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31.
Microtus species are very useful as experimental small animals with herbivorous characteristics. In this report, to approach establishment of the use of Japanese field voles (M. montebelli) and Hungarian voles (M. arvalis) as experimental animals, the biological characteristics, breeding methods and reproductive performance of these animal species were comparatively investigated. The number of chromosomes of M. arvalis is 12n = 46, differing from those of M. montebelli, 2n = 30. The breeding and reproduction of the Microtus species were relatively easily accomplished in the laboratory, by giving high fiber-containing rations. These animals prove to be polyestrous and showed postpartum estrous on the day of parturition. In the breeding by the continuous mating of the same pair, there was little or no delay in implantation due to lactation, especially in M. arvalis resulting in continuous birth at intervals of 20 to 21 days. On examination of vaginal smears, Japanese field voles (M. montebelli) did not show any definite pattern whereas 23 out of 30 voles from Hungary (M. arvalis) examined showed 6- to 18-day cycles. There were remarkable differences between the Japanese voles and the Hungarian voles, both biologically and reproductively. 相似文献
32.
Organizers of the Sixth International Symposium on the Biology of the Turbellaria 相似文献
33.
We have employed a new scale for characterizing chromosomal forms in the karyotypes of four species of Bipalium from five localities in Japan. Specimens of Bipalium nobile Kawakatsu et Makino, 1982, from Yokohama had a diploid chromosome number of 2x = 10 (2m + 2sm + 2sm + st & sm + 2sm); specimens of the same species from Toyonaka had this number as well but with slightly different chromosomal form (2m + 2sm + sm & st + 2st + m & sm). An undescribed species from Sanjô, Bipalium sp. 2, with two dorsal stripes and a yellow head crescent, had 2x = 10 (2m + 2sm + 2sm + 2sm + 2m); and another undescribed species from Chichijima Island, Bipalium sp. 3, with five dorsal stripes, had 2x = 10 (2m + 2sm + 2sm + 2sm + 2m). A non-sexual bipaliid tentatively identified as Bipalium kewense Moseley, 1878, from Chichijima Island had 2x = 18 (2m + 2m + 2m + 2sm + 2st + 2sm + 2sm + 2sm + 2sm). 相似文献
34.
Summary Deficiency of inorganic phosphate caused the hyper production of invertase and the derepression of acid phosphatase in a continuous culture ofSaccharomyces carlsbergensis. The specific invertase activity was 40,000 enzyme units per g dry cell weight at a dilution rate lower than 0.05 h–1 with a synthetic glucose medium of which the molecular ratio of KH2PO4 to glucose was less than 0.006. This activity is eight fold higher than in a batch growth and 1.5 fold as much as the highest enzyme activity observed so far in a glucose-limited continuous culture.For the hyper production of invertase, it is necessary to culture the yeast continuously by keeping the Nyholm's conservative inorganic phosphate concentration at less than 0.2 m mole per g dry weight cell. The derepression of acid phosphatase brought about by phosphate deficiency, was similar in both batch and continuous cultures.Nomenclature D
dilution rate of continuous culture (h–1)
- Ei
invertase concentration in culture (enzyme unit l–1)
- Ep
acid phosphatase concentration in culture (enzyme unit l–1)
- P
inorganic phosphate concentration in culture (mM)
- S
glucose concentration in culture (mM)
- X
cell concentration in culture (g dry weight cell l–1)
Greek Letter
specific rate of growth (h–1)
Suffix f
feed
- 0
initial value 相似文献
35.
Cellular localization of thiol-proteinase inhibitor in the epidermis of the newborn rat 总被引:4,自引:0,他引:4
Dr. Kimie Fukuyama Osamu Ohtani Toshihiko Hibino William L. Epstein 《Cell and tissue research》1982,222(2):313-323
Summary In cichlid, poecilid and centrarchid fishes luteinizing hormone releasing hormone (LHRH)-immunoreactive neurons are found in a cell group (nucleus olfactoretinalis) located at the transition between the ventral telencephalon and olfactory bulb. Processes of these neurons project to the contralateral retina, traveling along the border between the internal plexiform and internal nuclear layer, and probably terminating on amacrine or bipolar cells. Horseradish peroxidase (HRP) injected into the eye or optic nerve is transported retrogradely in the optic nerve to the contralateral nucleus olfactoretinalis where neuronal perikarya are labeled. Labeled processes leave this nucleus in a rostral direction and terminate in the olfactory bulb. The nucleus olfactoretinalis is present only in fishes, such as cichlids, poecilids and centrarchids, in which the olfactory bulbs border directly the telencephalic hemispheres. In cyprinid, silurid and notopterid fishes, in which the olfactory bulbs lie beneath the olfactory epithelium and are connected to the telencephalon via olfactory stalks, the nucleus olfactoretinalis or a comparable arrangement of LHRH-immunoreactive neurons is lacking. After retrograde transport of HRP in the optic nerve of these fishes no labeling of neurons in the telencephalon occurred. It is proposed that the nucleus olfactoretinalis anatomically and functionally interconnects and integrates parts of the olfactory and optic systems. 相似文献
36.
Kenji Katagiri Toshihiko Takeuchi Keiko Taniguchi Makoto Sasaki 《Analytical biochemistry》1978,86(1):159-165
Pancreatic elastase was isolated from acetone powder of porcine pancreas by a one step purification procedure on a trialanyl CH-Sepharose 4B affinity column. This column exhibited affinity not only for active elastase but also for trypsin and chymotrypsin which were present in the same pancreatic powder. However, as the extent of affinity toward elastase is considerably higher, the proper conditions were determined with which the adsorbed elastase was isolated in a highly purified form. The yield of elastolytic activity ranged from 60–85% and the purified elastase was shown to be one component by polyacrylamide disc electrophoresis. 相似文献
37.
Ruofan Wang Camille R. Simoneau Jessie Kulsuptrakul Mehdi Bouhaddou Katherine A. Travisano Jennifer M. Hayashi Jared Carlson-Stevermer James R. Zengel Christopher M. Richards Parinaz Fozouni Jennifer Oki Lauren Rodriguez Bastian Joehnk Keith Walcott Kevin Holden Anita Sil Jan E. Carette Nevan J. Krogan Andreas S. Puschnik 《Cell》2021,184(1):106-119.e14
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