1
|
Lin CJ, Hu F, Dubruille R, Vedanayagam J, Wen J, Smibert P, Loppin B, Lai EC. The hpRNA/RNAi Pathway Is Essential to Resolve Intragenomic Conflict in the Drosophila Male Germline. Dev Cell 2018; 46:316-326.e5. [PMID: 30086302 DOI: 10.1016/j.devcel.2018.07.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/13/2018] [Accepted: 07/02/2018] [Indexed: 11/27/2022]
Abstract
Intragenomic conflicts are fueled by rapidly evolving selfish genetic elements, which induce selective pressures to innovate opposing repressive mechanisms. This is patently manifest in sex-ratio (SR) meiotic drive systems, in which distorter and suppressor factors bias and restore equal transmission of X and Y sperm. Here, we reveal that multiple SR suppressors in Drosophila simulans (Nmy and Tmy) encode related hairpin RNAs (hpRNAs), which generate endo-siRNAs that repress the paralogous distorters Dox and MDox. All components in this drive network are recently evolved and largely testis restricted. To connect SR hpRNA function to the RNAi pathway, we generated D. simulans null mutants of Dcr-2 and AGO2. Strikingly, these core RNAi knockouts massively derepress Dox and MDox and are in fact completely male sterile and exhibit highly defective spermatogenesis. Altogether, our data reveal how the adaptive capacity of hpRNAs is critically deployed to restrict selfish gonadal genetic systems that can exterminate a species.
Collapse
Affiliation(s)
- Ching-Jung Lin
- Department of Developmental Biology, Sloan-Kettering Institute, 1275 York Ave, Box 252, New York, NY 10065, USA; Weill Graduate School of Medical Sciences, Weill Cornell Medical College, New York, NY 10065, USA
| | - Fuqu Hu
- Department of Developmental Biology, Sloan-Kettering Institute, 1275 York Ave, Box 252, New York, NY 10065, USA
| | - Raphaelle Dubruille
- Laboratoire de Biométrie et Biologie Evolutive - UMR5558, Université Claude Bernard Lyon I, 16, rue R. Dubois - Bât. G. Mendel, 69622 Villeurbanne Cedex, France
| | - Jeffrey Vedanayagam
- Department of Developmental Biology, Sloan-Kettering Institute, 1275 York Ave, Box 252, New York, NY 10065, USA
| | - Jiayu Wen
- Department of Developmental Biology, Sloan-Kettering Institute, 1275 York Ave, Box 252, New York, NY 10065, USA
| | - Peter Smibert
- Department of Developmental Biology, Sloan-Kettering Institute, 1275 York Ave, Box 252, New York, NY 10065, USA
| | - Benjamin Loppin
- Laboratoire de Biométrie et Biologie Evolutive - UMR5558, Université Claude Bernard Lyon I, 16, rue R. Dubois - Bât. G. Mendel, 69622 Villeurbanne Cedex, France
| | - Eric C Lai
- Department of Developmental Biology, Sloan-Kettering Institute, 1275 York Ave, Box 252, New York, NY 10065, USA.
| |
Collapse
|
2
|
Raychaudhuri N, Dubruille R, Orsi GA, Bagheri HC, Loppin B, Lehner CF. Transgenerational propagation and quantitative maintenance of paternal centromeres depends on Cid/Cenp-A presence in Drosophila sperm. PLoS Biol 2012; 10:e1001434. [PMID: 23300376 PMCID: PMC3531477 DOI: 10.1371/journal.pbio.1001434] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 10/17/2012] [Indexed: 01/28/2023] Open
Abstract
In Drosophila melanogaster, as in many animal and plant species, centromere identity is specified epigenetically. In proliferating cells, a centromere-specific histone H3 variant (CenH3), named Cid in Drosophila and Cenp-A in humans, is a crucial component of the epigenetic centromere mark. Hence, maintenance of the amount and chromosomal location of CenH3 during mitotic proliferation is important. Interestingly, CenH3 may have different roles during meiosis and the onset of embryogenesis. In gametes of Caenorhabditis elegans, and possibly in plants, centromere marking is independent of CenH3. Moreover, male gamete differentiation in animals often includes global nucleosome for protamine exchange that potentially could remove CenH3 nucleosomes. Here we demonstrate that the control of Cid loading during male meiosis is distinct from the regulation observed during the mitotic cycles of early embryogenesis. But Cid is present in mature sperm. After strong Cid depletion in sperm, paternal centromeres fail to integrate into the gonomeric spindle of the first mitosis, resulting in gynogenetic haploid embryos. Furthermore, after moderate depletion, paternal centromeres are unable to re-acquire normal Cid levels in the next generation. We conclude that Cid in sperm is an essential component of the epigenetic centromere mark on paternal chromosomes and it exerts quantitative control over centromeric Cid levels throughout development. Hence, the amount of Cid that is loaded during each cell cycle appears to be determined primarily by the preexisting centromeric Cid, with little flexibility for compensation of accidental losses.
Collapse
Affiliation(s)
- Nitika Raychaudhuri
- Institute of Molecular Life Sciences (IMLS), University of Zurich, Zurich, Switzerland
| | - Raphaelle Dubruille
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Université Claude Bernard Lyon I, Villeurbanne, France
| | - Guillermo A. Orsi
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Université Claude Bernard Lyon I, Villeurbanne, France
| | - Homayoun C. Bagheri
- Institute of Evolutionary Biology and Environmental Studies (IEES), University of Zurich, Zurich, Switzerland
| | - Benjamin Loppin
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Université Claude Bernard Lyon I, Villeurbanne, France
| | - Christian F. Lehner
- Institute of Molecular Life Sciences (IMLS), University of Zurich, Zurich, Switzerland
| |
Collapse
|
3
|
Dubruille R, Emery P. A Plastic Clock: How Circadian Rhythms Respond to Environmental Cues in Drosophila. Mol Neurobiol 2008; 38:129-45. [DOI: 10.1007/s12035-008-8035-y] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Accepted: 06/27/2008] [Indexed: 11/24/2022]
|
4
|
Bonnafe E, Touka M, AitLounis A, Baas D, Barras E, Ucla C, Moreau A, Flamant F, Dubruille R, Couble P, Collignon J, Durand B, Reith W. The transcription factor RFX3 directs nodal cilium development and left-right asymmetry specification. Mol Cell Biol 2004; 24:4417-27. [PMID: 15121860 PMCID: PMC400456 DOI: 10.1128/mcb.24.10.4417-4427.2004] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
There are five members of the RFX family of transcription factors in mammals. While RFX5 plays a well-defined role in the immune system, the functions of RFX1 to RFX4 remain largely unknown. We have generated mice with a deletion of the Rfx3 gene. RFX3-deficient mice exhibit frequent left-right (LR) asymmetry defects leading to a high rate of embryonic lethality and situs inversus in surviving adults. In vertebrates, specification of the LR body axis is controlled by monocilia in the embryonic node, and defects in nodal cilia consequently result in abnormal LR patterning. Consistent with this, Rfx3 is expressed in ciliated cells of the node and RFX3-deficient mice exhibit a pronounced defect in nodal cilia. In contrast to the case for wild-type embryos, for which we document for the first time a twofold increase in the length of nodal cilia during development, the cilia are present but remain markedly stunted in mutant embryos. Finally, we show that RFX3 regulates the expression of D2lic, the mouse orthologue of a Caenorhabditis elegans gene that is implicated in intraflagellar transport, a process required for the assembly and maintenance of cilia. In conclusion, RFX3 is essential for the differentiation of nodal monocilia and hence for LR body axis determination.
Collapse
Affiliation(s)
- E Bonnafe
- Centre de Génétique Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, F-69622 Villeurbanne, France
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Dubruille R, Laurençon A, Vandaele C, Shishido E, Coulon-Bublex M, Swoboda P, Couble P, Kernan M, Durand B. Drosophila regulatory factor X is necessary for ciliated sensory neuron differentiation. Development 2002; 129:5487-98. [PMID: 12403718 DOI: 10.1242/dev.00148] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Ciliated neurons play an important role in sensory perception in many animals. Modified cilia at dendrite endings serve as sites of sensory signal capture and transduction. We describe Drosophila mutations that affect the transcription factor RFX and genetic rescue experiments that demonstrate its central role in sensory cilium differentiation. Rfx mutant flies show defects in chemosensory and mechanosensory behaviors but have normal phototaxis, consistent with Rfx expression in ciliated sensory neurons and neuronal precursors but not in photoreceptors. The mutant behavioral phenotypes are correlated with abnormal function and structure of neuronal cilia, as shown by the loss of sensory transduction and by defects in ciliary morphology and ultrastructure. These results identify Rfx as an essential regulator of ciliated sensory neuron differentiation in Drosophila.
Collapse
Affiliation(s)
- Raphaelle Dubruille
- Centre de Génétique Moléculaire et Cellulaire, CNRS UMR-5534, Université Claude Bernard Lyon-1, 69622 Villeurbanne, France
| | | | | | | | | | | | | | | | | |
Collapse
|