Freeze-fracture evidence for high cholesterol content in nuclear membranes of a larval urodelan epidermis.
The treatment of the larval epidermis of the ovoviviparous salamander, Salamandra salamandra (L.), with filipin produces a high number (193/micrometer 2) of filipin-sterol complexes in the outer nuclear membrane and a markedly lower number (27/micrometer 2) in the inner membrane of the pavement cells as revealed by freeze-fracturing. Frequently a small zone immediately surrounding nuclear pores is free of membrane lesions. The nuclear envelopes of other cell types in the epidermis are free of filipin-induced protuberances. The results provide evidence for a high cholesterol content in nuclear membranes hitherto believed to be low in cholesterol.
D000818:Animals; D002784:Cholesterol / Q000378:metabolism*; D004817:Epidermis / Q000648:ultrastructure; D005614:Freeze Fracturing; D007814:Larva; D008563:Membrane Lipids / Q000378:metabolism*; D009685:Nuclear Envelope / Q000648:ultrastructure*; D012454:Salamandra
D008563:Membrane Lipids; D002784:Cholesterol