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Kitaoka M, Yamashita YM. Running the gauntlet: challenges to genome integrity in spermiogenesis. Nucleus 2024; 15:2339220. [PMID: 38594652 PMCID: PMC11005813 DOI: 10.1080/19491034.2024.2339220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 04/02/2024] [Indexed: 04/11/2024] Open
Abstract
Species' continuity depends on gametogenesis to produce the only cell types that can transmit genetic information across generations. Spermiogenesis, which encompasses post-meiotic, haploid stages of male gametogenesis, is a process that leads to the formation of sperm cells well-known for their motility. Spermiogenesis faces three major challenges. First, after two rounds of meiotic divisions, the genome lacks repair templates (no sister chromatids, no homologous chromosomes), making it incredibly vulnerable to any genomic insults over an extended time (typically days-weeks). Second, the sperm genome becomes transcriptionally silent, making it difficult to respond to new perturbations as spermiogenesis progresses. Third, the histone-to-protamine transition, which is essential to package the sperm genome, counterintuitively involves DNA break formation. How spermiogenesis handles these challenges remains poorly understood. In this review, we discuss each challenge and their intersection with the biology of protamines. Finally, we discuss the implication of protamines in the process of evolution.
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Affiliation(s)
- Maiko Kitaoka
- Whitehead Institute for Biomedical Research and Howard Hughes Medical Institute, Cambridge, MA, USA
| | - Yukiko M. Yamashita
- Whitehead Institute for Biomedical Research and Howard Hughes Medical Institute, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
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2
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Ridges JT, Bladen J, King TD, Brown NC, Large CRL, Cooper JC, Jones AJ, Loppin B, Dubruille R, Phadnis N. Overdrive is essential for targeted sperm elimination by Segregation Distorter. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.04.597441. [PMID: 38895353 PMCID: PMC11185633 DOI: 10.1101/2024.06.04.597441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Intra-genomic conflict driven by selfish chromosomes is a powerful force that shapes the evolution of genomes and species. In the male germline, many selfish chromosomes bias transmission in their own favor by eliminating spermatids bearing the competing homologous chromosomes. However, the mechanisms of targeted gamete elimination remain mysterious. Here, we show that Overdrive (Ovd), a gene required for both segregation distortion and male sterility in Drosophila pseudoobscura hybrids, is broadly conserved in Dipteran insects but dispensable for viability and fertility. In D. melanogaster, Ovd is required for targeted Responder spermatid elimination after the histone-to-protamine transition in the classical Segregation Distorter system. We propose that Ovd functions as a general spermatid quality checkpoint that is hijacked by independent selfish chromosomes to eliminate competing gametes.
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Affiliation(s)
- Jackson T. Ridges
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Jackson Bladen
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Thomas D. King
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Nora C. Brown
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | | | - Jacob C. Cooper
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Amanda J. Jones
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Benjamin Loppin
- Laboratoire de Biologie et Modélisation de la Cellule, École Normale Supérieure de Lyon, CNRS UMR5239, Université Claude Bernard Lyon 1, Lyon, France
| | - Raphaëlle Dubruille
- Laboratoire de Biologie et Modélisation de la Cellule, École Normale Supérieure de Lyon, CNRS UMR5239, Université Claude Bernard Lyon 1, Lyon, France
| | - Nitin Phadnis
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
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3
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Vitale M, Kranjc N, Leigh J, Kyrou K, Courty T, Marston L, Grilli S, Crisanti A, Bernardini F. Y chromosome shredding in Anopheles gambiae: Insight into the cellular dynamics of a novel synthetic sex ratio distorter. PLoS Genet 2024; 20:e1011303. [PMID: 38848445 PMCID: PMC11189259 DOI: 10.1371/journal.pgen.1011303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 06/20/2024] [Accepted: 05/14/2024] [Indexed: 06/09/2024] Open
Abstract
Despite efforts to explore the genome of the malaria vector Anopheles gambiae, the Y chromosome of this species remains enigmatic. The large number of repetitive and heterochromatic DNA sequences makes the Y chromosome exceptionally difficult to fully assemble, hampering the progress of gene editing techniques and functional studies for this chromosome. In this study, we made use of a bioinformatic platform to identify Y-specific repetitive DNA sequences that served as a target site for a CRISPR/Cas9 system. The activity of Cas9 in the reproductive organs of males caused damage to Y-bearing sperm without affecting their fertility, leading to a strong female bias in the progeny. Cytological investigation allowed us to identify meiotic defects and investigate sperm selection in this new synthetic sex ratio distorter system. In addition, alternative promoters enable us to target the Y chromosome in specific tissues and developmental stages of male mosquitoes, enabling studies that shed light on the role of this chromosome in male gametogenesis. This work paves the way for further insight into the poorly characterised Y chromosome of Anopheles gambiae. Moreover, the sex distorter strain we have generated promises to be a valuable tool for the advancement of studies in the field of developmental biology, with the potential to support the progress of genetic strategies aimed at controlling malaria mosquitoes and other pest species.
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Affiliation(s)
- Matteo Vitale
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Nace Kranjc
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Jessica Leigh
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Kyrous Kyrou
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Thomas Courty
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Louise Marston
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Silvia Grilli
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Andrea Crisanti
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Federica Bernardini
- Department of Life Sciences, Imperial College London, London, United Kingdom
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Courret C, Wei X, Larracuente AM. New perspectives on the causes and consequences of male meiotic drive. Curr Opin Genet Dev 2023; 83:102111. [PMID: 37704518 PMCID: PMC10842977 DOI: 10.1016/j.gde.2023.102111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 09/15/2023]
Abstract
Gametogenesis is vulnerable to selfish genetic elements that bias their transmission to the next generation by cheating meiosis. These so-called meiotic drivers are widespread in plants, animals, and fungi and can impact genome evolution. Here, we summarize recent progress on the causes and consequences of meiotic drive in males, where selfish elements attack vulnerabilities in spermatogenesis. Advances in genomics provide new insights into the organization and dynamics of driving chromosomes in natural populations. Common themes, including small RNAs, gene duplications, and heterochromatin, emerged from these studies. Interdisciplinary approaches combining evolutionary genomics with molecular and cell biology are beginning to unravel the mysteries of drive and suppression mechanisms. These approaches also provide insights into fundamental processes in spermatogenesis and chromatin regulation.
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Affiliation(s)
- Cécile Courret
- Department of Biology, University of Rochester, Rochester, NY 14627, USA. https://twitter.com/@CecileCourret
| | - Xiaolu Wei
- Department of Biology, University of Rochester, Rochester, NY 14627, USA. https://twitter.com/@xiaolu_wei
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5
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Herbette M, Ross L. Paternal genome elimination: patterns and mechanisms of drive and silencing. Curr Opin Genet Dev 2023; 81:102065. [PMID: 37413739 DOI: 10.1016/j.gde.2023.102065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/24/2023] [Accepted: 05/24/2023] [Indexed: 07/08/2023]
Abstract
In thousands of arthropod species, males inherit, but subsequently eliminate the entire haploid genome of their father. However, why this peculiar reproductive strategy evolved repeatedly across diverse species and what mechanisms are involved in paternal genome elimination (PGE) remains largely unknown. In this review, we summarize what we know about the patterns of paternal chromosome elimination during various stages of development in the diverse taxa that have been studied. We also discuss some other unusual features often associated with PGE, such as the transcriptional silencing of paternally derived chromosomes in males and sex determination through the early embryonic elimination of X chromosomes. Little is known about the molecular mechanisms underlying the parent-of-origin-dependent chromosome elimination and silencing under PGE, but we discuss the insight of several studies that are pioneering this work and highlight directions for future research.
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Affiliation(s)
- Marion Herbette
- School of Biological Sciences, Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Laura Ross
- School of Biological Sciences, Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh EH9 3FL, UK.
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6
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Vedanayagam J, Lin CJ, Papareddy R, Nodine M, Flynt AS, Wen J, Lai EC. Regulatory logic of endogenous RNAi in silencing de novo genomic conflicts. PLoS Genet 2023; 19:e1010787. [PMID: 37343034 DOI: 10.1371/journal.pgen.1010787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 05/17/2023] [Indexed: 06/23/2023] Open
Abstract
Although the biological utilities of endogenous RNAi (endo-RNAi) have been largely elusive, recent studies reveal its critical role in the non-model fruitfly Drosophila simulans to suppress selfish genes, whose unchecked activities can severely impair spermatogenesis. In particular, hairpin RNA (hpRNA) loci generate endo-siRNAs that suppress evolutionary novel, X-linked, meiotic drive loci. The consequences of deleting even a single hpRNA (Nmy) in males are profound, as such individuals are nearly incapable of siring male progeny. Here, comparative genomic analyses of D. simulans and D. melanogaster mutants of the core RNAi factor dcr-2 reveal a substantially expanded network of recently-emerged hpRNA-target interactions in the former species. The de novo hpRNA regulatory network in D. simulans provides insight into molecular strategies that underlie hpRNA emergence and their potential roles in sex chromosome conflict. In particular, our data support the existence of ongoing rapid evolution of Nmy/Dox-related networks, and recurrent targeting of testis HMG Box loci by hpRNAs. Importantly, the impact of the endo-RNAi network on gene expression flips the convention for regulatory networks, since we observe strong derepression of targets of the youngest hpRNAs, but only mild effects on the targets of the oldest hpRNAs. These data suggest that endo-RNAi are especially critical during incipient stages of intrinsic sex chromosome conflicts, and that continual cycles of distortion and resolution may contribute to speciation.
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Affiliation(s)
- Jeffrey Vedanayagam
- Developmental Biology Program, Sloan Kettering Institute, New York, New York, United States of America
| | - Ching-Jung Lin
- Developmental Biology Program, Sloan Kettering Institute, New York, New York, United States of America
- Weill Graduate School of Medical Sciences, Weill Cornell Medical College, New York, New York, United States of America
| | - Ranjith Papareddy
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Austria
| | - Michael Nodine
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Austria
| | - Alex S Flynt
- Cellular and Molecular Biology, University of Southern Mississippi, Hattiesburg, Mississippi, United States of America
| | - Jiayu Wen
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research The Australian National University, Canberra, Australia
| | - Eric C Lai
- Developmental Biology Program, Sloan Kettering Institute, New York, New York, United States of America
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7
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Vedanayagam J, Herbette M, Mudgett H, Lin CJ, Lai CM, McDonough-Goldstein C, Dorus S, Loppin B, Meiklejohn C, Dubruille R, Lai EC. Essential and recurrent roles for hairpin RNAs in silencing de novo sex chromosome conflict in Drosophila simulans. PLoS Biol 2023; 21:e3002136. [PMID: 37289846 DOI: 10.1371/journal.pbio.3002136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 04/21/2023] [Indexed: 06/10/2023] Open
Abstract
Meiotic drive loci distort the normally equal segregation of alleles, which benefits their own transmission even in the face of severe fitness costs to their host organism. However, relatively little is known about the molecular identity of meiotic drivers, their strategies of action, and mechanisms that can suppress their activity. Here, we present data from the fruitfly Drosophila simulans that address these questions. We show that a family of de novo, protamine-derived X-linked selfish genes (the Dox gene family) is silenced by a pair of newly emerged hairpin RNA (hpRNA) small interfering RNA (siRNA)-class loci, Nmy and Tmy. In the w[XD1] genetic background, knockout of nmy derepresses Dox and MDox in testes and depletes male progeny, whereas knockout of tmy causes misexpression of PDox genes and renders males sterile. Importantly, genetic interactions between nmy and tmy mutant alleles reveal that Tmy also specifically maintains male progeny for normal sex ratio. We show the Dox loci are functionally polymorphic within D. simulans, such that both nmy-associated sex ratio bias and tmy-associated sterility can be rescued by wild-type X chromosomes bearing natural deletions in different Dox family genes. Finally, using tagged transgenes of Dox and PDox2, we provide the first experimental evidence Dox family genes encode proteins that are strongly derepressed in cognate hpRNA mutants. Altogether, these studies support a model in which protamine-derived drivers and hpRNA suppressors drive repeated cycles of sex chromosome conflict and resolution that shape genome evolution and the genetic control of male gametogenesis.
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Affiliation(s)
- Jeffrey Vedanayagam
- Developmental Biology Program, Sloan-Kettering Institute, New York, New York, United States of America
| | - Marion Herbette
- Laboratoire de Biologie et Modélisation de la Cellule, École Normale Supérieure de Lyon CNRS UMR5239, Université Claude Bernard Lyon 1, Lyon, France
| | - Holly Mudgett
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Ching-Jung Lin
- Developmental Biology Program, Sloan-Kettering Institute, New York, New York, United States of America
- Weill Graduate School of Medical Sciences, Weill Cornell Medical College, New York, New York, United States of America
| | - Chun-Ming Lai
- Developmental Biology Program, Sloan-Kettering Institute, New York, New York, United States of America
| | | | - Stephen Dorus
- Center for Reproductive Evolution, Syracuse University, Syracuse, New York, United States of America
| | - Benjamin Loppin
- Laboratoire de Biologie et Modélisation de la Cellule, École Normale Supérieure de Lyon CNRS UMR5239, Université Claude Bernard Lyon 1, Lyon, France
| | - Colin Meiklejohn
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Raphaëlle Dubruille
- Laboratoire de Biologie et Modélisation de la Cellule, École Normale Supérieure de Lyon CNRS UMR5239, Université Claude Bernard Lyon 1, Lyon, France
| | - Eric C Lai
- Developmental Biology Program, Sloan-Kettering Institute, New York, New York, United States of America
- Weill Graduate School of Medical Sciences, Weill Cornell Medical College, New York, New York, United States of America
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Park JI, Bell GW, Yamashita YM. Derepression of Y-linked multicopy protamine-like genes interferes with sperm nuclear compaction in D. melanogaster. Proc Natl Acad Sci U S A 2023; 120:e2220576120. [PMID: 37036962 PMCID: PMC10120018 DOI: 10.1073/pnas.2220576120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 03/17/2023] [Indexed: 04/12/2023] Open
Abstract
Across species, sperm maturation involves the dramatic reconfiguration of chromatin into highly compact nuclei that enhance hydrodynamic ability and ensure paternal genomic integrity. This process is mediated by the replacement of histones by sperm nuclear basic proteins, also referred to as protamines. In humans, a carefully balanced dosage between two known protamine genes is required for optimal fertility. However, it remains unknown how their proper balance is regulated and how defects in balance may lead to compromised fertility. Here, we show that a nucleolar protein, modulo, a homolog of nucleolin, mediates the histone-to-protamine transition during Drosophila spermatogenesis. We find that modulo mutants display nuclear compaction defects during late spermatogenesis due to decreased expression of autosomal protamine genes (including Mst77F) and derepression of Y-linked multicopy Mst77F homologs (Mst77Y), leading to the mutant's known sterility. Overexpression of Mst77Y in a wild-type background is sufficient to cause nuclear compaction defects, similar to modulo mutant, indicating that Mst77Y is a dominant-negative variant interfering with the process of histone-to-protamine transition. Interestingly, ectopic overexpression of Mst77Y caused decompaction of X-bearing spermatids nuclei more frequently than Y-bearing spermatid nuclei, although this did not greatly affect the sex ratio of offspring. We further show that modulo regulates these protamine genes at the step of transcript polyadenylation. We conclude that the regulation of protamines mediated by modulo, ensuring the expression of functional ones while repressing dominant-negative ones, is critical for male fertility.
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Affiliation(s)
- Jun I. Park
- Life Sciences Institute, University of Michigan, Ann Arbor, MI48109
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI48109
- Medical Scientist Training Program, University of Michigan Medical School, Ann Arbor, MI48109
| | - George W. Bell
- Whitehead Institute for Biomedical Research, Cambridge, MA02142
| | - Yukiko M. Yamashita
- Whitehead Institute for Biomedical Research, Cambridge, MA02142
- Department of Biology, School of Science, Massachusetts Institute of Technology, Cambridge, MA02142
- HHMI, Cambridge, MA02142
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