Translation oocytes

The DNA for the GABAA-receptor channel has been translated to the respective RNA by in vitro transcription of the cDNAs (for a and P) inserted into plasmids. The two RNAs, when injected together into Xenopus oocytes, produced GABA-sensitive CP-currents [3]. 

Kanki, J. P, and Donoghue, D. J. (1991). Progression from meiosis I to meiosis II in Xenopus oocytes requires de novo translation of the mos" protooncogene. Proc. Natl. Acad. Sci. USASS 5794-5798. 

Figure 1. Expression of c-mos in mouse oocytes, c-mos is transcribed during oocyte growth and transcripts with short poly(A) tails are accumulated in fully-grown germinal vesicle (GV) stage oocytes. These transcripts are polyadenylated and translated following the resumption of meiosis and then degraded following fertilization and cleavage to the two-cell stage.

McGrew, L. L., Dworkin-Rastl, E., Dworkin, M. B and Richter, J. D. (1989). Poly(A) elongation during Xenopus oocyte maturation is required for translational recruitment and is mediated by a short sequence element. Genes Dev. 3 803-815. 

Vassalli, J. D., Huarte, J., Belin, D., Gubler, P., Vassalli, A., O Connell, M. L., Parton, L. A., Rickies, R. J., and Strickland, S. (1989). Regulated polyadenylation controls mRNA translation during meiotic maturation of mouse oocytes. Genes Dev. 3 2163-2171. 

Mailer Neither ribosomes nor mitochondria can explain translational limitations in the oocyte, because there are many more ribosomes and mitochondria than are needed yet protein synthesis is very limited. Every message put in is translated at the expense of some endogenous message. No one knows yet what the limiting factor for translation is in oocytes. 

Schwab MS, Kim SH, Terada N et al 1999 The p70(S6K) controls selective mRNA translation during oocyte maturation and early embryogenesis in Xenopus laevis. Mol Cell Biol 19 2485— 2494... 

Messenger RNA isolated from differentiated HL-60 cells is thus a convenient source of transcripts for the receptor, and this mRNA (50-100 ng) can be injected into X. laevis oocytes. These oocytes actively translate foreign mRNA molecules, and often the expressed protein is functional 2-5 days later, functional fMet-Leu-Phe receptors can be detected on the cell surface. The identity of a functional fMet-Leu-Phe receptor was confirmed because ... 

Oocytes from the South African clawed frog, Xenopus laevis, provide a reliable and powerful system for the transient heterologous expression of proteins. The use of this expression system has become very popular as oocytes have a high translational capacity and they are able to express multi-subunit proteins derived from exogenously introduced RNA or DNA. Furthermore, the expressed receptors frequently appear to be correctly assembled, post-translationally modified and oriented to the appropriate site. The relative scarcity of endogenous ion channels in the oocyte membrane makes it a versatile tool for the study of a range of heterologously expressed ion channel proteins. 

Xenopus oocytes show little species specificity for the type of foreign RNA or DNA they can finally translate into membrane proteins. 

Foreign proteins are correctly post-translationally modified (e.g., by glycosylation and pbospboryla-tion), and oocytes correctly orient multi-subunit proteins that acquire native activity. 

Barnard EA, MEedi R, Sumikawa K. 1982. Translational of exogenous messenger RNA coding for nicotinic acetylcholine receptors produces functional receptors in Xenopus oocytes. Proc R Soc Lond B 215 241. 

Colman A. 1984. Translation of eukaryotic messenger RNA in Xenopus oocytes. Transcription and translation a practical approach. Rickwood D, Hames BD, editors. Washington, DC Oxford University Press pp. 271-302. 

Gurdon IB, Lane CD, Woodland HR, Marbaix G. 1971. Use of frog eggs and oocytes for the study of messenger RNA and its translation in living cells. Nature. 233 177. 

Sumikawa K, Houghton M, Emtage JS, Richards BM, Barnard FA. 1981. Active multi-subunit ACh receptor assembled by translation of heterologous mRNA in Xenopus oocytes. 

The Lester and Dougherty labs, which have collaborated to extend the suppression mutagenesis technique to Xenopus oocytes with remarkable success [30, 31], began with a suppressor tRNA ( MN3 ) designed for in vivo use and demonstrated that it functioned more effectively in the oocyte system than a yeast tRNA -derived suppressor tRNA. They have since developed an alternative suppressor based on tRNA " from Tetrahymena thermophila that has proven to be considerably more versatile, efficient and accurate in the oocyte system [32], as well as showing good suppression efficiency in E. coli transcription-translation reactions [33]. 

Colman A (1984) Translation of eukaryotic mRNA in Xenopus oocytes. In Hames D, Higgins S (eds) Transcription and Translation - A Practical Approach. IRL Press, Oxford, p 271-301... 

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