Defects in nuclear transport enhance<i>Segregation Distortion</i>

McElroy, Jennifer M; McLean, Reid A; McLean, Janna R

doi:10.4161/fly.7474

Cited by 3 publications

(5 citation statements)

References 30 publications

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“…Thus, the SD phenotype production from the protamineRNAi-containing mutants suggests that ProtamineRNAi mimics the molecular action of Sd when in the presence of the modifiers of SD. Previously it has been shown that deleting genes involved in nuclear transport enhance distortion and that the gene with the strongest ability to enhance distortion values, embargoed, is involved in Ran-dependent nuclear transport (McElroy et al 2008). This study in tandem with our current finding that ProtamineRNAi induces distortion, further suggests that the nuclear import of protamines occurs through the Ran GAP/GEF system.…”

Section: Sd Stockssupporting

confidence: 83%

“…Additionally, the high levels of distortion observed in Bj1(RCC1) knockdowns supports the assertion that protamines are transported by the RanGAP/GEF pathway. McElroy et al (2008) found that deleting genes involved in nuclear transport enhances distortion and that the deletion most able to enhance distortion was for the gene, embargoed, which is implicated in nucleocytoplasmic transport (Quimby and Dasso 2003;Di Fiore et al 2004). Our current study, in tandem with the findings from McElroy et al (2008), suggest that the molecular underpinnings of distortion involve aberrant Ran-signaling impairing nuclear protamine import, which then inhibits the establishment of a protamine-rich chromatin complex and induces SD + spermatid failure.…”

Section: Discussionmentioning

confidence: 99%

“…The fact that the ProtRNAi mutants fail to elicit distortion indicates that if these two genes share a pathway, the action of E(SD) must come subsequent to the action of Sd, not before it, or more likely E(SD) has a role secondary to causing the mislocalization of Sd. Impaired nuclear transport is certainly a piece of the SD puzzle, as deleting proteins involved in nuclear transport elicits distortion (McElroy et al 2008). However, our findings suggest that E(SD) may have an additional function that is required for distortion, as neither knocking out the protamine transcript or reducing it in the presence of mutant RanGAP result in preferential transmission of Rsp s .…”

Section: Sd Stocksmentioning

confidence: 99%

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A Protamine Knockdown Mimics the Function ofSdinDrosophila melanogaster

Gingell¹,

McLean

2020

G3 Genes|Genomes|Genetics

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Segregation Distorter (SD) is an autosomal meiotic drive system found worldwide in natural populations of Drosophila melanogaster. This gene complex induces the preferential and nearly exclusive transmission of the SD chromosome in SD/SD+ males. This selfish propagation occurs through the interplay of the Sd locus, its enhancers and the Rsps locus during spermatid development. The key distorter locus, Sd, encodes a truncated but enzymatically active RanGAP (RanGTPase-activating protein), a key nuclear transport factor in the Ran signaling pathway. When encoded by Sd, RanGAP is mislocalized to the nucleus interior, which then traps Ran inside the nucleus and disrupts nuclear import. As a result of this aberrant nuclear transport, a process known as the histone-to-protamine transition that is required for proper spermatid condensation fails to occur in SD/SD+ males. In this process, sperm-specific protamine proteins enter the spermatid nucleus and replace the formerly chromatin-complexed histones. Previously, we have shown that mutations affecting nuclear import and export can enhance distortion in an SD background, thus verifying that a defect in nuclear transport is responsible for the unequal transmission of chromosomes. Herein, we show that specifically reducing protamines induces distortion in an SD background, verifying that protamines are transported via the RanGAP/GEF pathway and indicating that E(SD) plays a significant and unique role in the process of distortion.

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Section: Sd Stockssupporting

confidence: 83%

Section: Discussionmentioning

confidence: 99%

Section: Sd Stocksmentioning

confidence: 99%

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A Protamine Knockdown Mimics the Function ofSdinDrosophila melanogaster

Gingell¹,

McLean

2020

G3 Genes|Genomes|Genetics

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“…The genes of the Segregation Distorter (SD) system of Drosophila melanogaster and t-haplotypes in mouse have been cloned (Powers and Ganetzky, 1991;Herrmann et al, 1999) and their biochemical function revealed (Bauer et al, 2007;McElroy et al, 2008). Although both distortion systems are caused by the interaction of linked genes 'distorter' and 'responder' and resulted in dysfunctions of male gametes, underlying systems are different.…”

Section: Discussionmentioning

confidence: 99%

Molecular mapping of the suppressor gene Igc1 to the gametocidal gene Gc3-C1 in common wheat

et al. 2010

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Several species of the genus Aegilops, wild relatives of wheat (Triticum aestivum, 2n = 6x = 42, AABBDD) carry gametocidal (Gc) genes. Gc genes kill the gametes without themselves by causing chromosomal breakage during postmeiotic cell divisions, and therefore are strong segregation distorters. The Gc gene Gc3-C1 derived from chromosome 3C of Ae. triuncialis (2n = 4x = 28, CCUU) induces chromosomal breakage in wheat cultivar 'Chinese Spring' (CS) but not in cultivar 'Norin 26' (N26). This cultivar-specific inhibition of Gc function is caused by a suppressor gene Igc1 located on chromosome 3B of N26. Igc1 is presumed to be a modified Gc gene without breakage function because of its homoeology to Gc3-C1. Here we report the results of linkage and physical mapping of Igc1 to help elucidate the molecular mechanisms underlying Gc action. Segregation analysis of the phenotypic data in BC 1 F 1 mapping population of the cross between (CSxN26)F 1 and CS + 3C" showed a 1:1 segregation ratio indicating that Igc1 is a dominant gene. In the linkage analysis, three molecular marker loci Xgwm285, Xgwm376, and Xcfp1886 cosegregated with the Igc1 locus. Bin mapping assigned the loci Xgwm285 and Xcfp1886 to bin C-3BS1-0.33 and Xgwm376 to bin C-3BL2-0.22. Physical mapping using Gc-induced chromosomal deletion lines of chromosome 3B of N26 revealed that the Igc1 locus resides in 52.0% or 2.1% of bins C-3BS1-0.33 and C-3BL2-0.22, respectively. Pericentromeric localization of Igc1 in chromosome 3B of N26 may have a positive effect to keep the two-component system of the Gc action. Map-based cloning approach to isolate the Igc1 may be difficult because recombination is depleted in the pericentromeric region. As is shown in this study, the combination of genetic and physical mapping offers high efficiency to identify the regions where genes are located especially in regions with low levels of recombination.

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“…By contrast, increased expression of Ran or RanGEF is found to suppress meiotic drive in any case: expression of Sd-RanGAP, over-expression of wild-type RanGAP or additional doses of E(SD) in Rsp sensitive background (Kusano et al, 2001(Kusano et al, , 2002. It was found that mutations of several nuclear import and export factors enhance distortion, additionally indicating that nuclear transport is essential for segregation distortion (McElroy et al, 2008). Taken together, these data indicate that meiotic drive is caused by disruption of nuclear transport or signal transduction provided by Ran, where the balance of Ran and its cofactors plays a key role.…”

Section: Mechanisms Underlying Sd Actionmentioning

confidence: 97%

Functional Significance of Satellite DNAs: Insights From Drosophila

Шацких

Kotov

Adashev

et al. 2020

Front. Cell Dev. Biol.

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Since their discovery more than 60 years ago, satellite repeats are still one of the most enigmatic parts of eukaryotic genomes. Being non-coding DNA, satellites were earlier considered to be non-functional "junk," but recently this concept has been extensively revised. Satellite DNA contributes to the essential processes of formation of crucial chromosome structures, heterochromatin establishment, dosage compensation, reproductive isolation, genome stability and development. Genomic abundance of satellites is under stabilizing selection owing of their role in the maintenance of vital regions of the genome-centromeres, pericentromeric regions, and telomeres. Many satellites are transcribed with the generation of long or small non-coding RNAs. Misregulation of their expression is found to lead to various defects in the maintenance of genomic architecture, chromosome segregation and gametogenesis. This review summarizes our current knowledge concerning satellite functions, the mechanisms of regulation and evolution of satellites, focusing on recent findings in Drosophila. We discuss here experimental and bioinformatics data obtained in Drosophila in recent years, suggesting relevance of our analysis to a wide range of eukaryotic organisms.

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Defects in nuclear transport enhanceSegregation Distortion

Cited by 3 publications

References 30 publications

A Protamine Knockdown Mimics the Function ofSdinDrosophila melanogaster

A Protamine Knockdown Mimics the Function ofSdinDrosophila melanogaster

Molecular mapping of the suppressor gene Igc1 to the gametocidal gene Gc3-C1 in common wheat

Functional Significance of Satellite DNAs: Insights From Drosophila

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