ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Circular Dichroism (CD) and Linear Dichroism (LD) Microscopy measurements of single live polytene nuclei of the fleshfly Sarcophaga bullata suggest the existence of two groups of data. This was observed in both the linear and circular dichroism spectra indicating a difference in both the linear and chiral arrangements of the chromatin. The two groups of data were averaged separately and called nucleolus type 1 and type 2. The CD of nucleoli type 1 all show positive CD in the 260 nm wavelength. For the nucleoli type 2 the CD are very different, always negative, with maximum amplitude at 250 nm. The CD of the band, interband and transcriptionally active puffs show very similar CD spectra at 260 nm but differ at lower wavelength (between 245 and 260 nm). Differences are also observed in the LD measurements for nucleoli type 1 (LD maximum at 265 nm) vs. nucleoli type 2 (LD maximum centered at 250 nm). These differences are interpreted as a manifestation of large transcriptional activity for nucleolus type 1, and a more condensed structure and low transcriptional activity for nucleolus type 2.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360271106
