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61.
62.
We produced artificial interspecific chimeras by in vitro grafting, and obtained cytoplasmic male sterile (CMS) variants in the seed progenies derived from backcrossing the chimera with one of the mother plants, B. campestris cv. Komatsuna. The induced CMS has been stably inherited by crossing it with `Komatsuna', not with `Ruby Ball' cabbage. The nuclear component of CMS is complete `Komatsuna' type in morphology, chromosome number (2n = 20) and Southern blot using ribosomal 17S RNA gene as a probe. PCR analysis by using mitochondrial atpA primer showed the complete `Ruby Ball' type, suggesting nuclear-cytoplasmic exchange. However, Southern blot patterns were different among those of the CMS and both parents by using atpA. Recombination or some unknown change is supposed in the mitochondrial genome via the processes of synthesis and propagation of the chimeras. 相似文献
63.
Summary Interspecific Brassica chimeras (Brassica campestris+B. oleracea) were synthesized according to an in vitro graftculture method, and propagated by tissue culture of axillary buds or chimeric explants. A total of 127 regenerants obtained were investigated. The mericlinal chimera type was more easily produced than the other periclinal and revertant types. No sectorial chimera was produced. The flowering habit and inflorescence type of the chimeras were found to be controlled by the constitution of three tissue layers, but the petal shape and color were controlled only by the two outer tissue layers. Pollen viability of the chimeras were generally lower and more variable in parts than those of the parental types. 相似文献
64.
Yoko Sato Ryota Kuriwaki Shiki Hagino Megumi Shimazaki Rentsenkhand Sambuu Maki Hirata Fuminori Tanihara Mitsuhiro Takagi Masayasu Taniguchi Takeshige Otoi 《Reproduction in domestic animals》2020,55(2):209-216
In Mongolia, yak (Bos grunniens) are able to live in alpine areas and their products greatly influence the lives of the local people. Increased vigour in hybridized yak and cattle can offer benefits for livestock farmers. However, male hybrids show reproductive defects resulting from spermatogenesis arrest, affecting the conservation and maintenance of dominant traits in the next generation. The underlying mechanisms involved in hybrid cattle–yak infertility have recently been investigated; however, the genetic cause is still unclear. Androgens and androgen receptor (AR) signalling are required for spermatogenesis. We, therefore, evaluated the expression of AR, 3β-hydroxysteroid dehydrogenase (3βHSD) and 5α-reductase 2 (SRD5A2) in Leydig cells to investigate their function in cattle–yak spermatogenesis. Testicular tissues from yaks (1–3 years old) and hybrids (F1–F3, 2 years old) were collected and subjected to immunohistochemistry and image analyses to investigate the expression of each parameter in the Leydig cells. After maturation at 2 years, the expression levels of AR increased and the levels of 3βHSD decreased, but the SRD5A2 levels remained constant in yak. However, the cattle–yak hybrid F2 showed immature testicular development and significantly different expression levels of AR and 3βHSD compared with mature yak. These results suggest that the decreased expression of AR and increased expression of 3βHSD in the Leydig cells of cattle–yak hybrid testes may represent one of the causes of infertility. Our study might help in solving the problem of infertility in crossbreeding. 相似文献
65.
Determination of trace elements in otoliths of chum salmon Oncorhynchus keta by laser ablation-ICP-mass spectrometry 总被引:1,自引:0,他引:1
Trace element levels in the otoliths of chum salmon Oncorhynchus keta were examined by means of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). A close linear relationship
in the Sr/Ca ratios between X-ray analysis with an electron microprobe (EPMA) and LA-ICPMS analysis was found, suggesting
that the latter technique could be used to distinguish the marine and freshwater life phases. Mg, Zn, Ba and Sr concentrations
of the otoliths differed between the freshwater and seawater growth zones. Mg and Zn concentrations in the freshwater growth
zone were significantly higher than those in the seawater growth zone, while Sr and Ba concentration s in the former were
significantly lower than in the latter. The relationship between Sr concentration and Mg, Zn, and Ba concentrations at each
ablation showed significant correlations. These results suggest that trace element compositions may reflect differences between
freshwater and seawater environmental conditions. 相似文献
66.
Dias AA Silva FC Santos LS Ribeiro-Carvalho MM Sabbadini PS Santos CS Filardy AA Myioshi A Azevedo VA Hirata R Villas-Bôas MH Mattos-Guaraldi AL 《Veterinary microbiology》2011,153(3-4):323-331
During the last decade the majority of diphtheria cases in Europe had Corynebacterium ulcerans as the etiologic agent with dogs and cats as the reservoir hosts. However, little has been documented about the virulence factors of this zoonotic pathogen. To set up an in vivo experimental C. ulcerans infection model, conventional Swiss Webster mice were intravenously infected with different doses (from 1 × 10(7) to 5 × 10(9) bacteria per mouse) of C. ulcerans strains, namely 809 (from human lower respiratory tract), BR-AD22 (from asymptomatic dog nares) and CDC-KC279. Mortality rates were demonstrated by LD(50) values ranging from 1.9 × 10(8) to 1.3 × 10(9). Viable bacteria were recovered from blood, kidneys, liver, spleen and joints. For CDC-KC279 and 809 strains (2 × 10(8)mL(-1)) approximately 85% and 72% of animals with articular lesions were observed, respectively; BR-AD22-infected mice showed no signs of arthritis. CDC-KC279 and 809 strains exhibited higher arthritogenic potential when compared to the homologous toxigenic (ATCC27012) and non-toxigenic (ATCC27010) strains of Corynebacterium diphtheriae. A high number of affected joints and arthritis index in addition to the histopathological features, including subcutaneous edema, inflammatory infiltrate, damage to bone tissue and synoviocyte hypertrophy, indicated a strain-dependent ability of C. ulcerans strains to cause severe polyarthritis. A correlation between the arthritis index and systemic levels of IL-6 and TNF-α was observed for C. ulcerans strains, with the exception of the non-arthritogenic BR-AD22 strain. In conclusion, C. ulcerans revealed a strain-dependent arthritogenic potential independent of DNAse, PLD and diphtheria toxin production. 相似文献
67.
Hirata T Hoshina T Sasaki S Sasaki O Osawa T 《The Journal of reproduction and development》2007,53(2):171-177
We conducted a progesterone-based timed AI protocol after follicular fluid aspiration using the ovum pick-up (OPU) technique to examine its applicability to the suckled beef cow. A total of 19 beef cows were randomly allocated to one of the following three groups based on the number of days postpartum: 13 to 60 days (Group A: suckled; early postpartum period, n=9), 61 to 150 days (Group B: suckled; mid postpartum period, n=6), or 151 to 281 days (Group C: non-suckled; prolonged open period, n=4) postpartum. These cows were treated with follicular fluid aspiration and insertion of a progesterone-releasing intravaginal device (PRID) on day 0. The PRID was removed and 500 microg of cloprostenol was intramuscularly administered on day 7. A dose (100 microg) of fertirelin acetate was injected intramuscularly 48 hours later, and this was followed by a timed AI (TAI) after another 18 hours (day 10). Serum samples were taken on days 0, 7, 9, 10, 12, 17, 24 and 31 for determination of the estradiol-17beta (E(2)) and progesterone concentrations. Pregnancy diagnosis was made by rectal palpation approximately 60 days after TAI. There was no significant difference in the peripheral E(2) concentrations among the three groups during the period of the hormonal treatment. The average progesterone concentrations in Group A on day 17 were significantly higher than those in Group B and exceeded 1.0 ng/ml on day 17 and thereafter. There was no significant difference in the numbers of collected immature oocytes among the three groups. The pregnancy rates in Groups A, B, and C were 77.8% (7/9), 83.3% (5/6) and 50.0% (2/4), respectively. In conclusion, this timed AI protocol is applicable to suckled beef cows within the period of 60 days postpartum. 相似文献
68.
69.
Abstract One of the authors analyzed the brown spot symptoms developed on plant leaves caused by nutritional disorders using an X-ray Micro-Analyser (Sasaki et al. 1980). The use of an X-ray Fluorescence Element Mapping Spectrometer (XEMS) revealed that external and internal stresses such as X-ray irradiation and manganese excess induced the transport of manganese, and excess of manganese concentration as cationic Mn2+ was related to the formation of the abnormal brown spots (Watanabe and Kobayashi 1986; Watanabe et al. 1988). Since, the mechanism of the transport of manganese remains to be elucidated the analysis of the chemical state of manganese in plant is important. Since the valency of manganese readily changes depending on the redox potential, non-destructiye analysis may be effective. In fact, few studies have been carried out on the non-destructive determination of the manganese state in plant tissues. We studied the state of manganese in rice leaf in performing Extended X-ray Absorption Fine Structure (EXAFS) and X-ray Absorption Near Edge Structure (XANES) analyses by X-ray Absorption Spectrometry with syncrotron radiation as the analytical source. X-ray absorption spectrometry provides structural information about the local surroundings of a metal ion, the binding configuration, etc. The concept and method of analysis were reviewed in detail by Teo (1981). The advantage of these methods over the previous methods is reported and the state and transport of manganese in leaf are discussed. 相似文献
70.
The mycorrhizal enhancement of plant growth is generally attributed to increased nutrients uptake. A greenhouse experiment was conducted to investigate the effect of arbuscular mycorrhizal fungi (AMF) inoculation on the growth and nutrient uptake of directly seeded wetland rice. Seeds were germinated and inoculated with arbuscular mycorrhizal fungi or left uninoculated. The plants were grown at 60% of ‐0.03 MPa to establish the mycorrhizas. After 5 weeks, half of the pots were harvested and the rest were flooded with deionized water to maintain 3–5 cm of standing water until harvesting (122 days after sowing). Mycorrhizal fungal colonization of rice roots was 36.2% at harvest. Mycorrhizal fungi inoculated rice seedlings grew better compared to uninoculated seedlings and had increased grain yield (10%) at the harvesting stage. Shoot and root growth were effectively increased by AMF inoculation at the harvesting stage. The nitrogen (N) and phosphorus (P) acquisition of direct seeding wetland rice were significantly increased by AMF inoculation. The AMF enhanced N and P translocation through the hyphae from soils to roots/shoots to grains effectively. 相似文献