Biomaterial Database

Replication forms of the gene-sized DNA molecules of hypotrichous ciliates. 1983

K G Murti, and D M Prescott

Using a method for obtaining DNA from 10 to 40 macronuclei for electron microscopy, we analyzed the structure of gene-sized, linear DNA molecules from S-phase macronuclei of two hypotrichous ciliates, Euplotes eurystomus and Styx sp. Three types of putative replicating intermediates were observed: (i) molecules with a bubble close to one end, (ii) molecules with single forks, and (iii) molecules with two forks. We conclude that: (i) each macronuclear DNA molecule replicates as an independent unit, (ii) the molecules contain an origin of replication close to one or both ends, and (iii) the mode of replication is bidirectional.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D004261	DNA Replication	The process by which a DNA molecule is duplicated.	Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA
D005796	Genes	A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.	Cistron,Gene,Genetic Materials,Cistrons,Genetic Material,Material, Genetic,Materials, Genetic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D016798	Ciliophora	A phylum of EUKARYOTES characterized by the presence of cilia at some time during the life cycle. It comprises three classes: KINETOFRAGMINOPHOREA; OLIGOHYMENOPHOREA; and POLYMENOPHOREA.	Ciliata,Ciliatas,Ciliophoras