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排序方式: 共有171条查询结果,搜索用时 15 毫秒
1.
将不同直径牛卵泡内卵母细胞体外成熟培养22h后,对其体外受精后的卵裂率,胚胎发育速度和胚胎染色体异常发生率进行了研究。结果表明,体外受精后48h,直径3-6mm卵泡内卵母细胞外受精后的卵裂率明显高于直径1-2mm和7-10mm卵泡内卵母细胞体外受精后的卵裂率(P<0.05)。体外受精后48h,直径3-6mm包泡内卵母细胞体外受精后的胚胎的发育速度明显快于直径1-2mm和7-10mm卵泡组胚胎(P<0.05)。通过对不同卵裂期胚胎的染色体标本分析表明,直径1-2mm卵泡内卵母细胞体外受精后的胚胎染色体异常发生率明显高于直径3-6mm卵泡组(P<0.05),但与直径7-10mm卵泡组之间无显著性差异。 相似文献
2.
The aim of the present study was to determine the whole nucleotide sequence of the open reading frame of the sex‐determining region Y (SRY‐ORF) in wild sika deer. The SRY gene of wild sika deer was obtained by polymerase chain reaction (PCR) with DNA from blood samples. The whole nucleotide sequence of the SRY‐ORF in wild sika deer consisted of 687 bp and encoded 229 deduced amino acids. In comparison with the bovine SRY gene, the percentage of nucleotide sequence homology was 91.0% in the overall ORF, and those of the N‐terminal, high mobility group (HMG) box, and C‐terminal regions within ORF were 88.9%, 96.2% and 87.9%, respectively. The nucleotide sequences of sika deer SRY‐ORF characterized in the present study can be used for phylogenetic analysis or sexing in wild sika deer. 相似文献
3.
Kazuhiko ARAHARA Takashi MATSUMOTO Fumiki MORIMATSU Katsuhiko ARAI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(11):1503-1506
In this study, the effect of fibronectin on the neurite outgrowth from embryoid
bodies (EBs) in neurodifferentiated embryonal carcinoma P19 cells was examined. The
neurite outgrowth on fibronectin was maintained for a longer time in comparison with those
on collagen or laminin. Quantitative RT-PCR revealed that mRNA level corresponding to
sonic hedgehog (Shh) in neurodifferentiated P19 cells was upregulated on fibronectin,
whereas collagen or laminin did not affect. Further knockdown of integrin αv subunit in
P19 cells demonstrated that expression of Shh was mediated through interaction between
fibronectin and integrin. Additionally, exogenous Shh agonist accelerated neurite
outgrowth from embryonic stem cell-derived EBs without large change of neuronal phenotype
expression. Taken together, fibronectin could maintain neurite outgrowth via increased Shh
expression. 相似文献
4.
Kunio SUGAHARA Mako MATSUMOTO Motoko YAMADA Fumiaki YAOSHIZAWA Yutaka KARASAWA 《Animal Science Journal》2004,75(5):431-434
In order to determine the role of the cecum on energy use in growing chickens, metabolizability of the dietary energy and energy expenditure were examined in the week following bilateral ligation and washing out of the cecum. Apparent metabolizable energy (AME) values were 14.30 and 13.69 kJ/g air‐dry matter for sham‐operated and cecally ligated chickens, respectively. These values were found to be significantly different (P < 0.05). Although AME intake and fasting heat production were decreased by cecal ligation, the distribution of AME (measured as fasting and feeding heat production, as well as heat increment and energy retention, as a proportion of AME intake) was not affected. These results suggest that the cecum helps chickens extract AME from corn‐soybean type diets with little, if any, effect on AME use, based on the present study of growing chickens in the week following cecal ligation. 相似文献
5.
6.
Saori MIURA Noriyuki HORIUCHI Kotaro MATSUMOTO Yoshiyasu KOBAYASHI Shin-ichiro KAWAZU Hisashi INOKUMA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(7):883-887
Monoclonal integration of bovine leukemia virus (BLV) proviral DNA into bovine genomes
was detected in peripheral blood from two clinical cases of enzootic bovine leukosis (EBL)
without enlargement of superficial lymph nodes. A BLV-specific probe hybridized with 1 to
3 EcoRI and HindIII fragments in these 2 atypical EBL
cattle by Southern blotting and hybridization, as well as in 3 typical EBL cattle. The
probe also hybridized to a large number of EcoRI and
HindIII fragments in 5 cattle with persistent leukosis. These results
suggest that the detection of monoclonal integration of BLV provirus into the host genome
may serve as a marker of monoclonal proliferation and malignancy in difficult to diagnose
EBL cattle. 相似文献
7.
Toru TACHIBANA Ken Takeshi KUSAKABE Sayuri OSAKI Takeshi KURAISHI Shosaku HATTORI Midori YOSHIZAWA Chieko KAI Yasuo KISO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):161-165
The New World monkey Aotus spp. (night monkeys) are expected
for use of valuable experimental animal with the close species of Saimiri
spp. (squirrel monkeys). Saimiri is known to show spontaneous
hypercortisolemia, although few reports in Aotus. We compared basic
states of blood steroid hormones and histological structure of the adrenal glands in two
monkeys. Serum cortisol and ACTH levels were statistically lower in Aotus
than Saimiri. Conversely, Aotus adrenocortical area
showed significant enlargement, especially at the zona fasciculata. Electron microscopic
observation at Aotus fasciculata cells revealed notable accumulation of
large lipid droplets and irregular shapes of the mitochondrial cristae. These results
suggest potential differences in cellular activities for steroidogenesis between
Aotus and Saimiri and experimental usefulness in
adrenocortical physiology and pathological models. 相似文献
8.
Endometrial adenocarcinoma in the uterine corpus is a malignant cancer that occurs in menopausal women and aged rodents. Because of the similarities in pathogenesis and morphology of endometrial adenocarcinoma in rodents and humans, prediction of the modes of action (MOA) in uterine carcinogenesis is important for extrapolation of rodent data to humans. Three MOAs have been accepted as major pathways for uterine carcinogenesis in rodents: 1) estrogenic activity, 2) increased serum 17beta-estradiiol (E2) to progesterone (P4) ratio and 3) modulation of estrogen metabolism to produce 4-hydroxyestradiol via P450 induction. Inhibition of estrogen excretion and increased aromatase in situ in the tumor are also a potential pathway. Here, chemicals showing uterine carcinogenicity were chosen from approximately 300 pesticides evaluated in Japan within the past decade, and their mechanisms were predicted using parameters from mechanistic and toxicity studies. Seven pesticides increased uterine tumor formation in rats, and the pathways of 4 pesticides could be predicted based on various mechanistic studies. The MOAs of cyenopyrafen and benthiavalicarb-isopropyl were predicted to be modulation of estrogen metabolism, while those of pyriminobac-methyl and spirodiclofen were predicted to be increased E2 to P4 ratio. The driven pathways of metazosulfuron and isopyrazam could not be predicted using several mechanistic studies. No mechanistic studies have been reported for sedaxane, which has a chemical structure and toxicological profile similar to isopyrazam. Our results indicated that appropriate mechanistic studies are useful for mechanism prediction in risk assessment. From this analysis, a flowchart showing a decision tree for predictive MOAs in uterine carcinogenesis was proposed. 相似文献
9.
Yoshida M Shimomoto T Katashima S Watanabe G Taya K Maekawa A 《The Journal of reproduction and development》2004,50(3):349-360
Effects of maternal exposure to low doses of bisphenol A (BPA), including those comparable with human exposure levels, on growth and development of the female reproductive system and uterine carcinogenesis in Donryu rats were investigated. Dams were administered BPA (0, 0.006 and 6 mg/kg/day) daily by gavage from gestation day 2 up to the day before weaning (postnatal day 21 at offspring). The serum levels of BPA were significantly elevated in the dams receiving 6 mg/kg/day, however, BPA levels in the milk of dams, and those in the serum and liver of offspring were similar between control and treated groups. The treatment did not exert any influences on uterine development including weight, gland genesis and estrogen receptor alpha expression, vaginal opening and gonadotropin secretion in the female offspring up to puberty. After maturation, no effects were evident with regard to estrous cyclicity in female offspring treated with BPA. In addition, the treatment had no effects on age-related morphological changes of the reproductive and endocrine organs and uterine carcinogenesis until 15 months of age. The results demonstrate that maternal exposure to BPA at levels comparable to human exposure did not have any effects on the female reproductive system of offspring in rats. In addition, BPA was also found in the serum, milk and liver of control dams and pups, and low levels of BPA were detected in drinking water and pellet diet. The present study showed that the experimental animals were also exposed to environmental BPA in the animal room. 相似文献
10.
An electrofusion methodology for transferring meiosis-II chromosomes (M-II-t) has not been completely established. The present study compared the use of two temperatures (fusion at 37 C for Group A and 25 C for Group B) during an electrofusion procedure for mouse oocyte M-II-t and investigated the cytogenetic normality and developmental competence of embryos derived from in vitro fertilization using oocytes reconstructed by M-II-t. The M-II-t oocytes were fertilized in vitro and cultured to the blastocyst stage; the resultant embryos were analyzed cytogenetically. Subsequently, chromosomal normality of the resultant embryos at the prometaphase stage of first cleavage division and the integrity of the meiosis-II spindles of the reconstructed oocytes were analyzed. The success rate of electrofusion in Group B was 92.1%, which was significantly different from that in Group A (49.2%) (P<0.05). The fertilization rates (A, 80.7%; B, 77.2%) and development rates (A, 70.9%; B, 65.5%) in the M-II-t groups were significantly lower than those in the control group (95.0 and 92.2%, respectively) (P<0.05). The incidence of chromosomal abnormalities in the Group A embryos (20.5%) at the blastocyst stage was significantly higher than that in the control group embryos (8.5%) (P<0.05), but the incidence of chromosomal abnormalities in Group B (12.5%) was not significantly different compared with the other groups. A temperature of 25 C during the electrofusion procedure for M-II-t resulted in a good fusion rate, good development rate, and efficient production of chromosomally normal blastocysts. Furthermore, the incidence of chromosomal abnormalities in the first cleavage embryos at the prometaphase stage in Group B (9.6%) did not differ significantly from that in the control group (6.6%). The spindle morphology of the M-II-t oocytes in Group B was normal. 相似文献