Mouse oocytes transcribe injected Xenopus 5S RNA gene

Abstract

Transcripts produced after injection of the Xenopus 5S RNA gene into oocyte germinal vesicles of mice migrate electrophoretically with the 5S RNA marker, an indication that the gene is transcribed and processed with considerable accuracy. Approximately two 5S RNA molecules are transcribed per gene per hour. This system may be useful in studying DNA processing and gene regulation by the mammalian ovum and might be modified to allow permanent incorporation of specific genes into mice.

Fig. 1

Fluorograph of polyacrylamide gel electrophoretic separation of ³H-labeled RNA synthesized by 95 growing mouse oocytes after injection with (A) dilute salt solution and (B) dilute salt solution containing pXbs1 plasmid DNA (1 mg/ml). Each plasmid contained two repeating units of somatic 5S gene from Xenopus borealis. The positions of the nonradioactive marker 5S RNA and 4S RNA are indicated.

Fig. 2

Fluorograph of polyacrylamide gel electrophoretic separation of ³H-labeled RNA synthesized by 120 growing mouse oocytes after injection with (A) dilute salt solution, (B) dilute salt solution containing pXbs1 (0.5 mg/ml) and pAd123 (0.5 mg/ml), and (C) dilute salt solution containing pBR322 (1 mg/ml). Plasmid pAd123 has a 1.8-kilobase insert including the type 2 adenovirus-associated RNA gene (VA) and flanking regions (prepared by David Bogenhagen). The adenovirus gene is approximately 150 nucleotides (5S and 4S RNA genes are approximately 120 and 90 nucleotides, respectively). All three genes are transcribed by polymerase III. Procedures and labeling are as in Fig. 1.