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Is Blepharisma hyalinum Truly Unpigmented? 1
Author(s) -
LARSEN HANS FIND,
NILSSON JYTTE R.
Publication year - 1983
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1983.tb01039.x
Subject(s) - pigment , electron microscope , macronucleus , biology , chloroform , absorption (acoustics) , botany , chemistry , chromatography , biochemistry , materials science , optics , physics , organic chemistry , dna , composite material
. To answer whether Blepharisma hyalinum is truly unpigmented, the organism must be established in culture as pointed out by Giese in 1973. Accordingly, the present study deals with B. hyalinum kept in culture since its isolation in 1975. The organism still remains colorless after growth in the dark; however, it contains cortical granules resembling pigment granules in colored species. A comparative study was therefore undertaken of B. hyalinum and B. steini ; both species have a compact macronucleus, though of different shape. Crude pigment was extracted with acetone from organisms grown in the dark for three weeks and the maxima were measured by absorption. Purified pigment was obtained from TLC‐plate preparations and the absorption maxima were measured after removal of lipids with chloroform. No maxima characteristic of blepharismin were found in extracts of B. hyalinum , but these were present in extracts of B. steini. Electron microscopy of the cortical region revealed membrane‐bound granules in both species; these granules differed in content but not in their capacity to extrude. In B. hyalinum all granules had a homogenous electron‐dense substructure; in B. steini the granules had a net‐like granulated substructure of varying electron density. This difference corresponds to that published on “pigment” granules in albino and pigmented strains of B. undulans. Our conclusions are that B. hyalinum is unpigmented (and a valid separate species) and that the cortical granules may serve other functions than that of storing blepharismin.