کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5915983 1163348 2009 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The nucleolus in Entamoeba histolytica and Entamoeba invadens is located at the nuclear periphery
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شناسی مولکولی
پیش نمایش صفحه اول مقاله
The nucleolus in Entamoeba histolytica and Entamoeba invadens is located at the nuclear periphery
چکیده انگلیسی

The ribosomal RNA genes in the human parasite Entamoeba histolytica and its reptilian counterpart Entamoeba invadens are located on extrachromosomal circles. The expression of rRNA genes generally takes place in a specialized nuclear compartment-the nucleolus. In Entamoeba species the nuclear space that may be called the nucleolus has yet to be defined. Previous studies showed that the rDNA circles are located at the nuclear periphery. Here we have raised antibodies against the E. histolytica homologue of fibrillarin, a highly conserved protein known to be a marker for nucleolus. These antibodies cross-reacted preferentially with the nuclear periphery, forming a peripheral ring. There was complete colocalization of fibrillarin with the signal obtained by antibodies against E. histolytica RNA polymerase I (but not polymerase II and III), strongly suggesting that the nucleolus in E. histolytica is indeed located at the nuclear periphery. The dynamic nature of the nucleolus was evident when cells were subjected to a variety of growth stresses. Although the peripheral nucleolar structure was retained, stress was accompanied by significant cytoplasmic localization of RNA polymerase I, and to some extent fibrillarin. The nucleolus in E. invadens was also located at the nuclear periphery. When these cells were induced to encyst the nucleolar ring structure was lost, giving way to small, fragmented foci. This study gives the first clear insight into nucleolar structure in Entamoeba.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Molecular and Biochemical Parasitology - Volume 167, Issue 1, September 2009, Pages 72-80
نویسندگان
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