The very long telomeres in <Emphasis Type="Italic">Sorex granarius</Emphasis> (Soricidae,Eulipothyphla) contain ribosomal DNA |
| |
Authors: | Natalia S Zhdanova Julia M Minina Tatjana V Karamisheva Irena Draskovic Nikolai B Rubtsov Jose-Arturo Londoño-Vallejo |
| |
Institution: | (1) Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia;(2) Institut Curie, UMR7147, CNRS-UPMC, 26 rue d’Ulm, 75248 Paris, France |
| |
Abstract: | Two closely related shrew species, Sorex granarius and Sorex araneus, in which Robertsonian rearrangements have played a primary role in karyotype evolution, present very distinct telomere length
patterns. S. granarius displays hyperlong telomeres specifically associated with the short arms of acrocentrics, whereas telomere lengths in S. araneus are rather short and homogenous. Using a combined approach of chromosome and fibre FISH, modified Q-FISH, 3D-FISH, Ag-NOR
staining and TRF analysis, we carried out a comparative analysis of telomeric repeats and rDNA distribution on chromosome
ends of Sorex granarius. Our results show that rDNA sequences forming active nuclear organizing regions are interspersed with the long telomere tracts
of all short arms of acrocentrics. These observations suggest that the major rearrangements that gave rise to today’s karyotype
in S. granarius were accompanied by a profound reorganization of chromosome ends, which comprised extensive amplification of telomeric and
rDNA repeats on the short arms of acrocentrics and finally contributed to the stabilization of telomeres. This is the first
time that such telomeric structures have been observed in any mammalian species. |
| |
Keywords: | chromosome evolution rDNA shrew Sorex telomere |
本文献已被 SpringerLink 等数据库收录! |
|