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Kashiwazaki N Yamaguchi R Uesugi R Hishiyama N Kim M Nakatsukasa E Kojima Y Okuda Y Hisamatsu S Inomata T Shino M 《The Journal of reproduction and development》2005,51(6):735-739
We examined motility, plasma membrane integrity, and binding capacity to homologous zona pellucidae (ZP) of frozen/thawed epididymal cat sperm as a model species for endangered felines. Epididymal spermatozoa from 20 domestic cats were frozen with freezing egg-yolk extender containing 3.0% glycerol in 0.25-ml straws. Post-thaw motility and plasma membrane integrity of the frozen/thawed spermatozoa were 31.8 +/- 2.4% and 32.2 +/- 4.2%, respectively. The frozen/thawed spermatozoa were co-cultured with frozen/thawed immature homologous oocytes with intact ZP for 3 h to examine their ability to bind to the ZP. Sixteen of the 20 frozen/thawed sperm samples demonstrated the ability to bind to ZP. These results indicated that the freezing system for epididymal sperm used in the present study gives appropriate information for banking the genetic resources of wild felid species. 相似文献
33.
We conducted a field experiment to determine whether logs bored by male Platypus quercivorus beetle were less attractive to conspecifics after beetles had mated. Bored (with male beetles) and unbored logs were placed in a beetle-infested forest and enclosed within a cage. For half of the bored logs, female beetles were released to mate with the male beetles. Log attractiveness was determined by assessing the number of beetles captured on adhesive paper placed on each cage enclosing the log. On the logs on which female beetles were released, the number of beetles captured decreased distinctly after release, and did not differ from the number captured on the unbored logs. In contrast, the number of beetles captured on logs with only unpaired males was higher than the number captured on the unbored logs. This result confirms that the attractiveness of logs bored by male P. quercivorus beetles declines after mating occurs. To our knowledge, this is the first evidence for the relaxation of aggregation pheromone following mating for beetles in the subfamily Platypodinae. 相似文献
34.
We evaluated the differences in the use of a quartz filter and a polytetrafluoroethylene (PTFE) filter as a first (F0)-stage filter in a four-stage filter-pack method. A four-stage filter-pack method can completely collect sulfur species (SO2 and SO 4 2? ), nitrate species (HNO3 and NO 3 ? ), and ammonium species (NH3 and NH 4 + ) with little or no leakage irrespectively of the first-stage filter used. On the other hand, a seasonal variation was observed in the efficiency of collection between the quartz filter and the PTFE filter depending on the material to be collected. There was no seasonal variation in the efficiency of collection in sulfur species; in contrast, a clear seasonal variation was observed for the nitrate and ammonium species. As for NO 3 ? , the PTFE filter was more vulnerable than the quartz filter at air temperatures below 21°C, while the quartz filter was more vulnerable than the PTFE filter at air temperatures exceeding 21°C. A similar vulnerability for air temperature was observed for NH 4 + , although the threshold air temperature was 23°C for NH 4 + . Consequently, the evaporation loss of NO 3 ? would be mainly attributable to the volatilization of NH4NO3, although it is also partially due to the volatilization of NH4Cl. 相似文献
35.
H Sunagawa T Ohyama T Watanabe K Inoue 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1992,54(5):905-913
The complete nucleotide sequence of Clostridium botulinum type D strain CB16 neurotoxin was determined and the deduced amino acid sequence is reported here for the first time. The structure and function of botulinum type D neurotoxin is discussed from a molecular biological viewpoint. DNA was extracted from toxin-converting phage d-16 phi of C. botulinum type D strain CB16, and a fragment (about 10 kbp) coding for the neurotoxin was cloned into Escherichia coli using lambda gt11. A 21-mer oligonucleotide which corresponds to Phe7 to Val13 of the partial amino acid sequence near the N-terminus of the type D neurotoxin was synthesized and used as a probe to identify the gene encoding type D neurotoxin. The nucleotide sequence contained a single open reading frame coding for 1,275 amino acids (molecular weight of 146,785) and the deduced amino acid sequence corresponded exactly to the partial amino acid sequences determined by direct microsequencing of the neurotoxin fragments. In the dichain molecule of the neurotoxin, Thr2 and Asn443 formed the N-termini of the light chain (M.W. 50,410) and heavy chain (M.W. 96,394) respectively, and these two chains were linked with a disulfide bond between Cys437 on the light chain and Cys450 on the heavy chain. The nucleotide sequence of the D-CB16 neurotoxin differed from that previously reported for type D neurotoxin by three nucleotides. 相似文献
36.
The motor protein kinesin moves along microtubules, driven by adenosine triphosphate (ATP) hydrolysis. However, it remains unclear how kinesin converts the chemical energy into mechanical movement. We report crystal structures of monomeric kinesin KIF1A with three transition-state analogs: adenylyl imidodiphosphate (AMP-PNP), adenosine diphosphate (ADP)-vanadate, and ADP-AlFx (aluminofluoride complexes). These structures, together with known structures of the ADP-bound state and the adenylyl-(beta,gamma-methylene) diphosphate (AMP-PCP)-bound state, show that kinesin uses two microtubule-binding loops in an alternating manner to change its interaction with microtubules during the ATP hydrolysis cycle; loop L11 is extended in the AMP-PNP structure, whereas loop L12 is extended in the ADP structure. ADP-vanadate displays an intermediate structure in which a conformational change in two switch regions causes both loops to be raised from the microtubule, thus actively detaching kinesin. 相似文献
37.
Norio Kurihara Masahide Nohta Keiji Tanaka Makoto Kiso Toshio Fujita Minoru Nakajima 《Pesticide biochemistry and physiology》1977,7(4):332-340
Biodegradability of lindane analogs using house fly whole body, microsomes, and microsome supernatant fraction was examined. It decreased in the order of alkoxy ～ methylthio > methyl analogs > lindane in the whole body experiments, as well as with microsomes in the presence of NADPH. With the supernatant in the presence of glutathione, a different trend was observed. The synergistic effects of piperonyl butoxide when used together with lindane analogs were mostly explained in terms of the inhibition of the microsomal metabolism. Piperonyl butoxide was also shown to inhibit the penetration of compounds into the fly body and to make the central nervous system of the American cockroach less sensitive to the action of insecticides causing after and repetitive discharges. It was observed that the value of the percentage of metabolic disappearance of insecticides after a certain period decreases as the dose level initially applied in the whole body experiments increases. The synergistic ratio parallels the percentage of disappearance value after the insecticidal activity test period when a dose corresponding to the unsynergized LD50 is initially applied. When quantitative comparisons are required for biodegradability of insecticides using house flies as the test insects, it should be on the basis of direct metabolism experiments using a fixed dose throughout the series of insecticides, but not on the basis of the synergistic ratio. 相似文献
38.
To provide evidence for the aggregation ofPlatypus quercivorus (Murayama) (Coleoptera: Platypodidae) in association with the mass mortality of oak trees in Japan, we compared the number
of beetles attracted to oak logs bored by males with the number of beetles attracted to logs that had not been bored. Large
numbers of males and females were attracted to the bored logs, and the total numbers increased as the number of entry holes
in the logs increased. This result shows that both male and female beetles aggregate on logs bored by the males. We collected
a large number of beetles attracted to living trees bored by the beetles, and the total number of beetles collected increased
as the number of entry holes/m2 on the tree trunk increased. Beetles also aggregated on living trees bored by the males. 相似文献
39.
M Abduh Ibnu Hajar Hiroshi Inada Masahide Hasobe Takafumi Arimoto 《Fisheries Science》2008,74(3):461-468
ABSTRACT: To understand the mechanism of the behavioral response in the capture process of how fish recognize fishing gear and then how they can avoid the gear, the visual acuity of Pacific saury Cololabis saira was investigated by histological examination of the retina of individuals in the size range of 75–365 mm fork length (FL). The contour map of cone density distribution shows that the highest cone density is located in the temporal area of the retina, which indicated the visual axis as the forward direction. The visual acuity (VA) depends both on the focal length of the lens and the number of cones in the retina. The lens diameter increased linearly from 1.40 to 4.73 mm with fish growth, while the cone density decreased gradually from 765 to 378 cells/0.01 mm2 . Our results show that the visual acuity increases proportionately from 0.057 to 0.140 for individuals ranging in FL from 75 to 365 mm as expressed by the equation VA = 0.0065 × FL 0.5271 ( r 2 = 0.9624). 相似文献
40.
Spatiotemporal changes in growth patterns of chum salmon Oncorhynchus keta that returned to the Ishikari (Japan) and Namdae (Korea) rivers in 1984–1998 were investigated using scale analysis. Juvenile
chum salmon from both populations left coastal marine areas after spring at a size of over 8 cm fork length (FL). In summer,
juvenile salmon from the Namdae River entered the Okhotsk Sea at a larger FL than did Ishikari River juveniles. There were
no significant differences in annual growth between populations of 1-, 2-, and 4-year-old fish. For 3-year-old fish, however,
Namdae River salmon had significantly higher synchronous and sympatric growth than did Ishikari River salmon. Mean FL of adults
was also larger in Namdae River salmon than in Ishikari River salmon. Analysis of covariance (ANCOVA) results showed (1) negative
linear relations between FL and catch, (2) homogeneous slopes of those relations at regional and species levels, and (3) nonhomogeneous
slopes at the population level, indicating that density-dependent effects on growth were most significant at this level. We
concluded that growth of chum salmon was concurrently influenced by stronger effects of intrapopulation competition and weaker
effects of inter- and intraspecific interactions in the Bering Sea. 相似文献