1
|
Bladen J, Nam HJ, Phadnis N. Transformation of meiotic drive into hybrid sterility in Drosophila. Genetics 2024; 228:iyae133. [PMID: 39196789 DOI: 10.1093/genetics/iyae133] [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: 05/09/2024] [Accepted: 07/05/2024] [Indexed: 08/30/2024] Open
Abstract
Hybrid male sterility is one of the fastest evolving intrinsic reproductive barriers between recently isolated populations. A leading explanation for the evolution of hybrid male sterility involves genomic conflicts with meiotic drivers in the male germline. There are, however, few examples directly linking meiotic drive to hybrid sterility. In this study, we report that the Sex-Ratio chromosome of Drosophila pseudoobscura, which causes X-chromosome drive within the USA subspecies, causes near-complete male sterility when it is moved into the genetic background of the Bogota subspecies. In addition, we show that this new form of sterility is genetically distinct from the sterility of F1 hybrid males in crosses between USA males and Bogota females. Our observations provide a tractable study system where noncryptic drive within species is transformed into strong hybrid sterility between very young subspecies.
Collapse
Affiliation(s)
- Jackson Bladen
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Hyuck-Jin Nam
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Nitin Phadnis
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| |
Collapse
|
2
|
López Hernández JF, Rubinstein BY, Unckless RL, Zanders SE. Modeling the evolution of Schizosaccharomyces pombe populations with multiple killer meiotic drivers. G3 (BETHESDA, MD.) 2024; 14:jkae142. [PMID: 38938172 DOI: 10.1093/g3journal/jkae142] [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: 05/23/2024] [Revised: 05/23/2024] [Accepted: 06/03/2024] [Indexed: 06/29/2024]
Abstract
Meiotic drivers are selfish genetic loci that can be transmitted to more than half of the viable gametes produced by a heterozygote. This biased transmission gives meiotic drivers an evolutionary advantage that can allow them to spread over generations until all members of a population carry the driver. This evolutionary power can also be exploited to modify natural populations using synthetic drivers known as "gene drives." Recently, it has become clear that natural drivers can spread within genomes to birth multicopy gene families. To understand intragenomic spread of drivers, we model the evolution of 2 or more distinct meiotic drivers in a population. We employ the wtf killer meiotic drivers from Schizosaccharomyces pombe, which are multicopy in all sequenced isolates, as models. We find that a duplicate wtf driver identical to the parent gene can spread in a population unless, or until, the original driver is fixed. When the duplicate driver diverges to be distinct from the parent gene, we find that both drivers spread to fixation under most conditions, but both drivers can be lost under some conditions. Finally, we show that stronger drivers make weaker drivers go extinct in most, but not all, polymorphic populations with absolutely linked drivers. These results reveal the strong potential for natural meiotic drive loci to duplicate and diverge within genomes. Our findings also highlight duplication potential as a factor to consider in the design of synthetic gene drives.
Collapse
Affiliation(s)
| | - Boris Y Rubinstein
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Robert L Unckless
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS 66045, USA
| | - Sarah E Zanders
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
- Department of Cell Biology and Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
| |
Collapse
|
3
|
Berube B, Ernst E, Cahn J, Roche B, de Santis Alves C, Lynn J, Scheben A, Grimanelli D, Siepel A, Ross-Ibarra J, Kermicle J, Martienssen RA. Teosinte Pollen Drive guides maize diversification and domestication by RNAi. Nature 2024; 633:380-388. [PMID: 39112710 PMCID: PMC11390486 DOI: 10.1038/s41586-024-07788-0] [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] [Received: 06/14/2023] [Accepted: 07/04/2024] [Indexed: 08/17/2024]
Abstract
Selfish genetic elements contribute to hybrid incompatibility and bias or 'drive' their own transmission1,2. Chromosomal drive typically functions in asymmetric female meiosis, whereas gene drive is normally post-meiotic and typically found in males. Here, using single-molecule and single-pollen genome sequencing, we describe Teosinte Pollen Drive, an instance of gene drive in hybrids between maize (Zea mays ssp. mays) and teosinte mexicana (Z. mays ssp. mexicana) that depends on RNA interference (RNAi). 22-nucleotide small RNAs from a non-coding RNA hairpin in mexicana depend on Dicer-like 2 (Dcl2) and target Teosinte Drive Responder 1 (Tdr1), which encodes a lipase required for pollen viability. Dcl2, Tdr1 and the hairpin are in tight pseudolinkage on chromosome 5, but only when transmitted through the male. Introgression of mexicana into early cultivated maize is thought to have been critical to its geographical dispersal throughout the Americas3, and a tightly linked inversion in mexicana spans a major domestication sweep in modern maize4. A survey of maize traditional varieties and sympatric populations of teosinte mexicana reveals correlated patterns of admixture among unlinked genes required for RNAi on at least four chromosomes that are also subject to gene drive in pollen from synthetic hybrids. Teosinte Pollen Drive probably had a major role in maize domestication and diversification, and offers an explanation for the widespread abundance of 'self' small RNAs in the germ lines of plants and animals.
Collapse
Affiliation(s)
- Benjamin Berube
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Evan Ernst
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Jonathan Cahn
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Benjamin Roche
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | | | - Jason Lynn
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Armin Scheben
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | | | - Adam Siepel
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Jeffrey Ross-Ibarra
- Department of Evolution and Ecology, Center for Population Biology and Genome Center, University of California at Davis, Davis, CA, USA
| | - Jerry Kermicle
- Laboratory of Genetics, University of Wisconsin, Madison, WI, USA
| | - Robert A Martienssen
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
| |
Collapse
|
4
|
Bladen J, Nam HJ, Phadnis N. Transformation of meiotic drive into hybrid sterility in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.10.593569. [PMID: 38798315 PMCID: PMC11118531 DOI: 10.1101/2024.05.10.593569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Hybrid male sterility is one of the fastest evolving intrinsic reproductive barriers between recently isolated populations. A leading explanation for the evolution of hybrid male sterility involves genomic conflicts with meiotic drivers in the male germline. There are, however, few examples directly linking meiotic drive to hybrid sterility. Here, we report that the Sex-Ratio chromosome of Drosophila pseudoobscura, which causes X-chromosome drive within the USA subspecies, causes near complete male sterility when moved into the genetic background of the Bogota subspecies. In addition, we show that this new form of sterility is genetically distinct from the sterility of F1 hybrid males in crosses between USA males and Bogota females. Our observations provide a tractable study system where non-cryptic drive within species is transformed into strong hybrid sterility between very young subspecies.
Collapse
Affiliation(s)
- Jackson Bladen
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Hyuck-Jin Nam
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Nitin Phadnis
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| |
Collapse
|
5
|
Zheng JX, Du TY, Shao GC, Ma ZH, Jiang ZD, Hu W, Suo F, He W, Dong MQ, Du LL. Ubiquitination-mediated Golgi-to-endosome sorting determines the toxin-antidote duality of fission yeast wtf meiotic drivers. Nat Commun 2023; 14:8334. [PMID: 38097609 PMCID: PMC10721834 DOI: 10.1038/s41467-023-44151-9] [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: 05/20/2023] [Accepted: 12/01/2023] [Indexed: 12/17/2023] Open
Abstract
Killer meiotic drivers (KMDs) skew allele transmission in their favor by killing meiotic progeny not inheriting the driver allele. Despite their widespread presence in eukaryotes, the molecular mechanisms behind their selfish behavior are poorly understood. In several fission yeast species, single-gene KMDs belonging to the wtf gene family exert selfish killing by expressing a toxin and an antidote through alternative transcription initiation. Here we investigate how the toxin and antidote products of a wtf-family KMD gene can act antagonistically. Both the toxin and the antidote are multi-transmembrane proteins, differing only in their N-terminal cytosolic tails. We find that the antidote employs PY motifs (Leu/Pro-Pro-X-Tyr) in its N-terminal cytosolic tail to bind Rsp5/NEDD4 family ubiquitin ligases, which ubiquitinate the antidote. Mutating PY motifs or attaching a deubiquitinating enzyme transforms the antidote into a toxic protein. Ubiquitination promotes the transport of the antidote from the trans-Golgi network to the endosome, thereby preventing it from causing toxicity. A physical interaction between the antidote and the toxin enables the ubiquitinated antidote to translocate the toxin to the endosome and neutralize its toxicity. We propose that post-translational modification-mediated protein localization and/or activity changes may be a common mechanism governing the antagonistic duality of single-gene KMDs.
Collapse
Affiliation(s)
- Jin-Xin Zheng
- National Institute of Biological Sciences, Beijing, 102206, China
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Tong-Yang Du
- National Institute of Biological Sciences, Beijing, 102206, China
- College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Guang-Can Shao
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Zhu-Hui Ma
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Zhao-Di Jiang
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Wen Hu
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Fang Suo
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Wanzhong He
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, 102206, China
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, 102206, China.
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, 102206, China.
| |
Collapse
|
6
|
Coughlan JM. The role of conflict in shaping plant biodiversity. THE NEW PHYTOLOGIST 2023; 240:2210-2217. [PMID: 37667567 DOI: 10.1111/nph.19233] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 07/27/2023] [Indexed: 09/06/2023]
Abstract
Although intrinsic postzygotic reproductive barriers can play a fundamental role in speciation, their underlying evolutionary causes are widely debated. One hypothesis is that incompatibilities result from genomic conflicts. Here, I synthesize the evidence that conflict generates incompatibilities in plants, thus playing a creative role in plant biodiversity. While much evidence supports a role for conflict in several classes of incompatibility, integrating knowledge of incompatibility alleles with natural history can provide further essential tests. Moreover, comparative work can shed light on the relative importance of conflict in causing incompatibilities, including the extent to which their evolution is repeatable. Together, these approaches can provide independent lines of evidence that conflict causes incompatibilities, cementing its role in plant speciation.
Collapse
Affiliation(s)
- Jenn M Coughlan
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
| |
Collapse
|
7
|
Raban R, Marshall JM, Hay BA, Akbari OS. Manipulating the Destiny of Wild Populations Using CRISPR. Annu Rev Genet 2023; 57:361-390. [PMID: 37722684 PMCID: PMC11064769 DOI: 10.1146/annurev-genet-031623-105059] [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: 09/20/2023]
Abstract
Genetic biocontrol aims to suppress or modify populations of species to protect public health, agriculture, and biodiversity. Advancements in genome engineering technologies have fueled a surge in research in this field, with one gene editing technology, CRISPR, leading the charge. This review focuses on the current state of CRISPR technologies for genetic biocontrol of pests and highlights the progress and ongoing challenges of using these approaches.
Collapse
Affiliation(s)
- Robyn Raban
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California, San Diego, La Jolla, California, USA;
| | - John M Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, USA
| | - Bruce A Hay
- Division of Biology and Biological Engineering (BBE), California Institute of Technology, Pasadena, California, USA
| | - Omar S Akbari
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California, San Diego, La Jolla, California, USA;
| |
Collapse
|
8
|
You S, Zhao Z, Yu X, Zhu S, Wang J, Lei D, Zhou J, Li J, Chen H, Xiao Y, Chen W, Wang Q, Lu J, Chen K, Zhou C, Zhang X, Cheng Z, Guo X, Ren Y, Zheng X, Liu S, Liu X, Tian Y, Jiang L, Tao D, Wu C, Wan J. A toxin-antidote system contributes to interspecific reproductive isolation in rice. Nat Commun 2023; 14:7528. [PMID: 37980335 PMCID: PMC10657391 DOI: 10.1038/s41467-023-43015-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 09/18/2023] [Indexed: 11/20/2023] Open
Abstract
Breakdown of reproductive isolation facilitates flow of useful trait genes into crop plants from their wild relatives. Hybrid sterility, a major form of reproductive isolation exists between cultivated rice (Oryza sativa) and wild rice (O. meridionalis, Mer). Here, we report the cloning of qHMS1, a quantitative trait locus controlling hybrid male sterility between these two species. Like qHMS7, another locus we cloned previously, qHMS1 encodes a toxin-antidote system, but differs in the encoded proteins, their evolutionary origin, and action time point during pollen development. In plants heterozygous at qHMS1, ~ 50% of pollens carrying qHMS1-D (an allele from cultivated rice) are selectively killed. In plants heterozygous at both qHMS1 and qHMS7, ~ 75% pollens without co-presence of qHMS1-Mer and qHMS7-D are selectively killed, indicating that the antidotes function in a toxin-dependent manner. Our results indicate that different toxin-antidote systems provide stacked reproductive isolation for maintaining species identity and shed light on breakdown of hybrid male sterility.
Collapse
Affiliation(s)
- Shimin You
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Zhigang Zhao
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Xiaowen Yu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Shanshan Zhu
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China
| | - Jian Wang
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China
| | - Dekun Lei
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Jiawu Zhou
- Yunnan Seed Laboratory/Yunnan Key Laboratory for Rice Genetic Improvement, Food Crops Research Institute, Yunnan Academy of Agricultural Sciences (YAAS), Kunming, 650200, P. R. China
| | - Jing Li
- Yunnan Seed Laboratory/Yunnan Key Laboratory for Rice Genetic Improvement, Food Crops Research Institute, Yunnan Academy of Agricultural Sciences (YAAS), Kunming, 650200, P. R. China
| | - Haiyuan Chen
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Yanjia Xiao
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Weiwei Chen
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China
| | - Qiming Wang
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Jiayu Lu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Keyi Chen
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Chunlei Zhou
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Xin Zhang
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China
| | - Zhijun Cheng
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China
| | - Xiuping Guo
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China
| | - Yulong Ren
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China
| | - Xiaoming Zheng
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China
| | - Shijia Liu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Xi Liu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Yunlu Tian
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Ling Jiang
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China
| | - Dayun Tao
- Yunnan Seed Laboratory/Yunnan Key Laboratory for Rice Genetic Improvement, Food Crops Research Institute, Yunnan Academy of Agricultural Sciences (YAAS), Kunming, 650200, P. R. China.
| | - Chuanyin Wu
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China.
| | - Jianmin Wan
- State Key Laboratory for Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Zhongshan Biological Breeding Laboratory, Nanjing, 210095, China.
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China.
| |
Collapse
|
9
|
Berube B, Ernst E, Cahn J, Roche B, de Santis Alves C, Lynn J, Scheben A, Siepel A, Ross-Ibarra J, Kermicle J, Martienssen R. Teosinte Pollen Drive guides maize diversification and domestication by RNAi. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.12.548689. [PMID: 37503269 PMCID: PMC10370002 DOI: 10.1101/2023.07.12.548689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Meiotic drivers subvert Mendelian expectations by manipulating reproductive development to bias their own transmission. Chromosomal drive typically functions in asymmetric female meiosis, while gene drive is normally postmeiotic and typically found in males. Using single molecule and single-pollen genome sequencing, we describe Teosinte Pollen Drive, an instance of gene drive in hybrids between maize (Zea mays ssp. mays) and teosinte mexicana (Zea mays ssp. mexicana), that depends on RNA interference (RNAi). 22nt small RNAs from a non-coding RNA hairpin in mexicana depend on Dicer-Like 2 (Dcl2) and target Teosinte Drive Responder 1 (Tdr1), which encodes a lipase required for pollen viability. Dcl2, Tdr1, and the hairpin are in tight pseudolinkage on chromosome 5, but only when transmitted through the male. Introgression of mexicana into early cultivated maize is thought to have been critical to its geographical dispersal throughout the Americas, and a tightly linked inversion in mexicana spans a major domestication sweep in modern maize. A survey of maize landraces and sympatric populations of teosinte mexicana reveals correlated patterns of admixture among unlinked genes required for RNAi on at least 4 chromosomes that are also subject to gene drive in pollen from synthetic hybrids. Teosinte Pollen Drive likely played a major role in maize domestication and diversification, and offers an explanation for the widespread abundance of "self" small RNAs in the germlines of plants and animals.
Collapse
Affiliation(s)
- Benjamin Berube
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor NY11724
| | - Evan Ernst
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor NY11724
| | - Jonathan Cahn
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor NY11724
| | - Benjamin Roche
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor NY11724
| | | | - Jason Lynn
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor NY11724
| | - Armin Scheben
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor NY11724
| | - Adam Siepel
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor NY11724
| | - Jeffrey Ross-Ibarra
- Dept. of Evolution & Ecology, Center for Population Biology and Genome Center, University of California, Davis CA
| | - Jerry Kermicle
- Laboratory of Genetics, University of Wisconsin, Madison WI
| | - Rob Martienssen
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor NY11724
| |
Collapse
|
10
|
Long L, Xu W, Valencia F, Paaby AB, McGrath PT. A toxin-antidote selfish element increases fitness of its host. eLife 2023; 12:e81640. [PMID: 37874324 PMCID: PMC10629817 DOI: 10.7554/elife.81640] [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: 07/05/2022] [Accepted: 10/23/2023] [Indexed: 10/25/2023] Open
Abstract
Selfish genetic elements can promote their transmission at the expense of individual survival, creating conflict between the element and the rest of the genome. Recently, a large number of toxin-antidote (TA) post-segregation distorters have been identified in non-obligate outcrossing nematodes. Their origin and the evolutionary forces that keep them at intermediate population frequencies are poorly understood. Here, we study a TA element in Caenorhabditis elegans called zeel-1;peel-1. Two major haplotypes of this locus, with and without the selfish element, segregate in C. elegans. We evaluate the fitness consequences of the zeel-1;peel-1 element outside of its role in gene drive in non-outcrossing animals and demonstrate that loss of the toxin peel-1 decreased fitness of hermaphrodites and resulted in reductions in fecundity and body size. These findings suggest a biological role for peel-1 beyond toxin lethality. This work demonstrates that a TA element can provide a fitness benefit to its hosts either during their initial evolution or by being co-opted by the animals following their selfish spread. These findings guide our understanding on how TA elements can remain in a population where gene drive is minimized, helping resolve the mystery of prevalent TA elements in selfing animals.
Collapse
Affiliation(s)
- Lijiang Long
- School of Biological Sciences, Georgia Institute of TechnologyAtlantaUnited States
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of TechnologyAtlantaUnited States
| | - Wen Xu
- School of Biological Sciences, Georgia Institute of TechnologyAtlantaUnited States
| | - Francisco Valencia
- School of Biological Sciences, Georgia Institute of TechnologyAtlantaUnited States
| | - Annalise B Paaby
- School of Biological Sciences, Georgia Institute of TechnologyAtlantaUnited States
| | - Patrick T McGrath
- School of Biological Sciences, Georgia Institute of TechnologyAtlantaUnited States
- School of Physics, Georgia Institute of TechnologyAtlantaUnited States
| |
Collapse
|
11
|
Lai EC, Vogan AA. Proliferation and dissemination of killer meiotic drive loci. Curr Opin Genet Dev 2023; 82:102100. [PMID: 37625205 PMCID: PMC10900872 DOI: 10.1016/j.gde.2023.102100] [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: 04/14/2023] [Revised: 07/20/2023] [Accepted: 07/22/2023] [Indexed: 08/27/2023]
Abstract
Killer meiotic drive elements are selfish genetic entities that manipulate the sexual cycle to promote their own inheritance via destructive means. Two broad classes are sperm killers, typical of animals and plants, and spore killers, which are present in ascomycete fungi. Killer meiotic drive systems operate via toxins that destroy or disable meiotic products bearing the alternative allele. To avoid suicidal autotargeting, cells that bear these selfish elements must either lack the toxin target, or express an antidote. Historically, these systems were presumed to require large nonrecombining haplotypes to link multiple functional interacting loci. However, recent advances on fungal spore killers reveal that numerous systems are enacted by single genes, and similar molecular genetic studies in Drosophila pinpoint individual loci that distort gamete sex. Notably, many meiotic drivers duplicate readily, forming gene families that can have complex interactions within and between species, and providing substrates for their rapid functional diversification. Here, we summarize the known families of meiotic drivers in fungi and fruit flies, and highlight shared principles about their evolution and proliferation that promote the spread of these noxious genes.
Collapse
Affiliation(s)
- Eric C Lai
- Developmental Biology Program, Sloan Kettering Institute, 430 East 67th St, ROC-10, New York, NY 10065, USA.
| | - Aaron A Vogan
- Institute of Organismal Biology, Uppsala University, Norbyvägen 18D, Uppsala 752 36, Sweden.
| |
Collapse
|
12
|
Wang C, Wang J, Lu J, Xiong Y, Zhao Z, Yu X, Zheng X, Li J, Lin Q, Ren Y, Hu Y, He X, Li C, Zeng Y, Miao R, Guo M, Zhang B, Zhu Y, Zhang Y, Tang W, Wang Y, Hao B, Wang Q, Cheng S, He X, Yao B, Gao J, Zhu X, Yu H, Wang Y, Sun Y, Zhou C, Dong H, Ma X, Guo X, Liu X, Tian Y, Liu S, Wang C, Cheng Z, Jiang L, Zhou J, Guo H, Jiang L, Tao D, Chai J, Zhang W, Wang H, Wu C, Wan J. A natural gene drive system confers reproductive isolation in rice. Cell 2023; 186:3577-3592.e18. [PMID: 37499659 DOI: 10.1016/j.cell.2023.06.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 02/02/2023] [Accepted: 06/28/2023] [Indexed: 07/29/2023]
Abstract
Hybrid sterility restricts the utilization of superior heterosis of indica-japonica inter-subspecific hybrids. In this study, we report the identification of RHS12, a major locus controlling male gamete sterility in indica-japonica hybrid rice. We show that RHS12 consists of two genes (iORF3/DUYAO and iORF4/JIEYAO) that confer preferential transmission of the RHS12-i type male gamete into the progeny, thereby forming a natural gene drive. DUYAO encodes a mitochondrion-targeted protein that interacts with OsCOX11 to trigger cytotoxicity and cell death, whereas JIEYAO encodes a protein that reroutes DUYAO to the autophagosome for degradation via direct physical interaction, thereby detoxifying DUYAO. Evolutionary trajectory analysis reveals that this system likely formed de novo in the AA genome Oryza clade and contributed to reproductive isolation (RI) between different lineages of rice. Our combined results provide mechanistic insights into the genetic basis of RI as well as insights for strategic designs of hybrid rice breeding.
Collapse
Affiliation(s)
- Chaolong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jian Wang
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jiayu Lu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yehui Xiong
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhigang Zhao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaowen Yu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaoming Zheng
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jing Li
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Qibing Lin
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yulong Ren
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yang Hu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaodong He
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chao Li
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yonglun Zeng
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Rong Miao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Mali Guo
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Bosen Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ying Zhu
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Yunhui Zhang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Weijie Tang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yunlong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Benyuan Hao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Qiming Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Siqi Cheng
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaojuan He
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Bowen Yao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Junwen Gao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xufei Zhu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Hao Yu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yan Sun
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chunlei Zhou
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Hui Dong
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaoding Ma
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiuping Guo
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xi Liu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yunlu Tian
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Shijia Liu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chunming Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhijun Cheng
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Ling Jiang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Jiawu Zhou
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Huishan Guo
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Liwen Jiang
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Dayun Tao
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Jijie Chai
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Wei Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Haiyang Wang
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Chuanyin Wu
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Jianmin Wan
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| |
Collapse
|
13
|
Reinhardt JA, Baker RH, Zimin AV, Ladias C, Paczolt KA, Werren JH, Hayashi CY, Wilkinson GS. Impacts of Sex Ratio Meiotic Drive on Genome Structure and Function in a Stalk-Eyed Fly. Genome Biol Evol 2023; 15:evad118. [PMID: 37364298 PMCID: PMC10319772 DOI: 10.1093/gbe/evad118] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 06/02/2023] [Accepted: 06/15/2023] [Indexed: 06/28/2023] Open
Abstract
Stalk-eyed flies in the genus Teleopsis carry selfish genetic elements that induce sex ratio (SR) meiotic drive and impact the fitness of male and female carriers. Here, we assemble and describe a chromosome-level genome assembly of the stalk-eyed fly, Teleopsis dalmanni, to elucidate patterns of divergence associated with SR. The genome contains tens of thousands of transposable element (TE) insertions and hundreds of transcriptionally and insertionally active TE families. By resequencing pools of SR and ST males using short and long reads, we find widespread differentiation and divergence between XSR and XST associated with multiple nested inversions involving most of the SR haplotype. Examination of genomic coverage and gene expression data revealed seven X-linked genes with elevated expression and coverage in SR males. The most extreme and likely drive candidate involves an XSR-specific expansion of an array of partial copies of JASPer, a gene necessary for maintenance of euchromatin and associated with regulation of TE expression. In addition, we find evidence for rapid protein evolution between XSR and XST for testis expressed and novel genes, that is, either recent duplicates or lacking a Dipteran ortholog, including an X-linked duplicate of maelstrom, which is also involved in TE silencing. Overall, the evidence suggests that this ancient XSR polymorphism has had a variety of impacts on repetitive DNA and its regulation in this species.
Collapse
Affiliation(s)
| | - Richard H Baker
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, New York, USA
| | - Aleksey V Zimin
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Chloe Ladias
- Biology Department, State University of New York at Geneseo, Geneseo, New York, USA
| | - Kimberly A Paczolt
- Department of Biology, University of Maryland, College Park, Maryland, USA
| | - John H Werren
- Department of Biology, University of Rochester, Rochester, New York, USA
| | - Cheryl Y Hayashi
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, New York, USA
| | - Gerald S Wilkinson
- Department of Biology, University of Maryland, College Park, Maryland, USA
| |
Collapse
|
14
|
Brysch-Herzberg M, Jia GS, Sipiczki M, Seidel M, Li W, Assali I, Du LL. Schizosaccharomyces lindneri sp. nov., a fission yeast occurring in honey. Yeast 2023. [PMID: 37243506 DOI: 10.1002/yea.3857] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/26/2023] [Accepted: 04/30/2023] [Indexed: 05/29/2023] Open
Abstract
Two strains of fission yeast were isolated from honey. They differ from the type strain of Schizosaccharomyces octosporus by three substitutions in the D1/D2 domain of the nuclear 26S large subunit ribosomal RNA (rRNA) gene sequence, resulting in a 99.5% identity. In the internal transcribed spacer (ITS) region (consisting of ITS1, 5.8S rDNA, and ITS2), the strains differ from S. octosporus by 16 gaps and 91 substitutions, which is equivalent to an identity of 88.1%. Genome sequencing on one of the new strains revealed that the average nucleotide identity (ANI) between its genome and the reference genome of S. octosporus is 90.43% and there exist major genome rearrangements between the two genomes. Mating analysis revealed that S. octosporus and one of the new strains are completely reproductively separated. A strong prezygotic barrier exists and the few mating products consist of diploid hybrids that do not form recombinant ascospores. In the new strains, asci are either zygotic, arising from conjugation, or they develop without conjugation from asexual cells (azygotic). Compared to the currently recognized Schizosaccharomyces species, the spectrum of nutrients that are assimilated by the new strains is restricted. Of the 43 carbohydrates that were included in the physiological standard tests, only 7 were assimilated. According to the results of the genome sequence analysis, the mating trials, and the phenotypic characterization, the new species Schizosaccharomyces lindneri is described to accommodate the two strains (holotype: CBS 18203T and ex-type: MUCL 58363; MycoBank no.: MB 847838).
Collapse
Affiliation(s)
- Michael Brysch-Herzberg
- Laboratory for Wine Microbiology, Department International Business, Heilbronn University of Applied Sciences, Heilbronn, Germany
| | - Guo-Song Jia
- National Institute of Biological Sciences, Beijing, China
| | - Matthias Sipiczki
- Department of Genetics and Applied Microbiology, University of Debrecen, Debrecen, Hungary
| | - Martin Seidel
- Laboratory for Wine Microbiology, Department International Business, Heilbronn University of Applied Sciences, Heilbronn, Germany
| | - Wen Li
- National Institute of Biological Sciences, Beijing, China
| | - Imen Assali
- Laboratory for Wine Microbiology, Department International Business, Heilbronn University of Applied Sciences, Heilbronn, Germany
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| |
Collapse
|
15
|
Jia GS, Zhang WC, Liang Y, Liu XH, Rhind N, Pidoux A, Brysch-Herzberg M, Du LL. A high-quality reference genome for the fission yeast Schizosaccharomyces osmophilus. G3 (BETHESDA, MD.) 2023; 13:jkad028. [PMID: 36748990 PMCID: PMC10085805 DOI: 10.1093/g3journal/jkad028] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/23/2023] [Accepted: 01/23/2023] [Indexed: 02/08/2023]
Abstract
Fission yeasts are an ancient group of fungal species that diverged from each other from tens to hundreds of million years ago. Among them is the preeminent model organism Schizosaccharomyces pombe, which has significantly contributed to our understandings of molecular mechanisms underlying fundamental cellular processes. The availability of the genomes of S. pombe and 3 other fission yeast species S. japonicus, S. octosporus, and S. cryophilus has enabled cross-species comparisons that provide insights into the evolution of genes, pathways, and genomes. Here, we performed genome sequencing on the type strain of the recently identified fission yeast species S. osmophilus and obtained a complete mitochondrial genome and a nuclear genome assembly with gaps only at rRNA gene arrays. A total of 5,098 protein-coding nuclear genes were annotated and orthologs for more than 95% of them were identified. Genome-based phylogenetic analysis showed that S. osmophilus is most closely related to S. octosporus and these 2 species diverged around 16 million years ago. To demonstrate the utility of this S. osmophilus reference genome, we conducted cross-species comparative analyses of centromeres, telomeres, transposons, the mating-type region, Cbp1 family proteins, and mitochondrial genomes. These analyses revealed conservation of repeat arrangements and sequence motifs in centromere cores, identified telomeric sequences composed of 2 types of repeats, delineated relationships among Tf1/sushi group retrotransposons, characterized the evolutionary origins and trajectories of Cbp1 family domesticated transposases, and discovered signs of interspecific transfer of 2 types of mitochondrial selfish elements.
Collapse
Affiliation(s)
- Guo-Song Jia
- National Institute of Biological Sciences, Beijing 102206, China
| | - Wen-Cai Zhang
- National Institute of Biological Sciences, Beijing 102206, China
| | - Yue Liang
- National Institute of Biological Sciences, Beijing 102206, China
| | - Xi-Han Liu
- National Institute of Biological Sciences, Beijing 102206, China
| | - Nicholas Rhind
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Alison Pidoux
- Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Michael Brysch-Herzberg
- Laboratory for Wine Microbiology, Department International Business, Heilbronn University, Heilbronn 74081, Germany
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| |
Collapse
|
16
|
Arcangioli B, Gangloff S. The Fission Yeast Mating-Type Switching Motto: "One-for-Two" and "Two-for-One". Microbiol Mol Biol Rev 2023; 87:e0000821. [PMID: 36629411 PMCID: PMC10029342 DOI: 10.1128/mmbr.00008-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Schizosaccharomyces pombe is an ascomycete fungus that divides by medial fission; it is thus commonly referred to as fission yeast, as opposed to the distantly related budding yeast Saccharomyces cerevisiae. The reproductive lifestyle of S. pombe relies on an efficient genetic sex determination system generating a 1:1 sex ratio and using alternating haploid/diploid phases in response to environmental conditions. In this review, we address how one haploid cell manages to generate two sister cells with opposite mating types, a prerequisite to conjugation and meiosis. This mating-type switching process depends on two highly efficient consecutive asymmetric cell divisions that rely on DNA replication, repair, and recombination as well as the structure and components of heterochromatin. We pay special attention to the intimate interplay between the genetic and epigenetic partners involved in this process to underscore the importance of basic research and its profound implication for a better understanding of chromatin biology.
Collapse
Affiliation(s)
- Benoît Arcangioli
- Genome Dynamics Unit, Genomes and Genetics Department, Pasteur Institute, Paris, France
| | - Serge Gangloff
- Genome Dynamics Unit, Genomes and Genetics Department, Pasteur Institute, Paris, France
- UMR3525, Genetics of Genomes, CNRS-Pasteur Institute, Paris, France
| |
Collapse
|
17
|
A Natural Fungal Gene Drive Enacts Killing via DNA Disruption. mBio 2023; 14:e0317322. [PMID: 36537809 PMCID: PMC9972908 DOI: 10.1128/mbio.03173-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Fungal spore killers are a class of selfish genetic elements that positively bias their own inheritance by killing non-inheriting gametes following meiosis. As killing takes place specifically within the developing fungal ascus, a tissue which is experimentally difficult to isolate, our understanding of the mechanisms underlying spore killers are limited. In particular, how these loci kill other spores within the fungal ascus is largely unknown. Here, we overcome these experimental barriers by developing model systems in 2 evolutionary distant organisms, Escherichia coli (bacterium) and Saccharomyces cerevisiae (yeast), similar to previous approaches taken to examine the wtf spore killers. Using these systems, we show that the Podospora anserina spore killer protein SPOK1 enacts killing through targeting DNA. IMPORTANCE Natural gene drives have shaped the genomes of many eukaryotes and recently have been considered for applications to control undesirable species. In fungi, these loci are called spore killers. Despite their importance in evolutionary processes and possible applications, our understanding of how they enact killing is limited. We show that the spore killer protein Spok1, which has homologues throughout the fungal tree of life, acts via DNA disruption. Spok1 is only the second spore killer locus in which the cellular target of killing has been identified and is the first known to target DNA. We also show that the DNA disrupting activity of Spok1 is functional in both bacteria and yeast suggesting a highly conserved mode of action.
Collapse
|
18
|
Chou JY, Hsu PC, Leu JY. Enforcement of Postzygotic Species Boundaries in the Fungal Kingdom. Microbiol Mol Biol Rev 2022; 86:e0009822. [PMID: 36098649 PMCID: PMC9769731 DOI: 10.1128/mmbr.00098-22] [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: 01/01/2023] Open
Abstract
Understanding the molecular basis of speciation is a primary goal in evolutionary biology. The formation of the postzygotic reproductive isolation that causes hybrid dysfunction, thereby reducing gene flow between diverging populations, is crucial for speciation. Using various advanced approaches, including chromosome replacement, hybrid introgression and transcriptomics, population genomics, and experimental evolution, scientists have revealed multiple mechanisms involved in postzygotic barriers in the fungal kingdom. These results illuminate both unique and general features of fungal speciation. Our review summarizes experiments on fungi exploring how Dobzhansky-Muller incompatibility, killer meiotic drive, chromosome rearrangements, and antirecombination contribute to postzygotic reproductive isolation. We also discuss possible evolutionary forces underlying different reproductive isolation mechanisms and the potential roles of the evolutionary arms race under the Red Queen hypothesis and epigenetic divergence in speciation.
Collapse
Affiliation(s)
- Jui-Yu Chou
- Department of Biology, National Changhua University of Education, Changhua, Taiwan
| | - Po-Chen Hsu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Jun-Yi Leu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| |
Collapse
|
19
|
De Carvalho M, Jia GS, Nidamangala Srinivasa A, Billmyre RB, Xu YH, Lange JJ, Sabbarini IM, Du LL, Zanders SE. The wtf meiotic driver gene family has unexpectedly persisted for over 100 million years. eLife 2022; 11:e81149. [PMID: 36227631 PMCID: PMC9562144 DOI: 10.7554/elife.81149] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/21/2022] [Indexed: 11/21/2022] Open
Abstract
Meiotic drivers are selfish elements that bias their own transmission into more than half of the viable progeny produced by a driver+/driver- heterozygote. Meiotic drivers are thought to exist for relatively short evolutionary timespans because a driver gene or gene family is often found in a single species or in a group of very closely related species. Additionally, drivers are generally considered doomed to extinction when they spread to fixation or when suppressors arise. In this study, we examine the evolutionary history of the wtf meiotic drivers first discovered in the fission yeast Schizosaccharomyces pombe. We identify homologous genes in three other fission yeast species, S. octosporus, S. osmophilus, and S. cryophilus, which are estimated to have diverged over 100 million years ago from the S. pombe lineage. Synteny evidence supports that wtf genes were present in the common ancestor of these four species. Moreover, the ancestral genes were likely drivers as wtf genes in S. octosporus cause meiotic drive. Our findings indicate that meiotic drive systems can be maintained for long evolutionary timespans.
Collapse
Affiliation(s)
- Mickaël De Carvalho
- Stowers Institute for Medical ResearchKansas CityUnited States
- Open UniversityMilton KeynesUnited Kingdom
| | - Guo-Song Jia
- PTN Joint Graduate Program, School of Life Sciences, Tsinghua UniversityBeijingChina
- National Institute of Biological Sciences, BeijingBeijingChina
| | - Ananya Nidamangala Srinivasa
- Stowers Institute for Medical ResearchKansas CityUnited States
- Department of Molecular and Integrative Physiology, University of Kansas Medical CenterKansas CityUnited States
| | | | - Yan-Hui Xu
- National Institute of Biological Sciences, BeijingBeijingChina
| | - Jeffrey J Lange
- Stowers Institute for Medical ResearchKansas CityUnited States
| | | | - Li-Lin Du
- National Institute of Biological Sciences, BeijingBeijingChina
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua UniversityBeijingChina
| | - Sarah E Zanders
- Stowers Institute for Medical ResearchKansas CityUnited States
- Department of Molecular and Integrative Physiology, University of Kansas Medical CenterKansas CityUnited States
| |
Collapse
|
20
|
Abstract
Spore killers are specific genetic elements in fungi that kill sexual spores that do not contain them. A range of studies in the last few years have provided the long-awaited first insights into the molecular mechanistic aspects of spore killing in different fungal models, including both yeast-forming and filamentous Ascomycota. Here we describe these recent advances, focusing on the wtf system in the fission yeast Schizosaccharomyces pombe; the Sk spore killers of Neurospora species; and two spore-killer systems in Podospora anserina, Spok and [Het-s]. The spore killers appear thus far mechanistically unrelated. They can involve large genomic rearrangements but most often rely on the action of just a single gene. Data gathered so far show that the protein domains involved in the killing and resistance processes differ among the systems and are not homologous. The emerging picture sketched by these studies is thus one of great mechanistic and evolutionary diversity of elements that cheat during meiosis and are thereby preferentially inherited over sexual generations.
Collapse
Affiliation(s)
- Sven J Saupe
- Institut de Biochimie et de Génétique Cellulaire, CNRS UMR 5095, Université de Bordeaux, Bordeaux, France;
| | - Hanna Johannesson
- Department of Organismal Biology, Uppsala University, Uppsala, Sweden;
| |
Collapse
|
21
|
Komluski J, Stukenbrock EH, Habig M. Non-Mendelian transmission of accessory chromosomes in fungi. Chromosome Res 2022; 30:241-253. [PMID: 35881207 PMCID: PMC9508043 DOI: 10.1007/s10577-022-09691-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/15/2022] [Accepted: 04/11/2022] [Indexed: 11/27/2022]
Abstract
Non-Mendelian transmission has been reported for various genetic elements, ranging from small transposons to entire chromosomes. One prime example of such a transmission pattern are B chromosomes in plants and animals. Accessory chromosomes in fungi are similar to B chromosomes in showing presence/absence polymorphism and being non-essential. How these chromosomes are transmitted during meiosis is however poorly understood—despite their often high impact on the fitness of the host. For several fungal organisms, a non-Mendelian transmission or a mechanistically unique meiotic drive of accessory chromosomes have been reported. In this review, we provide an overview of the possible mechanisms that can cause the non-Mendelian transmission or meiotic drives of fungal accessory chromosomes. We compare processes responsible for the non-Mendelian transmission of accessory chromosomes for different fungal eukaryotes and discuss the structural traits of fungal accessory chromosomes affecting their meiotic transmission. We conclude that research on fungal accessory chromosomes, due to their small size, ease of sequencing, and epigenetic profiling, can complement the study of B chromosomes in deciphering factors that influence and regulate the non-Mendelian transmission of entire chromosomes.
Collapse
Affiliation(s)
- Jovan Komluski
- Environmental Genomics, Christian-Albrechts University of Kiel, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Eva H Stukenbrock
- Environmental Genomics, Christian-Albrechts University of Kiel, Kiel, Germany.
- Max Planck Institute for Evolutionary Biology, Plön, Germany.
| | - Michael Habig
- Environmental Genomics, Christian-Albrechts University of Kiel, Kiel, Germany.
- Max Planck Institute for Evolutionary Biology, Plön, Germany.
| |
Collapse
|
22
|
Brud E. Adaptive meiotic drive in selfing populations with heterozygote advantage. Theor Popul Biol 2022; 146:61-70. [PMID: 35839925 DOI: 10.1016/j.tpb.2022.06.001] [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: 06/11/2019] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 10/17/2022]
Abstract
The egalitarian allotment of gametes to each allele at a locus (Mendel's law of segregation) is a near-universal phenomenon characterizing inheritance in sexual populations. As exceptions to Mendel's law are known to occur, one can investigate why non-Mendelian segregation is not more common using modifier theory. Earlier work assuming sex-independent modifier effects in a random mating population with heterozygote advantage concluded that equal segregation is stable over long-term evolution. Subsequent investigation, however, demonstrated that the stability of the Mendelian scheme disappears when sex-specific modifier effects are allowed. Here I derive invasion conditions favoring the repeal of Mendelian law in mixed and obligate selfing populations. Oppositely-directed segregation distortion in the production of male and female gametes is selected for in the presence of overdominant fitness. The conditions are less restrictive than under panmixia in that strong selection can occur even without differential viability of reciprocal heterozygotes (i.e. in the absence of parent-of-origin effects at the overdominant fitness locus). Generalized equilibria are derived for full selfing.
Collapse
Affiliation(s)
- Evgeny Brud
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY, 11790, United States of America.
| |
Collapse
|
23
|
Simon M, Durand S, Ricou A, Vrielynck N, Mayjonade B, Gouzy J, Boyer R, Roux F, Camilleri C, Budar F. APOK3, a pollen killer antidote in Arabidopsis thaliana. Genetics 2022; 221:6603116. [PMID: 35666201 DOI: 10.1093/genetics/iyac089] [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: 04/28/2022] [Accepted: 05/27/2022] [Indexed: 11/14/2022] Open
Abstract
The principles of heredity state that the two alleles carried by a heterozygote are equally transmitted to the progeny. However, genomic regions that escape this rule have been reported in many organisms. It is notably the case of genetic loci referred to as gamete killers, where one allele enhances its transmission by causing the death of the gametes that do not carry it. Gamete killers are of great interest, particularly to understand mechanisms of evolution and speciation. Although being common in plants, only a few, all in rice, have so far been deciphered to the causal genes. Here, we studied a pollen killer found in hybrids between two accessions of Arabidopsis thaliana. Exploring natural variation, we observed this pollen killer in many crosses within the species. Genetic analyses revealed that three genetically linked elements are necessary for pollen killer activity. Using mutants, we showed that this pollen killer works according to a poison-antidote model, where the poison kills pollen grains not producing the antidote. We identified the gene encoding the antidote, a chimeric protein addressed to mitochondria. De novo genomic sequencing in twelve natural variants with different behaviors regarding the pollen killer revealed a hyper variable locus, with important structural variations particularly in killer genotypes, where the antidote gene recently underwent duplications. Our results strongly suggest that the gene has newly evolved within A. thaliana. Finally, we identified in the protein sequence polymorphisms related to its antidote activity.
Collapse
Affiliation(s)
- Matthieu Simon
- Université Paris-Saclay,INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000, Versailles, France
| | - Stéphanie Durand
- Université Paris-Saclay,INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000, Versailles, France
| | - Anthony Ricou
- Université Paris-Saclay,INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000, Versailles, France
| | - Nathalie Vrielynck
- Université Paris-Saclay,INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000, Versailles, France
| | | | - Jérôme Gouzy
- LIPME,Université de Toulouse,INRAE,CNRS, 31326 Castanet-Tolosan, France
| | - Roxane Boyer
- INRAE, GeT-PlaGe, Genotoul, 31326 Castanet-Tolosan, France(doi : 10.15454/1.5572370921303193E12)
| | - Fabrice Roux
- LIPME,Université de Toulouse,INRAE,CNRS, 31326 Castanet-Tolosan, France
| | - Christine Camilleri
- Université Paris-Saclay,INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000, Versailles, France
| | - Françoise Budar
- Université Paris-Saclay,INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000, Versailles, France
| |
Collapse
|
24
|
Vogan AA, Martinossi-Allibert I, Ament-Velásquez SL, Svedberg J, Johannesson H. The spore killers, fungal meiotic driver elements. Mycologia 2022; 114:1-23. [PMID: 35138994 DOI: 10.1080/00275514.2021.1994815] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
During meiosis, both alleles of any given gene should have equal chances of being inherited by the progeny. There are a number of reasons why, however, this is not the case, with one of the most intriguing instances presenting itself as the phenomenon of meiotic drive. Genes that are capable of driving can manipulate the ratio of alleles among viable meiotic products so that they are inherited in more than half of them. In many cases, this effect is achieved by direct antagonistic interactions, where the driving allele inhibits or otherwise eliminates the alternative allele. In ascomycete fungi, meiotic products are packaged directly into ascospores; thus, the effect of meiotic drive has been given the nefarious moniker, "spore killing." In recent years, many of the known spore killers have been elevated from mysterious phenotypes to well-described systems at genetic, genomic, and molecular levels. In this review, we describe the known diversity of spore killers and synthesize the varied pieces of data from each system into broader trends regarding genome architecture, mechanisms of resistance, the role of transposable elements, their effect on population dynamics, speciation and gene flow, and finally how they may be developed as synthetic drivers. We propose that spore killing is common, but that it is under-observed because of a lack of studies on natural populations. We encourage researchers to seek new spore killers to build on the knowledge that these remarkable genetic elements can teach us about meiotic drive, genomic conflict, and evolution more broadly.
Collapse
Affiliation(s)
- Aaron A Vogan
- Systematic Biology, Department of Organismal Biology, Uppsala University, 752 36, Uppsala, Sweden
| | - Ivain Martinossi-Allibert
- Systematic Biology, Department of Organismal Biology, Uppsala University, 752 36, Uppsala, Sweden.,Institut de Biochimie et de Génétique Cellulaire, UMR 5095 CNRS, Université de Bordeaux, 33077, Bordeaux CEDEX, France
| | - S Lorena Ament-Velásquez
- Systematic Biology, Department of Organismal Biology, Uppsala University, 752 36, Uppsala, Sweden
| | - Jesper Svedberg
- Department of Biomolecular Engineering, University of California, -Santa Cruz, Santa Cruz, California 95064
| | - Hanna Johannesson
- Systematic Biology, Department of Organismal Biology, Uppsala University, 752 36, Uppsala, Sweden
| |
Collapse
|
25
|
Kelemen RK, Elkrewi M, Lindholm AK, Vicoso B. Novel patterns of expression and recruitment of new genes on the t-haplotype, a mouse selfish chromosome. Proc Biol Sci 2022; 289:20211985. [PMID: 35135349 PMCID: PMC8826135 DOI: 10.1098/rspb.2021.1985] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The t-haplotype of mice is a classical model for autosomal transmission distortion. A largely non-recombining variant of the proximal region of chromosome 17, it is transmitted to more than 90% of the progeny of heterozygous males through the disabling of sperm carrying a standard chromosome. While extensive genetic and functional work has shed light on individual genes involved in drive, much less is known about the evolution and function of the rest of its hundreds of genes. Here, we characterize the sequence and expression of dozens of t-specific transcripts and of their chromosome 17 homologues. Many genes showed reduced expression of the t-allele, but an equal number of genes showed increased expression of their t-copy, consistent with increased activity or a newly evolved function. Genes on the t-haplotype had a significantly higher non-synonymous substitution rate than their homologues on the standard chromosome, with several genes harbouring dN/dS ratios above 1. Finally, the t-haplotype has acquired at least two genes from other chromosomes, which show high and tissue-specific expression. These results provide a first overview of the gene content of this selfish element, and support a more dynamic evolutionary scenario than expected of a large genomic region with almost no recombination.
Collapse
Affiliation(s)
- Reka K. Kelemen
- Institute of Science and Technology Austria, Am Campus, 1, 3400 Klosterneuburg, Austria
| | - Marwan Elkrewi
- Institute of Science and Technology Austria, Am Campus, 1, 3400 Klosterneuburg, Austria
| | - Anna K. Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse, 190, 8057 Zurich, Switzerland
| | - Beatriz Vicoso
- Institute of Science and Technology Austria, Am Campus, 1, 3400 Klosterneuburg, Austria
| |
Collapse
|
26
|
Zanders S, Johannesson H. Molecular Mechanisms and Evolutionary Consequences of Spore Killers in Ascomycetes. Microbiol Mol Biol Rev 2021; 85:e0001621. [PMID: 34756084 PMCID: PMC8579966 DOI: 10.1128/mmbr.00016-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In this review, we examine the fungal spore killers. These are meiotic drive elements that cheat during sexual reproduction to increase their transmission into the next generation. Spore killing has been detected in a number of ascomycete genera, including Podospora, Neurospora, Schizosaccharomyces, Bipolaris, and Fusarium. There have been major recent advances in spore killer research that have increased our understanding of the molecular identity, function, and evolutionary history of the known killers. The spore killers vary in the mechanism by which they kill and are divided into killer-target and poison-antidote drivers. In killer-target systems, the drive locus encodes an element that can be described as a killer, while the target is an allele found tightly linked to the drive locus but on the nondriving haplotype. The poison-antidote drive systems encode both a poison and an antidote element within the drive locus. The key to drive in this system is the restricted distribution of the antidote: only the spores that inherit the drive locus receive the antidote and are rescued from the toxicity of the poison. Spore killers also vary in their genome architecture and can consist of a single gene or multiple linked genes. Due to their ability to distort meiosis, spore killers gain a selective advantage at the gene level that allows them to increase in frequency in a population over time, even if they reduce host fitness, and they may have significant impact on genome architecture and macroevolutionary processes such as speciation.
Collapse
Affiliation(s)
- Sarah Zanders
- Stowers Institute for Medical Research, Kansas City, Kansas, USA
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Hanna Johannesson
- Department of Organismal Biology, Uppsala University, Uppsala, Sweden
| |
Collapse
|
27
|
López Hernández JF, Helston RM, Lange JJ, Billmyre RB, Schaffner SH, Eickbush MT, McCroskey S, Zanders SE. Diverse mating phenotypes impact the spread of wtf meiotic drivers in Schizosaccharomyces pombe. eLife 2021; 10:e70812. [PMID: 34895466 PMCID: PMC8789285 DOI: 10.7554/elife.70812] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 12/10/2021] [Indexed: 11/13/2022] Open
Abstract
Meiotic drivers are genetic elements that break Mendel's law of segregation to be transmitted into more than half of the offspring produced by a heterozygote. The success of a driver relies on outcrossing (mating between individuals from distinct lineages) because drivers gain their advantage in heterozygotes. It is, therefore, curious that Schizosaccharomyces pombe, a species reported to rarely outcross, harbors many meiotic drivers. To address this paradox, we measured mating phenotypes in S. pombe natural isolates. We found that the propensity for cells from distinct clonal lineages to mate varies between natural isolates and can be affected both by cell density and by the available sexual partners. Additionally, we found that the observed levels of preferential mating between cells from the same clonal lineage can slow, but not prevent, the spread of a wtf meiotic driver in the absence of additional fitness costs linked to the driver. These analyses reveal parameters critical to understanding the evolution of S. pombe and help explain the success of meiotic drivers in this species.
Collapse
Affiliation(s)
| | | | - Jeffrey J Lange
- Stowers Institute for Medical ResearchKansas CityUnited States
| | | | - Samantha H Schaffner
- Stowers Institute for Medical ResearchKansas CityUnited States
- Kenyon CollegeGambierUnited States
| | | | - Scott McCroskey
- Stowers Institute for Medical ResearchKansas CityUnited States
| | - Sarah E Zanders
- Stowers Institute for Medical ResearchKansas CityUnited States
- Department of Molecular and Integrative Physiology, University of Kansas Medical CenterKansas CityUnited States
| |
Collapse
|
28
|
Abstract
Sex, as well as meiotic recombination between homologous chromosomes, is nearly ubiquitous among eukaryotes. In those species that use it, recombination is important for chromosome segregation during gamete production, and thus for fertility. Strikingly, although in most species only one crossover event per chromosome is required to ensure proper segregation, recombination rates vary considerably above this minimum and show variation within and among species. However, whether this variation in recombination is adaptive or neutral and what might shape it remain unclear. Empirical studies and theory support the idea that recombination is generally beneficial but can also have costs. Here, we review variation in genome-wide recombination rates, explore what might cause this, and discuss what is known about its mechanistic basis. We end by discussing the environmental sensitivity of meiosis and recombination rates, how these features may relate to adaptation, and their implications for a broader understanding of recombination rate evolution. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
Affiliation(s)
- Ian R Henderson
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom;
| | - Kirsten Bomblies
- Plant Evolutionary Genetics, Institute of Molecular Plant Biology, Department of Biology, ETH Zürich, 8092 Zürich, Switzerland;
| |
Collapse
|
29
|
Martinossi-Allibert I, Veller C, Ament-Velásquez SL, Vogan AA, Rueffler C, Johannesson H. Invasion and maintenance of meiotic drivers in populations of ascomycete fungi. Evolution 2021; 75:1150-1169. [PMID: 33764512 DOI: 10.1111/evo.14214] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 02/25/2021] [Indexed: 12/30/2022]
Abstract
Meiotic drivers (MDs) are selfish genetic elements that are able to become overrepresented among the products of meiosis. This transmission advantage makes it possible for them to spread in a population even when they impose fitness costs on their host organisms. Whether an MD can invade a population, and subsequently reach fixation or coexist in a stable polymorphism, depends on the one hand on the biology of the host organism, including its life cycle, mating system, and population structure, and on the other hand on the specific fitness effects of the driving allele on the host. Here, we present a population genetic model for spore killing, a type of drive specific to fungi. We show how ploidy level, rate of selfing, and efficiency of spore killing affect the invasion probability of a driving allele and the conditions for its stable coexistence with a nondriving allele. Our model can be adapted to different fungal life cycles, and is applied here to two well-studied genera of filamentous ascomycetes known to harbor spore-killing elements, Neurospora and Podospora. We discuss our results in the light of recent empirical findings for these two systems.
Collapse
Affiliation(s)
| | - Carl Veller
- Department of Evolution and Ecology, University of California, Davis, California, 95616
| | | | - Aaron A Vogan
- Department of Organismal Biology, Uppsala University, Uppsala, 75236, Sweden
| | - Claus Rueffler
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, 75236, Sweden
| | - Hanna Johannesson
- Department of Organismal Biology, Uppsala University, Uppsala, 75236, Sweden
| |
Collapse
|
30
|
Abstract
In order to survive, most organisms must deal with parasites. Such parasites can be other organisms or, sometimes, selfish genes found within the host genome itself. While much is known about parasitic organisms, the interaction with their hosts, and their ability to spread within and between species, much less is known about selfish genes. We here identify a selfish “spore killer” gene in the fungus Neurospora sitophila. The gene appears to have evolved within the genus but has entered the species through hybridization and introgression. We also show that the host can counteract the gene through RNA interference. These results shed light on the diversity of selfish genes in terms of origin, evolution, and host interactions. Meiotic drive elements cause their own preferential transmission following meiosis. In fungi, this phenomenon takes the shape of spore killing, and in the filamentous ascomycete Neurospora sitophila, the Sk-1 spore killer element is found in many natural populations. In this study, we identify the gene responsible for spore killing in Sk-1 by generating both long- and short-read genomic data and by using these data to perform a genome-wide association test. We name this gene Spk-1. Through molecular dissection, we show that a single 405-nt-long open reading frame generates a product that both acts as a poison capable of killing sibling spores and as an antidote that rescues spores that produce it. By phylogenetic analysis, we demonstrate that the gene has likely been introgressed from the closely related species Neurospora hispaniola, and we identify three subclades of N. sitophila, one where Sk-1 is fixed, another where Sk-1 is absent, and a third where both killer and sensitive strain are found. Finally, we show that spore killing can be suppressed through an RNA interference-based genome defense pathway known as meiotic silencing by unpaired DNA. Spk-1 is not related to other known meiotic drive genes, and similar sequences are only found within Neurospora. These results shed light on the diversity of genes capable of causing meiotic drive, their origin and evolution, and their interaction with the host genome.
Collapse
|
31
|
Mechanisms of meiotic drive in symmetric and asymmetric meiosis. Cell Mol Life Sci 2021; 78:3205-3218. [PMID: 33449147 DOI: 10.1007/s00018-020-03735-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 11/13/2020] [Accepted: 12/08/2020] [Indexed: 12/22/2022]
Abstract
Meiotic drive, the non-Mendelian transmission of chromosomes to the next generation, functions in asymmetric or symmetric meiosis across unicellular and multicellular organisms. In asymmetric meiosis, meiotic drivers act to alter a chromosome's spatial position in a single egg. In symmetric meiosis, meiotic drivers cause phenotypic differences between gametes with and without the driver. Here we discuss existing models of meiotic drive, highlighting the underlying mechanisms and regulation governing systems for which the most is known. We focus on outstanding questions surrounding these examples and speculate on how new meiotic drive systems evolve and how to detect them.
Collapse
|
32
|
Ubiquitous Selfish Toxin-Antidote Elements in Caenorhabditis Species. Curr Biol 2021; 31:990-1001.e5. [PMID: 33417886 DOI: 10.1016/j.cub.2020.12.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/28/2020] [Accepted: 12/09/2020] [Indexed: 11/22/2022]
Abstract
Toxin-antidote elements (TAs) are selfish genetic dyads that spread in populations by selectively killing non-carriers. TAs are common in prokaryotes, but very few examples are known in animals. Here, we report the discovery of maternal-effect TAs in both C. tropicalis and C. briggsae, two distant relatives of C. elegans. In C. tropicalis, multiple TAs combine to cause a striking degree of intraspecific incompatibility: five elements reduce the fitness of >70% of the F2 hybrid progeny of two Caribbean isolates. We identified the genes underlying one of the novel TAs, slow-1/grow-1, and found that its toxin, slow-1, is homologous to nuclear hormone receptors. Remarkably, although previously known TAs act during embryonic development, maternal loading of slow-1 in oocytes specifically slows down larval development, delaying the onset of reproduction by several days. Finally, we found that balancing selection acting on linked, conflicting TAs hampers their ability to spread in populations, leading to more stable genetic incompatibilities. Our findings indicate that TAs are widespread in Caenorhabditis species and target a wide range of developmental processes and that antagonism between them may cause lasting incompatibilities in natural populations. We expect that similar phenomena exist in other animal species.
Collapse
|
33
|
Abstract
In life's constant battle for survival, it takes one to kill but two to conquer. Toxin-antitoxin or toxin-antidote (TA) elements are genetic dyads that cheat the laws of inheritance to guarantee their transmission to the next generation. This seemingly simple genetic arrangement—a toxin linked to its antidote—is capable of quickly spreading and persisting in natural populations. TA elements were first discovered in bacterial plasmids in the 1980s and have recently been characterized in fungi, plants, and animals, where they underlie genetic incompatibilities and sterility in crosses between wild isolates. In this review, we provide a unified view of TA elements in both prokaryotic and eukaryotic organisms and highlight their similarities and differences at the evolutionary, genetic, and molecular levels. Finally, we propose several scenarios that could explain the paradox of the evolutionary origin of TA elements and argue that these elements may be key evolutionary players and that the full scope of their roles is only beginning to be uncovered.
Collapse
Affiliation(s)
- Alejandro Burga
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Eyal Ben-David
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California, Los Angeles, California 90095, USA
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, The Hebrew University School of Medicine, Jerusalem 91120, Israel
| | - Leonid Kruglyak
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California, Los Angeles, California 90095, USA
| |
Collapse
|
34
|
Weisman CM, Murray AW, Eddy SR. Many, but not all, lineage-specific genes can be explained by homology detection failure. PLoS Biol 2020; 18:e3000862. [PMID: 33137085 PMCID: PMC7660931 DOI: 10.1371/journal.pbio.3000862] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 11/12/2020] [Accepted: 09/21/2020] [Indexed: 12/21/2022] Open
Abstract
Genes for which homologs can be detected only in a limited group of evolutionarily related species, called “lineage-specific genes,” are pervasive: Essentially every lineage has them, and they often comprise a sizable fraction of the group’s total genes. Lineage-specific genes are often interpreted as “novel” genes, representing genetic novelty born anew within that lineage. Here, we develop a simple method to test an alternative null hypothesis: that lineage-specific genes do have homologs outside of the lineage that, even while evolving at a constant rate in a novelty-free manner, have merely become undetectable by search algorithms used to infer homology. We show that this null hypothesis is sufficient to explain the lack of detected homologs of a large number of lineage-specific genes in fungi and insects. However, we also find that a minority of lineage-specific genes in both clades are not well explained by this novelty-free model. The method provides a simple way of identifying which lineage-specific genes call for special explanations beyond homology detection failure, highlighting them as interesting candidates for further study. Lineage-specific gene families may arise from evolutionary innovations such as de novo gene origination, or may simply mean that a similarity search program failed to identify more distant homologs. A new computational method for modeling the expected decay of similarity search scores with evolutionary distance allows distinction between the two explanations.
Collapse
Affiliation(s)
- Caroline M. Weisman
- Department of Molecular & Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Andrew W. Murray
- Department of Molecular & Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Sean R. Eddy
- Department of Molecular & Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts, United States of America
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
35
|
Gardiner DM, Rusu A, Barrett L, Hunter GC, Kazan K. Can natural gene drives be part of future fungal pathogen control strategies in plants? THE NEW PHYTOLOGIST 2020; 228:1431-1439. [PMID: 32593207 DOI: 10.1111/nph.16779] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 06/15/2020] [Indexed: 06/11/2023]
Abstract
Globally, fungal pathogens cause enormous crop losses and current control practices are not always effective, economical or environmentally sustainable. Tools enabling genetic management of wild pathogen populations could potentially solve many problems associated with plant diseases. A natural gene drive from a heterologous species can be used in the globally important cereal pathogen Fusarium graminearum to remove pathogenic traits from contained populations of the fungus. The gene drive element became fixed in a freely crossing population in only three generations. Repeat-induced point mutation (RIP), a natural genome defence mechanism in fungi that causes C to T mutations during meiosis in highly similar sequences, may be useful to recall the gene drive following release, should a failsafe mechanism be required. We propose that gene drive technology is a potential tool to control plant pathogens once its efficacy is demonstrated under natural settings.
Collapse
Affiliation(s)
- Donald M Gardiner
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation (CSIRO), 306 Carmody Road, St Lucia, Queensland, 4067, Australia
| | - Anca Rusu
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation (CSIRO), 306 Carmody Road, St Lucia, Queensland, 4067, Australia
| | - Luke Barrett
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clunies Ross Street, Acton, ACT, 2601, Australia
| | - Gavin C Hunter
- Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clunies Ross Street, Acton, ACT, 2601, Australia
| | - Kemal Kazan
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation (CSIRO), 306 Carmody Road, St Lucia, Queensland, 4067, Australia
| |
Collapse
|
36
|
Nuckolls NL, Mok AC, Lange JJ, Yi K, Kandola TS, Hunn AM, McCroskey S, Snyder JL, Bravo Núñez MA, McClain M, McKinney SA, Wood C, Halfmann R, Zanders SE. The wtf4 meiotic driver utilizes controlled protein aggregation to generate selective cell death. eLife 2020; 9:e55694. [PMID: 33108274 PMCID: PMC7591262 DOI: 10.7554/elife.55694] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 09/16/2020] [Indexed: 12/19/2022] Open
Abstract
Meiotic drivers are parasitic loci that force their own transmission into greater than half of the offspring of a heterozygote. Many drivers have been identified, but their molecular mechanisms are largely unknown. The wtf4 gene is a meiotic driver in Schizosaccharomyces pombe that uses a poison-antidote mechanism to selectively kill meiotic products (spores) that do not inherit wtf4. Here, we show that the Wtf4 proteins can function outside of gametogenesis and in a distantly related species, Saccharomyces cerevisiae. The Wtf4poison protein forms dispersed, toxic aggregates. The Wtf4antidote can co-assemble with the Wtf4poison and promote its trafficking to vacuoles. We show that neutralization of the Wtf4poison requires both co-assembly with the Wtf4antidote and aggregate trafficking, as mutations that disrupt either of these processes result in cell death in the presence of the Wtf4 proteins. This work reveals that wtf parasites can exploit protein aggregate management pathways to selectively destroy spores.
Collapse
Affiliation(s)
| | - Anthony C Mok
- Stowers Institute for Medical ResearchKansas CityUnited States
- University of Missouri-Kansas CityKansas CityUnited States
| | - Jeffrey J Lange
- Stowers Institute for Medical ResearchKansas CityUnited States
| | - Kexi Yi
- Stowers Institute for Medical ResearchKansas CityUnited States
| | - Tejbir S Kandola
- Stowers Institute for Medical ResearchKansas CityUnited States
- Open UniversityMilton KeynesUnited Kingdom
| | - Andrew M Hunn
- Stowers Institute for Medical ResearchKansas CityUnited States
| | - Scott McCroskey
- Stowers Institute for Medical ResearchKansas CityUnited States
| | - Julia L Snyder
- Stowers Institute for Medical ResearchKansas CityUnited States
| | | | | | - Sean A McKinney
- Stowers Institute for Medical ResearchKansas CityUnited States
| | | | - Randal Halfmann
- Stowers Institute for Medical ResearchKansas CityUnited States
- Department of Molecular and Integrative Physiology, University of Kansas Medical CenterKansas CityUnited States
| | - Sarah E Zanders
- Stowers Institute for Medical ResearchKansas CityUnited States
- Department of Molecular and Integrative Physiology, University of Kansas Medical CenterKansas CityUnited States
| |
Collapse
|
37
|
Bravo Núñez MA, Sabbarini IM, Eide LE, Unckless RL, Zanders SE. Atypical meiosis can be adaptive in outcrossed Schizosaccharomyces pombe due to wtf meiotic drivers. eLife 2020; 9:57936. [PMID: 32790622 PMCID: PMC7426094 DOI: 10.7554/elife.57936] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/21/2020] [Indexed: 01/11/2023] Open
Abstract
Killer meiotic drivers are genetic parasites that destroy ‘sibling’ gametes lacking the driver allele. The fitness costs of drive can lead to selection of unlinked suppressors. This suppression could involve evolutionary tradeoffs that compromise gametogenesis and contribute to infertility. Schizosaccharomyces pombe, an organism containing numerous gamete (spore)-killing wtf drivers, offers a tractable system to test this hypothesis. Here, we demonstrate that in scenarios analogous to outcrossing, wtf drivers generate a fitness landscape in which atypical spores, such as aneuploids and diploids, are advantageous. In this context, wtf drivers can decrease the fitness costs of mutations that disrupt meiotic fidelity and, in some circumstances, can even make such mutations beneficial. Moreover, we find that S. pombe isolates vary greatly in their ability to make haploid spores, with some isolates generating up to 46% aneuploid or diploid spores. This work empirically demonstrates the potential for meiotic drivers to shape the evolution of gametogenesis.
Collapse
Affiliation(s)
| | | | - Lauren E Eide
- Stowers Institute for Medical Research, Kansas City, United States.,University of Missouri-Kansas City, Kansas City, United States
| | - Robert L Unckless
- Department of Molecular Biosciences, University of Kansas, Lawrence, United States
| | - Sarah E Zanders
- Stowers Institute for Medical Research, Kansas City, United States.,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, United States
| |
Collapse
|
38
|
Abstract
Diversity within the fungal kingdom is evident from the wide range of morphologies fungi display as well as the various ecological roles and industrial purposes they serve. Technological advances, particularly in long-read sequencing, coupled with the increasing efficiency and decreasing costs across sequencing platforms have enabled robust characterization of fungal genomes. These sequencing efforts continue to reveal the rampant diversity in fungi at the genome level. Here, we discuss studies that have furthered our understanding of fungal genetic diversity and genomic evolution. These studies revealed the presence of both small-scale and large-scale genomic changes. In fungi, research has recently focused on many small-scale changes, such as how hypermutation and allelic transmission impact genome evolution as well as how and why a few specific genomic regions are more susceptible to rapid evolution than others. High-throughput sequencing of a diverse set of fungal genomes has also illuminated the frequency, mechanisms, and impacts of large-scale changes, which include chromosome structural variation and changes in chromosome number, such as aneuploidy, polyploidy, and the presence of supernumerary chromosomes. The studies discussed herein have provided great insight into how the architecture of the fungal genome varies within species and across the kingdom and how modern fungi may have evolved from the last common fungal ancestor and might also pave the way for understanding how genomic diversity has evolved in all domains of life.
Collapse
Affiliation(s)
- Shelby J. Priest
- Department of Molecular Genetics and Microbiology, Duke University Medical Centre, Durham, NC, USA
| | - Vikas Yadav
- Department of Molecular Genetics and Microbiology, Duke University Medical Centre, Durham, NC, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Centre, Durham, NC, USA
| |
Collapse
|
39
|
Maxwell PH. Diverse transposable element landscapes in pathogenic and nonpathogenic yeast models: the value of a comparative perspective. Mob DNA 2020; 11:16. [PMID: 32336995 PMCID: PMC7175516 DOI: 10.1186/s13100-020-00215-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/16/2020] [Indexed: 12/14/2022] Open
Abstract
Genomics and other large-scale analyses have drawn increasing attention to the potential impacts of transposable elements (TEs) on their host genomes. However, it remains challenging to transition from identifying potential roles to clearly demonstrating the level of impact TEs have on genome evolution and possible functions that they contribute to their host organisms. I summarize TE content and distribution in four well-characterized yeast model systems in this review: the pathogens Candida albicans and Cryptococcus neoformans, and the nonpathogenic species Saccharomyces cerevisiae and Schizosaccharomyces pombe. I compare and contrast their TE landscapes to their lifecycles, genomic features, as well as the presence and nature of RNA interference pathways in each species to highlight the valuable diversity represented by these models for functional studies of TEs. I then review the regulation and impacts of the Ty1 and Ty3 retrotransposons from Saccharomyces cerevisiae and Tf1 and Tf2 retrotransposons from Schizosaccharomyces pombe to emphasize parallels and distinctions between these well-studied elements. I propose that further characterization of TEs in the pathogenic yeasts would enable this set of four yeast species to become an excellent set of models for comparative functional studies to address outstanding questions about TE-host relationships.
Collapse
|
40
|
Adaptation to Industrial Stressors Through Genomic and Transcriptional Plasticity in a Bioethanol Producing Fission Yeast Isolate. G3-GENES GENOMES GENETICS 2020; 10:1375-1391. [PMID: 32086247 PMCID: PMC7144085 DOI: 10.1534/g3.119.400986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Schizosaccharomyces pombe is a model unicellular eukaryote with ties to the basic research, oenology and industrial biotechnology sectors. While most investigations into S. pombe cell biology utilize Leupold’s 972h- laboratory strain background, recent studies have described a wealth of genetic and phenotypic diversity within wild populations of S. pombe including stress resistance phenotypes which may be of interest to industry. Here we describe the genomic and transcriptomic characterization of Wilmar-P, an S. pombe isolate used for bioethanol production from sugarcane molasses at industrial scale. Novel sequences present in Wilmar-P but not in the laboratory S. pombe genome included multiple coding sequences with near-perfect nucleotide identity to Schizosaccharomyces octosporus sequences. Wilmar-P also contained a ∼100kb duplication in the right arm of chromosome III, a region harboring ght5+, the predominant hexose transporter encoding gene. Transcriptomic analysis of Wilmar-P grown in molasses revealed strong downregulation of core environmental stress response genes and upregulation of hexose transporters and drug efflux pumps compared to laboratory S. pombe. Finally, examination of the regulatory network of Scr1, which is involved in the regulation of several genes differentially expressed on molasses, revealed expanded binding of this transcription factor in Wilmar-P compared to laboratory S. pombe in the molasses condition. Together our results point to both genomic plasticity and transcriptomic adaptation as mechanisms driving phenotypic adaptation of Wilmar-P to the molasses environment and therefore adds to our understanding of genetic diversity within industrial fission yeast strains and the capacity of this strain for commercial scale bioethanol production.
Collapse
|
41
|
Dramatically diverse Schizosaccharomyces pombe wtf meiotic drivers all display high gamete-killing efficiency. PLoS Genet 2020; 16:e1008350. [PMID: 32032353 PMCID: PMC7032740 DOI: 10.1371/journal.pgen.1008350] [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: 08/01/2019] [Revised: 02/20/2020] [Accepted: 12/03/2019] [Indexed: 12/27/2022] Open
Abstract
Meiotic drivers are selfish alleles that can force their transmission into more than 50% of the viable gametes made by heterozygotes. Meiotic drivers are known to cause infertility in a diverse range of eukaryotes and are predicted to affect the evolution of genome structure and meiosis. The wtf gene family of Schizosaccharomyces pombe includes both meiotic drivers and drive suppressors and thus offers a tractable model organism to study drive systems. Currently, only a handful of wtf genes have been functionally characterized and those genes only partially reflect the diversity of the wtf gene family. In this work, we functionally test 22 additional wtf genes for meiotic drive phenotypes. We identify eight new drivers that share between 30–90% amino acid identity with previously characterized drivers. Despite the vast divergence between these genes, they generally drive into >85% of gametes when heterozygous. We also identify three wtf genes that suppress other wtf drivers, including two that also act as autonomous drivers. Additionally, we find that wtf genes do not underlie a weak (64% allele transmission) meiotic driver on chromosome 1. Finally, we find that some Wtf proteins have expression or localization patterns that are distinct from the poison and antidote proteins encoded by drivers and suppressors, suggesting some wtf genes may have non-meiotic drive functions. Overall, this work expands our understanding of the wtf gene family and the burden selfish driver genes impose on S. pombe. During gametogenesis, the two gene copies at a given locus, known as alleles, are each transmitted to 50% of the gametes (e.g. sperm). However, some alleles cheat so that they are found in more than the expected 50% of gametes, often at the expense of fertility. This selfish behavior is known as meiotic drive. Some members of the wtf gene family in the fission yeast Schizosaccharomyces pombe kill the gametes (spores) that do not inherit them, resulting in meiotic drive favoring the wtf allele. Other wtf genes act as suppressors of drive. However, the wtf gene family is diverse and only a small subset of the genes has been characterized. Here we analyze the functions of other members of this gene family and found eight new drivers as well as three new suppressors of drive. Surprisingly, we find that drive is relatively insensitive to changes in wtf gene sequence as highly diverged wtf genes execute gamete killing with similar efficiency. Finally, we also find that the expression and localization of some Wtf proteins are distinct from those of known drivers and suppressors, suggesting that these proteins may have non-meiotic drive functions.
Collapse
|
42
|
Zhang C, Wang D, Wang J, Sun Q, Tian L, Tang X, Yuan Z, He H, Yu S. Genetic Dissection and Validation of Chromosomal Regions for Transmission Ratio Distortion in Intersubspecific Crosses of Rice. FRONTIERS IN PLANT SCIENCE 2020; 11:563548. [PMID: 33193492 PMCID: PMC7655136 DOI: 10.3389/fpls.2020.563548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 09/17/2020] [Indexed: 05/17/2023]
Abstract
Transmission ratio distortion (TRD) refers to a widespread phenomenon in which one allele is transmitted by heterozygotes more frequently to the progeny than the opposite allele. TRD is considered as a mark suggesting the presence of a reproductive barrier. However, the genetic and molecular mechanisms underlying TRD in rice remain largely unknown. In the present study, a population of backcross inbred lines (BILs) derived from the cross of a japonica cultivar Nipponbare (NIP) and an indica variety 9311 was utilized to study the genetic base of TRD. A total of 18 genomic regions were identified for TRD in the BILs. Among them, 12 and 6 regions showed indica (9311) and japonica (NIP) alleles with preferential transmission, respectively. A series of F2 populations were used to confirm the TRD effects, including six genomic regions that were confirmed by chromosome segment substitution line (CSSL)-derived F2 populations from intersubspecific allelic combinations. However, none of the regions was confirmed by the CSSL-derived populations from intrasubspecific allelic combination. Furthermore, significant epistatic interaction was found between TRD1.3 and TRD8.1 suggesting that TRD could positively contribute to breaking intersubspecific reproductive barriers. Our results have laid the foundation for identifying the TRD genes and provide an effective strategy to breakdown TRD for breeding wide-compatible lines, which will be further utilized in the intersubspecific hybrid breeding programs.
Collapse
Affiliation(s)
- Chaopu Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Dianwen Wang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jilin Wang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Qiang Sun
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Li Tian
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xinxin Tang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhiyang Yuan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Hanzi He
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- *Correspondence: Hanzi He,
| | - Sibin Yu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Sibin Yu,
| |
Collapse
|
43
|
Fishman L, McIntosh M. Standard Deviations: The Biological Bases of Transmission Ratio Distortion. Annu Rev Genet 2019; 53:347-372. [DOI: 10.1146/annurev-genet-112618-043905] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The rule of Mendelian inheritance is remarkably robust, but deviations from the equal transmission of alternative alleles at a locus [a.k.a. transmission ratio distortion (TRD)] are also commonly observed in genetic mapping populations. Such TRD reveals locus-specific selection acting at some point between the diploid heterozygous parents and progeny genotyping and therefore can provide novel insight into otherwise-hidden genetic and evolutionary processes. Most of the classic selfish genetic elements were discovered through their biasing of transmission, but many unselfish evolutionary and developmental processes can also generate TRD. In this review, we describe methodologies for detecting TRD in mapping populations, detail the arenas and genetic interactions that shape TRD during plant and animal reproduction, and summarize patterns of TRD from across the genetic mapping literature. Finally, we point to new experimental approaches that can accelerate both detection of TRD and characterization of the underlying genetic mechanisms.
Collapse
Affiliation(s)
- Lila Fishman
- Division of Biological Sciences, University of Montana, Missoula, Montana 59812, USA
| | - Mariah McIntosh
- Division of Biological Sciences, University of Montana, Missoula, Montana 59812, USA
| |
Collapse
|
44
|
Bird A. The Selfishness of Law-Abiding Genes. Trends Genet 2019; 36:8-13. [PMID: 31662191 DOI: 10.1016/j.tig.2019.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/23/2019] [Accepted: 10/01/2019] [Indexed: 12/31/2022]
Abstract
Selfish genes were once controversial, but it is now accepted that the genome contains parasitic elements in addition to a complement of conventional genes. This opinion article argues that 'law-abiding' genes also indulge in game playing to ensure their propagation, so that initially nonessential processes secure a genetic heritage. A gene-centered view of this kind can help to explain otherwise puzzling aspects of biology, including the complexity and stability of living systems.
Collapse
Affiliation(s)
- Adrian Bird
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, The King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK.
| |
Collapse
|
45
|
Centromere repositioning causes inversion of meiosis and generates a reproductive barrier. Proc Natl Acad Sci U S A 2019; 116:21580-21591. [PMID: 31597736 PMCID: PMC6815110 DOI: 10.1073/pnas.1911745116] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Mutations in inner kinetochore components induce centromere repositioning without alteration in the centromeric DNA sequence, revealing a feedback mechanism underlying the high epigenetic stability of the centromere. This also provides a desirable experimental system to explore the functional significance of centromere positioning in meiosis. We discovered that in a heterozygotic meiosis, a repositioned centromere generates a reproductive barrier, suggesting a functional role of evolutionary new centromeres in speciation; furthermore, in a homozygotic meiosis, chromosomes carrying repositioned centromeres frequently undergo the 2 stages of meiotic segregation in an inverted order, demonstrating high flexibility in the meiotic process. The chromosomal position of each centromere is determined epigenetically and is highly stable, whereas incremental cases have supported the occurrence of centromere repositioning on an evolutionary time scale (evolutionary new centromeres, ENCs), which is thought to be important in speciation. The mechanisms underlying the high stability of centromeres and its functional significance largely remain an enigma. Here, in the fission yeast Schizosaccharomyces pombe, we identify a feedback mechanism: The kinetochore, whose assembly is guided by the centromere, in turn, enforces centromere stability. Upon going through meiosis, specific inner kinetochore mutations induce centromere repositioning—inactivation of the original centromere and formation of a new centromere elsewhere—in 1 of the 3 chromosomes at random. Repositioned centromeres reside asymmetrically in the pericentromeric regions and cells carrying them are competent in mitosis and homozygotic meiosis. However, when cells carrying a repositioned centromere are crossed with those carrying the original centromere, the progeny suffer severe lethality due to defects in meiotic chromosome segregation. Thus, repositioned centromeres constitute a reproductive barrier that could initiate genetic divergence between 2 populations with mismatched centromeres, documenting a functional role of ENCs in speciation. Surprisingly, homozygotic repositioned centromeres tend to undergo meiosis in an inverted order—that is, sister chromatids segregate first, and homologous chromosomes separate second—whereas the original centromeres on other chromosomes in the same cell undergo meiosis in the canonical order, revealing hidden flexibility in the perceived rigid process of meiosis.
Collapse
|
46
|
Tusso S, Nieuwenhuis BPS, Sedlazeck FJ, Davey JW, Jeffares DC, Wolf JBW. Ancestral Admixture Is the Main Determinant of Global Biodiversity in Fission Yeast. Mol Biol Evol 2019; 36:1975-1989. [PMID: 31225876 PMCID: PMC6736153 DOI: 10.1093/molbev/msz126] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mutation and recombination are key evolutionary processes governing phenotypic variation and reproductive isolation. We here demonstrate that biodiversity within all globally known strains of Schizosaccharomyces pombe arose through admixture between two divergent ancestral lineages. Initial hybridization was inferred to have occurred ∼20-60 sexual outcrossing generations ago consistent with recent, human-induced migration at the onset of intensified transcontinental trade. Species-wide heritable phenotypic variation was explained near-exclusively by strain-specific arrangements of alternating ancestry components with evidence for transgressive segregation. Reproductive compatibility between strains was likewise predicted by the degree of shared ancestry. To assess the genetic determinants of ancestry block distribution across the genome, we characterized the type, frequency, and position of structural genomic variation using nanopore and single-molecule real-time sequencing. Despite being associated with double-strand break initiation points, over 800 segregating structural variants exerted overall little influence on the introgression landscape or on reproductive compatibility between strains. In contrast, we found strong ancestry disequilibrium consistent with negative epistatic selection shaping genomic ancestry combinations during the course of hybridization. This study provides a detailed, experimentally tractable example that genomes of natural populations are mosaics reflecting different evolutionary histories. Exploiting genome-wide heterogeneity in the history of ancestral recombination and lineage-specific mutations sheds new light on the population history of S. pombe and highlights the importance of hybridization as a creative force in generating biodiversity.
Collapse
Affiliation(s)
- Sergio Tusso
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany
- Department of Evolutionary Biology, Science for Life Laboratories, Uppsala University, Uppsala, Sweden
| | - Bart P S Nieuwenhuis
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany
| | - Fritz J Sedlazeck
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
| | - John W Davey
- Bioscience Technology Facility, Department of Biology, University of York, York, United Kingdom
| | - Daniel C Jeffares
- Department of Biology, University of York, York, United Kingdom
- York Biomedical Research Institute (YBRI), University of York, York, United Kingdom
| | - Jochen B W Wolf
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany
- Department of Evolutionary Biology, Science for Life Laboratories, Uppsala University, Uppsala, Sweden
| |
Collapse
|
47
|
Genetic and genomic evolution of sexual reproduction: echoes from LECA to the fungal kingdom. Curr Opin Genet Dev 2019; 58-59:70-75. [PMID: 31473482 DOI: 10.1016/j.gde.2019.07.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/28/2019] [Accepted: 07/16/2019] [Indexed: 12/30/2022]
Abstract
Sexual reproduction is vastly diverse and yet highly conserved across the eukaryotic domain. This ubiquity suggests that the last eukaryotic common ancestor (LECA) was sexual. It is hypothesized that several critical processes in sexual reproduction, including cell fusion and meiosis, were acquired during the evolution from the first eukaryotic common ancestor (FECA) to the sexual LECA. However, it is challenging to delineate the exact origin and evolution of sexual reproduction given that both FECA and LECA are extinct. Studies of diverse eukaryotes have helped to shed light on this sexual evolutionary trajectory, revealing that a primordial sexual ploidy cycle likely involved endoreplication followed by concerted chromosome loss and that cell-cell fusion, meiosis, and sex determination later arose to shape modern sexual reproduction. Despite the general conservation of sexual reproduction processes throughout eukaryotes, modern sexual cycles are immensely diverse and complex. This diversity and complexity has become readily apparent in the fungal kingdom with the recent rapid expansion of whole-genome sequencing. This abundance of data, the variety of genetic tools available to manipulate and characterize fungi, and the thorough characterization of many fungal sexual cycles make the fungal kingdom an excellent forum, in which to study the conservation and diversification of sexual reproduction.
Collapse
|
48
|
Daugherty MD, Zanders SE. Gene conversion generates evolutionary novelty that fuels genetic conflicts. Curr Opin Genet Dev 2019; 58-59:49-54. [PMID: 31466040 DOI: 10.1016/j.gde.2019.07.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/15/2019] [Accepted: 07/20/2019] [Indexed: 12/21/2022]
Abstract
Genetic conflicts arise when the evolutionary interests of two genetic elements are not aligned. Conflicts between genomes (e.g. pathogen versus host) or within the same genome (e.g. internal parasitic DNA sequences versus the rest of the host genome) can both foster 'molecular arms races', in which genes on both sides of the conflict rapidly evolve due to bouts of adaptation and counter-adaptation. Importantly, a source of genetic novelty is needed to fuel these arms races. In this review, we highlight gene conversion as a major force in generating the novel alleles on which selection can act. Using examples from both intergenomic and intragenomic conflicts, we feature the mechanisms by which gene conversion facilitates the rapid evolution of genes in conflict.
Collapse
Affiliation(s)
- Matthew D Daugherty
- Section of Molecular Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA.
| | - Sarah E Zanders
- Stowers Institute for Medical Research, Kansas City, MO, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA.
| |
Collapse
|
49
|
Vogan AA, Ament-Velásquez SL, Granger-Farbos A, Svedberg J, Bastiaans E, Debets AJ, Coustou V, Yvanne H, Clavé C, Saupe SJ, Johannesson H. Combinations of Spok genes create multiple meiotic drivers in Podospora. eLife 2019; 8:46454. [PMID: 31347500 PMCID: PMC6660238 DOI: 10.7554/elife.46454] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 06/09/2019] [Indexed: 11/13/2022] Open
Abstract
Meiotic drive is the preferential transmission of a particular allele during sexual reproduction. The phenomenon is observed as spore killing in multiple fungi. In natural populations of Podospora anserina, seven spore killer types (Psks) have been identified through classical genetic analyses. Here we show that the Spok gene family underlies the Psks. The combination of Spok genes at different chromosomal locations defines the spore killer types and creates a killing hierarchy within a population. We identify two novel Spok homologs located within a large (74–167 kbp) region (the Spok block) that resides in different chromosomal locations in different strains. We confirm that the SPOK protein performs both killing and resistance functions and show that these activities are dependent on distinct domains, a predicted nuclease and kinase domain. Genomic and phylogenetic analyses across ascomycetes suggest that the Spok genes disperse through cross-species transfer, and evolve by duplication and diversification within lineages. In many organisms, most cells carry two versions of a given gene, one coming from the mother and the other from the father. An exception is sexual cells such as eggs, sperm, pollen or spores, which should only contain one variant of a gene. During their formation, these cells usually have an equal chance of inheriting one of the two gene versions. However, a certain class of gene variants called meiotic drivers can cheat this process and end up in more than half of the sexual cells; often, the cells that contain the drivers can kill sibling cells that do not carry these variants. This results in the selfish genetic elements spreading through populations at a higher rate, sometimes with severe consequences such as shifting the ratio of males to females. Meiotic drivers have been discovered in a wide range of organisms, from corn to mice to fruit flies and bread mold. They also exist in the fungus Podospora anserina, where they are called ‘spore killers’. Fungi are often used to study complex genetic processes, yet the identity and mode of action of spore killers in P. anserina were still unknown. Vogan, Ament-Velásquez et al. used a combination of genetic methods to identify three genes from the Spok family which are responsible for certain spores being able to kill their siblings. Two of these were previously unknown, and they could be found in different locations throughout the genome as part of a larger genetic region. Depending on the combination of Spok genes it carries, a spore can kill or be protected against other spores that contain different permutations of the genes. Copies of these genes were also shown to be present in other fungi, including species that are a threat to crops. Scientists have already started to create synthetic meiotic drivers to manipulate how certain traits are inherited within a population. This could be useful to control or eradicate pests and insects that transmit dangerous diseases. The results by Vogan, Ament-Velásquez et al. shine a light on the complex ways that natural meiotic drivers work, including how they can be shared between species; this knowledge could inform how to safely deploy synthetic drivers in the wild.
Collapse
Affiliation(s)
- Aaron A Vogan
- Organismal biology, Uppsala University, Uppsala, Sweden
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Ellison C, Bachtrog D. Recurrent gene co-amplification on Drosophila X and Y chromosomes. PLoS Genet 2019; 15:e1008251. [PMID: 31329593 PMCID: PMC6690552 DOI: 10.1371/journal.pgen.1008251] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 08/12/2019] [Accepted: 06/18/2019] [Indexed: 12/19/2022] Open
Abstract
Y chromosomes often contain amplified genes which can increase dosage of male fertility genes and counteract degeneration via gene conversion. Here we identify genes with increased copy number on both X and Y chromosomes in various species of Drosophila, a pattern that has previously been associated with sex chromosome drive involving the Slx and Sly gene families in mice. We show that recurrent X/Y co-amplification appears to be an important evolutionary force that has shaped gene content evolution of sex chromosomes in Drosophila. We demonstrate that convergent acquisition and amplification of testis expressed gene families are common on Drosophila sex chromosomes, and especially on recently formed ones, and we carefully characterize one putative novel X/Y co-amplification system. We find that co-amplification of the S-Lap1/GAPsec gene pair on both the X and the Y chromosome occurred independently several times in members of the D. obscura group, where this normally autosomal gene pair is sex-linked due to a sex chromosome-autosome fusion. We explore several evolutionary scenarios that would explain this pattern of co-amplification. Investigation of gene expression and short RNA profiles at the S-Lap1/GAPsec system suggest that, like Slx/Sly in mice, these genes may be remnants of a cryptic sex chromosome drive system, however additional transgenic experiments will be necessary to validate this model. Regardless of whether sex chromosome drive is responsible for this co-amplification, our findings suggest that recurrent gene duplications between X and Y sex chromosomes could have a widespread effect on genomic and evolutionary patterns, including the epigenetic regulation of sex chromosomes, the distribution of sex-biased genes, and the evolution of hybrid sterility.
Collapse
Affiliation(s)
- Christopher Ellison
- Department of Integrative Biology, University of California Berkeley, Berkeley, California, United States of America
| | - Doris Bachtrog
- Department of Integrative Biology, University of California Berkeley, Berkeley, California, United States of America
| |
Collapse
|