During macronuclear differentiation in ciliated protozoa, extensive DNA rearrangement and DNA excision processes occur, and these are most profound in stichotrichous ciliates, such as Stylonychia or Oxytricha. This review describes the morphological and molecular events taking place during macronuclear development in stichotrichous ciliates. Various models for the regulation of macronuclear differentiation have been proposed and will be discussed here. Finally, an attempt to speculate about the biological consequences of these rearrangement and excision processes will be made. Because specific elimination of DNA sequences not required in the differentiated nucleus can be regarded as the most extreme form of gene silencing, results obtained in these cells may also be relevant for our understanding of differentiation processes in higher eukaryotic organisms.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1089/dna.2008.0806 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Mismatch Repair Protein Msh6 Is Necessary for Nuclear Division and Gametogenesis in .
Int J Mol Sci
December 2023
Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China.
DNA mismatch repair (MMR) improves replication accuracy by up to three orders of magnitude. The MutS protein in or its eukaryotic homolog, the MutSα (Msh2-Msh6) complex, recognizes base mismatches and initiates the mismatch repair mechanism. Msh6 is an essential protein for assembling the heterodimeric complex.
View Article and Find Full Text PDFTiming and characteristics of nuclear events during conjugation and genomic exclusion in .
Mar Life Sci Technol
August 2022
Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China.
Ciliated protists are ideal material for studying the origin and evolution of sex, because of their nuclear dimorphism (containing both germline micronucleus and somatic macronucleus in the same cytoplasm), special sexual processes (conjugation and autogamy), and high diversity of mating-type systems. However, the study of sexual process is limited to only a few species, due to the difficulties in inducing or observing conjugation. In the present study, we investigate the conjugation process in : (1) of the three prezygotic divisions, all micronuclei undergo the first two divisions (meiosis I, II), while a variable number of nuclei undergo the third division (mitosis); (2) the synkaryon divides three times after fertilization, giving rise to eight products that differentiate into four macronuclear anlagen and four micronuclei; (3) cells restore the vegetative stage after two successive cell fissions during which the macronuclear anlagen are distributed into daughter cells without division, while micronuclei divide mitotically; (4) the parental macronucleus begins to fragment following the first meiotic division and finally degenerates completely; (5) the entire process takes about 110 h, of which about 85 h are required for macronuclear development.
View Article and Find Full Text PDFParamecium epigenetics in development and proliferation.
J Eukaryot Microbiol
September 2022
Molecular Cell Biology and Microbiology, School of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany.
The term epigenetics is used for any layer of genetic information aside from the DNA base-sequence information. Mammalian epigenetic research increased our understanding of chromatin dynamics in terms of cytosine methylation and histone modification during differentiation, aging, and disease. Instead, ciliate epigenetics focused more on small RNA-mediated effects.
View Article and Find Full Text PDFMicromanipulation in Paramecium: From non-mendelian inheritance to the outlook for versatile micromachines.
J Eukaryot Microbiol
September 2022
Department of Biological Science, Faculty of Sciences and Technology, Senshu University of Ishinomaki, Ishinomaki, Japan.
This review addresses nine areas of knowledge revealed by micromanipulations performed with Paramecium. Microinjection has shown that sexual maturation and senescence of Paramecium caudatum is a programmed process conducted by a specific gene and its product protein. In Paramecium tetraurelia, autogamy was revealed to depend on the number of DNA syntheses rather than the number of cell divisions in clonal aging.
View Article and Find Full Text PDFDocumentation of a new hypotrich species in the family Amphisiellidae, Lamtostyla gui n. sp. (Protista, Ciliophora) using a multidisciplinary approach.
Sci Rep
February 2020
Department of Biology, University of Pisa, Via Luca Ghini 13, Pisa, 56126, Italy.
An integrated approach considering both morphologic and molecular data is now required to improve biodiversity estimations and provide more robust systematics interpretations in hypotrichs, a highly differentiated group of ciliates. In present study, we document a new hypotrich species, Lamtostyla gui n. sp.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!