ISSN:
1420-9071
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary A strain ofParamaecium multimicronucleatum was exposed to a medium containingl-lysine; the concentrations of the amino acid were 0.1%, 0.5% and 1.0% for different sets of experiments. In these two latter concentrations, the macronucleus of the ciliate broke down into innumerable small fragments, the microspheres. The micronuclei remained inert. The microspheres left the body of paramaecium as cell-free, self-duplicating entities constituted of DNA and RNA and enveloped by a protein coat. They had no nuclear membrane and they resembled the prokaryotes. Grown in culture medium with 0.1% horse serum, the microspheres transformed into small amoebae having typical eukaryotic features. These amoebae maintained a typical cyst-trophic cycle during the successive sub-cultures; they had no similarity with the paramaecia.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01937398
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