Publication Date:
2008-03-15
Description:
The diplomonad parasite Giardia intestinalis contains two functionally equivalent nuclei that are inherited independently during mitosis. Although presumed to be asexual, Giardia has low levels of allelic heterozygosity, indicating that the two nuclear genomes may exchange genetic material. Fluorescence in situ hybridization performed with probes to an episomal plasmid suggests that plasmids are transferred between nuclei in the cyst, and transmission electron micrographs demonstrate fusion between cyst nuclei. Green fluorescent protein fusions of giardial homologs of meiosis-specific genes localized to the nuclei of cysts, but not the vegetative trophozoite. These data suggest that the fusion of nuclei, or karyogamy, and subsequently somatic homologous recombination facilitated by the meiosis gene homologs, occur in the giardial cyst.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Poxleitner, Marianne K -- Carpenter, Meredith L -- Mancuso, Joel J -- Wang, Chung-Ju R -- Dawson, Scott C -- Cande, W Zacheus -- 1F32GM078971/GM/NIGMS NIH HHS/ -- A1054693/PHS HHS/ -- New York, N.Y. -- Science. 2008 Mar 14;319(5869):1530-3. doi: 10.1126/science.1153752.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18339940" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Cell Nucleus/*physiology/ultrastructure
;
Giardia lamblia/*genetics/growth & development/ultrastructure
;
In Situ Hybridization, Fluorescence
;
*Membrane Fusion
;
Microscopy, Electron, Transmission
;
Nuclear Envelope/physiology
;
*Plasmids
;
Protozoan Proteins/genetics/*metabolism
;
Recombinant Fusion Proteins/metabolism
;
*Recombination, Genetic
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
