| 释义 |
paranemic, a.|pærəˈniːmɪk|
[f. para-1 + Gr. νῆµα thread + -ic.]
Of, pertaining to, or designating two or more like helices coiled together side by side in such a way that they may be fully separated without being unwound. Opp. plectonemic a.
1941[see plectonemic a.]. 1950Biol. Rev. XXV. 500 Until quite recently almost all observers were agreed that the plectonemic spiral was characteristic of mitosis and the paranemic of meiosis (meaning the first meiotic division). 1953Watson & Crick in Cold Spring Harbor Symp. Quant. Biol. XVIII. 129/2 With paranemic coiling, the specific pairing of bases [in DNA] would not allow the successive residues of each helix to be in equivalent orientation with regard to the helical axis. 1974F. Crick in Nature 26 Apr. 767/2 Looking back, I think we deserve some credit..for our forthright stand against paranemic (as opposed to plectonemic) coiling. |