Evidence that cryptomonad chloroplasts evolved from photosynthetic eukaryotic endosymbionts

1990 ◽  
Vol 95 (2) ◽  
pp. 303-308
Author(s):  
GEOFFREY IAN MCFADDEN
Keyword(s):  
In Situ Hybridization ◽  
Electron Microscopic ◽  
Subcellular Compartment ◽  
Unicellular Algae ◽  
Small Nucleus

Unicellular algae of the division Cryptophyta possess an unusual subcellular compartment of unknown derivation. This compartment, which is partitioned off from the main cytoplasm by two membranes, contains a chloroplast and a small nucleus-like organelle surrounded by ribosomelike particles. Electron-microscopic in situ hybridization has been used to show that the ribosomes in this subcellular compartment are eukaryotic. In addition, eukaryotic rRNA has been localised within the nucleus-like organelle, suggesting that the rRNAs may be transcribed from genes in this nucleus. This identification of a second, nucleuscontaining eukaryotic compartment within these cells supports the hypothesis that cryptomonads contain a reduced photosynthetic eukaryotic endosymbiont.

In Situ Hybridization at the Electron Microscopic Level Using a Bromodeoxyuridine Labeled DNA Probe

1993 ◽  
Vol 68 (3) ◽  
pp. 169-174 ◽  
Author(s):  
Chong-Hua Yao ◽  
Sohei Kitazawa ◽  
Takahiro Fujimori ◽  
Sakan Maeda
Keyword(s):  
In Situ Hybridization ◽  
Microscopic Level ◽  
Dna Probe ◽  
Electron Microscopic Level ◽  
Electron Microscopic

Adaptation of a preembedding electron microscopic in situ hybridization for detection of the telomere region in human interphase nuclei

1998 ◽  
Vol 31 (1) ◽  
pp. 49-52
Author(s):  
Kouko Nagano-Tatsumi ◽  
Satomi Haga ◽  
Manabu Maeda ◽  
Yoshiaki Nawa ◽  
Hiroshi Yamamoto
Keyword(s):  
In Situ Hybridization ◽  
Electron Microscopic ◽  
Interphase Nuclei ◽  
Telomere Region

scholarly journals Electron microscopic detection of RNA sequences by non-radioactive in situ hybridization in the mollusk Lymnaea stagnalis.

1992 ◽  
Vol 40 (11) ◽  
pp. 1647-1657 ◽  
Author(s):  
R W Dirks ◽  
A G Van Dorp ◽  
J Van Minnen ◽  
J A Fransen ◽  
M Van der Ploeg ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Lymnaea Stagnalis ◽  
Pond Snail ◽  
28S Rrna ◽  
Electron Microscopic ◽  
Rna Sequences ◽  
Double Labeling ◽  
Thin Sections ◽  
Cell Hormone

The subcellular localization of mRNA sequences encoding neuropeptides in neuropeptidergic cells of the pond snail Lymnaea stagnalis was investigated at the electron microscopic (EM) level by non-radioactive in situ hybridization. Various classes of probes specific for 28S rRNA and for the ovulation hormone (caudodorsal cell hormone; CDCH) mRNA were labeled with biotin or digoxigenin and were detected after hybridization with gold-labeled antibodies. Hybridizations were performed on ultra-thin sections of both Lowicryl-embedded and frozen cerebral ganglia, and a comparison demonstrated that most intense hybridization signals with an acceptable preservation of morphology were obtained with ultra-thin cryosections. Addition of 0.1% glutaraldehyde to the formaldehyde fixative improved the morphology, but on Lowicryl sections this added fixative resulted in a decrease of label intensity. A variety of probes, including plasmids, PCR products, and oligonucleotides, were used and all provided good results, although the use of oligonucleotides on Lowicryl sections resulted in decreased gold labeling. The gold particles were found mainly associated with rough endoplasmic reticulum (RER) but were also observed in lysosomal structures. Finally, the in situ hybridization method presented in this study proved to be compatible with the immunocytochemical detection of the caudodorsal cell hormone, as demonstrated by double labeling experiments.

Sign in / Sign up

Export Citation Format

Share Document