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R Furrer

Publications and source records attributed to R Furrer.

23 records · Page 2Linked to original sources
PubMed1976

Physical characteristics of mouse sperm nuclei.

The nuclei of epididymal sperm, isolated from C57BL/6J and CBA/J inbred mice by their resistance to trypsin digestion, retain the shape differences of the intact sperm head. Various physical characteristics of these nuclei were measured and compared. The measurement of the projected dimensions of nuclei showed that the CBA nuclei are 13.5% longer than C57BL/6 nuclei (8.64 +/- 0.02 mum compared with 7.61 +/- 0.02 mum), 0.8% narrower (3.51 +/- 0.01 vs. 3.54 +/-0.01 mum) with 6.8% more area (22.34 +/- 0.10 vs. 20.91 +/- 0.09 mum2). However, the volumes of the nuclei as based on reconstructing calibrated electronmicrographs of serial sections of the nuclei indicated that CBA are about 7% smaller than C57BL/6 nuclei (3.72 +/- 0.08 vs. 4.01 +/- 0.03 mum3). The buoyant density of the CBA nuclei is 1.435 +/- 0.002 g/cm3 compared with 1.433 +/- 0.002 g/cm3 for the C57BL/6 nuclei as determined on linear CsCl and Renografin-76 density gradients and confirmed by a technique utilizing physiological tonicities. Therefore, the average mass of the CBA nuclei is less than that of the C57BL/6 nuclei (5.34 +/- 0.12 vs. 5.75 +/- 0.05 pg). The sedimentation velocities at unit gravity of nuclei from 11 inbred strains differ over a range of more than 6% with CBA nuclei sedimenting about 2.0% more slowly than C57BL/6 nuclei. We show that for these nuclei the sedimentation velocity can be related to their buoyant density, volume and a sedimentation shape factor. Within the errors of our measurements of these various characteristics, it was found that C57BL/6 and CBA nuclei have similar sedimentation shape factors. Therefore, the difference in sedimentation velocity between these nuclei appears to be primarily a result of differences in volume. The possible applications of these techniques to the physical separation of sperm are evaluated in the discussion.

Animals↗
PubMed1970

The separation, physical characterization, and differentiation kinetics of spermatogonial cells of the mouse.

By means of the velocity sedimentation technique for cell separation, single cell suspensions from the testes of the mouse could be separated into at least seven peaks each with a different sedimentation velocity. These were named and characterized as follows: alpha (12 mm/hr); beta (10 mm/hr); gamma (6.5 mm/hr); delta (4.3 mm/hr); theta (broad peak with median 2.5 mm/hr); kappa (1.1 mm/hr); lambda (0.75 mm/hr). Tritiated thymidine was injected into thirty groups of mice. The spermatogonial cells of each group were separated at one hour and then at daily intervals, and the acid insoluble activity of each fraction was measured. This method enabled us to determine the differentiation patterns of mouse spermatogenesis by following the thymidine label with time. It was found that the spermatogonia and primary spermatocytes formed the theta peak with S-phase spermatogonia and primary spermatocytes having a similar sedimentation velocity of 2.1 mm/hr. The beta cells were identified as late pachytenes and diplotene cells, the gamma cells as secondary spermatocytes, the delta cells as earliest spermatids, the kappa cells as spermatids, and the lambda cells as mature spermatozoa.

Animals↗