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21.
Flagella and their microtubules obtained from sea urchin ( Hemicentrotus pulcherrimus ) spermatozoa were injected into unfertilized eggs of the medaka ( Oryzias latipes ) with a micropipette. Upon activation, some of the eggs began the first cleavage with three or more irregular blastomeres, and developed to the morula stage. It is suggested that sperm flagellar microstubule material is one of the cleavage initiation substances. 相似文献
22.
MASASHI RYUZAKI AKISHIGE OHTA MIEKO OSHIMA 《Development, growth & differentiation》1981,23(5):507-513
The positional distribution of fatty acids in choline- and ethanolamine phosphoglycerides from the livers of polycystic disease-bearing rats and stomachs of gastric tumor-bearing rats was analyzed and compared to that in normal rat liver and stomach. Polycystic disease and gastric tumors were induced with N-Methyl-N'-Nitro-N-Nitrosoguanidine. There was no significant difference between diseased and normal organs with respect to the composition of fatty acids at the 1-position, except that diseased livers exhibited an increase of approximately 22% in 16: 0 fatty acid and a decrease of approximately 12% in 18: 1 fatty acid. However, in diseased organs, there were marked quantitative changes in the positional distribution of fatty acids at the 2-position, their composition exhibiting greater saturation. Furthermore, in diseased organs, there was an increase in 15: 0 fatty acid at the 2-position of ethanolamine phosphoglycerides. 相似文献
23.
Ten chloroplast microsatellite markers were developed from Japanese plum (Prunus salicina) based on nucleotide sequences of c. 4300 bp from six chloroplast regions. Out of 10 microsatellites, seven markers contained mononucleotide repeats. Almost all microsatellites displayed discrete amplified fragments for 17 species in Prunus. The microsatellites generated 46 different fragment types and differentiated all used species. Polymorphism was also observed within species for all microsatellites. 相似文献
24.
25.
SEVERAL slow-moving abnormal haemoglobins associated with thalassaemia-like stigmata have been encountered during the past 13 yr1–6. The non-α-chains of these haemoglobins are the fusion products7 of δ and β-chains; the N-terminal end containing a part of the β-chain joined to a fragment of the β -chain ending in the C-terminal. But no structural variants of anti-Lepore type (fused in reverse β-δ) have yet been demonstrated. In a systematic screening survey for abnormal haemoglobins8, we discovered a new variant named Hb Miyada which may possess a fused non-α-chain. 相似文献
26.
In C57Black/Tw mice given injections of 1 μg estradiol-17β (E) for 5 days beginning on the day of birth, and killed a few days after the treatment, the vaginal epithelium showed estrogen-dependent proliferation and parakeratosis. In contrast, in the mice treated neonatally with 30 μg E for 5 days, the vaginal epithelium exhibited estrogen-independent proliferation and cornification or parakeratosis. Two peaks occurred in the mitotic rate in vaginal epithelial cells in the proximal and middle vaginae of the 1 μgE-treated mice, at 1 and 5 days of age, respectively, while the first peak was lacking in the distal vagina. The mitotic activity in 1 μgE-treated mice declined to the control level at 60 days. In the 30 μgE-treated animals also, 2 peaks were found in the mitotic rate at 1 and 7 days in both the proximal and middle vaginae. In contrast to the 1 μgE-treated mice, although the rate dropped once at 10 days, it increased again at 20 days and remained high thereafter. The second peak at 7 days of age coincided with the active proliferation of nodules appearing in the 30 μgE-treated mice. In the distal vagina, a peak occurred in the mitotic rate at 7 days without a preceding peak like that observed in the other parts of the vagina following the first injection of E on the day of birth. 相似文献
27.
Makoto ASAHINA Fumi SHIMIZU Masayuki OHTA Michiyasu TAKEYAMA Ryuichi TOZAWA 《Experimental Animals》2015,64(3):313-321
Nephropathy frequently co-occurs with metabolic syndrome in humans. Metabolic syndrome is
a cluster of metabolic diseases including obesity, diabetes, hypertension, and
dyslipidemia, and some previous studies revealed that dyslipidemia contributes to the
progression of kidney dysfunction. To establish a new nephropathy model with metabolic
syndrome, we produced human apolipoprotein B (apoB) transgenic (Tg.)
SHR/NDmcr-cp (SHR-cp/cp) rats, in which dyslipidemia
is exacerbated more than in an established metabolic syndrome model,
SHR-cp/cp rats. Human apoB Tg. SHR-cp/cp rats showed
obesity, hyperinsulinemia, hypertension, and severe hyperlipidemia. They also exhibited
exacerbated early-onset proteinuria, accompanied by increased kidney injury and increased
oxidative and inflammatory markers. Histological analyses revealed the characteristic
features of human apoB Tg. SHR-cp/cp rats including prominent
glomerulosclerosis with lipid accumulation. Our newly established human apoB Tg.
SHR-cp/cp rat could be a useful model for the nephropathy in metabolic
syndrome and for understanding the interaction between dyslipidemia and renal dysfunction
in metabolic syndrome. 相似文献
28.
SADAAKI KOIZUMI 《The Journal of eukaryotic microbiology》1966,13(1):73-76
SYNOPSIS. Some of the serotypes in Paramecium caudatum are described in this paper. Immobilization antigens of P. caudatum have been obtained by extracting paramecia in a dilute salt solution containing 15% alcohol. Immobilization antigen F from stock 162 has been isolated and has a sedimentation coefficient of 9.3 Svedbergs, diffusion coefficient of 2.3 × 10-7 cm/sec, and molecular weight of approximately 340,000. 相似文献
29.
Oxalate supplied to Lemna gibba L. in sterile culture was readily absorbed, stimulating growth and increasing the uptake of calcium when this element was present in the nutrient medium; in the absence of calcium, deficiency symptoms rapidly appeared. EDTA at low concentrations stimulated growth, but concentrations equivalent to those of calcium reduced the uptake of both calcium and oxalate; developing daughter fronds were chlorotic and cells from these tissues appeared to be calcium deficient. 相似文献
30.
Requirement of Extracellular Calcium Ions for the Early Fertilization Events in the Medaka Egg 总被引:1,自引:1,他引:0
The requirement for calcium and the change in calcium content in eggs of Oryzias iatipes during the cortical reaction and sperm penetration were examined. Naked eggs failed to exhibit the cortical reaction upon insemination under Ca Mg-free conditions. These eggs exhibited the cortical reaction by reinsemination in the presence of extracellular Ca2+ . The effect of extracellular Ca2+ on sperm penetration could be replaced by one of several divalent cations in the external medium. Unlike the cortical reaction, sperm penetration failed to be induced by microinjection to increase intracellular Ca2+ . Verapamil significantly reduced the action of extracellular Ca2+ or Ba2+ of divalent cations examined in fertilization, while TEA and TTX had no effect on fertilization in the presence of these cations. No 45 Ca uptake into the egg proper was recognized before completion of the cortical reaction. These observations suggest that extracellular divalent cations are indispensable for sperm stimulation of the egg and its penetration into the egg, for which an influx of Ca2+ from the external medium is not required. 相似文献