RESUMEN
An improved method of sperm selection by glass wool filtration is introduced. After incubation of glass wool filtrates for 30 min at 37 degrees C in a conical-shaped 1.5-ml tube, an enrichment of highly motile spermatozoa was found in the bottom layer of the tube. The effect turned out to be dependent on the conical shape of the tube, as it was not observed in flat-bottomed tubes. Native ejaculates (obtained from 30 men) and their glass wool filtrates were analysed by cell counter, computer-assisted sperm-motility analysis, morphological differentiation and supravital staining of spermatozoa. When 400 microl of ejaculate, diluted with 800 microl of medium, was applied to the top of a column consisting of a 1-ml disposable syringe barrel gently packed with 15 mg of glass wool to a depth of 6 mm, an enrichment of viable spermatozoa was found in the first three 100-microl fractions taken from the bottom of the tube. It is the simplicity of this technique that makes it so easily applicable.
Asunto(s)
Separación Celular/métodos , Filtración , Vidrio , Espermatozoides/citología , Espermatozoides/fisiología , Adhesión Celular , Humanos , Masculino , Microscopía Electrónica de Rastreo , Recuento de Espermatozoides , Motilidad Espermática , Espermatozoides/anomalíasRESUMEN
Monospecific polyclonal antisera raised against Rhizobium leguminosarum bv. trifolii R39, a bacterium which was isolated originally from red clover nodules, were used to study the colonization of roots of leguminous and nonleguminous plants (Pisum sativum, Lupinus albus, Triticúm aestivum, and Zea mays) after inoculation. Eight weeks after inoculation of soil-grown plants, between 0.1 and 1% of the total bacterial population in the rhizospheres of all inoculated plants were identified as R. leguminosarum bv. trifolii R39. To characterize the associative colonization of the nonleguminous plants by R.leguminosarum bv. trifolii R39 in more detail, a time course study was performed with inoculated roots of Z. mays. R. leguminosarum bv. trifolii R39 was found almost exclusively in the rhizosphere soil and on the rhizoplane 4 weeks after inoculation. Colonization of inner root tissues was detected only occasionally at this time. During the process of attachment of R. leguminosarum bv. trifolii R39 to the rhizoplane, bacterial lipopolysaccharides were overexpressed, and this may be important for plant-microbe interaction. Fourteen weeks after inoculation, microcolonies of R. leguminosarum bv. trifolii R39 were detected in lysed cells of the root cortex as well as in intracellular space of central root cylinder cells. At the beginning of flowering (18 weeks after inoculation), the number of R. leguminosarum bv. trifolii R39 organisms decreased in the rhizosphere soil, rhizoplane, and inner root tissue.