pyreninn.
/pʌɪˈriːnɪn/, /ˈpʌɪrənɪn/, U.S. /paɪˈrin(ᵻ)n/, /ˈpaɪrən(ə)n/ Cell Biology. disused.
The substance of which a cell nucleolus is composed.
ΚΠ
1890 Cent. Dict. Pyrenin, according to F. Schwartz, the chemical substance composing the nucleoli of a cell.
1893 Lancet 18 Mar. 575/2 They [sc. nucleins poor in nucleic acid] occur in nature in the nucleoli (pyrenin).
1900 E. B. Wilson Cell (ed. 2) i. 41 The following classification of the nuclear substances, proposed by Schwarz in 1887, has been widely accepted, though open to criticism on various grounds. 1. Chromatin... 2. Linin... 3. Paralinin... 4. Pyrenin or Parachromatin. The inner mass of true nucleoli. 5. Amphipyrenin.
1924 Science 6 June 498/2 A more or less thin layer of liquid substance (pyrenin?), clothing the hard internal stalk and merging (during the telophase) into the pyrenin-nucleoli.
This entry has been updated (OED Third Edition, December 2007; most recently modified version published online March 2022).
<
n.1890