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1.
2.
A chromosomal method to distinguish between X- and Y-bearing spermatozoa of the bull in zona-free hamster ova 总被引:1,自引:0,他引:1
The interspecific in-vitro fertilization system using zona-free hamster ova was adopted to distinguish chromosomally between X- and Y-bearing bull spermatozoa. Frozen semen samples were thawed and washed with modified BWW medium including 0.3% BSA (pH 7.2) to remove cryoprotective medium. Motile spermatozoa were recovered from the semen by the 'swim-up' method. These spermatozoa were treated with ionophore A23187 to facilitate capacitation. Adequate capacitation of spermatozoa was found by their movement patterns and the insemination was performed at the optimum time. The fertilized ova were cultured in Medium TC199 with 10% FBS including podophyllotoxin and vinblastine until they reached first cleavage metaphase. Chromosome slides were prepared by our gradual fixation-air drying method. The success rate of the method was 56% of the number corresponding to the zona-free ova used. Altogether 1116 spermatozoa from 4 different bulls were successfully analysed and the ratio of X- and Y-bearing spermatozoa was 542:574 (P greater than 0.3). 相似文献
3.
Hydrogen peroxide was formed in isolated cell walls from Marchantiapolymorpha L. in the presence of MnCl2 by either NADH or NADPHoxidation. This reaction was stimulated by phenols such as 2,4-dichlorophenolor p-coumarate, suggesting a reaction similar to that proposedfor the last step of lignification in higher plant cells, althoughbryophytes have been reported to be devoid of lignin. (Received June 16, 1987; Accepted March 3, 1987) 相似文献
4.
The relationship between nitrification potential and nitrogen accumulation was studied in an early successional sere on Mt.
Fuji. Soil organic nitrogen accumulated with the invasion ofPolygonum cuspidatum and successively withMiscanthus oligostachyus and other species. Laboratory incubation experiments showed a higher nitrification potential at theM. oligostachyus state. The numbers of nitrifying bacteria increased with the progress of succession. No significant difference in nitrate
reductase activity was found between pioneer and succeeding species. The soil solution at theM. oligostachyus stage contained a lower level of nitrate than rainwater, while that of the bare ground and theP. cuspidatum stage contained a higher nitrate level than rainwater. It was concluded that the high nitrate levels in the soil solution
of the bare ground and theP. cuspidatum stage were due to lower nitrate-absorbing activity, leading to loss of nitrogen with precipitation, while the lower nitrate
levels at theM. oligostachyus stage when higher nitrification activity occurred were due to higher nitrate-absorbing activity, preventing net loss of nitrogen
from the ecosystem. 相似文献
5.
Tatsuo Nakahara Makoto Hirano Takashi Matsumoto Toshihide Kuroki Yoshinori Tatebayashi Tetsuyuki Tsutsumi Kouji Nishiyama Hiroaki Ooboshi Kaoru Nakamura Hiroshi Yao Akio Shiraishi Michinori Waki Hideyuki Uchimura 《Neurochemical research》1990,15(6):609-611
DNA and RNA contents in 20 brain regions or nuclei of the rat were determined by a highly sensitive method using high-performance liquid chromatography with electrochemical detection. The high DNA and RNA contents were found in the hypothalamic nuclei, especially the median eminence-arcuate nucleus. These results may be available for the preparation of nucleic acids as the regional control. 相似文献
6.
Analysis of restriction profiles of Mitochondrial DNA from Sporothrix schenckii and related fungi 总被引:5,自引:0,他引:5
Restriction profiles by HaeIII of mitochondrial DNA were studied for classification and distinction of Sporothrix schenckii (100 strains), S. schenckii var. luriei (1), S. curviconia (1), S. inflata (7), Ceratocystis stenoceras (17) and C. minor (7). These 6 species showed unique restriction profiles which could be discriminated from each other. S. schenckii was further separable into 11 types, S. inflata into 4 types, C. stenoceras into 4 types and C. minor into 7 types based on restriction profile heterogeneity. 相似文献
7.
Immunocytochemical studies on the pituitary pars distalis of the Japanese long-fingered bat,Miniopterus schreibersii fuliginosus 总被引:1,自引:0,他引:1
Professor Shin-ichi Mikami Shin Chiba Hitoshi Hojo Kazuyuki Taniguchi Kaoru Kubokawa Susumu Ishii 《Cell and tissue research》1988,251(2):291-299
Summary Immunocytochemical studies were performed to describe the characteristics of cell types and their distribution in the pars distalis of Japanese long-fingered bat, Miniopterus schreibersii fuliginosus, collected at various stages of the reproductive cycle. Six distinct cell types have been identified in the pars distalis by the unlabeled immunoperoxidase technique and by the ABC method. Growth hormone (GH) and prolactin (PRL) cells were immunostained with antisera against chicken GH and ovine PRL. The GH-immunoreactive cells were round or oval orangeophilic cells distributed throughout the pars distalis with prominent aggregation in the posterolateral region. The PRL cells were pleomorphic carminophilic cells that occurred in small groups within the central and dorsocaudal regions of the pars distalis. They were sparsely distributed in the central region of the pars distalis in the hibernating bats, but increased significantly in the pregnant and lactating bats. The adrenocorticotropic (ACTH) cells were large round or polygonal amphophilic cells in the rostroventral and ventrolateral regions of the pars distalis. The thyrotropic (TSH) cells were small rounded or polygonal and distributed mainly in the ventrolateral region of the pars distalis. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) cells were identified immunocytochemically with antisera against the specific beta subunits of ovine LH and rat FSH. There were two populations of LH and FSH cells, one aggregated in the zona tuberalis and the other scattered singly throughout the rest of the pars distalis. The aggregated cells were immunoreactive with both antisera directed to LH and FSH, while scattered cells were reactive solely with antiserum to either LH or FSH and exhibited seasonal variations. In females, the proportional volume of the pars distalis occupied by LH cells was significantly reduced during pregnancy and lactation. No evidence of involution was observed in pars distalis cells except for PRL cells in males or females during hibernation. 相似文献
8.
Masaki Tateno 《Ecological Research》1988,3(3):267-277
Air-dried fresh and dead specimens ofPolygonum cuspidatum were incubated for 250 days in the laboratory, and the growth and turnover of microbial biomass-C in the organic matter were
studied. The biomass-C in the fresh leaf and fresh stem attained maximum levels on day 14 and day 7, respectively, and then
settled down to stable levels. In the dead leaf and dead stem, increase in biomass-C ceased by day 4 and the biomass-C levels
did not change thereafter. The turnover time of the biomass-C was estimated from the amount of biomass-C and the release rate
of CO2-C. The turnover was rapid in the early period of incubation. Then the turnover time became longer and after incubation for
70 days the values approached those in natural soils (longer than 16 days). During the incubation period, nitrogen was not
mineralized in any organic matter. In the dead leaf and dead stem, asymbiotic nitrogen fixation activity increased after incubation
for about 40 days and disappeared by the end of the incubation period, whereas nitrogen fixation was hardly detected in the
fresh leaf and fresh stem. 相似文献
9.
Yasukazu Yamada Haruko Goto Kaoru Suzumori Ritsuko Adachi Nobuaki Ogasawara 《Human genetics》1992,90(4):379-384
Five independent mutations in the hypoxanthine guanine phosphoribosyltransferase (HPRT) gene were identified in a partially HPRT deficient patient with gout and in four Lesch-Nyhan patients. Using the polymerase chain reaction (PCR) technique coupled with direct sequencing, the nucleotide sequences of the entire HPRT coding region amplified from the cDNA and also of each exon amplified form the genomic DNA were analyzed. Three independent point mutations in the coding region were detected in the partially HPRT deficient patient (Case 1) and in two Lesch-Nyhan patients (Case 2 and 3), resulting in single amino acid substitutions. The family study of Case 3, utilizing a PvuII restriction site created in the mutant gene, indicated that the mother was a heterozygote, and a sister and a fetal brother had inherited the normal HPRT gene from the mother. In two other mutants causing Lesch-Nyhan syndrome, a portion of the HPRT gene was deleted, and RNA splicing was missing in both mutants. A 4-bp deletion at the 5 end of exon 4 resulted in formation of three different types of abnormal mRNA (Case 4). The other mutant (Case 5) produced abnormal mRNA including 26bp of intron 8 instead of the deleted 58bp at the 5 end of exon 9, because of a 74-bp deletion from intron 8 to exon 9. 相似文献
10.
Maternal care in the red-headed spruce web-spinning sawfly,Cephalcia isshikii (Hymenoptera: Pamphiliidae) 总被引:1,自引:0,他引:1
We describe oviposition and maternal behavior in the sawfly Cephalcia isshikiiand examine the adaptive significance of this behavior. Females deposited eggs in a single but loose cluster on needles of terminal twigs of spruces, Piceaspp., and remained with the eggs usually on the underside of the twig facing toward the tip. The female attended her eggs until death without taking food but did not follow the first-instar larvae that moved from natal needles even if she survived until then. When the female was disturbed, she usually moved toward the source and attempted to bite it. Though at much lower frequencies, this aggressive behavior was also observed in gravid females and even in males. Field observations and female removal experiments indicated that the female enhanced the survival of the eggs through the reduction of arthropod prédation. 相似文献