Determination of Feeder Cell‐Based Cellular Niches Supporting the Colonization and Maintenance of Spermatogonial Stem Cells from Prepubertal Domestic Cat Testes     

JI Yun  HJ Park  MH Park  MS Kim  JH Choi  E Lee  SP Gong  JM Lim  ST Lee 《Reproduction in domestic animals》2014,49(5):705-710

Recently, isolation and in vitro culture of putative spermatogonial stem cells (SSCs) in the domestic cat have been conducted. However, the cellular niche conditions that facilitate the establishment and long‐term maintenance of feline SSCs (FSSCs) have not been described. Therefore, we investigated the type of feeder cells used to stimulate colony formation and growth of FSSCs among the various factors in the FSSC niche. Spermatogonial stem cells isolated from feline testes were cultured on mitotically inactivated testicular stromal cells (TSCs) derived from cats, dogs and mice, and mouse embryonic fibroblasts (MEFs). The formation and growth of colonies derived from SSCs cultured on each type of feeder cell were identified at passage 0, and the morphology, alkaline phosphatase (AP) activity and expression of SSC‐specific genes in surviving colonies were investigated at passage 4. Among these diverse feeder cells, TSCs from cat showed the greatest colony formation, growth and maintenance of FSSCs, and SSC colonies cultured by passage 4 showed a typical dome‐shaped morphology, AP activity and expression of SSC‐specific genes (NANOG, OCT4, SOX2 and CD9). Accordingly, these results demonstrate that feline TSCs could be used as feeder cells to support the establishment and maintenance of SSCs from domestic cats.  相似文献   

Monitoring distances travelled by horses using GPS tracking collars     

BA Hampson  JM Morton  PC Mills  MG Trotter  DW Lamb  CC Pollitt 《Australian veterinary journal》2010,88(5):176-181

Objective The aims of this work were to (1) develop a low-cost equine movement tracking collar based on readily available components, (2) conduct preliminary studies assessing the effects of both paddock size and internal fence design on the movements of domestic horses, with and without foals at foot, and (3) describe distances moved by mares and their foals. Additional monitoring of free-ranging feral horses was conducted to allow preliminary comparisons with the movement of confined domestic horses. Procedures A lightweight global positioning system (GPS) data logger modified from a personal/vehicle tracker and mounted on a collar was used to monitor the movement of domestic horses in a range of paddock sizes and internal fence designs for 6.5-day periods. Results In the paddocks used (0.8–16 ha), groups of domestic horses exhibited a logarithmic response in mean daily distance travelled as a function of increasing paddock size, tending asymptotically towards approximately 7.5 km/day. The distance moved by newborn foals was similar to their dams, with total distance travelled also dependent on paddock size. Without altering available paddock area, paddock design, with the exception of a spiral design, did not significantly affect mean daily distance travelled. Feral horses (17.9 km/day) travelled substantially greater mean daily distances than domestic horses (7.2 km/day in 16-ha paddock), even when allowing for larger paddock size. Conclusions Horses kept in stables or small yards and paddocks are quite sedentary in comparison with their feral relatives. For a given paddock area, most designs did not significantly affect mean daily distance travelled.  相似文献   

Unusual osteochondral lesions of the talus in a horse     

CM SIMPSON  JM LUMSDEN 《Australian veterinary journal》2001,79(11):752-755

A 2-year-old Thoroughbred gelding was evaluated for a grade 3 out of 5 unilateral hind limb lameness. Flexion of the right hock and stifle joints (spavin test) exacerbated the lameness. Response to intra-articular and perineural anaesthesia isolated the source of lameness to the tarsocrural area, despite an absence of tarsocrural joint effusion. Routine radiographic examination of the hock did not reveal any significant abnormalities. Skeletal nuclear scintigraphic evaluation revealed a focal region of increased bone activity in the proximal medial trochlear ridge of the talus. Flexed lateromedial radiographic views identified three discrete semicircular lytic lesions at the proximal articular margin of the medial trochlear ridge of the talus. Conservative management of the lesions was associated with a successful return to racing. The location and appearance of the osteochondral lesions of this report have not been previously reported and may be a manifestation of developmental orthopaedic disease and abnormal endochondral ossification. Nuclear scintigraphy and flexed lateromedial radiographic views facilitated identification of the lesions. This radiographic view is recommended when lameness is isolated to the tarsocrural joint and standard radio-graphic projections fail to identify a cause.  相似文献   

Effect of aflatoxin B1 on resistance induced by Bordetella bronchiseptica vaccine in rabbits   总被引：1，自引：0，他引：1  

M C Venturini  C J Perfumo  M A Risso  C M Gomez  M V Piscopo  M Sala de Miguel  H Godoy 《Veterinary microbiology》1990,25(2-3):209-216

The effects of aflatoxin B1 on the development of the immune response to oil-adjuvanted Bordetella bronchiseptica vaccine and on acquired resistance to bacterial challenge were studied in rabbits. The doses of aflatoxin used were insufficient to produce clinical intoxication. Rabbits were randomly assigned to three groups, each having six animals: control (T), vaccinated (V), and vaccinated plus aflatoxin (VA) at 0.05 mg/kg daily per os. Groups V and VA were vaccinated twice, and the three groups were subsequently challenged with virulent B. bronchiseptica. The average weight gain at weekly intervals was significantly reduced in group VA, and no statistically significant differences were found in the titers of agglutinating antibodies between groups V and VA. There were significant differences between groups V and VA in the extent and severity of the pneumonic process, group VA being most affected. Results indicated that agglutinating antibody titers were not related to the level of protection in the latter group. Other mechanisms, such as alveolar macrophage activity and cell-mediated immunity, were implicated in the impairment of the acquired resistance in rabbits subclinically intoxicated with aflatoxin.  相似文献   

Italian rice varieties: historical data, molecular markers and pedigrees to reveal their genetic relationships     

A. Spada    R. Mantegazza    M. Biloni    E. Caporali  F. Sala 《Plant Breeding》2004,123(2):105-111

Two molecular marker approaches [amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR)] were employed to study genomic relationship among 96 rice cultivars. These included most of the best reputed Italian accessions. AFLP produced 461 fragments, 248 (53%) of which were polymorphic, SSR produced four to 11 alleles in the 12 genomic loci investigated. Genomic similarity was estimated independently for the two molecular marker techniques. Both AFLP and SSR dendrograms agree in splitting the cultivars into two main clusters: a small one, comprising four exotic accessions, and a larger one which could be split into four subgroups. These were also analysed on the basis of historical and pedigree information. This is the first report on the application of DNA polymorphism analysis to reveal genomic relationship among cultivated Italian rice germplasm. Results will be useful for breeding programmes.  相似文献   

Influence of vine training and sunlight exposure on the 3-alkyl-2-methoxypyrazines content in musts and wines from the Vitis vinifera variety cabernet sauvignon   总被引：1，自引：0，他引：1  

Sala C  Busto O  Guasch J  Zamora F 《Journal of agricultural and food chemistry》2004,52(11):3492-3497

The influence of vine training and sunlight exposure on the 3-alkyl-2-methoxypyrazines contents in musts and wines was studied by means of two previously reported methods based on headspace solid-phase micro-extraction. Experimental samples were monitored throughout grape ripening and wine making. 3-Isobutyl-2-methoxypyrazine, 3-sec-butyl-2-methoxypyrazine and 3-isopropyl-2-methoxypyrazine were identified. The 3-isobutyl-2-methoxypyrazine content decreased throughout grape ripening in all of the sample types studied. After 1 day of maceration with the skins, there was an increase, but after racking, no further increase was observed. No significant differences between samples were found during grape ripening. Wines from goblet-trained vines, however, contained significantly less 3-isobutyl-2-methoxypyrazine. Clusters protected from sunlight since the beginning of the veraison resulted in wines with a significantly lower content of this compound than the control samples.  相似文献   

Subcellular calcium transients visualized by confocal microscopy in a voltage-clamped vertebrate neuron   总被引：25，自引：0，他引：25  

A Hernández-Cruz  F Sala  P R Adams 《Science (New York, N.Y.)》1990,247(4944):858-862

Confocal laser-scanned microscopy and long-wavelength calcium (Ca2+) indicators were combined to monitor both sustained and rapidly dissipating Ca2+ gradients in voltage-clamped sympathetic neurons isolated from the bullfrog. After a brief activation of voltage-dependent Ca2+ channels, Ca2+ spreads inwardly, and reaches the center of these spherical cells in about 300 milliseconds. Although the Ca2+ redistribution in the bulk of the cytosol could be accounted for with a radial diffusion model, local nonlinearities, suggesting either nonuniform Ca2+ entry or spatial buffering, could be seen. After electrical stimulation, Ca2+ signals in the nucleus were consistently larger and decayed more slowly than those in the cytosol. A similar behavior was observed when release of intracellular Ca2+ was induced by caffeine, suggesting that in both cases large responses originate from Ca2+ release sites near or within the nucleus. These results are consistent with an amplification mechanism involving Ca2(+)-induced Ca2+ release, which could be relevant to activity-dependent, Ca2(+)-regulated nuclear events.  相似文献   

Metathesis of Alkanes Catalyzed by Silica-Supported Transition Metal Hydrides     

V Vidal  A Theolier  J Thivolle-Cazat  JM Basset 《Science (New York, N.Y.)》1997,276(5309):99-102

The silica-supported transition metal hydrides (=Si-O-Si=)(=Si-O-)2Ta-H and (=Si-O-)xM-H (M, chromium or tungsten) catalyze the metathesis reaction of linear or branched alkanes into the next higher and lower alkanes at moderate temperature (25degrees to 200degreesC). With (=Si-O-Si=)(=Si-O-)2Ta-H, ethane was transformed at room temperature into an equimolar mixture of propane and methane. Higher and lower homologs were obtained from propane, butane, and pentane as well as from branched alkanes such as isobutane and isopentane. The mechanism of the step leading to carbon-carbon bond cleavage and formation likely involves a four-centered transition state between a tantalum-alkyl intermediate and a carbon-carbon final sigma-bond of a second molecule of alkane.  相似文献   

Spatial Variability of Turbulent Mixing in the Abyssal Ocean   总被引：3，自引：0，他引：3  

KL Polzin  JM Toole  JR Ledwell  RW Schmitt 《Science (New York, N.Y.)》1997,276(5309):93-96

Ocean microstructure data show that turbulent mixing in the deep Brazil Basin of the South Atlantic Ocean is weak at all depths above smooth abyssal plains and the South American Continental Rise. The diapycnal diffusivity there was estimated to be less than or approximately equal to 0.1 x 10(-4) meters squared per second. In contrast, mixing rates are large throughout the water column above the rough Mid-Atlantic Ridge, and the diffusivity deduced for the bottom-most 150 meters exceeds 5 x 10(-4) meters squared per second. Such patterns in vertical mixing imply that abyssal circulations have complex spatial structures that are linked to the underlying bathymetry.  相似文献   

Ecology. Are U.S. coral reefs on the slippery slope to slime?     

Pandolfi JM  Jackson JB  Baron N  Bradbury RH  Guzman HM  Hughes TP  Kappel CV  Micheli F  Ogden JC  Possingham HP  Sala E 《Science (New York, N.Y.)》2005,307(5716):1725-1726

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