tailieunhanh - Báo cáo sinh học: " Interindividual and intercellular polymorphisms of Ag-NOR pattern in mink embryo siblings"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Interindividual and intercellular polymorphisms of Ag-NOR pattern in mink embryo siblings | Genet Sei Evol 1994 26 475-484 Elsevier INRA 13 JANV 1995 475 Original article Interindividual and intercellular polymorphisms of Ag-NOR pattern in mink embryo siblings GK Isakova Institute of Cytology and Genetics Russian Academy of Sciences Siberian Branch 630090 Novosibirsk Russia Received 24 February 1993 accepted 19 May 1994 Summary - The variability of the silver-staining pattern of the nucleolus organizing regions Ag-NOR pattern was studied in hepatocytes from 9 mink embryo siblings including a pair of monochorionic presumably monozygotic co-twins. Both the number of Ag-NORs and the mean size of Ag-spots per cell were found to be identical in monochorionic twins. All other sibs had patterns different from each other and from co-twins. Intercellular variation of both the number and size of Ag-stained regions as measured by the coefficient of variation was similar only in monochorionic twins. The data indicate that both the interindividual and intercellular variations of the Ag-NOR pattern are highly heritable. The mechanisms underlying the Ag-NOR pattern polymorphisms are discussed. It is proposed that at least 2 independently inherited routes for the variable expression of the ribosomal gene system exist 1 polymorphism for rDNA array and 2 polymorphism for rRNA gene expression. mink embryo chromosome nucleolus organizing region silver staining Resume Polymorphisme interindividuel et intercellulaire de la coloration à 1 argent des regions des organisateurs nucléolaires chez des embryons de vison. La variabilité de la coloration à I argent des regions des organisateurs nucléolaires Ag-NOR a été étudiée sur des hepatocytes de 9 embryons de vison germains de portée et incluant une paire de jumeaux monochorioniques presumes monozygotes. A la fois le nombre des Ag-NOR et la taille moyenne des taches d argent par cellule se sont trouvés être identiques chez les jumeaux monochorioniques. Les autres germains avaient tous des patrons differents entre eux et differents