Abstract
The method of ultrathin sections of unsquashed salivary gland polytene chromosomes of Ch. thummi was applied to their ultrastructural mapping. There was a good agreement between electron micrographs and Hägele's light microscopic map (1970) with respect to the pattern and number of bands. 94% of bands were identified in larval and prepupal chromosomes. In Ch. thummi, band thickness varied from 0.05–0.5 μm. Most characteristic were 0.2–0.3 μm bands. Morphologically, bands were classified as: continuous (frequently with holes and gaps), discrete, dotted and continuous-discrete, discrete-dotted.Band morphology is related to band size, such that smaller bands, as a rule, were also dotted. Bands beginning to puff likewise became dotted. Interbands in unsquashed chromosome sections were from 0.05–0.15 μm. The smallest interbands contained only fibrils, in the larger interbands few granules could be observed. This makes interbands distinguishable from a typical puff with many such granules.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Beermann, W.: Riesenchromosomen. Protoplasmatologia 6/D — Wien: Springer-Verlag 1962
Beermann, W.: Chromomeres and genes. In: Developmental Studies on giant chromosomes (W. Beermann, ed.), p. 1–33. Berlin-Heidelberg-New York: Springer 1972
Berendes, H. D.: Electron microscopical mapping of giant chromosomes. Dros. Inf. Serv. 43, 115–116 (1968)
Berendes, H. D.: Polytene chromosome structure at the submicroscopic level. 1. A map of region X, 1-4E of Drosophila melanogaster. Chromosoma (Berl.) 29, 118–130 (1970)
Bernhard, W.: A new staining procedure for electron microscopical cytology. J. Ultrastruct. Res. 27, 250–265 (1969)
Bridges, C. B.: A revised map of the salivary gland X-chromosome of Drosophila melanogaster. J. Heredity 29, 11–13 (1938)
Daneholt, B., Edström, I.-E.: The content of DNA in individual polytene chromosomes of Chironomus tentans. Cytogenetics 6, 350–356 (1967)
Edström, I.-E.: Polytene chromosomes in studies of gene expression. In: The cell nucleus, vol. 2, p. 293–332. New York-San-Francisco-London: Academic press 1974
Gruzdev, A. D., Kiknadze, I. I.: On the connection of polytene chromosomes with the nuclear membrane. Cytologia (USSR) 12, 919–921 (1970)
Hägele, K.: DNS-Replikationsmuster der Speicheldrüsen-Chromosomen von Chironomiden. Chromosoma (Berl.) 31, 91–138 (1970)
Kiknadze, I. I.: Polytene chromosomes as a model of interphase chromosome. Cytologia (Russ.) 13, 716–732 (1971)
Kiknadze, I. I., Vlasova, I. E., Sherudilo, A. I.: Quantitative analysis of DNA content in the salivary chromosomes of Chironomus thummi at larval and prepupal stages. Cell Different. 3, 323–334 (1975)
Kimoto, G.: An attachment of the salivary gland chromosomes to the nuclear membrane found in Ch. dorsalis. Cytologia (Tokyo) 23, 478–484 (1958)
Laird, Ch. D.: DNA of Drosophila chromosomes. Ann. Rev. Genet. 7, 177–204 (1973)
Panitz, R.: Über die Rolle der Chromosomen bei der Informationsübertragung in höheren Organismen. Biol. Zbl. 87, 545–565 (1968)
Perov, N. A., Chentsov, Y. S.: Electron microscopic studies of the larval salivary gland chromosomes of Chironomus plumosus. Dokl. Akad. Nauk USSR 196, 1452–1456 (1971)
Perov, N. A., Kiknadze, I. I., Chentsov, Y. S.: Ultrastructural organization of the salivary gland polytene chromosomes of Chironomus thummi. Cytologia (USSR) 17, 390–397 (1975)
Reynolds, E. S.: The use of lead citrate at high pH as an electron opague stain in electron microscopy. J. biophys. biochem. Cytol. 17, 208–212 (1963)
Rudkin, G. T.: The relative mutabilitis of DNA in regions of the X-chromosome of Drosophila melanogaster. Genetics 52, 665–681 (1965)
Sorsa, M.: Ultra-structure of polytene chromosome in Drosophila melanogaster with special reference to electron microscopic mapping of chromosome 3R. Ann. Acad. Sci. fenn., Ser. A, IV, 151, 1–18 (1969)
Sorsa, V., Green, M. M., Beermann, W.: Cytogenetic fine structure and chromosomal localization of white gene in D. melanogaster. Nature (Lond.), New Biol. 245, 34–37 (1973)
Sorsa, V., Sorsa, M.: Ideas on the linear organization of chromosomes reviewed by electron microscopic studies of streched salivary chromosomes. Ann. Acad. Sci. fenn., Ser. A, IV, Biol. 134, 3–16, (1968)
Sorsa, M., Sorsa, V.: Electron microscopic mapping of salivary chromosome X in D. melanogaster. Genetics 74, part 2, 262 (1973)
Vlasova, I. E., Kiknadze, I. I., Sherudilo, A. I.: The DNA replication during chromosome polytenization in Ch. thummi-ontogenesis. Dokl. Akad. Nauk USSR 203, 459–469 (1972)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kiknadze, I.I., Perov, N.A. & Chentsov, Y.S. Electron microscopic studies on the polytene chromosomes of Chironomus thummi salivary glands. Chromosoma 55, 91–103 (1976). https://doi.org/10.1007/BF00288332
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00288332