CIRCULAR DICHROISM AND THERMAL DENATURATION STUDIES OF CHROMATIN AND DNA EROM BRDUTREATED EMBRYONIC CHICKEN NEURAL RETINA
5-溴脱氧尿嘧啶核苷对鸡胚神经视纲膜染色质、DNA的园二色性光谱与热变性的影响

o-B r o m o - 2' - deoxyuridiue (Brdu), an analogue of thymidine, is used to prob gene regulation during the histogenesis and biochemical differentation in chick embryonic neural retina.After short treatment with Brdu, the histogenesis of 6-day retina was inhibited irreversibly. These effects of inhibition were. however, reversible in 7-day retina and absent in 9 - day retina.The study of CD spectra of DNA from 6, 7 and 9 - day retina showed that Brdu treatment caused a blue shift and an increased positive ellipticity in the 260-280 nm region and an increased negative ellipticity in 290-300 nm region in CD spectra. When the same observation wa; made in the chromatir. these changes in CD spectra were obvious in 6 and 7 day retina, but barely detectable in 9 - day retina. Analysis of thermal stability of Brdu- treated DNA also revealed that Brdu treatment causes an increase in melting temperature and hyperchromic effect in DNA from 6, 7 and 9 - day retina. Again, these effects were apparent only for 6 and 7-day retina.