排序方式: 共有65条查询结果,搜索用时 31 毫秒
21.
22.
The two closely related hypotrichous ciliate species, Stylonychia lemnae and S. mytilus, have been compared with respect to their isoenzyme patterns, their macronuclear DNA banding patterns, and micronuclear DNA banding patterns after restriction enzyme digestion. Since macronuclear DNA contains mainly protein-coding sequences and since the micronuclear DNA patterns represent mainly the repetitive fraction of the genome, these results, together with the isoenzyme patterns, reflect differences on three different levels of molecular evolution between morphologically very similar species. Each of the three methods allows an unequivocal identification of each of the two species. Intraspecific variation seems to be greatest among the repetitive sequences of the micronuclear genomes. By using the isoenzyme data and the formula of Nei (19) the genetic distance between the two species is calculated and compared with the results from other protozoa and different Drosophila species. Despite their morphological similarity, the two species show a considerable amount of evolutionary divergence on the three molecular levels which have been investigated. 相似文献
23.
Kyung-Chul?Choi Peter?CK?Leung Eui-Bae?JeungEmail author 《Reproductive biology and endocrinology : RB&E》2005,3(1):66
Although Calbindin-D9k (CaBP-9k), a cytosolic calcium binding protein which has calcium binding sites, is expressed in various
tissues, i.e., intestine, uterus, and placenta, potential roles of this gene and its protein are not clearly understood. Uterine
CaBP-9k may be involved in controlling myometrial activity related with intracellular calcium level and is not under the control
of vitamin D despite the presence of vitamin D receptors. But, it is under the control of the sex steroid hormones, estrogen
(E2) and progesterone (P4), in female reproductive systems including the uterus and placenta. Thus, in this review, we summarize
recent research literature in regards to the expression and regulation of CaBP-9k in mammals and introduce the research data
of recent studies by us and others. 相似文献
24.
Nian-Kang Sun Chun-Ling Sun Chia-Hua Lin Li-Mai Pai Chuck CK Chao 《Journal of biomedical science》2010,17(1):27
Background
We observed previously that cisplatin-resistant HeLa cells were cross-resistant to UV light due to accumulation of DDB2, a protein implicated in DNA repair. More recently, we found that cFLIP, which represents an anti-apoptotic protein whose level is induced by DDB2, was implicated in preventing apoptosis induced by death-receptor signaling. In the present study, we investigated whether DDB2 has a protective role against UV irradiation and whether cFLIP is also involved in this process. 相似文献25.
Summary Androgenesis has been induced in excised anthers of two tetraploid species ofArachis. The pollen underwent various modes of development leading to the formation of pollen-embryos and callus. 相似文献
26.
27.
Treatment of rats with selenium (6 and 8 ppm in diet) for 6 and 9 weeks resulted in decrease in testicular protein, phospholipid content and LDH activity and an increase in the lipid, cholesterol content and activity of ACP and ALP. These alterations have been discussed in relation to interference of selenium in various metabolic processes of testis. It seems that selenium affects the oxido-reductase activity of glutathione and resulting in oxidative damage to testis. 相似文献
28.
Avian diversity in four areas of agrifields of Punjab Agricultural University (PAU), Ludhiana was studied in order to find a correlation between agricultural land use, woody vegetation and the occurrence of bird species. The areas included College Orchard (Transect I), Agrifields of Oil seed section of Department of Plant Breeding and Genetics adjacent to orchards of PAU (Transect II), Crop field area of Department of Plant Breeding and Genetics on the back of Thapar Hall, PAU (Transect III) and Experimental area of Department of Plant Breeding and Genetics of PAU (Transect IV) which was without any trees around it. A total of 12,642 birds including 30 different species were recorded in all the four transects. The total no. of birds (5,074) and species (22) was highest in transect IV. House crow, red wattled lapwing, rose ringed parakeet and common myna were found to be the dominant birds in Transect I, II, III and IV respectively. Species richness and species diversity varied throughout the year. All the four areas had one or the other crop which attracted a number of bird species for food and the adjacent woody vegetation in Transect I, II and III providing nesting, perching and roosting sites to birds. It reveals that both the trees and food availability in the agrifields attract different bird species for different purposes like food, nesting and roosting. 相似文献
29.
Adult female mice were superovulated with PMSG followed by HCG and 140 blastocysts and 69 morulae were recovered from 24 mice. On the basis of the response, mice were divided into six groups; non responders, 1-5, 6-10, 11-20, 21-30 and >30 embryos. The ovaries of the animals were pooled group wise, homogenized in PBS (pH 7.4) and after centrifugation for 10-15 minutes, the supernatant was analyzed for the enzymes, guanine oxaloacetate transaminase (GOT), guanine pymvate transaminase (GPT), acid phosphatases (ACP) and alkaline phosphatases (AKP). Acid and alkaline phosphatase activities did not show any variation in relation to response to superovulation but GOT and GPT showed significantly increased activity in response to induction of superovulation. A statistically significant positive correlation was found between GOT and GPT activities and the superovulatory response in mice. 相似文献
30.
Kyung-Chul?Choi Nelly?Auersperg Peter?CK?LeungEmail author 《Reproductive biology and endocrinology : RB&E》2003,1(1):71
Mitogen-activated protein kinases (MAPKs) are a group of serine/threonine kinases which are activated in response to a diverse
array of extracellular stimuli and mediate signal transduction from the cell surface to the nucleus. It has been demonstrated
that MAPKs are activated by external stimuli including chemotherapeutic agents, growth factors and reproductive hormones in
ovarian surface epithelial cells. Thus, the MAPK signaling pathway may play an important role in the regulation of proliferation,
survival and apoptosis in response to these external stimuli in ovarian cancer. In this article, an activation of the MAPK
signaling cascade by several key reproductive hormones and growth factors in epithelial ovarian cancer is reviewed. 相似文献