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61.
Shinichi Nakagawa Terry D. Bannister Fiona R. Jensen Donald A. McLean Joseph R. Waas 《Biology and Fertility of Soils》2002,35(5):390-392
Animals that can distinguish kin from non-kin may enhance their breeding success through "optimal outbreeding". Although relatedness can influence the breeding success of earthworms, no studies of kin discrimination have been conducted in any Oligochaeta species. We determined whether Eisenia fetida Sav. would discriminate kin and change breeding effort with them. The number of cocoons produced (fecundity), viable cocoons, and hatchlings produced by full sibling (inbreeding) and non-sibling (outbreeding) pairs, from different populations, were compared; in this species, fecundity is a reliable indicator of the occurrence and frequency of mating. There were no significant differences in fecundity between inbreeding and outbreeding pairs, so we obtained no evidence for differential investment based on kinship. However, sibling pairs hatched a significantly greater proportion of their cocoons than non-sibling pairs, suggesting that outbreeding depression may reduce reproductive success. We also provide the first evidence for the possibility of parthenogenesis in this species. 相似文献
62.
63.
Structural characterization and biological activities of an exopolysaccharide kefiran produced by Lactobacillus kefiranofaciens WT-2B(T) 总被引:1,自引:0,他引:1
Maeda H Zhu X Suzuki S Suzuki K Kitamura S 《Journal of agricultural and food chemistry》2004,52(17):5533-5538
Lactobacillus kefiranofaciens, isolated from kefir grains, produces an extracellular polysaccharide when cultured, not only in PYG10 medium but also in a liquid medium containing a rice hydrolysate that had been previously degraded by treatment with a glucoamylase. The maximum yield of the polysaccharide, using the rice hydrolysate as the medium, was 2.5 g/L after a 7-day culture period at pH 5.0 and 33 degrees C. Compositional analysis, methylation analysis, specific rotation, and (1)H and (13)C NMR spectroscopy revealed that the structures of polysaccharides obtained from these two different culture media are essentially identical. The polysaccharide is composed of a hexasaccharide repeating unit and, thus, is known as kefiran. The weight-average molecular weight and the z-average radius of gyration of a sample, purified from the rice hydrolysate medium, were determined to be 7.6 x 10(5) g/mol and 39.9 nm, respectively, by gel permeation chromatography equipped with a multiangle laser-light-scattering photometer. Changes in blood pressure and serum components were examined in SHRSP/Hos rats, using doses of 100 and 300 mg of kefiran/kg of rat. A suppression in the increase in blood pressure was observed in these rats after 30 days. This activity is discussed in terms of the concentration of serum components of the rat, with emphasis on lipid components such as cholesterols, triglycerides, and free fatty acids. 相似文献
64.
Shinichi Ogiyama Kazunori Sakamoto Hiroyuki Suzuki Shingo Ushio Tetsuo Anzai Kazuyuki Inubushi 《Soil Science and Plant Nutrition》2005,51(6):801-808
An experiment was conducted to examine the accumulation and mobility of heavy metals (Zn and Cu) at different depths in three types of arable soils (Brown Lowland soil, Andosol, and Brown Forest soil) amended with cattle and pig farmyard manures for 5 years. Nitric-perchloric acid digestion was performed for the determination of the total amounts of heavy metals, and 0.1 M hydrochloric acid extraction was performed for the determination of the amounts of soluble heavy metals. Results of the soil analysis indicated that pig farmyard manure application resulted in serious contamination of arable soils with Zn and potentially Cu. Especially, the Brown Forest soil displayed a high ability to accumulate heavy metals on the soil surface. Total-Zn concentration in surface soils was considerably affected by the holding capacity of soluble-Zn traction. Although the Andosol amended with pig farmyard manure showed higher concentrations of heavy metals related to the higher ability of retention on a weight basis, the soil did not contribute to high heavy metal accumulation because of its low bulk density. Heavy metals were easily leached in sandy soils such as Brown Lowland soil, and Cu was potentially stable compared with Zn. We suggest that long-term pig farmyard manure application to the Brown Lowland soil and Andosol with a light soil texture is associated with a higher risk of groundwater pollution than the application to the Brown Forest soil. 相似文献
65.
Shinichi YONEKURA Akio OKA Masanobu NODA Norio UOZUMI Tomo YONEZAWA Kazuo KATOH Yoshiaki OBARA 《Animal Science Journal》2002,73(1):51-57
The objective of this study was to investigate the relationship between marbling and serum leptin concentrations. First, we compared serum leptin concentrations between Japanese Black cattle and Holstein calves, and found that the mean serum concentration was significantly higher (P < 0.05) in Japanese Black cattle (2.67 ± 0.41 ng/mL, n = 13) than in Holstein calves (1.79 ± 0.43 ng/mL, n = 5). We then examined the effects of roughage intake or vitamin A on the serum leptin concentrations in Japanese Black cattle. Although the leptin concentrations for the high roughage group were significantly higher than those for the low roughage group at 4, 7 and 20 months old, there was no significant difference in the carcass characteristics of the two groups. In addition, although there was a significant difference in the marbling score between the high vitamin A group and low vitamin A group, there was no significant difference in serum leptin concentrations between the groups. These results suggest that although serum leptin concentrations were not significantly correlated to the marbling scores they may be related to the genetic advantage for marbling in Japanese Black cattle. 相似文献
66.
Hara H Abdalla H Morita H Kuwayama M Hirabayashi M Hochi S 《The Journal of reproduction and development》2011,57(3):428-432
This study was designed to investigate whether freeze-dried (FD) bull spermatozoa maintained the function of the microtubule-organizing center (MTOC) after rehydration and intracytoplasmic sperm injection (ICSI). In a preliminary attempt, the cleavage and blastocyst formation rates in FD-ICSI zygotes (36 and 1%, respectively) were found to be considerably lower than those in control ICSI zygotes (67 and 21%, respectively) or in IVF zygotes (78 and 43%, respectively). An alkaline comet assay indicated that the DNA fragmentation index (length of comet tail % DNA liberated) was not significantly different between fresh and FD spermatozoa. In the main experiment, formation of sperm-asters in the FD-ICSI oocytes 7 h postinsemination occurred at a similar rate when compared with the control ICSI oocytes (41 vs. 49%). Among the oocytes exhibiting sperm aster formation, the extent of microtubule network assembly was comparable between the FD-ICSI and control ICSI groups. However, the MTOC of the ICSI oocytes was not as functional as that of IVF oocytes in terms of the aster formation rate (97%) and the fluorescent intensity of the microtubule network (2.0 folds). These results suggest that the freeze-drying process per se had no adverse effect on maintaining the MTOC function in bull spermatozoa. 相似文献
67.
Hochi S Abdalla H Hara H Hirabayashi M 《The Journal of reproduction and development》2011,57(5):557-563
Freeze-drying (lyophilization) has been proposed as an alternative method for sperm preservation to overcome the disadvantages of the current cryopreservation method such as the high maintenance cost of frozen stocks, the problems associated with transportation of frozen materials and the potential risk of total loss of the frozen stock. Since freeze-dried spermatozoa after rehydration lose their motility, which is an essential requirement to complete physiological fertilization, a relatively difficult microinsemination technique must be applied to rehydrated spermatozoa. Theoretically, it has been supposed that freeze-dried spermatozoa could maintain their functions and abilities to interact with the oocyte cytoplasm after prolonged storage at refrigerator temperature. However, sufficient yield of transferable blastocysts and production of live offspring derived from freeze-dried sperm samples are still subjects to be challenged and overcome in large domestic species. 相似文献
68.
69.
Hiroki Toyoshima Ami Miyata Risako Yoshida Taichiro Ishige Shinichi Takaichi Shinji Kawasaki 《Marine drugs》2021,19(6)
Photooxidative stress-inducible water-soluble astaxanthin-binding proteins, designated as AstaP, were identified in two Scenedesmaceae strains, Coelastrella astaxanthina Ki-4 and Scenedesmus obtusus Oki-4N; both strains were isolated under high light conditions. These AstaPs are classified as a novel family of carotenoprotein and are useful for providing valuable astaxanthin in water-soluble form; however, the distribution of AstaP orthologs in other microalgae remains unknown. Here, we examined the distribution of AstaP orthologs in the family Scenedesmaceae with two model microalgae, Chlamydomonas reinhardtii and Chlorella variabilis. The expression of AstaP orthologs under photooxidative stress conditions was detected in cell extracts of Scenedesmaceae strains, but not in model algal strains. Aqueous orange proteins produced by Scenedesmaceae strains were shown to bind astaxanthin. The protein from Scenedesmus costatus SAG 46.88 was purified. It was named ScosAstaP and found to bind astaxanthin. The deduced amino acid sequence from a gene encoding ScosAstaP showed 62% identity to Ki-4 AstaP. The expression of the genes encoding AstaP orthologs was shown to be inducible under photooxidative stress conditions; however, the production amounts of AstaP orthologs were estimated to be approximately 5 to 10 times lower than that of Ki-4 and Oki-4N. 相似文献
70.
AbstractBiochar application to soils can mitigate carbon dioxide (CO2) by increasing soil carbon (C) sink, but also causes increased CO2 released from soils through priming effects of soil organic carbon (SOC). However, priming effects of biochar application on SOC are complex, showing inconsistent results, and further complicated when applied with other substrates such as organic amendment (OA). Incubation experiments were conducted using Typic Durudand with bamboo (Phyllostanchys edulis Carrière) biochar (400°C) and OA (crotalaria) applied individually, simultaneously or with biochar applied 5 weeks prior to OA application. After 56 d of incubation, cumulative CO2 released from soils with no amendments (control), biochar only (BC), OA only (OA), simultaneous (BC+OA), and differently timed (BCP+OA) applications reached 313, 326, 1270, 1535 and 1311 mg CO2 kg?1, respectively. The OA application distinctly increased CO2 released from the soils due to its decomposition. The OA decomposition rates were comparable with OA and BC+OA, while those with BCP+OA were lower than those with other treatments during early incubation. Net CO2 (CO2-(treatment) ? CO2-control) from soils with BC, OA, BC+OA and BCP+OA yielded 13, 957, 1222 and 998 mg CO2 kg?1, respectively. Primed CO2-BC of 13 mg CO2 kg?1 was equivalent to 4.2% of priming effect relative to CO2-control. Primed CO2-BC+OA [net CO2-BC+OA ? (net CO2-BC + net CO2-OA)] and primed CO2-BCP+OA were 252 and 28 mg CO2 kg?1, equivalent to 26% and 2.9% of priming effects relative to sum of net CO2-BC + net CO2-OA, respectively. The priming effect with BC was negligible likely because of limited amounts of biochar labile C to induce co-metabolism, while BC+OA showed a modest priming effect most likely as a result of co-metabolism induced by additional mineralization of presumably SOC and/or biochar, because the OA decomposition rates were not affected by biochar application. The priming effect with BCP+OA was comparable to that with BC likely due to changes in soil properties caused by biochar application prior to OA, likely from slowed decomposition rates of OA. 相似文献