Data/hora: 05/06/2024 14:28:16

Provedor de dados: 	48	
País: 	Chile	
Título: 	Quantitative analysis of nucleolar chromatin distribution in the complex convoluted nucleoli of Didinium nasutum (Ciliophora)	
Autores: 	Leonova,Olga G; Karajan,Bella P; Ivlev,Yuri F; Ivanova,Julia L; Skarlato,Sergei O; Popenko,Vladimir I.	
Data: 	2013-01-01	
Ano: 	2013	
Palavras-chave: 	3D reconstruction; Ciliates; Electron microscopy; Macronucleus; Nucleoli.	
Resumo: 	We have earlier shown that the typical Didinium nasutum nucleolus is a complex convoluted branched domain, comprising a dense fibrillar component located at the periphery of the nucleolus and a granular component located in the central part. Here our main interest was to study quantitatively the spatial distribution of nucleolar chromatin structures in these convoluted nucleoli. There are no "classical" fibrillar centers in D.nasutum nucleoli. The spatial distribution of nucleolar chromatin bodies, which play the role of nucleolar organizers in the macronucleus of D.nasutum, was studied using 3D reconstructions based on serial ultrathin sections. The relative number of nucleolar chromatin bodies was determined in macronuclei of recently fed, starved D.nasutum cells and in resting cysts. This parameter is shown to correlate with the activity of the nucleolus. However, the relative number of nucleolar chromatin bodies in different regions of the same convoluted nucleolus is approximately the same. This finding suggests equal activity in different parts of the nucleolar domain and indicates the existence of some molecular mechanism enabling it to synchronize this activity in D. nasutum nucleoli. Our data show that D. nasutum nucleoli display bipartite structure. All nucleolar chromatin bodies are shown to be located outside of nucleoli, at the periphery of the fibrillar component.	
Tipo: 	Journal article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602013000100010	
Editor: 	Sociedad de Biología de Chile	
Formato: 	text/html	
Fonte: 	Biological Research  v.46 n.1 2013