Proposed Genetic Nomenclature Rules for Tetrahymena thermophila, Paramecium primaurelia and Paramecium tetraurelia

Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 459-462 ◽  
Author(s):  
◽  
Sally Lyman Allen ◽  
Marsha I Altschuler ◽  
Peter J Bruns ◽  
Jean Cohen ◽  
...  
Keyword(s):  
Tetrahymena Thermophila ◽  
Ciliated Protozoa ◽  
Paramecium Tetraurelia ◽  
Short Introduction ◽  
Genetic Nomenclature

Abstract The genetics of the ciliated protozoa Tetrahymena thermophila and certain species of Paramecium (P. primaurelia and P. tetraurelia) have reached a level of maturity such that rules for genetic nomenclature for micronuclear and macronuclear genetics need to be clarified for workers in the field as well as for other geneticists. After a short introduction, the rules follow.

scholarly journals A Developmentally Regulated Gene, ASI2, Is Required for Endocycling in the Macronuclear Anlagen of Tetrahymena

2010 ◽  
Vol 9 (9) ◽  
pp. 1343-1353 ◽  
Author(s):  
Lihui Yin ◽  
Susan T. Gater ◽  
Kathleen M. Karrer
Keyword(s):  
Signal Transduction ◽  
Mitotic Cycle ◽  
Tetrahymena Thermophila ◽  
Germ Line ◽  
Ciliated Protozoa ◽  
Dna Rearrangement ◽  
Developmentally Regulated ◽  
Content Type ◽  
Molecular Events ◽  
Multicellular Organisms

ABSTRACT Ciliated protozoa contain two types of nuclei, germ line micronuclei (Mic) and transcriptionally active macronuclei (Mac). During sexual reproduction, the parental Mac degenerates and a new Mac develops from a mitotic product of the zygotic Mic. Macronuclear development involves extensive endoreplication of the genome. The present study shows that endoreplication of macronuclear DNA in Tetrahymena is an example of endocyling, a variant of the mitotic cycle with alternating S and G phases in the absence of cell division. Thus, endocycling is conserved from ciliates to multicellular organisms. The gene ASI2 in Tetrahymena thermophila encodes a putative signal transduction receptor. ASI2 is nonessential for vegetative growth, but it is upregulated during development of the new Mac. Cells that lack ASI2 in the developing Mac anlagen are arrested in endoreplication of the DNA and die. This study shows that ASI2 is also transcribed in the parental Mac early in conjugation and that transcription of ASI2 in the parental Mac supports endoreplication of the DNA during early stages of development of the Mac anlagen. Other molecular events in Mac anlage development, including developmentally regulated DNA rearrangement, occur normally in matings between ASI2 knockouts, suggesting that ASI2 specifically regulates endocycling in Tetrahymena.

Toxicity of ZnO and CuO nanoparticles to ciliated protozoa Tetrahymena thermophila

Toxicology ◽  
2010 ◽  
Vol 269 (2-3) ◽  
pp. 182-189 ◽  
Author(s):  
Monika Mortimer ◽  
Kaja Kasemets ◽  
Anne Kahru
Keyword(s):  
Tetrahymena Thermophila ◽  
Cuo Nanoparticles ◽  
Ciliated Protozoa

The ciliated protozoa Tetrahymena thermophila as a bionsensor to detect mycotoxins

1994 ◽  
Vol 19 (6) ◽  
pp. 489-491 ◽  
Author(s):  
L. Benitez ◽  
A. Martin-Gonzalez ◽  
P. Gilardi ◽  
T. Soto ◽  
J. Rodriguez Lecea ◽  
...  
Keyword(s):  
Tetrahymena Thermophila ◽  
Ciliated Protozoa

Identification of a spindle-associated protein in ciliate micronuclei

1989 ◽  
Vol 93 (2) ◽  
pp. 287-298
Author(s):  
GUY KERYER ◽  
NICOLE GARREAU DE LOUBRESSE ◽  
NICOLE BORDES ◽  
MICHEL BORNENS
Keyword(s):  
Cell Cycle ◽  
Monoclonal Antibody ◽  
Nuclear Envelope ◽  
Mammalian Cells ◽  
Fibrous Material ◽  
Cortical Microtubule ◽  
Ciliated Protozoa ◽  
Paramecium Tetraurelia ◽  
Electron Microscope Level ◽  
Microtubule Organizing Centres

Ciliated protozoa display a nuclear dualism, with germinal micronuciei and a somatic macronucleus. During mitosis, which proceeds without disruption of the nuclear envelope, a spindle is organized within the micronucleus from, presumably, intranuclear microtubule-organizing centres (MTOCs). In order to characterize these MTOCs, monoclonal antibodies generated against human centrosomes were screened on several ciliates and particularly on Paramecium tetraurelia. In this ciliate, the monoclonal antibody CTR 532, which decorates centrosomal and spindle-associated components in mammalian cells, specifically labelled the micronuclei during interphase. At the electron-microscope level, it stained a fibrous material surrounding microtubules localized on the inner face of the nuclear envelope. During mitosis this decoration extended all over the metaphase spindle. At all stages of the cell cycle, the decoration remained specific to the micronucleus and was absent not only from all of the various cytoplasmic and cortical microtubule arrays but also from the macronuclei, even at early stages of their development from the zygotic nucleus. CTR 532 recognizes a single 170x103 Mr polypeptide in the cytoskeletal fraction that contains micronuclei and this polypeptide is absent in the cytoskeletal fraction of amicronucleate cells.

scholarly journals The Conjugation-Specific Die5 Protein Is Required for Development of the Somatic Nucleus in both Paramecium and Tetrahymena

2010 ◽  
Vol 9 (7) ◽  
pp. 1087-1099 ◽  
Author(s):  
Atsushi Matsuda ◽  
Annie Wan-Yi Shieh ◽  
Douglas L. Chalker ◽  
James D. Forney
Keyword(s):  
Gene Disruption ◽  
Tetrahymena Thermophila ◽  
Paramecium Tetraurelia ◽  
Somatic Nucleus ◽  
Genome Amplification ◽  
Content Type ◽  
Chromosome Fragmentation ◽  
Genome Reorganization ◽  
Somatic Genome ◽  
Nuclear Differentiation

ABSTRACTDevelopment in ciliated protozoa involves extensive genome reorganization within differentiating macronuclei, which shapes the somatic genome of the next vegetative generation. Major events of macronuclear differentiation include excision of internal eliminated sequences (IESs), chromosome fragmentation, and genome amplification. Proteins required for these events include those with homology throughout eukaryotes as well as proteins apparently unique to ciliates. In this study, we identified the ciliate-specificDefective inIESExcision 5 (DIE5) genes ofParamecium tetraurelia(PtDIE5) andTetrahymena thermophila(TtDIE5) as orthologs that encode nuclear proteins expressed exclusively during development. Abrogation of PtDie5 protein (PtDie5p) function by RNA interference (RNAi)-mediated silencing or TtDie5p by gene disruption resulted in the failure of developing macronuclei to differentiate into new somatic nuclei.TetrahymenaΔDIE5cells arrested late in development and failed to complete genome amplification, whereas RNAi-treatedParameciumcells highly amplified new macronuclear DNA before the failure in differentiation, findings that highlight clear differences in the biology of these distantly related species. Nevertheless, IES excision and chromosome fragmentation failed to occur in either ciliate, which strongly supports that Die5p is a critical player in these processes. InTetrahymena, loss of zygotic expression during development was sufficient to block nuclear differentiation. This observation, together with the finding that knockdown of Die5p inParameciumstill allows genome amplification, indicates that this protein acts late in macronuclear development. Even though DNA rearrangements in these two ciliates look to be quite distinct, analysis ofDIE5establishes the action of a conserved mechanism within the genome reorganization pathway.

scholarly journals Evolutionary Conservation of Sequences Directing Chromosome Breakage and rDNA Palindrome Formation in Tetrahymenine Ciliates

Genetics ◽  
1996 ◽  
Vol 144 (4) ◽  
pp. 1479-1487 ◽  
Author(s):  
Robert S Coyne ◽  
Meng-Chao Yao
Keyword(s):  
Dna Sequence ◽  
Tetrahymena Thermophila ◽  
Chromosome Breakage ◽  
Evolutionary Conservation ◽  
Rdna Locus ◽  
Inverted Repeats ◽  
Ciliated Protozoa ◽  
Evolutionary Time ◽  
Additional Species ◽  
Cis Acting

Extensive, programmed chromosome breakage occurs during formation of the somatic macronucleus of ciliated protozoa. The cis-acting signal directing breakage has been most rigorously defined in Tetrahymena thermophila, where it consists of a 15-bp DNA sequence known as Cbs, for chromosome breakage sequence. We have identified sequences identical or nearly identical to the T. thermophila Cbs at sites of breakage flanking the germline micronuclear rDNA locus of six additional species of Tetrahymena as well as members of two related genera. Other general features of the breakage site are also conserved, but surprisingly, the orientation and number of copies of Cbs are not always conserved, suggesting the occurrence of germline rearrangement events over evolutionary time. At one end of the T. thermophila micronuclear rDNA locus, a pair of short inverted repeats adjacent to Cbs directs the formation of a giant palindromic molecule. We have examined the corresponding sequences from two other Tetrahymena species. We find the sequence to be partially conserved, as previously implied from analysis of macronuclear rDNA, but of variable length and organization.

Sign in / Sign up

Export Citation Format

Share Document