1
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Perales IE, Jones SD, Piaszynski KM, Geyer PK. Developmental changes in nuclear lamina components during germ cell differentiation. Nucleus 2024; 15:2339214. [PMID: 38597409 PMCID: PMC11008544 DOI: 10.1080/19491034.2024.2339214] [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: 02/20/2024] [Accepted: 04/02/2024] [Indexed: 04/11/2024] Open
Abstract
The nuclear lamina (NL) changes composition for regulation of nuclear events. We investigated changes that occur in Drosophila oogenesis, revealing switches in NL composition during germ cell differentiation. Germline stem cells (GSCs) express only LamB and predominantly emerin, whereas differentiating nurse cells predominantly express LamC and emerin2. A change in LamC-specific localization also occurs, wherein phosphorylated LamC redistributes to the nuclear interior only in the oocyte, prior to transcriptional reactivation of the meiotic genome. These changes support existing concepts that LamC promotes differentiation, a premise that was tested. Remarkably ectopic LamC production in GSCs did not promote premature differentiation. Increased LamC levels in differentiating germ cells altered internal nuclear structure, increased RNA production, and reduced female fertility due to defects in eggshell formation. These studies suggest differences between Drosophila lamins are regulatory, not functional, and reveal an unexpected robustness to level changes of a major scaffolding component of the NL.
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Affiliation(s)
- Isabella E. Perales
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA, USA
| | - Samuel D. Jones
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA, USA
| | | | - Pamela K. Geyer
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA, USA
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2
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Joshi JN, Changela N, Mahal L, Jang J, Defosse T, Wang LI, Das A, Shapiro JG, McKim K. Meiosis-specific functions of kinetochore protein SPC105R required for chromosome segregation in Drosophila oocytes. Mol Biol Cell 2024; 35:ar105. [PMID: 38865189 DOI: 10.1091/mbc.e24-02-0067] [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] [Indexed: 06/13/2024] Open
Abstract
The reductional division of meiosis I requires the separation of chromosome pairs towards opposite poles. We have previously implicated the outer kinetochore protein SPC105R/KNL1 in driving meiosis I chromosome segregation through lateral attachments to microtubules and coorientation of sister centromeres. To identify the domains of SPC105R that are critical for meiotic chromosome segregation, an RNAi-resistant gene expression system was developed. We found that the SPC105R C-terminal domain (aa 1284-1960) is necessary and sufficient for recruiting NDC80 to the kinetochore and building the outer kinetochore. Furthermore, the C-terminal domain recruits BUBR1, which in turn recruits the cohesion protection proteins MEI-S332 and PP2A. Of the remaining 1283 amino acids, we found the first 473 are most important for meiosis. The first 123 amino acids of the N-terminal half of SPC105R contain the conserved SLRK and RISF motifs that are targets of PP1 and Aurora B kinase and are most important for regulating the stability of microtubule attachments and maintaining metaphase I arrest. The region between amino acids 124 and 473 are required for lateral microtubule attachments and biorientation of homologues, which are critical for accurate chromosome segregation in meiosis I.
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Affiliation(s)
- Jay N Joshi
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854
| | - Neha Changela
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854
| | - Lia Mahal
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854
| | - Janet Jang
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854
| | - Tyler Defosse
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854
| | - Lin-Ing Wang
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854
| | - Arunika Das
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854
| | - Joanatta G Shapiro
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854
| | - Kim McKim
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ 08854
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3
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Lababede A, Man B, Crown N. Genetic background effects on meiotic recombination. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001247. [PMID: 39027731 PMCID: PMC11255868 DOI: 10.17912/micropub.biology.001247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 06/24/2024] [Accepted: 06/24/2024] [Indexed: 07/20/2024]
Abstract
Genetic background is a strong driver of phenotype, and when analyzing a mutant phenotype, it is critical that a genetically comparable wildtype stock is used as a control. Many of the Drosophila melanogaster meiotic mutants were isolated in EMS screens or created by P-element mutagenesis and do not have a congenic or isogenic wildtype control. We show here that the y 1 stock, commonly used for transgenesis in D. melanogaster , shows significantly higher meiotic crossover rates, and there is likely a modifier of meiosis or germline development in the genetic background of this popular stock.
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Affiliation(s)
- Ayah Lababede
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Bowen Man
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Nicole Crown
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States
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4
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Hughes SE, Price A, Briggs S, Staber C, James M, Anderson M, Hawley RS. A transcriptomics-based RNAi screen for regulators of meiosis and early stages of oocyte development in Drosophila melanogaster. G3 (BETHESDA, MD.) 2024; 14:jkae028. [PMID: 38333961 PMCID: PMC10989863 DOI: 10.1093/g3journal/jkae028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 02/10/2024]
Abstract
A properly regulated series of developmental and meiotic events must occur to ensure the successful production of gametes. In Drosophila melanogaster ovaries, these early developmental and meiotic events include the production of the 16-cell cyst, meiotic entry, synaptonemal complex (SC) formation, recombination, and oocyte specification. In order to identify additional genes involved in early oocyte development and meiosis, we reanalyzed 3 published single-cell RNA-seq datasets from Drosophila ovaries, using vasa (germline) together with c(3)G, cona, and corolla (SC) as markers. Our analysis generated a list of 2,743 co-expressed genes. Many known SC-related and early oocyte development genes fell within the top 500 genes on this list, as ranked by the abundance and specificity of each gene's expression across individual analyses. We tested 526 available RNAi lines containing shRNA constructs in germline-compatible vectors representing 331 of the top 500 genes. We assessed targeted ovaries for SC formation and maintenance, oocyte specification, cyst development, and double-strand break dynamics. Six uncharacterized genes exhibited early developmental defects. SC and developmental defects were observed for additional genes not well characterized in the early ovary. Interestingly, in some lines with developmental delays, meiotic events could still be completed once oocyte specificity occurred indicating plasticity in meiotic timing. These data indicate that a transcriptomics approach can be used to identify genes involved in functions in a specific cell type in the Drosophila ovary.
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Affiliation(s)
- Stacie E Hughes
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Andrew Price
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Salam Briggs
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Cynthia Staber
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Morgan James
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Madelyn Anderson
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - R Scott Hawley
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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5
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Jones G, Kleckner N, Zickler D. Meiosis through three centuries. Chromosoma 2024; 133:93-115. [PMID: 38730132 PMCID: PMC11180163 DOI: 10.1007/s00412-024-00822-0] [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] [Indexed: 05/12/2024]
Abstract
Meiosis is the specialized cellular program that underlies gamete formation for sexual reproduction. It is therefore not only interesting but also a fundamentally important subject for investigation. An especially attractive feature of this program is that many of the processes of special interest involve organized chromosomes, thus providing the possibility to see chromosomes "in action". Analysis of meiosis has also proven to be useful in discovering and understanding processes that are universal to all chromosomal programs. Here we provide an overview of the different historical moments when the gap between observation and understanding of mechanisms and/or roles for the new discovered molecules was bridged. This review reflects also the synergy of thinking and discussion among our three laboratories during the past several decades.
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Affiliation(s)
- Gareth Jones
- School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Nancy Kleckner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA.
| | - Denise Zickler
- Institute for Integrative Biology of the Cell (I2BC), Centre National de La Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, 91198, Gif-Sur-Yvette, France
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6
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Graham EL, Fernandez J, Gandhi S, Choudhry I, Kellam N, LaRocque JR. The impact of developmental stage, tissue type, and sex on DNA double-strand break repair in Drosophila melanogaster. PLoS Genet 2024; 20:e1011250. [PMID: 38683763 PMCID: PMC11057719 DOI: 10.1371/journal.pgen.1011250] [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: 12/15/2023] [Accepted: 04/04/2024] [Indexed: 05/02/2024] Open
Abstract
Accurate repair of DNA double-strand breaks (DSBs) is essential for the maintenance of genome integrity, as failure to repair DSBs can result in cell death. The cell has evolved two main mechanisms for DSB repair: non-homologous end-joining (NHEJ) and homology-directed repair (HDR), which includes single-strand annealing (SSA) and homologous recombination (HR). While certain factors like age and state of the chromatin are known to influence DSB repair pathway choice, the roles of developmental stage, tissue type, and sex have yet to be elucidated in multicellular organisms. To examine the influence of these factors, DSB repair in various embryonic developmental stages, larva, and adult tissues in Drosophila melanogaster was analyzed through molecular analysis of the DR-white assay using Tracking across Indels by DEcomposition (TIDE). The proportion of HR repair was highest in tissues that maintain the canonical (G1/S/G2/M) cell cycle and suppressed in both terminally differentiated and polyploid tissues. To determine the impact of sex on repair pathway choice, repair in different tissues in both males and females was analyzed. When molecularly examining tissues containing mostly somatic cells, males and females demonstrated similar proportions of HR and NHEJ. However, when DSB repair was analyzed in male and female premeiotic germline cells utilizing phenotypic analysis of the DR-white assay, there was a significant decrease in HR in females compared to males. This study describes the impact of development, tissue-specific cycling profile, and, in some cases, sex on DSB repair outcomes, underscoring the complexity of repair in multicellular organisms.
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Affiliation(s)
- Elizabeth L. Graham
- Department of Human Science, School of Health, Georgetown University Medical Center, Washington, District of Columbia, United States of America
| | - Joel Fernandez
- Department of Human Science, School of Health, Georgetown University Medical Center, Washington, District of Columbia, United States of America
| | - Shagun Gandhi
- Department of Human Science, School of Health, Georgetown University Medical Center, Washington, District of Columbia, United States of America
| | - Iqra Choudhry
- Department of Human Science, School of Health, Georgetown University Medical Center, Washington, District of Columbia, United States of America
| | - Natalia Kellam
- Department of Human Science, School of Health, Georgetown University Medical Center, Washington, District of Columbia, United States of America
| | - Jeannine R. LaRocque
- Department of Human Science, School of Health, Georgetown University Medical Center, Washington, District of Columbia, United States of America
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7
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Joshi JN, Changela N, Mahal L, Defosse T, Jang J, Wang LI, Das A, Shapiro JG, McKim K. Meiosis-specific functions of kinetochore protein SPC105R required for chromosome segregation in Drosophila oocytes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.14.585003. [PMID: 38559067 PMCID: PMC10980020 DOI: 10.1101/2024.03.14.585003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The reductional division of meiosis I requires the separation of chromosome pairs towards opposite poles. We have previously implicated the outer kinetochore protein SPC105R/KNL1 in driving meiosis I chromosome segregation through lateral attachments to microtubules and co-orientation of sister centromeres. To identify the domains of SPC105R that are critical for meiotic chromosome segregation, an RNAi-resistant gene expression system was developed. We found that SPC105R's C-terminal domain (aa 1284-1960) is necessary and sufficient for recruiting NDC80 to the kinetochore and building the outer kinetochore. Furthermore, the C-terminal domain recruits BUBR1, which in turn recruits the cohesion protection proteins MEI-S332 and PP2A. Of the remaining 1283 amino acids, we found the first 473 are most important for meiosis. The first 123 amino acids of the N-terminal half of SPC105R contain the conserved SLRK and RISF motifs that are targets of PP1 and Aurora B kinase and are most important for regulating the stability of microtubule attachments and maintaining metaphase I arrest. The region between amino acids 124 and 473 are required for two activities that are critical for accurate chromosome segregation in meiosis I, lateral microtubule attachments and bi-orientation of homologs.
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8
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Sun S, Defosse T, Boyd A, Sop J, Verderose F, Surray D, Aziz M, Howland M, Wu S, Changela N, Jang J, Schindler K, Xing J, McKim KS. Whole transcriptome screening for novel genes involved in meiosis and fertility in Drosophila melanogaster. Sci Rep 2024; 14:3602. [PMID: 38351116 PMCID: PMC10864285 DOI: 10.1038/s41598-024-53346-z] [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: 05/30/2023] [Accepted: 01/31/2024] [Indexed: 02/16/2024] Open
Abstract
Reproductive success requires the development of viable oocytes and the accurate segregation of chromosomes during meiosis. Failure to segregate chromosomes properly can lead to infertility, miscarriages, or developmental disorders. A variety of factors contribute to accurate chromosome segregation and oocyte development, such as spindle assembly and sister chromatid cohesion. However, many proteins required for meiosis remain unknown. In this study, we aimed to develop a screening pipeline for identifying novel meiotic and fertility genes using the genome of Drosophila melanogaster. To accomplish this goal, genes upregulated within meiotically active tissues were identified. More than 240 genes with no known function were silenced using RNA interference (RNAi) and the effects on meiosis and fertility were assessed. We identified 94 genes that when silenced caused infertility and/or high levels of chromosomal nondisjunction. The vast majority of these genes have human and mouse homologs that are also poorly studied. Through this screening process, we identified novel genes that are crucial for meiosis and oocyte development but have not been extensively studied in human or model organisms. Understanding the function of these genes will be an important step towards the understanding of their biological significance during reproduction.
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Affiliation(s)
- Siqi Sun
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Tyler Defosse
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Ayla Boyd
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Joel Sop
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Faith Verderose
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Diya Surray
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Mark Aziz
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Margaret Howland
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Siwen Wu
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Neha Changela
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Janet Jang
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ, 08854, USA
| | - Karen Schindler
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
- Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, 145 Bevier Road, Piscataway, NJ, 08854, USA
| | - Jinchuan Xing
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
- Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, 145 Bevier Road, Piscataway, NJ, 08854, USA.
| | - Kim S McKim
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
- Waksman Institute, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, NJ, 08854, USA.
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9
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Lepesant JA, Roland-Gosselin F, Guillemet C, Bernard F, Guichet A. The Importance of the Position of the Nucleus in Drosophila Oocyte Development. Cells 2024; 13:201. [PMID: 38275826 PMCID: PMC10814754 DOI: 10.3390/cells13020201] [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: 11/22/2023] [Revised: 01/12/2024] [Accepted: 01/16/2024] [Indexed: 01/27/2024] Open
Abstract
Oogenesis is a developmental process leading to the formation of an oocyte, a haploid gamete, which upon fertilisation and sperm entry allows the male and the female pronuclei to fuse and give rise to a zygote. In addition to forming a haploid gamete, oogenesis builds up a store of proteins, mRNAs, and organelles in the oocyte needed for the development of the future embryo. In several species, such as Drosophila, the polarity axes determinants of the future embryo must be asymmetrically distributed prior to fertilisation. In the Drosophila oocyte, the correct positioning of the nucleus is essential for establishing the dorsoventral polarity axis of the future embryo and allowing the meiotic spindles to be positioned in close vicinity to the unique sperm entry point into the oocyte.
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Affiliation(s)
| | | | | | | | - Antoine Guichet
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013 Paris, France; (J.-A.L.); (F.R.-G.); (C.G.); (F.B.)
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10
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Berg C, Sieber M, Sun J. Finishing the egg. Genetics 2024; 226:iyad183. [PMID: 38000906 PMCID: PMC10763546 DOI: 10.1093/genetics/iyad183] [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: 07/05/2023] [Accepted: 09/27/2023] [Indexed: 11/26/2023] Open
Abstract
Gamete development is a fundamental process that is highly conserved from early eukaryotes to mammals. As germ cells develop, they must coordinate a dynamic series of cellular processes that support growth, cell specification, patterning, the loading of maternal factors (RNAs, proteins, and nutrients), differentiation of structures to enable fertilization and ensure embryonic survival, and other processes that make a functional oocyte. To achieve these goals, germ cells integrate a complex milieu of environmental and developmental signals to produce fertilizable eggs. Over the past 50 years, Drosophila oogenesis has risen to the forefront as a system to interrogate the sophisticated mechanisms that drive oocyte development. Studies in Drosophila have defined mechanisms in germ cells that control meiosis, protect genome integrity, facilitate mRNA trafficking, and support the maternal loading of nutrients. Work in this system has provided key insights into the mechanisms that establish egg chamber polarity and patterning as well as the mechanisms that drive ovulation and egg activation. Using the power of Drosophila genetics, the field has begun to define the molecular mechanisms that coordinate environmental stresses and nutrient availability with oocyte development. Importantly, the majority of these reproductive mechanisms are highly conserved throughout evolution, and many play critical roles in the development of somatic tissues as well. In this chapter, we summarize the recent progress in several key areas that impact egg chamber development and ovulation. First, we discuss the mechanisms that drive nutrient storage and trafficking during oocyte maturation and vitellogenesis. Second, we examine the processes that regulate follicle cell patterning and how that patterning impacts the construction of the egg shell and the establishment of embryonic polarity. Finally, we examine regulatory factors that control ovulation, egg activation, and successful fertilization.
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Affiliation(s)
- Celeste Berg
- Department of Genome Sciences, University of Washington, Seattle, WA 98195-5065USA
| | - Matthew Sieber
- Department of Physiology, UT Southwestern Medical Center, Dallas, TX 75390USA
| | - Jianjun Sun
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269USA
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11
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Tian Y, Liu L, Gao J, Wang R. Homologous chromosome pairing: The linchpin of accurate segregation in meiosis. J Cell Physiol 2024; 239:3-19. [PMID: 38032002 DOI: 10.1002/jcp.31166] [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: 09/09/2023] [Revised: 11/13/2023] [Accepted: 11/20/2023] [Indexed: 12/01/2023]
Abstract
Meiosis is a specialized cell division that occurs in sexually reproducing organisms, generating haploid gametes containing half the chromosome number through two rounds of cell division. Homologous chromosomes pair and prepare for their proper segregation in subsequent divisions. How homologous chromosomes recognize each other and achieve pairing is an important question. Early studies showed that in most organisms, homologous pairing relies on homologous recombination. However, pairing mechanisms differ across species. Evidence indicates that chromosomes are dynamic and move during early meiotic stages, facilitating pairing. Recent studies in various model organisms suggest conserved mechanisms and key regulators of homologous chromosome pairing. This review summarizes these findings and compare similarities and differences in homologous chromosome pairing mechanisms across species.
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Affiliation(s)
- Yuqi Tian
- Center for Cell Structure and Function, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, China
| | - Libo Liu
- Center for Cell Structure and Function, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, China
| | - Jinmin Gao
- Center for Cell Structure and Function, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, China
| | - Ruoxi Wang
- Center for Cell Structure and Function, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, China
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12
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Wood BW, Shi X, Weil TT. F-actin coordinates spindle morphology and function in Drosophila meiosis. PLoS Genet 2024; 20:e1011111. [PMID: 38206959 PMCID: PMC10807755 DOI: 10.1371/journal.pgen.1011111] [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: 04/12/2023] [Revised: 01/24/2024] [Accepted: 12/13/2023] [Indexed: 01/13/2024] Open
Abstract
Meiosis is a highly conserved feature of sexual reproduction that ensures germ cells have the correct number of chromosomes prior to fertilization. A subset of microtubules, known as the spindle, are essential for accurate chromosome segregation during meiosis. Building evidence in mammalian systems has recently highlighted the unexpected requirement of the actin cytoskeleton in chromosome segregation; a network of spindle actin filaments appear to regulate many aspects of this process. Here we show that Drosophila oocytes also have a spindle population of actin that appears to regulate the formation of the microtubule spindle and chromosomal movements throughout meiosis. We demonstrate that genetic and pharmacological disruption of the actin cytoskeleton has a significant impact on spindle morphology, dynamics, and chromosome alignment and segregation during maturation and the metaphase-anaphase transition. We further reveal a role for calcium in maintaining the microtubule spindle and spindle actin. Together, our data highlights potential conservation of morphology and mechanism of the spindle actin during meiosis.
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Affiliation(s)
- Benjamin W. Wood
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Xingzhu Shi
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Timothy T. Weil
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
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13
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Sarkar K, Kotb NM, Lemus A, Martin ET, McCarthy A, Camacho J, Iqbal A, Valm AM, Sammons MA, Rangan P. A feedback loop between heterochromatin and the nucleopore complex controls germ-cell-to-oocyte transition during Drosophila oogenesis. Dev Cell 2023; 58:2580-2596.e6. [PMID: 37673064 DOI: 10.1016/j.devcel.2023.08.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 04/12/2023] [Accepted: 08/09/2023] [Indexed: 09/08/2023]
Abstract
Germ cells differentiate into oocytes that launch the next generation upon fertilization. How the highly specialized oocyte acquires this distinct cell fate is poorly understood. During Drosophila oogenesis, H3K9me3 histone methyltransferase SETDB1 translocates from the cytoplasm to the nucleus of germ cells concurrently with oocyte specification. Here, we discovered that nuclear SETDB1 is required for silencing a cohort of differentiation-promoting genes by mediating their heterochromatinization. Intriguingly, SETDB1 is also required for upregulating 18 of the ∼30 nucleoporins (Nups) that compose the nucleopore complex (NPC), promoting NPC formation. NPCs anchor SETDB1-dependent heterochromatin at the nuclear periphery to maintain H3K9me3 and gene silencing in the egg chambers. Aberrant gene expression due to the loss of SETDB1 or Nups results in the loss of oocyte identity, cell death, and sterility. Thus, a feedback loop between heterochromatin and NPCs promotes transcriptional reprogramming at the onset of oocyte specification, which is critical for establishing oocyte identity.
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Affiliation(s)
- Kahini Sarkar
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Noor M Kotb
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA; Department of Biomedical Sciences, School of Public Health, University at Albany SUNY, Albany, NY 12222, USA
| | - Alex Lemus
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Elliot T Martin
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Alicia McCarthy
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Justin Camacho
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Ayman Iqbal
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Alex M Valm
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Morgan A Sammons
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Prashanth Rangan
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA.
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14
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Tu R, Tang XA, Xu R, Ping Z, Yu Z, Xie T. Gap junction-transported cAMP from the niche controls stem cell progeny differentiation. Proc Natl Acad Sci U S A 2023; 120:e2304168120. [PMID: 37603749 PMCID: PMC10468610 DOI: 10.1073/pnas.2304168120] [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: 03/13/2023] [Accepted: 07/22/2023] [Indexed: 08/23/2023] Open
Abstract
The niche has been shown to control stem cell self-renewal in different tissue types and organisms. Recently, a separate niche has been proposed to control stem cell progeny differentiation, called the differentiation niche. However, it remains poorly understood whether and how the differentiation niche directly signals to stem cell progeny to control their differentiation. In the Drosophila ovary, inner germarial sheath (IGS) cells contribute to two separate niche compartments for controlling both germline stem cell (GSC) self-renewal and progeny differentiation. In this study, we show that IGS cells express Inx2 protein, which forms gap junctions (GJs) with germline-specific Zpg protein to control stepwise GSC lineage development, including GSC self-renewal, germline cyst formation, meiotic double-strand DNA break formation, and oocyte specification. Germline-specific Zpg and IGS-specific Inx2 knockdowns cause similar defects in stepwise GSC development. Additionally, secondary messenger cAMP is transported from IGS cells to GSCs and their progeny via GJs to activate PKA signaling for controlling stepwise GSC development. Therefore, this study demonstrates that the niche directly controls GSC progeny differentiation via the GJ-cAMP-PKA signaling axis, which provides important insights into niche control of stem cell differentiation and highlights the importance of GJ-transported cAMP in tissue regeneration. This may represent a general strategy for the niche to control adult stem cell development in various tissue types and organisms since GJs and cAMP are widely distributed.
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Affiliation(s)
- Renjun Tu
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
| | - Xiaohan Alex Tang
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
| | - Rui Xu
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
| | - Zhaohua Ping
- Stowers Institute for Medical Research, Kansas City, MO64110
| | - Zulin Yu
- Stowers Institute for Medical Research, Kansas City, MO64110
| | - Ting Xie
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
- Stowers Institute for Medical Research, Kansas City, MO64110
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15
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Benner L, Muron S, Oliver B. Female germline expression of OVO transcription factor bridges Drosophila generations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.25.554887. [PMID: 37662231 PMCID: PMC10473757 DOI: 10.1101/2023.08.25.554887] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
OVO is required for karyotypically female germ cell viability but has no known function in the male germline in Drosophila. ovo is autoregulated by two antagonistic isoforms, OVO-A and OVO-B. All ovo- alleles were created as partial revertants of the antimorphic ovoD1 allele. Creation of new targeted alleles in an ovo+ background indicated that disrupting the germline-specific exon extension of ovo-B leads to an arrested egg chamber phenotype, rather than germ cell death. RNA-seq analysis, including >1K full length cDNAs, indicates that ovo utilizes a number of unannotated splice variations in the extended exon and a minor population of ovo-B transcripts utilizes an alternative splice. This indicates that classical ovo alleles such as ovoD1rv23, are not truly null for ovo, and are likely to be weak antimorphs. To generate bonafide nulls, we deleted the ovo-A and ovo-B promoters showing that only ovo-B is required for female germ cell viability and there is an early and polyphasic developmental requirement for ovo-B in the female germline. To visualize OVO expression and localization, we endogenously tagged ovo and found nuclear OVO in all differentiating female germ cells throughout oogenesis in adults. We also found that OVO is maternally deposited into the embryo, where it showed nuclear localization in newly formed pole cells. Maternal OVO persisted in embryonic germ cells until zygotic OVO expression was detectable, suggesting that there is continuous nuclear OVO expression in the female germline in the transition from one generation to the next.
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Affiliation(s)
- Leif Benner
- Section of Developmental Genomics, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Savannah Muron
- Section of Developmental Genomics, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Brian Oliver
- Section of Developmental Genomics, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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16
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Breznak SM, Peng Y, Deng L, Kotb NM, Flamholz Z, Rapisarda IT, Martin ET, LaBarge KA, Fabris D, Gavis ER, Rangan P. H/ACA snRNP-dependent ribosome biogenesis regulates translation of polyglutamine proteins. SCIENCE ADVANCES 2023; 9:eade5492. [PMID: 37343092 PMCID: PMC10284551 DOI: 10.1126/sciadv.ade5492] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 05/17/2023] [Indexed: 06/23/2023]
Abstract
Stem cells in many systems, including Drosophila germline stem cells (GSCs), increase ribosome biogenesis and translation during terminal differentiation. Here, we show that the H/ACA small nuclear ribonucleoprotein (snRNP) complex that promotes pseudouridylation of ribosomal RNA (rRNA) and ribosome biogenesis is required for oocyte specification. Reducing ribosome levels during differentiation decreased the translation of a subset of messenger RNAs that are enriched for CAG trinucleotide repeats and encode polyglutamine-containing proteins, including differentiation factors such as RNA-binding Fox protein 1. Moreover, ribosomes were enriched at CAG repeats within transcripts during oogenesis. Increasing target of rapamycin (TOR) activity to elevate ribosome levels in H/ACA snRNP complex-depleted germlines suppressed the GSC differentiation defects, whereas germlines treated with the TOR inhibitor rapamycin had reduced levels of polyglutamine-containing proteins. Thus, ribosome biogenesis and ribosome levels can control stem cell differentiation via selective translation of CAG repeat-containing transcripts.
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Affiliation(s)
- Shane M. Breznak
- Department of Biological Sciences, RNA Institute, University at Albany, 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222, USA
| | - Yingshi Peng
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Limin Deng
- Department of Biological Sciences, RNA Institute, University at Albany, 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222, USA
- Department of Chemistry, University of Connecticut, 55N Eagleville Rd, Storrs, CT 06269, USA
| | - Noor M. Kotb
- Department of Biological Sciences, RNA Institute, University at Albany, 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222, USA
- Department of Biomedical Sciences, University at Albany School of Public Health, Albany, NY 12144, USA
| | - Zachary Flamholz
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Ian T. Rapisarda
- Department of Biological Sciences, RNA Institute, University at Albany, 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222, USA
- Lake Erie College of Osteopathic Medicine, College of Medicine, 1858 W Grandview Blvd, Erie, PA 16509, USA
| | - Elliot T. Martin
- Department of Biological Sciences, RNA Institute, University at Albany, 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222, USA
| | - Kara A. LaBarge
- Department of Biological Sciences, RNA Institute, University at Albany, 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222, USA
| | - Dan Fabris
- Department of Biological Sciences, RNA Institute, University at Albany, 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222, USA
- Department of Chemistry, University of Connecticut, 55N Eagleville Rd, Storrs, CT 06269, USA
| | - Elizabeth R. Gavis
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Prashanth Rangan
- Department of Biological Sciences, RNA Institute, University at Albany, 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222, USA
- Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA
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17
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Cabrita B, Martinho RG. Genetic and Epigenetic Regulation of Drosophila Oocyte Determination. J Dev Biol 2023; 11:21. [PMID: 37367475 DOI: 10.3390/jdb11020021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/18/2023] [Accepted: 05/20/2023] [Indexed: 06/28/2023] Open
Abstract
Primary oocyte determination occurs in many organisms within a germ line cyst, a multicellular structure composed of interconnected germ cells. However, the structure of the cyst is itself highly diverse, which raises intriguing questions about the benefits of this stereotypical multicellular environment for female gametogenesis. Drosophila melanogaster is a well-studied model for female gametogenesis, and numerous genes and pathways critical for the determination and differentiation of a viable female gamete have been identified. This review provides an up-to-date overview of Drosophila oocyte determination, with a particular emphasis on the mechanisms that regulate germ line gene expression.
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Affiliation(s)
- Brigite Cabrita
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Agra do Crasto, Edifício 30, 3810-193 Aveiro, Portugal
| | - Rui Gonçalo Martinho
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Agra do Crasto, Edifício 30, 3810-193 Aveiro, Portugal
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18
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Hanlon SL, Hawley RS. B chromosomes reveal a female meiotic drive suppression system in Drosophila melanogaster. Curr Biol 2023:S0960-9822(23)00476-1. [PMID: 37146608 DOI: 10.1016/j.cub.2023.04.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 03/08/2023] [Accepted: 04/13/2023] [Indexed: 05/07/2023]
Abstract
Selfish genetic elements use a myriad of mechanisms to drive their inheritance and ensure their survival into the next generation, often at a fitness cost to its host.1,2 Although the catalog of selfish genetic elements is rapidly growing, our understanding of host drive suppression systems that counteract self-seeking behavior is lacking. Here, we demonstrate that the biased transmission of the non-essential, non-driving B chromosomes in Drosophila melanogaster can be achieved in a specific genetic background. Combining a null mutant of matrimony, a gene that encodes a female-specific meiotic regulator of Polo kinase,3,4 with the TM3 balancer chromosome creates a driving genotype that is permissive for the biased transmission of the B chromosomes. This drive is female-specific, and both genetic components are necessary, but not individually sufficient, for permitting a strong drive of the B chromosomes. Examination of metaphase I oocytes reveals that B chromosome localization within the DNA mass is mostly abnormal when drive is the strongest, indicating a failure of the mechanism(s) responsible for the proper distribution of B chromosomes. We propose that some proteins important for proper chromosome segregation during meiosis, like Matrimony, may have an essential role as part of a meiotic drive suppression system that modulates chromosome segregation to prevent genetic elements from exploiting the inherent asymmetry of female meiosis.
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Affiliation(s)
- Stacey L Hanlon
- Genetics and Genomics, Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA; Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA.
| | - R Scott Hawley
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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19
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Li H, Berent E, Hadjipanteli S, Galey M, Muhammad-Lahbabi N, Miller DE, Crown KN. Heterozygous inversion breakpoints suppress meiotic crossovers by altering recombination repair outcomes. PLoS Genet 2023; 19:e1010702. [PMID: 37053290 PMCID: PMC10128924 DOI: 10.1371/journal.pgen.1010702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 04/25/2023] [Accepted: 03/15/2023] [Indexed: 04/15/2023] Open
Abstract
Heterozygous chromosome inversions suppress meiotic crossover (CO) formation within an inversion, potentially because they lead to gross chromosome rearrangements that produce inviable gametes. Interestingly, COs are also severely reduced in regions nearby but outside of inversion breakpoints even though COs in these regions do not result in rearrangements. Our mechanistic understanding of why COs are suppressed outside of inversion breakpoints is limited by a lack of data on the frequency of noncrossover gene conversions (NCOGCs) in these regions. To address this critical gap, we mapped the location and frequency of rare CO and NCOGC events that occurred outside of the dl-49 chrX inversion in D. melanogaster. We created full-sibling wildtype and inversion stocks and recovered COs and NCOGCs in the syntenic regions of both stocks, allowing us to directly compare rates and distributions of recombination events. We show that COs outside of the proximal inversion breakpoint are distributed in a distance-dependent manner, with strongest suppression near the inversion breakpoint. We find that NCOGCs occur evenly throughout the chromosome and, importantly, are not suppressed near inversion breakpoints. We propose a model in which COs are suppressed by inversion breakpoints in a distance-dependent manner through mechanisms that influence DNA double-strand break repair outcome but not double-strand break formation. We suggest that subtle changes in the synaptonemal complex and chromosome pairing might lead to unstable interhomolog interactions during recombination that permits NCOGC formation but not CO formation.
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Affiliation(s)
- Haosheng Li
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Erica Berent
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Savannah Hadjipanteli
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Miranda Galey
- Division of Genetic Medicine, Department of Pediatrics, University of Washington and Seattle Children's Hospital, Seattle, Washington, United States of America
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Nigel Muhammad-Lahbabi
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Danny E Miller
- Division of Genetic Medicine, Department of Pediatrics, University of Washington and Seattle Children's Hospital, Seattle, Washington, United States of America
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
- Brotman Baty Institute for Precision Medicine, University of Washington, Seattle, Washington, United States of America
| | - K Nicole Crown
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
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20
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Koury SA. Predicting recombination suppression outside chromosomal inversions in Drosophila melanogaster using crossover interference theory. Heredity (Edinb) 2023; 130:196-208. [PMID: 36721031 PMCID: PMC10076299 DOI: 10.1038/s41437-023-00593-x] [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: 10/03/2022] [Revised: 01/20/2023] [Accepted: 01/20/2023] [Indexed: 02/02/2023] Open
Abstract
Recombination suppression in chromosomal inversion heterozygotes is a well-known but poorly understood phenomenon. Surprisingly, recombination suppression extends far outside of inverted regions where there are no intrinsic barriers to normal chromosome pairing, synapsis, double-strand break formation, or recovery of crossover products. The interference hypothesis of recombination suppression proposes heterozygous inversion breakpoints possess chiasma-like properties such that recombination suppression extends from these breakpoints in a process analogous to crossover interference. This hypothesis is qualitatively consistent with chromosome-wide patterns of recombination suppression extending to both inverted and uninverted regions of the chromosome. The present study generated quantitative predictions for this hypothesis using a probabilistic model of crossover interference with gamma-distributed inter-event distances. These predictions were then tested with experimental genetic data (>40,000 meioses) on crossing-over in intervals that are external and adjacent to four common inversions of Drosophila melanogaster. The crossover interference model accurately predicted the partially suppressed recombination rates in euchromatic intervals outside inverted regions. Furthermore, assuming interference does not extend across centromeres dramatically improved model fit and partially accounted for excess recombination observed in pericentromeric intervals. Finally, inversions with breakpoints closest to the centromere had the greatest excess of recombination in pericentromeric intervals, an observation that is consistent with negative crossover interference previously documented near Drosophila melanogaster centromeres. In conclusion, the experimental data support the interference hypothesis of recombination suppression, validate a mathematical framework for integrating distance-dependent effects of structural heterozygosity on crossover distribution, and highlight the need for improved modeling of crossover interference in pericentromeric regions.
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Affiliation(s)
- Spencer A Koury
- Department of Ecology and Evolution, Stony Brook University, 650 Life Sciences Building, Stony Brook, NY, 11794, USA.
- 2613 Ashwood Ave, Nashville, TN, 37212, USA.
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21
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Breznak SM, Kotb NM, Rangan P. Dynamic regulation of ribosome levels and translation during development. Semin Cell Dev Biol 2023; 136:27-37. [PMID: 35725716 DOI: 10.1016/j.semcdb.2022.06.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/20/2022] [Accepted: 06/12/2022] [Indexed: 01/11/2023]
Abstract
The ability of ribosomes to translate mRNAs into proteins is the basis of all life. While ribosomes are essential for cell viability, reduction in levels of ribosomes can affect cell fate and developmental transitions in a tissue specific manner and can cause a plethora of related diseases called ribosomopathies. How dysregulated ribosomes homeostasis influences cell fate and developmental transitions is not fully understood. Model systems such as Drosophila and C. elegans oogenesis have been used to address these questions since defects in conserved steps in ribosome biogenesis result in stem cell differentiation and developmental defects. In this review, we first explore how ribosome levels affect stem cell differentiation. Second, we describe how ribosomal modifications and incorporation of ribosomal protein paralogs contribute to development. Third, we summarize how cells with perturbed ribosome biogenesis are sensed and eliminated during organismal growth.
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Affiliation(s)
- Shane M Breznak
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY, 12222, USA
| | - Noor M Kotb
- Department of Biomedical Sciences, The School of Public Health, University at Albany SUNY, 11 Albany, NY 12222, USA
| | - Prashanth Rangan
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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22
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Beachum AN, Hinnant TD, Williams AE, Powell AM, Ables ET. β-importin Tnpo-SR promotes germline stem cell maintenance and oocyte differentiation in female Drosophila. Dev Biol 2023; 494:1-12. [PMID: 36450333 PMCID: PMC9870978 DOI: 10.1016/j.ydbio.2022.11.006] [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: 09/22/2021] [Revised: 11/09/2022] [Accepted: 11/21/2022] [Indexed: 11/29/2022]
Abstract
Germ cell development requires interplay between factors that balance cell fate and division. Early in their development, germ cells in many organisms divide mitotically with incomplete cytokinesis. Key regulatory events then lead to the specification of mature gametes, marked by the switch to a meiotic cell cycle program. Though the regulation of germ cell proliferation and meiosis are well understood, how these events are coordinated during development remains incompletely described. Originally characterized in their role as nucleo-cytoplasmic shuttling proteins, β-importins exhibit diverse functions during male and female gametogenesis. Here, we describe novel, distinct roles for the β-importin, Transportin-Serine/Arginine rich (Tnpo-SR), as a regulator of the mitosis to meiosis transition in the Drosophila ovary. We find that Tnpo-SR is necessary for germline stem cell (GSC) establishment and self-renewal, likely by controlling the response of GSCs to bone morphogenetic proteins. Depletion of Tnpo-SR results in germ cell counting defects and loss of oocyte identity. We show that in the absence of Tnpo-SR, proteins typically suppressed in germ cells when they exit mitosis fail to be down-regulated, and oocyte-specific factors fail to accumulate. Together, these findings provide new insight into the balance between germ cell division and differentiation and identify novel roles for β-importins in germ cell development.
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Affiliation(s)
- Allison N Beachum
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA
| | - Taylor D Hinnant
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA
| | - Anna E Williams
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA
| | - Amanda M Powell
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA
| | - Elizabeth T Ables
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA.
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23
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Mitochondrial remodelling is essential for female germ cell differentiation and survival. PLoS Genet 2023; 19:e1010610. [PMID: 36696418 PMCID: PMC9901744 DOI: 10.1371/journal.pgen.1010610] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 02/06/2023] [Accepted: 01/09/2023] [Indexed: 01/26/2023] Open
Abstract
Stem cells often possess immature mitochondria with few inner membrane invaginations, which increase as stem cells differentiate. Despite this being a conserved feature across many stem cell types in numerous organisms, how and why mitochondria undergo such remodelling during stem cell differentiation has remained unclear. Here, using Drosophila germline stem cells (GSCs), we show that Complex V drives mitochondrial remodelling during the early stages of GSC differentiation, prior to terminal differentiation. This endows germline mitochondria with the capacity to generate large amounts of ATP required for later egg growth and development. Interestingly, impairing mitochondrial remodelling prior to terminal differentiation results in endoplasmic reticulum (ER) lipid bilayer stress, Protein kinase R-like ER kinase (PERK)-mediated activation of the Integrated Stress Response (ISR) and germ cell death. Taken together, our data suggest that mitochondrial remodelling is an essential and tightly integrated aspect of stem cell differentiation. This work sheds light on the potential impact of mitochondrial dysfunction on stem and germ cell function, highlighting ER lipid bilayer stress as a potential major driver of phenotypes caused by mitochondrial dysfunction.
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24
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Klucnika A, Mu P, Jezek J, McCormack M, Di Y, Bradshaw CR, Ma H. REC drives recombination to repair double-strand breaks in animal mtDNA. J Cell Biol 2023; 222:e202201137. [PMID: 36355348 PMCID: PMC9652705 DOI: 10.1083/jcb.202201137] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 09/09/2022] [Accepted: 10/19/2022] [Indexed: 11/11/2022] Open
Abstract
Mechanisms that safeguard mitochondrial DNA (mtDNA) limit the accumulation of mutations linked to mitochondrial and age-related diseases. Yet, pathways that repair double-strand breaks (DSBs) in animal mitochondria are poorly understood. By performing a candidate screen for mtDNA repair proteins, we identify that REC-an MCM helicase that drives meiotic recombination in the nucleus-also localizes to mitochondria in Drosophila. We show that REC repairs mtDNA DSBs by homologous recombination in somatic and germline tissues. Moreover, REC prevents age-associated mtDNA mutations. We further show that MCM8, the human ortholog of REC, also localizes to mitochondria and limits the accumulation of mtDNA mutations. This study provides mechanistic insight into animal mtDNA recombination and demonstrates its importance in safeguarding mtDNA during ageing and evolution.
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Affiliation(s)
- Anna Klucnika
- Wellcome/Cancer Research UK Gurdon Institute, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Peiqiang Mu
- Wellcome/Cancer Research UK Gurdon Institute, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, South China Agricultural University, Guangzhou, Guangdong, China
| | - Jan Jezek
- Wellcome/Cancer Research UK Gurdon Institute, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Matthew McCormack
- Wellcome/Cancer Research UK Gurdon Institute, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Ying Di
- Wellcome/Cancer Research UK Gurdon Institute, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | | | - Hansong Ma
- Wellcome/Cancer Research UK Gurdon Institute, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
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25
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Hill HJ, Golic KG. Chromosome Tug of War: Dicentric Chromosomes and the Centromere Strength Hypothesis. Cells 2022; 11:3550. [PMID: 36428979 PMCID: PMC9688759 DOI: 10.3390/cells11223550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 11/09/2022] [Indexed: 11/12/2022] Open
Abstract
It has been 70 years since the concept of varied centromere strengths was introduced based on the behavior of dicentric chromosomes. One of the key conclusions from those early experiments was that some centromeres could pull with sufficient force to break a dicentric chromosome bridge, while others could not. In the ensuing decades there have been numerous studies to characterize strengths of the various components involved, such as the spindle, the kinetochore, and the chromosome itself. We review these various measurements to determine if the conclusions about centromere strength are supported by current evidence, with special attention to characterization of Drosophila melanogaster kinetochores upon which the original conclusions were based.
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Affiliation(s)
| | - Kent G. Golic
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
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26
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Feijão T, Marques B, Silva RD, Carvalho C, Sobral D, Matos R, Tan T, Pereira A, Morais-de-Sá E, Maiato H, DeLuca SZ, Martinho RG. Polycomb group (PcG) proteins prevent the assembly of abnormal synaptonemal complex structures during meiosis. Proc Natl Acad Sci U S A 2022; 119:e2204701119. [PMID: 36215502 PMCID: PMC9586294 DOI: 10.1073/pnas.2204701119] [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: 03/16/2022] [Accepted: 07/18/2022] [Indexed: 11/18/2022] Open
Abstract
The synaptonemal complex (SC) is a proteinaceous scaffold that is assembled between paired homologous chromosomes during the onset of meiosis. Timely expression of SC coding genes is essential for SC assembly and successful meiosis. However, SC components have an intrinsic tendency to self-organize into abnormal repetitive structures, which are not assembled between the paired homologs and whose formation is potentially deleterious for meiosis and gametogenesis. This creates an interesting conundrum, where SC genes need to be robustly expressed during meiosis, but their expression must be carefully regulated to prevent the formation of anomalous SC structures. In this manuscript, we show that the Polycomb group protein Sfmbt, the Drosophila ortholog of human MBTD1 and L3MBTL2, is required to avoid excessive expression of SC genes during prophase I. Although SC assembly is normal after Sfmbt depletion, SC disassembly is abnormal with the formation of multiple synaptonemal complexes (polycomplexes) within the oocyte. Overexpression of the SC gene corona and depletion of other Polycomb group proteins are similarly associated with polycomplex formation during SC disassembly. These polycomplexes are highly dynamic and have a well-defined periodic structure. Further confirming the importance of Sfmbt, germ line depletion of this protein is associated with significant metaphase I defects and a reduction in female fertility. Since transcription of SC genes mostly occurs during early prophase I, our results suggest a role of Sfmbt and other Polycomb group proteins in downregulating the expression of these and other early prophase I genes during later stages of meiosis.
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Affiliation(s)
- Tália Feijão
- Algarve Biomedical Center Research Institute, Universidade do Algarve, 8005-139 Faro, Portugal
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, 4200-135 Portugal
- Department of Medical Sciences and Institute for Biomedicine, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Bruno Marques
- Algarve Biomedical Center Research Institute, Universidade do Algarve, 8005-139 Faro, Portugal
| | - Rui D. Silva
- Algarve Biomedical Center Research Institute, Universidade do Algarve, 8005-139 Faro, Portugal
- Faculty of Medicine and Biomedical Sciences, Universidade do Algarve, 8005-139 Faro, Portugal
| | - Célia Carvalho
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Daniel Sobral
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2819-516 Caparica, Portugal
- Applied Molecular Biosciences Unit (UCIBIO), Department of Life Sciences, School of Science and Technology, NOVA University Lisbon, Caparica, 2819-516 Portugal
| | - Ricardo Matos
- Algarve Biomedical Center Research Institute, Universidade do Algarve, 8005-139 Faro, Portugal
| | - Tian Tan
- Department of Biology, Brandeis University, Waltham, MA 02453
| | - António Pereira
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, 4200-135 Portugal
| | - Eurico Morais-de-Sá
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, 4200-135 Portugal
| | - Hélder Maiato
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, 4200-135 Portugal
| | | | - Rui Gonçalo Martinho
- Algarve Biomedical Center Research Institute, Universidade do Algarve, 8005-139 Faro, Portugal
- Department of Medical Sciences and Institute for Biomedicine, Universidade de Aveiro, 3810-193 Aveiro, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
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27
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Billmyre KK. Chromosome-specific behaviors during early meiosis. Curr Top Dev Biol 2022; 151:127-154. [PMID: 36681468 DOI: 10.1016/bs.ctdb.2022.05.002] [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] [Indexed: 01/25/2023]
Abstract
Inheriting the wrong number of chromosomes is one of the leading causes of infertility and birth defects in humans. However, in many organisms, individual chromosomes vary dramatically in both organization, sequence, and size. Chromosome segregation systems must be capable of accounting for these differences to reliably segregate chromosomes. During gametogenesis, meiosis ensures that all chromosomes segregate properly into gametes (i.e., egg or sperm). Interestingly, not all chromosomes exhibit the same dynamics during meiosis, which can lead to chromosome-specific behaviors and defects. This review will summarize some of the chromosome-specific meiotic events that are currently known and discuss their impact on meiotic outcomes.
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28
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Vernizzi L, Lehner CF. Dispersive forces and resisting spot welds by alternative homolog conjunction govern chromosome shape in Drosophila spermatocytes during prophase I. PLoS Genet 2022; 18:e1010327. [PMID: 35895750 PMCID: PMC9359577 DOI: 10.1371/journal.pgen.1010327] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 08/08/2022] [Accepted: 07/05/2022] [Indexed: 11/19/2022] Open
Abstract
The bivalent chromosomes that are generated during prophase of meiosis I comprise a pair of homologous chromosomes. Homolog pairing during prophase I must include mechanisms that avoid or eliminate entanglements between non-homologous chromosomes. In Drosophila spermatocytes, non-homologous associations are disrupted by chromosome territory formation, while linkages between homologous chromosomes are maintained by special conjunction proteins. These proteins function as alternative for crossovers that link homologs during canonical meiosis but are absent during the achiasmate Drosophila male meiosis. How and where within bivalents the alternative homolog conjunction proteins function is still poorly understood. To clarify the rules that govern territory formation and alternative homolog conjunction, we have analyzed spermatocytes with chromosomal aberrations. We examined territory formation after acute chromosome cleavage by Cas9, targeted to the dodeca satellite adjacent to the centromere of chromosome 3 specifically in spermatocytes. Moreover, we studied territory organization, as well as the eventual orientation of chromosomes during meiosis I, in spermatocytes with stable structural aberrations, including heterozygous reciprocal autosomal translocations. Our observations indicate that alternative homolog conjunction is applied in a spatially confined manner. Comparable to crossovers, only a single conjunction spot per chromosome arm appears to be applied usually. These conjunction spots resist separation by the dispersing forces that drive apart homologous pericentromeric heterochromatin and embedded centromeres within territories, as well as the distinct chromosomal entities into peripheral, maximally separated territories within the spermatocyte nucleus. Already the primordial eukaryote appears to have used meiosis for sexual reproduction, because this sophisticated process follows a canonical program in lineages ranging from unicellular organisms to plants and animals. The maternal and paternal copies of a particular chromosome, i.e., the homologs, are first physically linked into a bivalent before the first meiotic division. Linkage is essential for error-free chromosome segregation. In canonical meiosis, linkage is achieved by crossovers. These are regulated so that each chromosome pair is linked, but only by very few crossovers. Surprisingly, crossovers are absent during meiosis in males of the fruit fly Drosophila melanogaster. Instead, an alternative homolog conjunction system is used. It is not yet clear how this functions. Here, we demonstrate that the alternative chromosome glue appears to be applied in a locally restricted manner rather than all along the paired homologs. Just two spots of glue appear to conjoin the two homologous chromosomes usually, with one spot linking the left and another the right chromosome arm. Thus, number and location of linkages appear to be similar as crossovers, raising the possibility of mechanistic similarities in the establishment of the two distinct types of homolog linkage.
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Affiliation(s)
- Luisa Vernizzi
- Department of Molecular Life Science (DMLS), University of Zurich, Zurich, Switzerland
| | - Christian F. Lehner
- Department of Molecular Life Science (DMLS), University of Zurich, Zurich, Switzerland
- * E-mail:
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29
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Abstract
We discuss the genetic, demographic, and selective forces that are likely to be at play in restricting observed levels of DNA sequence variation in natural populations to a much smaller range of values than would be expected from the distribution of census population sizes alone-Lewontin's Paradox. While several processes that have previously been strongly emphasized must be involved, including the effects of direct selection and genetic hitchhiking, it seems unlikely that they are sufficient to explain this observation without contributions from other factors. We highlight a potentially important role for the less-appreciated contribution of population size change; specifically, the likelihood that many species and populations may be quite far from reaching the relatively high equilibrium diversity values that would be expected given their current census sizes.
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Affiliation(s)
- Brian Charlesworth
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jeffrey D Jensen
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
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30
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Dudka D, Lampson MA. Centromere drive: model systems and experimental progress. Chromosome Res 2022; 30:187-203. [PMID: 35731424 DOI: 10.1007/s10577-022-09696-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/11/2022] [Accepted: 04/19/2022] [Indexed: 11/28/2022]
Abstract
Centromeres connect chromosomes and spindle microtubules to ensure faithful chromosome segregation. Paradoxically, despite this conserved function, centromeric DNA evolves rapidly and centromeric proteins show signatures of positive selection. The centromere drive hypothesis proposes that centromeric DNA can act like a selfish genetic element and drive non-Mendelian segregation during asymmetric female meiosis. Resulting fitness costs lead to genetic conflict with the rest of the genome and impose a selective pressure for centromeric proteins to adapt by suppressing the costs. Here, we describe experimental model systems for centromere drive in yellow monkeyflowers and mice, summarize key findings demonstrating centromere drive, and explain molecular mechanisms. We further discuss efforts to test if centromeric proteins are involved in suppressing drive-associated fitness costs, highlight a model for centromere drive and suppression in mice, and put forth outstanding questions for future research.
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Affiliation(s)
- Damian Dudka
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Michael A Lampson
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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31
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Martin ET, Sarkar K, McCarthy A, Rangan P. Oo-site: A dashboard to visualize gene expression during Drosophila oogenesis suggests meiotic entry is regulated post-transcriptionally. Biol Open 2022; 11:275394. [PMID: 35579517 PMCID: PMC9148541 DOI: 10.1242/bio.059286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/19/2022] [Indexed: 11/20/2022] Open
Abstract
Determining how stem cell differentiation is controlled has important implications for understanding the etiology of degenerative disease and designing regenerative therapies. In vivo analyses of stem cell model systems have revealed regulatory paradigms for stem cell self-renewal and differentiation. The germarium of the female Drosophila gonad, which houses both germline and somatic stem cells, is one such model system. Bulk mRNA sequencing (RNA-seq), single-cell RNA-seq (scRNA-seq), and bulk translation efficiency (polysome-seq) of mRNAs are available for stem cells and their differentiating progeny within the Drosophila germarium. However, visualizing those data is hampered by the lack of a tool to spatially map gene expression and translational data in the germarium. Here, we have developed Oo-site (https://www.ranganlab.com/Oo-site), a tool for visualizing bulk RNA-seq, scRNA-seq, and translational efficiency data during different stages of germline differentiation, which makes these data accessible to non-bioinformaticians. Using this tool, we recapitulated previously reported expression patterns of developmentally regulated genes and discovered that meiotic genes, such as those that regulate the synaptonemal complex, are regulated at the level of translation.
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Affiliation(s)
- Elliot T Martin
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Kahini Sarkar
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA.,Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Alicia McCarthy
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Prashanth Rangan
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA.,Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA
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32
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A Brief History of Drosophila (Female) Meiosis. Genes (Basel) 2022; 13:genes13050775. [PMID: 35627159 PMCID: PMC9140851 DOI: 10.3390/genes13050775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/16/2022] [Accepted: 04/20/2022] [Indexed: 02/07/2023] Open
Abstract
Drosophila has been a model system for meiosis since the discovery of nondisjunction. Subsequent studies have determined that crossing over is required for chromosome segregation, and identified proteins required for the pairing of chromosomes, initiating meiotic recombination, producing crossover events, and building a spindle to segregate the chromosomes. With a variety of genetic and cytological tools, Drosophila remains a model organism for the study of meiosis. This review focusses on meiosis in females because in male meiosis, the use of chiasmata to link homologous chromosomes has been replaced by a recombination-independent mechanism. Drosophila oocytes are also a good model for mammalian meiosis because of biological similarities such as long pauses between meiotic stages and the absence of centrosomes during the meiotic divisions.
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33
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Chakravarti A, Thirimanne HN, Brown S, Calvi BR. Drosophila p53 isoforms have overlapping and distinct functions in germline genome integrity and oocyte quality control. eLife 2022; 11:61389. [PMID: 35023826 PMCID: PMC8758136 DOI: 10.7554/elife.61389] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 12/13/2021] [Indexed: 12/13/2022] Open
Abstract
p53 gene family members in humans and other organisms encode a large number of protein isoforms whose functions are largely undefined. Using Drosophila as a model, we find that a p53B isoform is expressed predominantly in the germline where it colocalizes with p53A into subnuclear bodies. It is only p53A, however, that mediates the apoptotic response to ionizing radiation in the germline and soma. In contrast, p53A and p53B are both required for the normal repair of meiotic DNA breaks, an activity that is more crucial when meiotic recombination is defective. We find that in oocytes with persistent DNA breaks p53A is also required to activate a meiotic pachytene checkpoint. Our findings indicate that Drosophila p53 isoforms have DNA lesion and cell type-specific functions, with parallels to the functions of mammalian p53 family members in the genotoxic stress response and oocyte quality control.
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Affiliation(s)
| | | | - Savanna Brown
- Department of Biology, Indiana University, Bloomington, United States
| | - Brian R Calvi
- Department of Biology, Indiana University, Bloomington, United States
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34
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McCarthy A, Sarkar K, Martin ET, Upadhyay M, Jang S, Williams ND, Forni PE, Buszczak M, Rangan P. Msl3 promotes germline stem cell differentiation in female Drosophila. Development 2022; 149:dev199625. [PMID: 34878097 PMCID: PMC8783043 DOI: 10.1242/dev.199625] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 11/19/2021] [Indexed: 01/07/2023]
Abstract
Gamete formation from germline stem cells (GSCs) is essential for sexual reproduction. However, the regulation of GSC differentiation is incompletely understood. Set2, which deposits H3K36me3 modifications, is required for GSC differentiation during Drosophila oogenesis. We discovered that the H3K36me3 reader Male-specific lethal 3 (Msl3) and histone acetyltransferase complex Ada2a-containing (ATAC) cooperate with Set2 to regulate GSC differentiation in female Drosophila. Msl3, acting independently of the rest of the male-specific lethal complex, promotes transcription of genes, including a germline-enriched ribosomal protein S19 paralog RpS19b. RpS19b upregulation is required for translation of RNA-binding Fox protein 1 (Rbfox1), a known meiotic cell cycle entry factor. Thus, Msl3 regulates GSC differentiation by modulating translation of a key factor that promotes transition to an oocyte fate.
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Affiliation(s)
- Alicia McCarthy
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Kahini Sarkar
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Elliot T. Martin
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Maitreyi Upadhyay
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Seoyeon Jang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Nathan D. Williams
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Paolo E. Forni
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Michael Buszczak
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Prashanth Rangan
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
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35
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Meiosis initiation: a story of two sexes in all creatures great and small. Biochem J 2021; 478:3791-3805. [PMID: 34709374 PMCID: PMC8589329 DOI: 10.1042/bcj20210412] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/29/2021] [Accepted: 10/06/2021] [Indexed: 12/22/2022]
Abstract
Meiosis facilitates diversity across individuals and serves as a major driver of evolution. However, understanding how meiosis begins is complicated by fundamental differences that exist between sexes and species. Fundamental meiotic research is further hampered by a current lack of human meiotic cells lines. Consequently, much of what we know relies on data from model organisms. However, contextualising findings from yeast, worms, flies and mice can be challenging, due to marked differences in both nomenclature and the relative timing of meiosis. In this review, we set out to combine current knowledge of signalling and transcriptional pathways that control meiosis initiation across the sexes in a variety of organisms. Furthermore, we highlight the emerging links between meiosis initiation and oncogenesis, which might explain the frequent re-expression of normally silent meiotic genes in a variety of human cancers.
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36
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Imai Y, Olaya I, Sakai N, Burgess SM. Meiotic Chromosome Dynamics in Zebrafish. Front Cell Dev Biol 2021; 9:757445. [PMID: 34692709 PMCID: PMC8531508 DOI: 10.3389/fcell.2021.757445] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/14/2021] [Indexed: 11/13/2022] Open
Abstract
Recent studies in zebrafish have revealed key features of meiotic chromosome dynamics, including clustering of telomeres in the bouquet configuration, biogenesis of chromosome axis structures, and the assembly and disassembly of the synaptonemal complex that aligns homologs end-to-end. The telomere bouquet stage is especially pronounced in zebrafish meiosis and sub-telomeric regions play key roles in mediating pairing and homologous recombination. In this review, we discuss the temporal progression of these events in meiosis prophase I and highlight the roles of proteins associated with meiotic chromosome architecture in homologous recombination. Finally, we discuss the interplay between meiotic mutants and gonadal sex differentiation and future research directions to study meiosis in living cells, including cell culture.
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Affiliation(s)
- Yukiko Imai
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Japan
| | - Ivan Olaya
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, United States.,Integrative Genetics and Genomics Graduate Group, University of California, Davis, Davis, CA, United States
| | - Noriyoshi Sakai
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Japan.,Department of Genetics, School of Life Sciences, SOKENDAI (The Graduate University for Advanced Studies), Mishima, Japan
| | - Sean M Burgess
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, United States
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37
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Gebert D, Neubert LK, Lloyd C, Gui J, Lehmann R, Teixeira FK. Large Drosophila germline piRNA clusters are evolutionarily labile and dispensable for transposon regulation. Mol Cell 2021; 81:3965-3978.e5. [PMID: 34352205 PMCID: PMC8516431 DOI: 10.1016/j.molcel.2021.07.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/23/2021] [Accepted: 07/10/2021] [Indexed: 12/13/2022]
Abstract
PIWI proteins and their guiding Piwi-interacting small RNAs (piRNAs) are crucial for fertility and transposon defense in the animal germline. In most species, the majority of piRNAs are produced from distinct large genomic loci, called piRNA clusters. It is assumed that germline-expressed piRNA clusters, particularly in Drosophila, act as principal regulators to control transposons dispersed across the genome. Here, using synteny analysis, we show that large clusters are evolutionarily labile, arise at loci characterized by recurrent chromosomal rearrangements, and are mostly species-specific across the Drosophila genus. By engineering chromosomal deletions in D. melanogaster, we demonstrate that the three largest germline clusters, which account for the accumulation of >40% of all transposon-targeting piRNAs in ovaries, are neither required for fertility nor for transposon regulation in trans. We provide further evidence that dispersed elements, rather than the regulatory action of large Drosophila germline clusters in trans, may be central for transposon defense.
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Affiliation(s)
- Daniel Gebert
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
| | - Lena K Neubert
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
| | - Catrin Lloyd
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
| | - Jinghua Gui
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
| | - Ruth Lehmann
- Howard Hughes Medical Institute (HHMI) and Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA.
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38
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Beachum AN, Whitehead KM, McDonald SI, Phipps DN, Berghout HE, Ables ET. Orphan nuclear receptor ftz-f1 (NR5A3) promotes egg chamber survival in the Drosophila ovary. G3-GENES GENOMES GENETICS 2021; 11:6114459. [PMID: 33693603 PMCID: PMC8022936 DOI: 10.1093/g3journal/jkab003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 11/30/2020] [Indexed: 11/12/2022]
Abstract
Gamete production in mammals and insects is controlled by cell signaling pathways that facilitate communication between germ cells and somatic cells. Nuclear receptor signaling is a key mediator of many aspects of reproduction, including gametogenesis. For example, the NR5A subfamily of nuclear receptors is essential for gonad development and sex steroid production in mammals. Despite the original identification of the NR5A subfamily in the model insect Drosophila melanogaster, it has been unclear whether Drosophila NR5A receptors directly control oocyte production. Ftz-f1 is expressed throughout the ovary, including in germline stem cells, germline cysts, and several populations of somatic cells. We show that ftz-f1 is required in follicle cells prior to stage 10 to promote egg chamber survival at the mid-oogenesis checkpoint. Our data suggest that egg chamber death in the absence of ftz-f1 is due, at least in part, to failure of follicle cells to exit the mitotic cell cycle or failure to accumulate oocyte-specific factors in the germline. Taken together, these results show that, as in mammals, the NR5A subfamily promotes maximal reproductive output in Drosophila. Our data underscore the importance of nuclear receptors in the control of reproduction and highlight the utility of Drosophila oogenesis as a key model for unraveling the complexity of nuclear receptor signaling in gametogenesis.
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Affiliation(s)
- Allison N Beachum
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | | | | | - Daniel N Phipps
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Hanna E Berghout
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Elizabeth T Ables
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
- Corresponding author: Department of Biology, East Carolina University, 1001 E. 10th St., Mailstop 551, 553 Science & Technology Building, Greenville, NC 27858, USA.
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39
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Neiswender H, Goldman CH, Veeranan-Karmegam R, Gonsalvez GB. Dynein light chain-dependent dimerization of Egalitarian is essential for maintaining oocyte fate in Drosophila. Dev Biol 2021; 478:76-88. [PMID: 34181915 DOI: 10.1016/j.ydbio.2021.06.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/02/2021] [Accepted: 06/17/2021] [Indexed: 11/28/2022]
Abstract
Egalitarian (Egl) is an RNA adaptor for the Dynein motor and is thought to link numerous, perhaps hundreds, of mRNAs with Dynein. Dynein, in turn, is responsible for the transport and localization of these mRNAs. Studies have shown that efficient mRNA binding by Egl requires the protein to dimerize. We recently demonstrated that Dynein light chain (Dlc) is responsible for facilitating the dimerization of Egl. Mutations in Egl that fail to interact with Dlc do not dimerize, and as such, are defective for mRNA binding. Consequently, this mutant does not efficiently associate with BicaudalD (BicD), the factor responsible for linking the Egl/mRNA complex with Dynein. In this report, we tested whether artificially dimerizing this Dlc-binding mutant using a leucine zipper would restore mRNA binding and rescue mutant phenotypes in vivo. Interestingly, we found that although artificial dimerization of Egl restored BicD binding, it only partially restored mRNA binding. As a result, Egl-dependent phenotypes, such as oocyte specification and mRNA localization, were only partially rescued. We hypothesize that Dlc-mediated dimerization of Egl results in a three-dimensional conformation of the Egl dimer that is best suited for mRNA binding. Although the leucine zipper restores Egl dimerization, it likely does not enable Egl to assemble into the conformation required for maximal mRNA binding activity.
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Affiliation(s)
- Hannah Neiswender
- Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1460 Laney Walker Blvd, Augusta, GA, 30912, USA
| | - Chandler H Goldman
- Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1460 Laney Walker Blvd, Augusta, GA, 30912, USA
| | - Rajalakshmi Veeranan-Karmegam
- Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1460 Laney Walker Blvd, Augusta, GA, 30912, USA
| | - Graydon B Gonsalvez
- Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1460 Laney Walker Blvd, Augusta, GA, 30912, USA.
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40
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Palacios V, Kimble GC, Tootle TL, Buszczak M. Importin-9 regulates chromosome segregation and packaging in Drosophila germ cells. J Cell Sci 2021; 134:237786. [PMID: 33632744 DOI: 10.1242/jcs.258391] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 02/10/2021] [Indexed: 12/29/2022] Open
Abstract
Germ cells undergo distinct nuclear processes as they differentiate into gametes. Although these events must be coordinated to ensure proper maturation, the stage-specific transport of proteins in and out of germ cell nuclei remains incompletely understood. Our efforts to genetically characterize Drosophila genes that exhibit enriched expression in germ cells led to the finding that loss of the highly conserved Importin β/karyopherin family member Importin-9 (Ipo9, herein referring to Ranbp9) results in female and male sterility. Immunofluorescence and fluorescent in situ hybridization revealed that Ipo9KO mutants display chromosome condensation and segregation defects during meiosis. In addition, Ipo9KO mutant males form abnormally structured sperm and fail to properly exchange histones for protamines. Ipo9 physically interacts with proteasome proteins, and Ipo9 mutant males exhibit disruption of the nuclear localization of several proteasome components. Thus, Ipo9 coordinates the nuclear import of functionally related factors necessary for the completion of gametogenesis. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Victor Palacios
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Garrett C Kimble
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Tina L Tootle
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Michael Buszczak
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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Mytlis A, Elkouby YM. Live and Time-Lapse Imaging of Early Oogenesis and Meiotic Chromosomal Dynamics in Cultured Juvenile Zebrafish Ovaries. Methods Mol Biol 2021; 2218:137-155. [PMID: 33606229 DOI: 10.1007/978-1-0716-0970-5_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Oocyte production is crucial for sexual reproduction. Recent findings in zebrafish and other established model organisms emphasize that the early steps of oogenesis involve the coordination of simultaneous and tightly sequential processes across cellular compartments and between sister cells. To fully understand the mechanistic framework of these coordinated processes, cellular and morphological analysis in high temporal resolution is required. Here, we provide a protocol for four-dimensional live time-lapse analysis of cultured juvenile zebrafish ovaries. We describe how multiple-stage oocytes can be simultaneously analyzed in single ovaries, and several ovaries can be processed in single experiments. In addition, we detail adequate conditions for quantitative image acquisition. Finally, we demonstrate that using this protocol, we successfully capture rapid meiotic chromosomal movements in early prophase for the first time in zebrafish oocytes, in four dimensions and in vivo. Our protocol expands the use of the zebrafish as a model system to understand germ cell and ovarian development in postembryonic stages.
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Affiliation(s)
- Avishag Mytlis
- Department of Developmental Biology and Cancer Research, The Hebrew University of Jerusalem, Faculty of Medicine, Institute for Medical Research - Israel-Canada (IMRIC), Jerusalem, Israel
| | - Yaniv M Elkouby
- Department of Developmental Biology and Cancer Research, The Hebrew University of Jerusalem, Faculty of Medicine, Institute for Medical Research - Israel-Canada (IMRIC), Jerusalem, Israel.
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42
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Flynn JM, Long M, Wing RA, Clark AG. Evolutionary Dynamics of Abundant 7-bp Satellites in the Genome of Drosophila virilis. Mol Biol Evol 2021; 37:1362-1375. [PMID: 31960929 DOI: 10.1093/molbev/msaa010] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The factors that drive the rapid changes in abundance of tandem arrays of highly repetitive sequences, known as satellite DNA, are not well understood. Drosophila virilis has one of the highest relative amounts of simple satellites of any organism that has been studied, with an estimated >40% of its genome composed of a few related 7-bp satellites. Here, we use D. virilis as a model to understand technical biases affecting satellite sequencing and the evolutionary processes that drive satellite composition. By analyzing sequencing data from Illumina, PacBio, and Nanopore platforms, we identify platform-specific biases and suggest best practices for accurate characterization of satellites by sequencing. We use comparative genomics and cytogenetics to demonstrate that the highly abundant AAACTAC satellite family arose from a related satellite in the branch leading to the virilis phylad 4.5-11 Ma before exploding in abundance in some species of the clade. The most abundant satellite is conserved in sequence and location in the pericentromeric region but has diverged widely in abundance among species, whereas the satellites nearest the centromere are rapidly turning over in sequence composition. By analyzing multiple strains of D. virilis, we saw that the abundances of two centromere-proximal satellites are anticorrelated along a geographical gradient, which we suggest could be caused by ongoing conflicts at the centromere. In conclusion, we illuminate several key attributes of satellite evolutionary dynamics that we hypothesize to be driven by processes including selection, meiotic drive, and constraints on satellite sequence and abundance.
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Affiliation(s)
- Jullien M Flynn
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY
| | - Manyuan Long
- Department of Ecology and Evolution, University of Chicago, Chicago, IL
| | - Rod A Wing
- School of Plant Sciences, Arizona Genomics Institute, University of Arizona, Tucson, AZ
| | - Andrew G Clark
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY
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43
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Oberhofer G, Ivy T, Hay BA. Split versions of Cleave and Rescue selfish genetic elements for measured self limiting gene drive. PLoS Genet 2021; 17:e1009385. [PMID: 33600432 PMCID: PMC7951863 DOI: 10.1371/journal.pgen.1009385] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 03/11/2021] [Accepted: 01/28/2021] [Indexed: 12/26/2022] Open
Abstract
Gene drive elements promote the spread of linked traits, providing methods for changing the composition or fate of wild populations. Drive mechanisms that are self-limiting are attractive because they allow control over the duration and extent of trait spread in time and space, and are reversible through natural selection as drive wanes. Self-sustaining Cleave and Rescue (ClvR) elements include a DNA sequence-modifying enzyme such as Cas9/gRNAs that disrupts endogenous versions of an essential gene, a tightly linked recoded version of the essential gene resistant to cleavage (the Rescue), and a Cargo. ClvR spreads by creating loss-of-function (LOF) conditions in which those without ClvR die because they lack functional copies of the essential gene. We use modeling to show that when the Rescue-Cargo and one or both components required for LOF allele creation (Cas9 and gRNA) reside at different locations (split ClvR), drive of Rescue-Cargo is self-limiting due to a progressive decrease in Cas9 frequency, and thus opportunities for creation of LOF alleles, as spread occurs. Importantly, drive strength and duration can be extended in a measured manner-which is still self-limiting-by moving the two components close enough to each other that they experience some degree of linkage. With linkage, Cas9 transiently experiences drive by hitchhiking with Rescue-Cargo until linkage disequilibrium between the two disappears, a function of recombination frequency and number of generations, creating a novel point of control. We implement split ClvR in Drosophila, with key elements on different chromosomes. Cargo/Rescue/gRNAs spreads to high frequency in a Cas9-dependent manner, while the frequency of Cas9 decreases. These observations show that measured, transient drive, coupled with a loss of future drive potential, can be achieved using the simple toolkit that make up ClvR elements-Cas9 and gRNAs and a Rescue/Cargo.
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Affiliation(s)
- Georg Oberhofer
- California Institute of Technology, Pasadena, California, United States of America
| | - Tobin Ivy
- California Institute of Technology, Pasadena, California, United States of America
| | - Bruce A. Hay
- California Institute of Technology, Pasadena, California, United States of America
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44
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Coelho VL, de Brito TF, de Abreu Brito IA, Cardoso MA, Berni MA, Araujo HMM, Sammeth M, Pane A. Analysis of ovarian transcriptomes reveals thousands of novel genes in the insect vector Rhodnius prolixus. Sci Rep 2021; 11:1918. [PMID: 33479356 PMCID: PMC7820597 DOI: 10.1038/s41598-021-81387-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 12/30/2020] [Indexed: 01/29/2023] Open
Abstract
Rhodnius prolixus is a Triatominae insect species and a primary vector of Chagas disease. The genome of R. prolixus has been recently sequenced and partially assembled, but few transcriptome analyses have been performed to date. In this study, we describe the stage-specific transcriptomes obtained from previtellogenic stages of oogenesis and from mature eggs. By analyzing ~ 228 million paired-end RNA-Seq reads, we significantly improved the current genome annotations for 9206 genes. We provide extended 5' and 3' UTRs, complete Open Reading Frames, and alternative transcript variants. Strikingly, using a combination of genome-guided and de novo transcriptome assembly we found more than two thousand novel genes, thus increasing the number of genes in R. prolixus from 15,738 to 17,864. We used the improved transcriptome to investigate stage-specific gene expression profiles during R. prolixus oogenesis. Our data reveal that 11,127 genes are expressed in the early previtellogenic stage of oogenesis and their transcripts are deposited in the developing egg including key factors regulating germline development, genome integrity, and the maternal-zygotic transition. In addition, GO term analyses show that transcripts encoding components of the steroid hormone receptor pathway, cytoskeleton, and intracellular signaling are abundant in the mature eggs, where they likely control early embryonic development upon fertilization. Our results significantly improve the R. prolixus genome and transcriptome and provide novel insight into oogenesis and early embryogenesis in this medically relevant insect.
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Affiliation(s)
- Vitor Lima Coelho
- Institute of Biomedical Sciences (ICB), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Maira Arruda Cardoso
- Institute of Biomedical Sciences (ICB), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Mateus Antonio Berni
- Institute of Biomedical Sciences (ICB), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Helena Maria Marcolla Araujo
- Institute of Biomedical Sciences (ICB), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Rio de Janeiro, Brazil
| | - Michael Sammeth
- Institute of Biophysics Carlos Chagas Filho (IBCCF), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Department of Applied Sciences, Institute of Bioanalysis, Coburg University, Coburg, Germany
| | - Attilio Pane
- Institute of Biomedical Sciences (ICB), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
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45
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Dattoli AA, Carty BL, Kochendoerfer AM, Morgan C, Walshe AE, Dunleavy EM. Asymmetric assembly of centromeres epigenetically regulates stem cell fate. J Cell Biol 2020; 219:133868. [PMID: 32328637 PMCID: PMC7147107 DOI: 10.1083/jcb.201910084] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/10/2019] [Accepted: 02/10/2020] [Indexed: 02/07/2023] Open
Abstract
Centromeres are epigenetically defined by CENP-A–containing chromatin and are essential for cell division. Previous studies suggest asymmetric inheritance of centromeric proteins upon stem cell division; however, the mechanism and implications of selective chromosome segregation remain unexplored. We show that Drosophila female germline stem cells (GSCs) and neuroblasts assemble centromeres after replication and before segregation. Specifically, CENP-A deposition is promoted by CYCLIN A, while excessive CENP-A deposition is prevented by CYCLIN B, through the HASPIN kinase. Furthermore, chromosomes inherited by GSCs incorporate more CENP-A, making stronger kinetochores that capture more spindle microtubules and bias segregation. Importantly, symmetric incorporation of CENP-A on sister chromatids via HASPIN knockdown or overexpression of CENP-A, either alone or together with its assembly factor CAL1, drives stem cell self-renewal. Finally, continued CENP-A assembly in differentiated cells is nonessential for egg development. Our work shows that centromere assembly epigenetically drives GSC maintenance and occurs before oocyte meiosis.
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Affiliation(s)
- Anna Ada Dattoli
- Centre for Chromosome Biology, Biomedical Sciences, National University of Ireland Galway, Galway, Ireland, UK
| | - Ben L Carty
- Centre for Chromosome Biology, Biomedical Sciences, National University of Ireland Galway, Galway, Ireland, UK
| | - Antje M Kochendoerfer
- Centre for Chromosome Biology, Biomedical Sciences, National University of Ireland Galway, Galway, Ireland, UK
| | - Conall Morgan
- Centre for Chromosome Biology, Biomedical Sciences, National University of Ireland Galway, Galway, Ireland, UK
| | - Annie E Walshe
- Centre for Chromosome Biology, Biomedical Sciences, National University of Ireland Galway, Galway, Ireland, UK
| | - Elaine M Dunleavy
- Centre for Chromosome Biology, Biomedical Sciences, National University of Ireland Galway, Galway, Ireland, UK
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46
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Tu R, Duan B, Song X, Chen S, Scott A, Hall K, Blanck J, DeGraffenreid D, Li H, Perera A, Haug J, Xie T. Multiple Niche Compartments Orchestrate Stepwise Germline Stem Cell Progeny Differentiation. Curr Biol 2020; 31:827-839.e3. [PMID: 33357404 DOI: 10.1016/j.cub.2020.12.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 11/17/2020] [Accepted: 12/15/2020] [Indexed: 11/28/2022]
Abstract
The niche controls stem cell self-renewal and progenitor differentiation for maintaining adult tissue homeostasis in various organisms. However, it remains unclear whether the niche is compartmentalized to control stem cell self-renewal and stepwise progeny differentiation. In the Drosophila ovary, inner germarial sheath (IGS) cells form a niche for controlling germline stem cell (GSC) progeny differentiation. In this study, we have identified four IGS subpopulations, which form linearly arranged niche compartments for controlling GSC maintenance and multi-step progeny differentiation. Single-cell analysis of the adult ovary has identified four IGS subpopulations (IGS1-IGS4), the identities and cellular locations of which have been further confirmed by fluorescent in situ hybridization. IGS1 and IGS2 physically interact with GSCs and mitotic cysts to control GSC maintenance and cyst formation, respectively, whereas IGS3 and IGS4 physically interact with 16-cell cysts to regulate meiosis, oocyte development, and cyst morphological change. Finally, one follicle cell progenitor population has also been transcriptionally defined for facilitating future studies on follicle stem cell regulation. Therefore, this study has structurally revealed that the niche is organized into multiple compartments for orchestrating stepwise adult stem cell development and has also provided useful resources and tools for further functional characterization of the niche in the future.
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Affiliation(s)
- Renjun Tu
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Bo Duan
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Xiaoqing Song
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Shiyuan Chen
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Allison Scott
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Kate Hall
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Jillian Blanck
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Dustin DeGraffenreid
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Hua Li
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Anoja Perera
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Jeff Haug
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Ting Xie
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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47
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Wei KHC, Mantha A, Bachtrog D. The Theory and Applications of Measuring Broad-Range and Chromosome-Wide Recombination Rate from Allele Frequency Decay around a Selected Locus. Mol Biol Evol 2020; 37:3654-3671. [PMID: 32658965 PMCID: PMC7743735 DOI: 10.1093/molbev/msaa171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Recombination is the exchange of genetic material between homologous chromosomes via physical crossovers. High-throughput sequencing approaches detect crossovers genome wide to produce recombination rate maps but are difficult to scale as they require large numbers of recombinants individually sequenced. We present a simple and scalable pooled-sequencing approach to experimentally infer near chromosome-wide recombination rates by taking advantage of non-Mendelian allele frequency generated from a fitness differential at a locus under selection. As more crossovers decouple the selected locus from distal loci, the distorted allele frequency attenuates distally toward Mendelian and can be used to estimate the genetic distance. Here, we use marker selection to generate distorted allele frequency and theoretically derive the mathematical relationships between allele frequency attenuation, genetic distance, and recombination rate in marker-selected pools. We implemented nonlinear curve-fitting methods that robustly estimate the allele frequency decay from batch sequencing of pooled individuals and derive chromosome-wide genetic distance and recombination rates. Empirically, we show that marker-selected pools closely recapitulate genetic distances inferred from scoring recombinants. Using this method, we generated novel recombination rate maps of three wild-derived strains of Drosophila melanogaster, which strongly correlate with previous measurements. Moreover, we show that this approach can be extended to estimate chromosome-wide crossover interference with reciprocal marker selection and discuss how it can be applied in the absence of visible markers. Altogether, we find that our method is a simple and cost-effective approach to generate chromosome-wide recombination rate maps requiring only one or two libraries.
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Affiliation(s)
- Kevin H-C Wei
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA
| | - Aditya Mantha
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA
| | - Doris Bachtrog
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA
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48
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Winbush A, Singh ND. Genomics of Recombination Rate Variation in Temperature-Evolved Drosophila melanogaster Populations. Genome Biol Evol 2020; 13:6008691. [PMID: 33247719 PMCID: PMC7851596 DOI: 10.1093/gbe/evaa252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Meiotic recombination is a critical process that ensures proper segregation of chromosome homologs through DNA double-strand break repair mechanisms. Rates of recombination are highly variable among various taxa, within species, and within genomes with far-reaching evolutionary and genomic consequences. The genetic basis of recombination rate variation is therefore crucial in the study of evolutionary biology but remains poorly understood. In this study, we took advantage of a set of experimental temperature-evolved populations of Drosophila melanogaster with heritable differences in recombination rates depending on the temperature regime in which they evolved. We performed whole-genome sequencing and identified several chromosomal regions that appear to be divergent depending on temperature regime. In addition, we identify a set of single-nucleotide polymorphisms and associated genes with significant differences in allele frequency when the different temperature populations are compared. Further refinement of these gene candidates emphasizing those expressed in the ovary and associated with DNA binding reveals numerous potential candidate genes such as Hr38, EcR, and mamo responsible for observed differences in recombination rates in these experimental evolution lines thus providing insight into the genetic basis of recombination rate variation.
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Affiliation(s)
- Ari Winbush
- Department of Biology, Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, USA
| | - Nadia D Singh
- Department of Biology, Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, USA
- Corresponding author: E-mail:
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49
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Cherezov RO, Vorontsova JE, Simonova OB. TBP-Related Factor 2 as a Trigger for Robertsonian Translocations and Speciation. Int J Mol Sci 2020; 21:E8871. [PMID: 33238614 PMCID: PMC7700478 DOI: 10.3390/ijms21228871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 11/16/2022] Open
Abstract
Robertsonian (centric-fusion) translocation is the form of chromosomal translocation in which two long arms of acrocentric chromosomes are fused to form one metacentric. These translocations reduce the number of chromosomes while preserving existing genes and are considered to contribute to speciation. We asked whether hypomorphic mutations in genes that disrupt the formation of pericentromeric regions could lead to centric fusion. TBP-related factor 2 (Trf2) encodes an alternative general transcription factor. A decrease of TRF2 expression disrupts the structure of the pericentromeric regions and prevents their association into chromocenter. We revealed several centric fusions in two lines of Drosophila melanogaster with weak Trf2 alleles in genetic experiments. We performed an RNAi-mediated knock-down of Trf2 in Drosophila and S2 cells and demonstrated that Trf2 upregulates expression of D1-one of the major genes responsible for chromocenter formation and nuclear integrity in Drosophila. Our data, for the first time, indicate that Trf2 may be involved in transcription program responsible for structuring of pericentromeric regions and may contribute to new karyotypes formation in particular by promoting centric fusion. Insight into the molecular mechanisms of Trf2 function and its new targets in different tissues will contribute to our understanding of its phenomenon.
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Affiliation(s)
| | | | - Olga B. Simonova
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Vavilova str. 26, 119991 Moscow, Russia; (R.O.C.); (J.E.V.)
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50
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Hsu SJ, Stow EC, Simmons JR, Wallace HA, Lopez AM, Stroud S, Labrador M. Mutations in the insulator protein Suppressor of Hairy wing induce genome instability. Chromosoma 2020; 129:255-274. [PMID: 33140220 DOI: 10.1007/s00412-020-00743-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 12/14/2022]
Abstract
Insulator proteins orchestrate the three-dimensional organization of the genome. Insulators function by facilitating communications between regulatory sequences and gene promoters, allowing accurate gene transcription regulation during embryo development and cell differentiation. However, the role of insulator proteins beyond genome organization and transcription regulation remains unclear. Suppressor of Hairy wing [Su(Hw)] is a Drosophila insulator protein that plays an important function in female oogenesis. Here we find that su(Hw) has an unsuspected role in genome stability during cell differentiation. We show that su(Hw) mutant developing egg chambers have poorly formed microtubule organization centers (MTOCs) in the germarium and display mislocalization of the anterior/posterior axis specification factor gurken in later oogenesis stages. Additionally, eggshells from partially rescued su(Hw) mutant female germline exhibit dorsoventral patterning defects. These phenotypes are very similar to phenotypes found in the important class of spindle mutants or in piRNA pathway mutants in Drosophila, in which defects generally result from the failure of germ cells to repair DNA damage. Similarities between mutations in su(Hw) and spindle and piRNA mutants are further supported by an excess of DNA damage in nurse cells, and because Gurken localization defects are partially rescued by mutations in the ATR (mei-41) and Chk1 (grapes) DNA damage response genes. Finally, we also show that su(Hw) mutants produce an elevated number of chromosome breaks in dividing neuroblasts from larval brains. Together, these findings suggest that Su(Hw) is necessary for the maintenance of genome integrity during Drosophila development, in both germline and dividing somatic cells.
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Affiliation(s)
- Shih-Jui Hsu
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Emily C Stow
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, 37996, USA
| | - James R Simmons
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Heather A Wallace
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Andrea Mancheno Lopez
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Shannon Stroud
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Mariano Labrador
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, 37996, USA.
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