Summary
Plant materials of both dicotyledonous and monocotyledonous groups were subjected to treatment with alloxan followed by coumarin, phenols, oxyquinoline etc. for 3 to 4 hours.
Root tips were then heated in an orcein-acid mixture for 10 to 40 seconds and studied after mounting in 1% orcein. Clear metaphase plates were obtained after 10 seconds of heating, whereas after 20 and 30 seconds considerable erosion and fragmentation respectively were recorded. Complete loss of stainability resulted after heating for 40 seconds.
Fragmentation is caused only by orcein under heat conditions. This is demonstrated by control series checking all variables.
Pretreatment with the chemicals stated is of absolute necessity for fragmentation. It is suggested that this pretreatment causes depolymerisation of DNA and lability of nucleoprotein linkage at certain segments from which the DNA becomes detached during subsequent heating.
Of all the chemicals tested for pretreatment effects, marked positive results were obtained with alloxan (1 hour) followed by coumarin (2 hours at 16–20 ° C.). Phenols also gave positive results. The other chemicals tried need slightly longer time of treatment for fragment induction.
Similar content being viewed by others
Bibliography
D'Amato, F.: Recente acquisizioni nel oampo della chemogenetiea. 1. Prodotti di ricambo organico come agenti mutagenic. Caryologia (Pisa) 3, 249–259 (1950a).
— The chromosome breaking activity of chemicals as studied by the Allium cepa test. Publ. Staz. zool. Napoli 22, Suppl., 158–170 (1950b).
— Studio statistico dell'attivita mutagena dell'acridina e derivati. Caryologia (Pisa) 2, 229–297 (1950c).
— Chromosome breakages by brilliant cresyl blue. Caryologia (Pisa) 3, 299–304 (1951).
Gray, L. H.: Characteristics of chromosome breakage by different reagents. Heredity (Lond.) Suppl. 6, 311–315 (1953).
Koller, P. C.: The integration of nuclear and cytoplasmic activities of the cell. Proc. 6th Internat. Congr. Exper. Cyt. 1948, p. 85–92.
Levan, A.: The influence on chromosomes and mitosis of chemicals as studied by the Allium cepa test. Proc. 8th Internat. Congr. Genet. Hereditas (Lund) Suppl., 325–337 (1949).
Levan, A., and J. H. Tjio: Induction of chromosome fragmentation by phenols. Hereditas (Lund) 34, 453–489 (1948).
Oehlkers, F.: Chromosome breaks influenced by chemicals. Heredity (Lond.) Suppl. 6, 95–105 (1953).
Sharma, A. K., and A. K. Bal: Coumarin in chromosome analysis. Stain. Technol. 28, 255–257 (1953).
- An investigation on the effect of certain chemicals on the nucleus and their possibility in chromosome analysis. Abs. Proc. 41st Ind. Sci. Congr. 1954, p. 148.
Sharma, A. K., and Dipti Bhattacharjee: Permanent mount of chromosomes after 8-oxyquinoline treatment and squashing. Stain. Technol. 27, 201–203 (1952).
Sharma, A. K., and Chitra Ghosh: Oxyquinoline as an ingredient in a new fixative for chromosome analysis. Sci. Cult. 16, 268–269 (1950).
Stålfelt, M. G.: Appendix on „The effect of oxyquinoline on protoplasmic viscosity“. Ann. Estac. Exper. Aula dei 2, 21–64 (1950).
Tjio, J. H., and A. Levan: The use of oxyquinoline in chromosome analysis. Ann. Estac. Exper. Aula dei. 2, 21–64 (1950).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sharma, A.K., Roy, M. Orcein staining and the study of the effect of chemicals on chromosomes. Chromosoma 7, 275–280 (1955). https://doi.org/10.1007/BF00329728
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00329728