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Circles in spermatocyte chromatin loops. Electron microscopy and AgAs-NORs studies

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Summary

We describe the production of circles in chromomeric loops during the pachytene stage of the spermatocytes. These circles are found attached to chromatin or already free in the nucleoplasm. Each circle measures an average of 3700 Å in circunference. We suggest that such circles might indicate the presence of tandem repetitions.

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Authors and Affiliations

  1. Serviço de Genética, Instituto Butantan, Caixa Postal 65, São Paulo, Brazil

    Maria Luiza Beçak, Sylvia Mendes Carneiro & K. Fukuda

Authors
  1. Maria Luiza Beçak
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  2. Sylvia Mendes Carneiro
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  3. K. Fukuda
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Additional information

This work was supported by grants from Brazilian National Research Council-CNPq, Fundaçaó de Amparo à Pesquisa do Estado de S. Paulo-FAPESP and Instituto Butantan Research Found-FEDIB.

We are grateful to Dr A. Brunner, Jr, for the permission to use the electron microscope.

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Beçak, M.L., Carneiro, S.M. & Fukuda, K. Circles in spermatocyte chromatin loops. Electron microscopy and AgAs-NORs studies. Experientia 34, 171–173 (1978). https://doi.org/10.1007/BF01944658

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