Transcription of chick genes by mammalian RNA polymerase II in chick erythrocyte‐mammalian cell heterokaryons

Zuckerman, Steven H.; Linder, Stig; Ringertz, Nils R.

doi:10.1002/jcp.1041130117

Cited by 13 publications

(2 citation statements)

References 33 publications

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“…Recent evidence indicates that in heterokaryons rat RNA polymerase II is actively transcribing the chick genome (16). Our present results suggest but do not prove that rat polymerase of type I is actually transcribing the chick rRNA genes.…”

Section: Resultscontrasting

confidence: 97%

“…The time and location of polymerase-I-antigenicity agree also with the appearance of a-amanitin-resistant RNA polymerase activity (14) as detected by a cytochemical assay based on incubation with labeled nucleoside triphosphates and drugs (15). Using this type of assay as well as biochemical techniques, we recently demonstrated that rat RNA polymerase II enters the nucleoplasm of chick nuclei in rat-chick heterokaryons and is active in transcribing some of the chick globin genes (16). We conclude that during reactivation mammalian RNA polymerases of the types I and II migrate into the chick erythrocyte nuclei and become distributed in their respective subeompartments.…”

Section: Resultssupporting

confidence: 53%

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Migration of rat RNA polymerase I into chick erythrocyte nuclei undergoing reactivation in chick-rat heterokaryons.

Scheer¹,

Lanfranchi²,

Rose³

et al. 1983

The Journal of Cell Biology

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Transcriptionally inactive chick erythrocyte nuclei were reactivated by Sendal virusinduced fusion of erythrocytes with rat L6J1 myoblasts. We used antibodies to trace the appearance of a specific protein engaged in transcription of a defined class of genes, those coding for rRNA, during reactivation. Using immunofluorescence microscopy, we found increasing amounts of rat RNA polymerase I to appear, during a certain period of time after fusion, in the reforming nucleoli of the chick nuclei. Amounts of rat RNA polymerase I sufficient to be detected by immunofluorescence microscopy had accumulated in the newly developed chick nucleoli 72-190 h after fusion was initiated. This time interval coincides with the time when chick rRNA synthesis can first be detected. The results raise the possibility that during these stages of the reactivation process chick rRNA genes are transcribed by heterologous RNA polymerase I molecules of rat origin.Mature chick erythrocytes are terminally differentiated cells in which the nuclear chromatin is tightly condensed, and in which replication, as well as transcription, have almost completely stopped (l). After fusion with actively transcribing mammalian cells, the nuclei of chick erythrocytes undergo a reactivation process characterized by an increase in nuclear size and protein content and by dispersion of chromatin and development of nucleoli (2-6). This increase of nuclear size is paralleled by a selective uptake of mammalian nucleusspecific proteins (4, 7) as well as by disappearance of some specific components of the chick erythrocyte chromatin (7,8).In the present study we examined the nucleocytoplasmic exchange of specific proteins during the reactivation of chick erythrocyte nuclei in heterokaryons. To this end we used an antiserum against rat RNA polymerase I (9), which does not cross-react with the corresponding enzyme from nonmammalian species (Fig. I b)) We show that rat RNA polymerase I molecules entered the chick nucleus during the reactivation process and accumulated in the reforming nucleolus. MATERIALS AND METHODSCells: L6Jl, a myogenic subclone of Yaffe's L6 rat myoblast line (10), isolated in our laboratory by John Coleman (see reference I l), was cultured on Dulbecco's minimal essential medium (DME) containing 10% fetal calf serum.Scheer, V., and K. M. Rose, manuscript submitted for publication.Cells were plated on glass hemocytometer cover glasses at a density of approximately 50,000 cells/cm 2 in 20 cm 2 plastic dishes. The following day, cells were treated with 0.2 ~,g/ml of mitomycin C (Sigma Chemical Co., St. Louis, MO) for 16 h and then fused with chick erythrocytes.FIGURE 1 Cultured chick fibroblasts as seen with phase-contrast (a) and epifluorescence (b) optics after staining with antibodies to rat RNA polymerase I. Chick nucleoli are completely negative (denoted by arrows in a). Bar, 10/~m. x 1,000.

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Section: Resultscontrasting

confidence: 97%

Section: Resultssupporting

confidence: 53%

Migration of rat RNA polymerase I into chick erythrocyte nuclei undergoing reactivation in chick-rat heterokaryons.

Scheer¹,

Lanfranchi²,

Rose³

et al. 1983

The Journal of Cell Biology

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Changes in nuclear antigens during reactivation of chick erythrocyte nuclei in heterokaryons

Nyman

Lanfranchi

Bergman

et al. 1984

Journal Cellular Physiology

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Reactivation of dormant chick erythrocyte (CE) nuclei was studied by fusing chick red cells with rat myoblasts, HeLa cells, and chick fibroblasts. Heterokaryons representing different stages of nuclear reactivation were fixed and examined for nuclear antigens using polyclonal patient autoantisera reacting with mammalian (human, mouse, and rat) nuclear envelope, nucleoplasm, and chromatin (DNA) antigens. Reactivation of CE nuclei was associated with marked changes in nuclear antigenicity. In rat myoblast and HeLa heterokaryons the CE nuclei acquired mammalian nucleoplasmic and nuclear envelope antigens in the corresponding nuclear subcompartments. Drastic changes in nuclear antigenicity were noted also in heterokaryons stained with DNA antisera. The compact chromatin of nuclei in mature chick erythrocytes showed little binding of DNA antibodies. Isolated nuclei on the other hand gave a strong immunofluorescence. CE nuclei in heterokaryons were strongly positive during the early stages of nuclear reactivation but then exhibited decreased reactivity. An unexpected finding was a marked reduction in the capacity of mammalian nuclei in heterokaryons to bind DNA-antibodies. This observation is discussed in relation to the previous finding that in CE-heterokaryons these nuclei often show reduced transcription and replication. The present results indicate that in heterokaryons both types of nuclei exchange macromolecules of regulatory importance via the common cytoplasm.

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Blastocysts produced by nuclear transfer between chicken blastodermal cells and rabbit oocytes

Liu

Zhenming²,

Chen

et al. 2004

Molecular Reproduction Devel

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Interspecies nuclear transfer (INT) has been used as an invaluable tool for studying nucleus-cytoplasm interactions; and it may also be a method for rescuing endangered species whose oocytes are difficult to obtain. In the present study, we investigated interaction of the chicken genome with the rabbit oocyte cytoplasm. When chicken blastodermal cells were transferred into the perivitelline space of rabbit oocytes, 79.3% of the couplets were fused and 9.7% of the fused embryos developed to the blastocyst stage. Both M199 and SOF medium were used for culturing chicken-rabbit cloned embryos; embryo development was arrested at the 8-cell stage obtained in SOF medium, while the rates of morulae and blastocysts were 12.1 and 9.7%, respectively, in M199 medium. Polymerase chain reaction (PCR) amplification of nuclear DNA and karyotype analyses confirmed that genetic material of morulae and blastocysts was derived from the chicken donor cells. Analysis mitochondrial constitution of the chicken-rabbit cloned embryos found that mitochondria, from both donor cells and enucleated oocytes, co-existed. Our results suggest that: (1) chicken genome can coordinate with rabbit oocyte cytoplasm in early embryo development; (2) there may be an 8- to 16-cell stage block for the chicken-rabbit cloned embryos when cultured in vitro; (3) mitochondrial DNA from the chicken donor cells was not eliminated until the blastocyst stage in the chicken-rabbit cloned embryos; (4) factors existing in ooplasm for somatic nucleus reprogramming may be highly conservative.

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Transcription of chick genes by mammalian RNA polymerase II in chick erythrocyte‐mammalian cell heterokaryons

Cited by 13 publications

References 33 publications

Migration of rat RNA polymerase I into chick erythrocyte nuclei undergoing reactivation in chick-rat heterokaryons.

Migration of rat RNA polymerase I into chick erythrocyte nuclei undergoing reactivation in chick-rat heterokaryons.

Changes in nuclear antigens during reactivation of chick erythrocyte nuclei in heterokaryons

Blastocysts produced by nuclear transfer between chicken blastodermal cells and rabbit oocytes

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