Abstract
Electron microscopic observations on sections of squashed glutar-aldehyde-fixed salivary gland X-chromosomes ofDrosophila melanogaster provided an ultrastructural map of the band sequence of region 1A1 to 4E3. Comparison of this map with the map of Bridges (1938) revealed a significantly lower number of bands. Only 67% of the bands depicted in Bridges' map could be identified. This discrepancy seems to be a consequence mainly of the absence of doublet characters of bands on Bridges' map. — A possible relationship between bands and genes is discussed for some regions, including the white-Notch region. It appears that a one to one relationship between bands and genes does exist for two regions, whereas in region 3C1–3C7 more genes than bands are present. In this respect the structural organization of bands at the submicroscopic level is discussed. — The average DNA content of a band at the haploid level is calculated on the basis of the reduction in band number to be 4.5 × 10−5 picogram.
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References
Arcos-Terán, L., Beermann, W.: Changes of DNA replication behavior associated with intragenic changes of thewhite region inDrosophila melanogaster. Chromosoma (Berl.)25, 377–391 (1968).
Ashburner, M.: Patterns of puffing activity in the salivary gland chromosomes ofDrosophila. II. The X-chromosome puffing patterns ofD. melanogaster andD. simulans. Chromosoma (Berl.)27, 47–63 (1969).
Becker, H. J.: Die Puffs der Speicheldrüsenchromosomen vonDrosophila melanogaster. I. Mitt. Beobachtungen zum Verhalten des Puffmusters im Normalstamm und bei zwei Mutanten,giant undletfial-giant-larvae. Chromosoma (Berl.)10, 654–678 (1959).
Beermann, W.: Riesenchromosomen. Protoplasmatologia VI/D. Wien: Springer 1962.
—: Differentiation at the level of chromosomes. In: Cell differentiation and Morphogenesis. Amsterdam: North Holland Publ. Comp. 1966.
Berendes, H. D.: Electron microscopical mapping of giant chromosomes. Dros. Inf. Serv.43, 115–116 (1968).
—, Beermann, W.: Biochemical activity of interphase chromosomes (polytene chromosomes). In: Handbook of molecular cytology (ed. A. Lima-de-Faria). Amsterdam: North Holland Publ. Comp. 1969.
—, Meyer, G. F.: A specific chromosome element, the telomere ofDrosophila polytene chromosomes. Chromosoma (Berl.)25, 184–197 (1968).
Bridges, C. B.: Salivary chromosome maps with a key to the banding of the chromosomes ofDrosophila melanogaster. J. Hered.26, 60–64 (1935).
—: A revised map of the salivary gland X-chromosome ofDrosophila melanogasfer. J. Hered.29, 11–13 (1938).
Bridges, P. N.: A new map of the salivary 2L-chromosome ofDrosophila melanogaster. J. Hered.33, 403–408 (1942).
Cooper, K. W.: Cytogenetic analysis of major heterochromatic elements (especially Xh and Y) inDrosophila melanogaster and the theory of “heterochromatin”. Chromosoma (Berl.)10, 535–588 (1959).
Edström, J.-E.: Chromosomal RNA and other nuclear RNA fractions. In: The role of chromosomes in development (ed. M. Locke). New York: Academic Press 1964.
Gersh, E. S.: Genetic effects associated with band 3C1 of the salivary gland X-chromosome ofDrosophila melanogaster. Genetics56, 309–319 (1967).
Green, M. M.: Variegation of the eye color mutantzeste as a function of rearrangements at thewhite locus inDrosophila melanogaster. Biol. Zbl.86, 211–220 (1967).
Heitz, E., Bauer, H.: Beweise für die Chromosomennatur der Kernschleifen in den Knauelkernen vonBibio hortulanus L. Z. Zellforsch.17, 67–82 (1933).
Judd, B. H.: An analysis of mutations confined to a small region of the X-chromosome ofDrosophila melanogaster. Science138, 990–991 (1962).
Kaufmann, T. C., Shen, M. W., Judd, B. H.: The complementation map of mutations in a small region of the X-chromosome ofDrosophila melanogaster. Genetics61, 30–31 (1969).
Lefevre, G.: Mutant phenotypes immediately to the left ofw. Dros. Inf. Serv.43, 165 (1968).
—, Wilkins, M. D.: Cytogenetic studies on thewhite locus inDrosophila melanogaster. Genetics53, 175–187 (1966).
Muller, H. J., Prokofyeva, A. A.: The individual gene in relation to the chromomere and the chromosome. Proc. nat. Acad. Sci. (Wash.)21, 16–26 (1935).
Painter, T. S.: Salivary chromosomes and the attack on the gene. J. Hered.25, 465–476 (1934).
Rayle, R. E., Green, M. M.: A contribution to the genetic fine structure of the region adjacent to white inDrosophila melanogaster. Genetica (s' Gravenhage)39, 497–507 (1968).
Rudkin, G.: The relative mutabilities of DNA in regions of the X-ehromosome ofDrosophila melanogaster. Genetics52, 665–681 (1965).
Sorsa, M.: Ultrastructure of the polytene chromosome inDrosophila melanogaster with special reference to electron microscopic mapping of chromosome 3 R. Ann. Acad. Sci. fenn., Ser. A, IV Biologica151, 1–18 (1969).
Sorsa, V., Sorsa, M.: Ideas on the linear organization of chromosomes revived by electron microscopic studies of stretched salivary chromosomes. Ann. Acad. Sci. fenn., Ser. A, IV Biologica134, 3–16 (1968).
Wolstenholme, D. R., Dawid, I. B., Ristow, H.: An electron microscope study of DNA molecules fromChironomus tentans andChironomus thummi. Genetics60 769–770 (1968).
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Berendes, H.D. Polytene chromosome structure at the submicroscopic level. Chromosoma 29, 118–130 (1970). https://doi.org/10.1007/BF01183664
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DOI: https://doi.org/10.1007/BF01183664