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PREPARATION AND PROPERTIES OF NUCLEI FROM THE POSTERIOR SILK GLANDS OF THE SILKWORM BOMBYX MORI
Author(s) -
CORNET P.,
CHAVANCY G.,
DAILLIE J.
Publication year - 1978
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1978.00251.x
Subject(s) - bombyx mori , silk , rna , chromatin , transcription (linguistics) , dna , rnase p , sieve (category theory) , nucleus , microbiology and biotechnology , in vitro , cleavage (geology) , biology , chemistry , biochemistry , materials science , gene , fracture (geology) , paleontology , linguistics , philosophy , mathematics , combinatorics , composite material
An original method to isolate nuclei from the posterior part of the silk glands has been developed. After a collagenase and Triton X–100 treatment, silk glands were filtered through a steel sieve. This step, which is the most efficient one for the purification, is followed by several washings. The preparation of nuclei is fairly pure, RNA: DNA ratio being 0.3 at the end of the whole procedure, and the final DNA recovery quite satisfactory (40–60%). Although chromatin of the purified nuclei is unusually condensed, and in spite of RNase activity, RNA transcription measured in vitro is quantitatively significant (0.01 % of the total DNA). This transcription, resulting from the activity of endogenous RNA polymerases, reaches a maximum when nuclei were extracted from animals on the 4th day of the fifth instar. Differences with results obtained in vivo are discussed.