The Journal Club: Highlights on Recent Papers-13.

We are delighted to share with you our thirteenth Journal Club and highlight some of the most interesting papers published recently [...

The Journal Club: Highlights on Recent Papers-12.

We are delighted to share with you our twelfth Journal Club and highlight some of the most interesting papers published recently [...

A DEAD-box RNA helicase mediates meiotic silencing by unpaired DNA.

During the sexual phase of Neurospora crassa, unpaired genes are subject to a silencing mechanism known as meiotic silencing by unpaired DNA (MSUD). MSUD targets the transcripts of an unpaired gene and utilizes typical RNA interference factors for its process. Using a reverse genetic screen, we have identified a meiotic silencing gene called sad-9, which encodes a DEAD-box RNA helicase.

The Journal Club: Highlights on Recent Papers-11.

We are delighted to share with you our eleventh Journal Club and highlight some of the most interesting papers published recently [...

Involvement of RNA granule proteins in meiotic silencing by unpaired DNA.

In Neurospora crassa, expression from an unpaired gene is suppressed by a mechanism known as meiotic silencing by unpaired DNA (MSUD). MSUD utilizes common RNA interference (RNAi) factors to silence target mRNAs. Here, we report that Neurospora CAR-1 and CGH-1, homologs of two Caenorhabditis elegans RNA granule components, are involved in MSUD.

The Journal Club: Highlights on Recent Papers-9.

We are delighted to share with you our ninth Journal Club and highlight some of the most interesting papers published recently [...

An NCBP3-Domain Protein Mediates Meiotic Silencing by Unpaired DNA.

In the filamentous fungus , genes unpaired during meiosis are silenced by a process known as meiotic silencing by unpaired DNA (MSUD). MSUD utilizes common RNA interference (RNAi) proteins, such as Dicer and Argonaute, to target homologous mRNAs for silencing. Previously, we demonstrated that nuclear cap-binding proteins NCBP1 and NCBP2 are involved in MSUD.

The Journal Club: Highlights on Recent Papers-7.

We are delighted to share with you our seventh Journal Club and highlight some of the most interesting papers published recently [...

Identification of , a Meiotic Driver Undergoing RNA Editing in .

is a meiotic drive element that was discovered in wild populations of fungi over 40 years ago. While early studies quickly determined that transmits itself through sexual reproduction in a biased manner via spore killing, the genetic factors responsible for this phenomenon have remained mostly unknown. Here, we identify and characterize , a gene required for -based spore killing.

Suppressors of Meiotic Silencing by Unpaired DNA.

Meiotic silencing by unpaired DNA (MSUD) is a gene silencing process that occurs within meiotic cells of and other fungi. We have previously developed a high-throughput screen to identify suppressors of this silencing pathway. Here, a list of MSUD suppressor candidates from a single pass of the first 84 plates of the knockout library is provided.

The Non-Coding RNA Journal Club: Highlights on Recent Papers-6.

We are delighted to share with you our sixth Journal Club and highlight some of the most interesting papers published recently [...

An RNA Recognition Motif-Containing Protein Functions in Meiotic Silencing by Unpaired DNA.

Meiotic silencing by unpaired DNA (MSUD) is a biological process that searches pairs of homologous chromosomes (homologs) for segments of DNA that are unpaired. Genes found within unpaired segments are silenced for the duration of meiosis. In this report, we describe the identification and characterization of , a gene that encodes a protein with an RNA recognition motif (RRM).

The Nuclear Cap-Binding Complex Mediates Meiotic Silencing by Unpaired DNA.

In the filamentous fungus , cross walls between individual cells are normally incomplete, making the entire fungal network vulnerable to attack by viruses and selfish DNAs. Accordingly, several genome surveillance mechanisms are maintained to help the fungus combat these repetitive elements. One of these defense mechanisms is called meiotic silencing by unpaired DNA (MSUD), which identifies and silences unpaired genes during meiosis.

Complex formation of RNA silencing proteins in the perinuclear region of Neurospora crassa.

In Neurospora, genes not paired during meiosis are targeted by meiotic silencing by unpaired DNA (MSUD). Here, our bimolecular fluorescence complementation (BiFC) study suggests that RNA-directed RNA polymerase, Dicer, Argonaute, and others form a silencing complex in the perinuclear region, with intimate interactions among the majority of them. We have also shown that SAD-2 is likely the anchor for this assembly.

Efficient detection of unpaired DNA requires a member of the rad54-like family of homologous recombination proteins.

Meiotic silencing by unpaired DNA (MSUD) is a process that detects unpaired regions between homologous chromosomes and silences them for the duration of sexual development. While the phenomenon of MSUD is well recognized, the process that detects unpaired DNA is poorly understood. In this report, we provide two lines of evidence linking unpaired DNA detection to a physical search for DNA homology.

A critical component of meiotic drive in Neurospora is located near a chromosome rearrangement.

Neurospora fungi harbor a group of meiotic drive elements known as Spore killers (Sk). Spore killer-2 (Sk-2) and Spore killer-3 (Sk-3) are two Sk elements that map to a region of suppressed recombination. Although this recombination block is limited to crosses between Sk and Sk-sensitive (Sk(S)) strains, its existence has hindered Sk characterization.

Novel proteins required for meiotic silencing by unpaired DNA and siRNA generation in Neurospora crassa.

During meiosis in the filamentous fungus Neurospora crassa, unpaired genes are identified and silenced by a process known as meiotic silencing by unpaired DNA (MSUD). Previous work has uncovered six proteins required for MSUD, all of which are also essential for meiotic progression. Additionally, they all localize in the perinuclear region, suggesting that it is a center of MSUD activity.

Identification of small RNAs associated with meiotic silencing by unpaired DNA.

In Neurospora crassa, unpaired genes are silenced by a mechanism called meiotic silencing by unpaired DNA (MSUD). Although some RNA interference proteins are necessary for this process, its requirement of small RNAs has yet to be formally established. Here we report the characterization of small RNAs targeting an unpaired region, using Illumina sequencing.

Molecular dissection of Neurospora Spore killer meiotic drive elements.

Meiotic drive is a non-Mendelian inheritance phenomenon in which certain selfish genetic elements skew sexual transmission in their own favor. In some cases, progeny or gametes carrying a meiotic drive element can survive preferentially because it causes the death or malfunctioning of those that do not carry it. In Neurospora, meiotic drive can be observed in fungal spore killing.

SAD-3, a Putative Helicase Required for Meiotic Silencing by Unpaired DNA, Interacts with Other Components of the Silencing Machinery.

In Neurospora crassa, genes lacking a pairing partner during meiosis are suppressed by a process known as meiotic silencing by unpaired DNA (MSUD). To identify novel MSUD components, we have developed a high-throughput reverse-genetic screen for use with the N. crassa knockout library.

Fluorescent and bimolecular-fluorescent protein tagging of genes at their native loci in Neurospora crassa using specialized double-joint PCR plasmids.

The double-joint polymerase chain reaction (DJ-PCR) is a technique that can be used to construct vectors for targeted genome integration without laborious subcloning steps. Here we report the availability of plasmids that facilitate DJ-PCR-based construction of Neurospora crassa tagging vectors. These plasmids allow the creation of green or red fluorescent protein (GFP or RFP) tagging vectors for protein localization studies, as well as split-yellow fluorescent protein (YFP) tagging vectors for bimolecular fluorescence complementation (BiFC) analyses.

QIP, a protein that converts duplex siRNA into single strands, is required for meiotic silencing by unpaired DNA.

RNA interference (RNAi) depends on the production of small RNA to regulate gene expression in eukaryotes. Two RNAi systems exist to control repetitive selfish elements in Neurospora crassa. Quelling targets transgenes during vegetative growth, whereas meiotic silencing by unpaired DNA (MSUD) silences unpaired genes during meiosis.

Characterization of interactions between and among components of the meiotic silencing by unpaired DNA machinery in Neurospora crassa using bimolecular fluorescence complementation.

Bimolecular fluorescence complementation (BiFC) is based on the complementation between two nonfluorescent fragments of the yellow fluorescent protein (YFP) when they are united by interactions between proteins covalently linked to them. We have successfully applied BiFC in Neurospora crassa using two genes involved in meiotic silencing by unpaired DNA (MSUD) and observed macromolecular complex formation involving only SAD-1 proteins, only SAD-2 proteins, and mixtures of SAD-1 and SAD-2 proteins.