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Pdsg1 and Pdsg2, novel proteins involved in developmental genome remodelling in Paramecium.

Arambasic M, Sandoval PY, Hoehener C, Singh A, Swart EC, Nowacki M - PLoS ONE (2014)

Bottom Line: We show that these proteins are necessary for the excision of germline-limited DNA during development and the survival of sexual progeny.Knockdown of PDSG1 and PDSG2 genes affects the populations of small RNAs known to be involved in the programming of DNA elimination (scanRNAs and iesRNAs) and chromatin modification patterns during development.Our results suggest an association between RNA-mediated trans-generational epigenetic signal and chromatin modifications in the process of Paramecium genome reorganization.

View Article: PubMed Central - PubMed

Affiliation: Institute of Cell Biology, University of Bern, Bern, Switzerland.

ABSTRACT
The epigenetic influence of maternal cells on the development of their progeny has long been studied in various eukaryotes. Multicellular organisms usually provide their zygotes not only with nutrients but also with functional elements required for proper development, such as coding and non-coding RNAs. These maternally deposited RNAs exhibit a variety of functions, from regulating gene expression to assuring genome integrity. In ciliates, such as Paramecium these RNAs participate in the programming of large-scale genome reorganization during development, distinguishing germline-limited DNA, which is excised, from somatic-destined DNA. Only a handful of proteins playing roles in this process have been identified so far, including typical RNAi-derived factors such as Dicer-like and Piwi proteins. Here we report and characterize two novel proteins, Pdsg1 and Pdsg2 (Paramecium protein involved in Development of the Somatic Genome 1 and 2), involved in Paramecium genome reorganization. We show that these proteins are necessary for the excision of germline-limited DNA during development and the survival of sexual progeny. Knockdown of PDSG1 and PDSG2 genes affects the populations of small RNAs known to be involved in the programming of DNA elimination (scanRNAs and iesRNAs) and chromatin modification patterns during development. Our results suggest an association between RNA-mediated trans-generational epigenetic signal and chromatin modifications in the process of Paramecium genome reorganization.

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Related in: MedlinePlus

Subcellular localization of Pdsg1-GFP and Pdsg2-GFP fusion proteins during development.1. Graphical representation of C-terminally tagged PDSG1 with GFP. 2. Graphical representation of N-terminally tagged PDSG2 with GFP. (A–E) Localization pattern of PDSG1-GFP. (F–J) Localization pattern of Pdsg2-GFP. (A, F) Vegetative cells with the intact MAC. (B, C, G, H) beginning of old MAC fragmentation that represents early development. (D, I) Middle stage of development with fragmented MAC. (E, J) Late development when new MAC is formed while the fragments of the old MAC are still present in the cytoplasm. Magenta: DAPI; green: GFP; white arrow: old macronucleus; arrowheads: new MAC (NM).
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pone-0112899-g002: Subcellular localization of Pdsg1-GFP and Pdsg2-GFP fusion proteins during development.1. Graphical representation of C-terminally tagged PDSG1 with GFP. 2. Graphical representation of N-terminally tagged PDSG2 with GFP. (A–E) Localization pattern of PDSG1-GFP. (F–J) Localization pattern of Pdsg2-GFP. (A, F) Vegetative cells with the intact MAC. (B, C, G, H) beginning of old MAC fragmentation that represents early development. (D, I) Middle stage of development with fragmented MAC. (E, J) Late development when new MAC is formed while the fragments of the old MAC are still present in the cytoplasm. Magenta: DAPI; green: GFP; white arrow: old macronucleus; arrowheads: new MAC (NM).

Mentions: GFP fusion proteins were generated in order to monitor the subcellular localization of Pdsg1 and Pdsg2 during development (Fig. 2). The expression of Pdsg1-GFP and Pdsg2-GFP was undetectable during vegetative growth (Fig. 2A, F). Furthermore, both Pdsg1-GFP and Pdsg2-GFP signals were exclusively detected during development.


Pdsg1 and Pdsg2, novel proteins involved in developmental genome remodelling in Paramecium.

Arambasic M, Sandoval PY, Hoehener C, Singh A, Swart EC, Nowacki M - PLoS ONE (2014)

Subcellular localization of Pdsg1-GFP and Pdsg2-GFP fusion proteins during development.1. Graphical representation of C-terminally tagged PDSG1 with GFP. 2. Graphical representation of N-terminally tagged PDSG2 with GFP. (A–E) Localization pattern of PDSG1-GFP. (F–J) Localization pattern of Pdsg2-GFP. (A, F) Vegetative cells with the intact MAC. (B, C, G, H) beginning of old MAC fragmentation that represents early development. (D, I) Middle stage of development with fragmented MAC. (E, J) Late development when new MAC is formed while the fragments of the old MAC are still present in the cytoplasm. Magenta: DAPI; green: GFP; white arrow: old macronucleus; arrowheads: new MAC (NM).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4232520&req=5

pone-0112899-g002: Subcellular localization of Pdsg1-GFP and Pdsg2-GFP fusion proteins during development.1. Graphical representation of C-terminally tagged PDSG1 with GFP. 2. Graphical representation of N-terminally tagged PDSG2 with GFP. (A–E) Localization pattern of PDSG1-GFP. (F–J) Localization pattern of Pdsg2-GFP. (A, F) Vegetative cells with the intact MAC. (B, C, G, H) beginning of old MAC fragmentation that represents early development. (D, I) Middle stage of development with fragmented MAC. (E, J) Late development when new MAC is formed while the fragments of the old MAC are still present in the cytoplasm. Magenta: DAPI; green: GFP; white arrow: old macronucleus; arrowheads: new MAC (NM).
Mentions: GFP fusion proteins were generated in order to monitor the subcellular localization of Pdsg1 and Pdsg2 during development (Fig. 2). The expression of Pdsg1-GFP and Pdsg2-GFP was undetectable during vegetative growth (Fig. 2A, F). Furthermore, both Pdsg1-GFP and Pdsg2-GFP signals were exclusively detected during development.

Bottom Line: We show that these proteins are necessary for the excision of germline-limited DNA during development and the survival of sexual progeny.Knockdown of PDSG1 and PDSG2 genes affects the populations of small RNAs known to be involved in the programming of DNA elimination (scanRNAs and iesRNAs) and chromatin modification patterns during development.Our results suggest an association between RNA-mediated trans-generational epigenetic signal and chromatin modifications in the process of Paramecium genome reorganization.

View Article: PubMed Central - PubMed

Affiliation: Institute of Cell Biology, University of Bern, Bern, Switzerland.

ABSTRACT
The epigenetic influence of maternal cells on the development of their progeny has long been studied in various eukaryotes. Multicellular organisms usually provide their zygotes not only with nutrients but also with functional elements required for proper development, such as coding and non-coding RNAs. These maternally deposited RNAs exhibit a variety of functions, from regulating gene expression to assuring genome integrity. In ciliates, such as Paramecium these RNAs participate in the programming of large-scale genome reorganization during development, distinguishing germline-limited DNA, which is excised, from somatic-destined DNA. Only a handful of proteins playing roles in this process have been identified so far, including typical RNAi-derived factors such as Dicer-like and Piwi proteins. Here we report and characterize two novel proteins, Pdsg1 and Pdsg2 (Paramecium protein involved in Development of the Somatic Genome 1 and 2), involved in Paramecium genome reorganization. We show that these proteins are necessary for the excision of germline-limited DNA during development and the survival of sexual progeny. Knockdown of PDSG1 and PDSG2 genes affects the populations of small RNAs known to be involved in the programming of DNA elimination (scanRNAs and iesRNAs) and chromatin modification patterns during development. Our results suggest an association between RNA-mediated trans-generational epigenetic signal and chromatin modifications in the process of Paramecium genome reorganization.

Show MeSH
Related in: MedlinePlus