The physicochemical property of shark type I collagen gel and membrane     

Nomura Y  Toki S  Ishii Y  Shirai K 《Journal of agricultural and food chemistry》2000,48(6):2028-2032

The physicochemical properties of shark type I collagen gel and membrane were not same as those of pig type I collagen. The denaturation temperature of shark collagen gel was about 15 degrees C lower. According to scanning electronic micrography, the diameter of shark collagen fibril was relatively thin and more homogeneous. The breaking strength of shark collagen gel was greater, and shark collagen membrane had a greater mechanical strength and a higher water vapor sorption.  相似文献   

Effectiveness of some management procedures for seed regeneration of plant genetic resources accessions     

K. Yonezawa  T. Ishii  T. Nomura  H. Morishima 《Genetic Resources and Crop Evolution》1996,43(6):517-524

Procedures for seed regeneration of plant genetic resource accessions were investigated in terms of their effect on the variance effective population size and the probability that the initial allelic diversity is maintained after 10 and 20 cycles of regeneration. Four regeneration systems were compared: a bulk system (BL) where seeds are collected and treated in bulk, a partial sampling system (PS) where seeds are collected from not all, but some plants in the population with an equal number of offspring being raised from each sampled plant, a single seed system (SS) where accessions are regenerated so that each plant leaves one progeny, and the biparental mating system (BP) of Gale & Lawrence (1984) where plants are pollinated in pairs with one offspring being raised from each of the paired plants, or two offspring from one of the paired plants. It was shown that the relative efficiency of the four systems largely depends on the rate of selfing and that differences in the effective population size of the systems increase with increasing rates of selfing. The SS system gave by far the largest effective population size in regenerating the seed of moderately or highly selfing species. Although the BP system gave the largest effective size for outcrossing species, the SS system, when combined with selfing, gave a much larger effective size. The BL and PS systems were in no case the most effective. Of these two, PS system with a sampling fraction of 50% was as effective as BL, but less effective with a sampling fraction smaller than 50%. Calculations of the maintenance of the allelic diversity, however, revealed that differences between the systems are not appreciably large unless the accessions are regenerated over 10 or more cycles with 50 or fewer plants.  相似文献   

Development of a rapid method for identifying asparagus super-males using, N-(4-chloro-2-trifluoromethylphenyl)-N'- propoxyacetamidine to induce flowering   总被引：2，自引：0，他引：2  

Takahiro Sonoda  Hajime Iwamura  Atsuko Uragami  Masayuki Ohwada 《Euphytica》2003,129(2):169-174

In order to shorten the term for the identification of asparagus super-maleplants, a method usingN-(4-chloro-2-trifluoromethylphenyl)-N'-pro-poxyacetamidine (AM12) toinduce flowering was developed. This method is conducted as follows: seedsfrom andromonoecious flowers are treated with AM12 to induce flowersto form on the seedlings, the new male flowers are crossed with normalfemale flowers, and the progeny seeds are again treated with AM12 toidentify super-male plants from the sex ratio of the seedlings.Asparagus officinalis cv. `UC157' seeds were treated with AM12.The seedlings were induced to flower at a high frequency in 25 days. Thesex ratio of the plants was 1:1 and the male flowers had the pollengermination ability. One male flower induced by AM12 was crossed withfemale plant. This cross produced many progeny seeds. The seeds weretreated again with AM12, and induced to flower. Two super-male plantswere found among the progeny of andromonoecious flowers of the all-malecultivar `Gijnlim' within six months by this method. This method thusshortens the time for identifying super-males. Since the female flowers werefertile as well, AM12 treatment would also be effective for cross breeding.  相似文献   

Comparison of two models to estimate genetic parameters for number of born alive in pigs     

Ayane Konta  Shinichiro Ogawa  Makoto Kimata  Kazuo Ishii  Yoshinobu Uemoto  Masahiro Satoh 《Animal Science Journal》2020,91(1)

The performance of the two‐trait animal model that regards the first parity and later parities as two different traits in estimating genetic parameters for number of born alive (NBA) was examined using real and simulated data. Genetic parameters for NBA were estimated in purebred Landrace and Large White pigs using a single‐trait repeatability model (Model 1) that regards all parities as the same trait and a two‐trait animal model (Model 2) that regards the first and the later parities as different traits. For Model 2, the permanent environmental effect was fitted to only the records of the later parities. Heritability for NBA estimated using Model 1 was 0.12 for Landrace and 0.11 for Large White. Estimated heritability for NBA of the first parity and the later parities was 0.21 and 0.16, respectively, for Landrace; 0.18 and 0.16, respectively, for Large White obtained using Model 2, and higher than those in both breeds obtained using Model 1. Further results based on data simulated using the Monte Carlo method suggest that estimated additive genetic variance could be more biased using Model 2 than Model 1.  相似文献   

Role of urine in the spawning of female rose bitterling,Rhodeus ocellatus ocellatus     

Takahiro Matsubara 《Fish physiology and biochemistry》1994,13(5):399-405

This study clarified the spawning mechanism of female rose bitterling, Rhodeus ocellatus ocellatus, with special emphasis on the physical role of urine. Ovulated females ingested a significantly greater quantity of water by drinking than non-ovulated fish. The body weight of ovulated females increased about 1.3% while it decreased 1.0% in non-ovulated females. Urine volume in the urinary bladder increased rapidly before spawning, synchronized with the spawning cycle. On the other hand, little urine remained in specimens which had completed spawning. Histological observation demonstrated that the oviduct and the ureter joined at the proximal part of the ovipositor. On the basis of these anatomical and physiological results, it is proposed that urine plays the physical role of pushing the ovulated eggs through the elongated ovipositor during spawning.  相似文献   

Polypolar spindle formation during first cell cycle in rainbow trout <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis> embryos after heat-shock treatment     

Xuelian Zhang  Takahiro Asami  Hiroshi Onozato 《Fisheries Science》2007,73(6):1325-1331

ABSTRACT:   Heat shock has been used to inhibit cleavage for the induction of monogenic diploids or tetraploids in animals, but usually the success rate is low. Heat-shocked rainbow trout Oncorhynchus mykiss embryos were used in this histological study to clarify the causes of this low success rate. Embryos treated with hydrostatic pressure were used for comparison. After heat shock had disorganized the spindles, polypolar (tripolar or tetrapolar) spindles in addition to bipolar spindles were often reassembled soon after treatment. The embryos then completed tripolar or tetrapolar division at the first mitosis, and directly turned into three- or four-cell embryos as a result of the first cleavage. During the second mitosis, a monopolar spindle was formed in each blastomere of four-cell embryos and approximately 60% of three-cell embryos. In the remaining three-cell embryos, two of the three blastomeres formed a monopolar spindle, and the third one formed a bipolar spindle. The formation of polypoles is assumed to be caused by insufficient disorganization of daughter centrioles and splitting from the mother centriole by heat shock. Polypolar division is considered to be the cause of aneuploidy and the low success rate of chromosome set doubling. In the case of hydrostatic pressure treatment, the regenerated spindles were bipolar in almost all embryos.  相似文献   

Light acclimation potential and carry-over effects vary among three evergreen tree species with contrasting patterns of leaf emergence and maturation     

Ishii H  Ohsugi Y 《Tree physiology》2011,31(8):819-830

We compared light acclimation potential among three evergreen broadleaved species with contrasting patterns of shoot elongation, leaf emergence and leaf maturation. Understory saplings were transferred to a high-light environment before bud break, grown for 13 months, and then transferred back to the understory to observe subsequent carry-over effects. Acclimation potential was highest and sapling mortality was lowest for Cinnamomum japonicum Sieb. ex Nakai. Indeterminate growth and successive leaf emergence allowed this species to acclimate to both high and low light by adjusting leaf production as well as leaf properties. Sapling mortality occurred after both transfers for Camellia japonica L., which also has indeterminate growth and successive leaf emergence. In this species, carry-over effects were observed at the individual level, but leaf-level acclimation potential was high. Acclimation potential was lowest and sapling mortality occurred soon after the transfer to high light for Quercus glauca Thunb. ex Murray. Determinate growth and flush-type leaf emergence resulted in significant carry-over effects in this species. Indeterminate growth and successive leaf emergence increase whole-plant acclimation potential by extending the period of growth and architectural development during the growing season. Similarly, we inferred that delayed leaf maturation, observed in many evergreen species, increases the acclimation potential of current-year leaves by extending the period of leaf development. In evergreen species, the acclimation potential of preexisting leaves determines the role that leaf turnover plays in whole-plant light acclimation, resulting in diverse strategies for light acclimation among species, as observed in this study.  相似文献   

Chromosome arm location of the gene controlling leaf pubescence of a Chinese local wheat cultivar ‘Hong-mang-mai’     

Shin Taketa  C.L. Chang  Makoto Ishii  Kazuyoshi Takeda 《Euphytica》2002,125(2):141-147

The inheritance of the leaf pubescence character of a Chinese local wheat cultivar ‘Hon-mang-mai’ was investigated by monosomic and telosomic analyses. Leaf pubescence was evaluated by observation of the adaxial side of the penultimate leaf of adult plants. F₁ hybrids of ‘Hong-mang-mai’ with a non-pubescent cultivar ‘Chinese Spring’ had leaf pubescence, but its density was about a half of that of ‘Hong-mang-mai’. In the F₂ generation, the segregation ratio of pubescent to non-pubescent plants fitted a ratio of 3: 1, suggesting that leaf pubescence was controlled by one dominant gene. Monosomic analysis revealed that the gene for pubescence is located on chromosome 7B. Telosomic analysis showed that the gene is located on the short arm of chromosome 7B with a distance of 14.3%from the centromere. This gene is not allelic with the previously reported hairy leaf gene Hl on chromosome 4B, and therefore, is designated Hl2, hairy leaf 2. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Alterations of lymphocyte subpopulations in healthy dogs with aging and in dogs with cancer     

Watabe A  Fukumoto S  Komatsu T  Endo Y  Kadosawa T 《Veterinary immunology and immunopathology》2011,142(3-4):189-200

Changes in an individual's immune status are considered major contributing factors towards the morbidity of cancer and mortality of aging. To evaluate age-related changes in the immune status of dogs, the immunophenotypes (CD3, CD4, CD8 and CD21) of peripheral blood lymphocytes were measured in 160 healthy dogs aged from 1 to 17 years, and in 365 dogs with various tumors and at various stages. In healthy dogs, the absolute numbers of white blood cells, lymphocytes, and CD3(+), CD4(+) and CD21(+) lymphocytes decreased significantly with age. The relative percentages of lymphocytes and CD4(+) cells decreased significantly, while CD8(+) cells increased significantly with age. The CD4:CD8 ratio showed a significant age-related decrease. In contrast, dogs with tumors possessed significantly lower absolute numbers and relative percentages of all lymphocyte phenotypes, while the CD4:CD8 ratio was significantly higher than in age-matched controls. The relative percentages of CD3(+) and CD8(+) lymphocytes were significantly lower in dogs with distant metastases compared with dogs without metastases, and the CD4:CD8 ratio increased with advanced stage. These observations illustrate the significant changes in immune status with age and the presence of marked immunological defects in a large-scale study of dogs with advanced tumors.  相似文献   

Enhanced Urinary Bladder, Liver and Colon Carcinogenesis in Zucker Diabetic Fatty Rats in a Multiorgan Carcinogenesis Bioassay: Evidence for Mechanisms Involving Activation of PI3K Signaling and Impairment of p53 on Urinary Bladder Carcinogenesis     

Ishii N  Wei M  Kakehashi A  Doi K  Yamano S  Inaba M  Wanibuchi H 《Journal of toxicologic pathology》2011,24(1):25-36

In the present study, modifying effects of diabetes on carcinogenesis induced in type 2 diabetes mellitus model Zucker diabetic fatty (ZDF) rats were investigated using a multiorgan carcinogenesis bioassay. Our re sults demonstrated enhancement of urinary bladder, colon and liver carcinogenesis in ZDF rats treated with five types of carcinogens (DMBDD). Elevated insulin and leptin and decreased adiponectin levels in the serum may be responsible for the high susceptibility of type 2 diabetes mellitus model rats to carcinogenesis in these organs. Possible mechanisms of increased susceptibility of diabetic rats to bladder carcinogenesis could be activation of the PI3K pathway and suppression of p53 in the urothelium in consequence of the above serum protein alterations.  相似文献