Wagner, C. A., Ott, M., Klingel, K., et al. 2003;227:245-58. Since then, most of the polyploids have become functional diploids in terms of gene expression patterns. (1971) Use of frog eggs and oocytes for the study of messenger RNA and its translation in living cells. B., Lane, C. D., Woodland, H. R., et al. 2.4D). Oogenesis in the anuran Xenopus laevis can be divided into six stages based on the anatomy of the developing oocyte. Xenopus laevis (frog) embryos are well-suited to model congenital kidney diseases and to explore the mechanisms that cause these developmental defects. DI-fusion Ultrastructure of Xenopus laevis oocytes after injection of. Sarah S. Conte, Elsbeth L. Walker, in Current Topics in Membranes, 2012. Here we demonstrate cytoplasmic microinjection of Xenopus laevis oocytes with a nuclear import substrate, as well as preparation of the injected oocytes for visualization by … P.Hanke, R.Grygorczyk, A.Tintschl, H.Fasold1 and H.Passow Single cell experimentation in Xenopus laevis oocytes is a routine for experimental biologists. One of the most important aspects is that expressed foreign proteins always preserve their native biological activities, thus allowing functional studies of the expressed proteins. These oocytes were subdivided into six regions perpendicular to their animal‐vegetal axis. During the primary oocyte stage of oogenesis, the nucleus is called a germinal vesicle. Finally, insulin was found recently to provoke meiosis (18). Twenty species are currently described within it. Most generally, it is very interesting to note that the parasites harbored by X. tropicalis and X. epitropicalis differ from those found in association with other Xenopus species (Tinsley and Jackson, 1998). According to many authors, the 2n = 20 karyotype of X. tropicalis forms the basis of the entire polyploid series in the genus (e.g., Tymowska, 1991). This service is more advanced with JavaScript available, Membrane Transporters Recently, Araki, Murata, and Murata (2011) used electrophysiological methods to study the substrate specificity of HvYSL2. Birnstiel's purification of the X. laevis rDNA genes was the first isolation of a specific gene from any organism, and it occurred 10 years before cloning. The vocal apparatus of the clawed frog is designed for underwater sound production (Deuchar, 1975). The widespread use of the oocyte expression system is based upon the fact that oocytes can not only translate exogenous RNA from various sources efficiently and faithfully, but also carry out posttranslational modifications, such as precursor processing, phosphorylation, glycosylation, intracellular trafficking and protein targeting into the plasma membrane, complex subunit assembly, and even exporting secretory proteins. N2 - The possibility that maternal RNA may be localized in specific oocyte regions was examined in fully grown oocytes of Xenopus laevis. Alijevic O, McHugh D, Rufener L, Mazurov A, Hoeng J, Peitsch M (2020) An electrophysiological characterization of naturally occurring tobacco alkaloids and their action on human alpha4beta2 and alpha7 nicotinic acetylcholine receptors. In order to reach developing oocytes where it is sequestered, it must exit the circulatory system and traverse several follicular tissue layers including the theca, the follicle cell layer, and the vitelline envelope. pus (zĕn′ə-pəs) n. Any of various aquatic, tongueless, clawed frogs of the genus Xenopus of southern Africa, certain species of which, especially the African clawed frog, are widely used for biological research. John P. Leonard, in Methods in Neurosciences, 1989. Xsix3 is first detected by in situ hybridization at stage 12 along with the other early expressed EFTFs (this group also includes Xpax6, Xrax, Xlhx2, and Xtbx3) (Zuber et al., 2003). Xenopus are one of the few groups of polyploid frogs with a well-characterized sex-determination system. After co-injection of Xenopus egg extracts and single mouse cumulus cells into enucleated mouse oocytes, statistically higher pronucleus formation and development rates were observed in the egg Extract− co-injected group compared with those in the no egg extract-injected (NT) group (38–66% vs 18–34%, P <0.001). Such cells are undergoing spontaneous maturation. When only a few oocytes are required, a piece of ovary may be removed from anesthetized females through a ventral incision about 1 cm in length, and the wound is then closed with three stitches of sterile catgut. Here we show that: oligomycin sensitive ATP synthase activity is significantly greater (~170 vs. 20 nmol/min −1 /mg −1) in testes compared to oocytes in Xenopus laevis (X. laevis). (Biochemical changes during progesterone-induced maturation in Xenopus laevis oocytes. This approach effectively reduces the size of the cDNA library to be screened and increases the probability of successful isolation of the target cDNA. The females are killed by decapitation after 10–15 min of anesthesia in 0.2% MS222 (Sandoz, Basel, Switzerland). Emed Res 2: 100008. Female X. laevis laevis are larger than males and average 110 mm in length (Kobel et al., 1996). The skin secretions of Xenopus include thyrotropin releasing hormone, caerulein, and xenopsin. The lungs, heart, and liver of Xenopus are large, and the urinary bladder is spherical. The ovarian lobes are pulled apart by blunt dissection with fine forceps and small clumps of oocytes are isolated. Once the natural substrate, gp43, was cloned, the cleavage site was found to be Gly-Ser-Arg↓ [7–9]. We have used rhodamine-conjugated phalloidin and confocal microscopy to examine the organisation of filamentous actin (F-actin) during oogenesis in Xenopus laevis.F-actin was restricted to a thin shell in the cortex of oogonia and post-mitotic oocytes less than 35 μm in diameter. (A) Development of ICSI embryos to each stage is summarized. Activity assays can be performed using isolated egg envelopes and SDS-PAGE to detect the gp43 to gp41 shift. Background of Xenopus. The frog's skin is kept moist during surgery to prevent acidification. Selection of oocytes is an often-overlooked important step. exocytosis in Xenopus laevis oocytes and eggs in response to cytosolic Ca ~÷. The coevolutionary influence of polyploidy goes a step further in this regard, because it appears that allopolyploidy may confer some resistance to certain species of these parasites (Jackson and Tinsley, 2003). Once a method is successfully developed, a great deal of data can be obtained for the transporter in question by bathing oocytes in different metal chelate solutions and/or adding various inhibitors. They are described to displace calcium from membrane sites, to inhibit CaATPase or to regulate the activity of adenylate cyclase (4,17). If healthy oocytes die quickly after only 1 day, it may help to switch antibiotics and use 0.1 mg/ml gentamycin. Bioz Stars score: 90/100, based on 1 PubMed citations. Xenopus laevis oviductin cleaves egg envelope glycoprotein gp43 to gp41 [6]. Activity is increased by 40% in the presence of 10 mM CaCl2, and is irreversibly inhibited by the removal of Ca2+ with EGTA [5]. Publications. Function i. 1. Each region was analyzed to determine the amount of total cellular RNA, poly(A)+RNA, and newly synthesized ribosomal RNA. This strategy has been successfully employed in cloning the proton-coupled peptide transporter from rabbit intestine (PEPT1) (28). Activity in Xenopus laevis Oocytes. Neither progesterone (as well as other active steroids) nor the various pharmacological agents mentioned above were able to reinitiate meiosis when injected inside the oocyte at internal concentration comparable to that applied in the external medium. It is known that this ion does not penetrate the cells and interferes with Ca2+-movements from membrane sites and/or adenylate cyclase activity (15). The collagenase treatment should be terminated when about 50% of the oocytes are stripped of overlying follicle cells (1.5–3 hr). MPF can directly induce the breakdown of germinal vesicle (GVBD) when injected into oocytes which have not been exposed to progesterone (2,3,7,8). xenopus. Abstract Xenopus oocytes are a versatile expression system particularly suited for membrane transporters and channels. Figure 3: Development of ICSI embryos, produced from in vitro matured oocytes. For this reason, and despite decades of work on X. laevis, research in developmental genetics is shifting to the smaller, faster-developing, and genetically much more convenient diploid Xenopus tropicalis (Vogel, 1999). However, work over the last several years has shown that intact Xenopus eggs and embryos are also powerful models for visualization and characterization of cell cycle-regulated cytoskeletal dynamics. Stage I consists of small (50 to 100 μ) colorless oocytes whose cytoplasm is transparent. Xenopus laevis Oocytes. It was observed that OsYSL2 can transport Fe(II)–NA and Mn(II)–NA, but not Fe(III)–DMA or Mn(II)–DMA, among various other metals tested (Koike et al., 2004). Please Specify Uncurling arrive around 38 NF
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