitrogen and phosphorus contents were greatest in the high molecular weight fractions and decreased considerably with decreasing humic acid molecular weight. The change in nitrogen content was accounted for mainly by the loss of amino acid nitrogen. By contrast, sulphur contents remained constant throughout the molecular weight range. These changes may reflect part of the process whereby nutrient elements, combined organically within humic acid, are made available for plant growth. 相似文献
8.
The amount and chemical nature of soil organic sulphur was determined in several pairs of soils taken from long-term pasture and adjacent, continuously cultivated sites. Similar determinations were also carried out on organic matter extracts obtained from the soils. The lower levels of sulphur in the arable soils compared with pasture soils were assumed to have resulted from the mineralisation of organic matter brought about by cultivation. Losses of sulphur caused by this mineralisation were found to occur in all three organic fractions examined. A high proportion (75%) of the sulphur lost consisted of carbon-bonded sulphur with only 25% derived from HI-reducible forms. Despite this, it is suggested that, of the two forms, HI-reducible sulphur has a more transitory nature and is possibly of greater importance in the short-term mineralisation of sulphur whereas carbon-bonded sulphur passes through an HI-reducible form prior to release as inorganic sulphur. It is suggested that the sulphur present in the fulvic acid pool could, likewise, be most important for short-term mineralisation. 相似文献
9.
Some observations on the desorption and distribution behaviour of copper with soil components 总被引:2,自引:0,他引:2
The ability of copper adsorbed by soil components to desorb back into solution was studied by means of experiments using radioactive 64Cu. It was demonstrated that the amounts of copper which can be readily desorbed from soil components are very small. A dialysis equilibration technique was used to examine the distribution of adsorbed copper between individual materials in a multi-component system. Where only adsorption of copper was involved, the distribution of copper between soil materials was found to agree with predictions based on adsorption studies with individual materials. However, where desorption was involved, as in the experiments on the redistribution of copper between components after an initial adsorption, the results were strongly governed by the poor reversibility of copper adsorption. It is clear that desorption or lack of desorption is very important in affecting plant availability of indigenous or added soil copper and in controlling the distribution of copper added to soils. 相似文献
10.
Disease of geese caused by a new herpesvirus 总被引:3,自引:0,他引:3
PJ KETTERER BJ RODWELL HA WESTBURY† PT HOOPER† AR MACKENZIE‡ JG DINGLE§ HC PRIOR 《Australian veterinary journal》1990,67(12):446-448
A goose flock farmed outdoors in south-eastern Queensland suffered an outbreak of peracute disease with high death rate (97%). Small button ulcers and large plaques overlying lymphocyte aggregates were present on the mucosa of the small intestine of affected birds. Small white foci of necrosis and focal haemorrhages were seen in the livers. Numerous intranuclear inclusion bodies were observed microscopically in hepatocytes and a herpesvirus which grew rapidly in chicken kidney cells was isolated from tissues. Duck virus enteritis (DVE) was suspected but DVE antiserums failed to neutralise the virus. Further serological studies with a limited range of known avian herpesviruses have failed to identify the virus. Experimental transmission resulted in high mortality in geese (100%), lower mortality in ducklings and nil mortality in chickens. Surveillance studies showed no evidence of infection in domestic and wild birds beyond the original farm and the infection appears not to have been established in the area. Wild ducks, which were frequent visitors to the farm dam, were considered the most likely source of the infection. 相似文献