1
|
Saccone G. A history of the genetic and molecular identification of genes and their functions controlling insect sex determination. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 151:103873. [PMID: 36400424 DOI: 10.1016/j.ibmb.2022.103873] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 06/16/2023]
Abstract
The genetics of the sex determination regulatory cascade in Drosophila melanogaster has a fascinating history, interlinked with the foundation of the Genetics discipline itself. The discovery that alternative splicing rather than differential transcription is the molecular mechanism underlying the upstream control of sex differences in the Drosophila model system was surprising. This notion is now fully integrated into the scientific canon, appearing in many genetics textbooks and online education resources. In the last three decades, it was a key reference point for starting evolutionary studies in other insect species by using homology-based approaches. This review will introduce a very brief history of Drosophila genetics. It will describe the genetic and molecular approaches applied for the identifying and cloning key genes involved in sex determination in Drosophila and in many other insect species. These comparative analyses led to supporting the idea that sex-determining pathways have evolved mainly by recruiting different upstream signals/genes while maintaining widely conserved intermediate and downstream regulatory genes. The review also provides examples of the link between technological advances and research achievements, to stimulate reflections on how science is produced. It aims to hopefully strengthen the related historical and conceptual knowledge of general readers of other disciplines and of younger geneticists, often focused on the latest technical-molecular approaches.
Collapse
Affiliation(s)
- Giuseppe Saccone
- Department of Biology, University of Naples Federico II, Via Cinthia 26, 80126, Naples, Italy.
| |
Collapse
|
2
|
Kojin BB, Compton A, Adelman ZN, Tu Z. Selective targeting of biting females to control mosquito-borne infectious diseases. Trends Parasitol 2022; 38:791-804. [PMID: 35952630 PMCID: PMC9372635 DOI: 10.1016/j.pt.2022.05.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/20/2022] [Accepted: 05/23/2022] [Indexed: 10/18/2022]
Abstract
Mosquitoes are vectors for a number of infectious diseases. Only females feed on blood to provision for their embryos and, in doing so, transmit pathogens to the associated vertebrate hosts. Therefore, sex is an important phenotype in the context of genetic control programs, both for sex separation in the rearing facilities to avoid releasing biting females and for ways to distort the sex ratio towards nonbiting males. We review recent progress in the fundamental knowledge of sex determination and sex chromosomes in mosquitoes and discuss new methods to achieve sex separation and sex ratio distortion to help control mosquito-borne infectious diseases. We conclude by suggesting a few critical areas for future research.
Collapse
Affiliation(s)
- Bianca B Kojin
- Department of Entomology and Agrilife Research, Texas A&M University, College Station, TX, USA
| | - Austin Compton
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA; Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Zach N Adelman
- Department of Entomology and Agrilife Research, Texas A&M University, College Station, TX, USA.
| | - Zhijian Tu
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA; Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA.
| |
Collapse
|
3
|
Estimating female malaria mosquito age by quantifying Y-linked genes in stored male spermatozoa. Sci Rep 2022; 12:10570. [PMID: 35732703 PMCID: PMC9217924 DOI: 10.1038/s41598-022-15021-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/16/2022] [Indexed: 11/19/2022] Open
Abstract
Vector control strategies are among the most effective measures to combat mosquito-borne diseases, such as malaria. These strategies work by altering the mosquito age structure through increased mortality of the older female mosquitoes that transmit pathogens. However, methods to monitor changes to mosquito age structure are currently inadequate for programmatic implementation. Female mosquitoes generally mate a single time soon after emergence and draw down spermatozoa reserves with each oviposition cycle. Here, we demonstrate that measuring spermatozoa quantity in female Anopheles mosquitoes is an effective approach to assess mosquito age. Using multiplexed qPCR targeted at male spermatozoa, we show that Y-linked genes in female mosquitoes are exclusively found in the spermatheca, the organ that houses spermatozoa, and the quantity of these gene sequences significantly declines with age. The method can accurately identify mosquitoes more than 10 days old and thus old enough to potentially transmit pathogens harbored in the salivary glands during blood feeding. Furthermore, mosquito populations that differ by 10% in daily survivorship have a high likelihood of being distinguished using modest sample sizes, making this approach scalable for assessing the efficacy of vector intervention control programs.
Collapse
|
4
|
Liu P, Jin B, Li X, Zhao Y, Gu J, Biedler JK, Tu ZJ, Chen XG. Nix is a male-determining factor in the Asian tiger mosquito Aedes albopictus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 118:103311. [PMID: 31901476 DOI: 10.1016/j.ibmb.2019.103311] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 12/26/2019] [Accepted: 12/27/2019] [Indexed: 05/06/2023]
Abstract
The initial signal that governs sex determination is highly variable among insects. A homolog of Nix, the male-determining factor in Aedes aegypti, was previously found in the Asian tiger mosquito Ae. albopictus. Here we show that the Ae. albopictus Nix (AalNix) is more complex in gene structure and splice isoforms than its Ae. aegypti homolog (AaeNix). AalNix shows a similar transcription profile compared to AaeNix. CRISPR/Cas9-mediated knockouts of AalNix in vivo and in the Ae. albopictus C6/36 cells lead to a shift of dsx and fru splicing towards the female isoforms. G0 knockout males showed feminization and deformities including feminized antennae, absence or partial absence of gonocoxites, gonostyli, testes and accessory glands, and the formation of ovaries. Despite ~70 MY of divergence, Nix functions as a conserved male-determining factor in the two most important arboviral vectors, namely Ae. aegypti and Ae. albopictus.
Collapse
Affiliation(s)
- Peiwen Liu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Binbin Jin
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Xiaocong Li
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Yijie Zhao
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Jinbao Gu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - James K Biedler
- Department of Biochemistry and the Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Zhijian Jake Tu
- Department of Biochemistry and the Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, 24061, USA.
| | - Xiao-Guang Chen
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, 510515, China.
| |
Collapse
|
5
|
Qi Y, Wu Y, Saunders R, Chen XG, Mao C, Biedler JK, Tu ZJ. Guy1, a Y-linked embryonic signal, regulates dosage compensation in Anopheles stephensi by increasing X gene expression. eLife 2019; 8:43570. [PMID: 30888319 PMCID: PMC6440743 DOI: 10.7554/elife.43570] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 03/16/2019] [Indexed: 12/22/2022] Open
Abstract
We previously showed that Guy1, a primary signal expressed from the Y chromosome, is a strong candidate for a male-determining factor that confers female-specific lethality in Anopheles stephensi (Criscione et al., 2016). Here, we present evidence that Guy1 increases X gene expression in Guy1-transgenic females from two independent lines, providing a mechanism underlying the Guy1-conferred female lethality. The median level gene expression (MGE) of X-linked genes is significantly higher than autosomal genes in Guy1-transgenic females while there is no significant difference in MGE between X and autosomal genes in wild-type females. Furthermore, Guy1 significantly upregulates at least 40% of the 996 genes across the X chromosome in transgenic females. Guy1-conferred female-specific lethality is remarkably stable and completely penetrant. These findings indicate that Guy1 regulates dosage compensation in An. stephensi and components of dosage compensation may be explored to develop novel strategies to control mosquito-borne diseases.
Collapse
Affiliation(s)
- Yumin Qi
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia, United States.,Fralin Life Science Institute, Virginia Tech, Blacksburg, Virginia, United States
| | - Yang Wu
- Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangdong, China
| | - Randy Saunders
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia, United States.,Fralin Life Science Institute, Virginia Tech, Blacksburg, Virginia, United States
| | - Xiao-Guang Chen
- Fralin Life Science Institute, Virginia Tech, Blacksburg, Virginia, United States
| | - Chunhong Mao
- Biocomplexity Institute of Virginia Tech, Virginia Tech, Blacksburg, Virginia, United States
| | - James Kite Biedler
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia, United States.,Fralin Life Science Institute, Virginia Tech, Blacksburg, Virginia, United States
| | - Zhijian Jake Tu
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia, United States.,Fralin Life Science Institute, Virginia Tech, Blacksburg, Virginia, United States
| |
Collapse
|
6
|
Wu Y, Hu W, Biedler JK, Chen XG, Tu ZJ. Pure early zygotic genes in the Asian malaria mosquito Anopheles stephensi. Parasit Vectors 2018; 11:652. [PMID: 30583723 PMCID: PMC6304767 DOI: 10.1186/s13071-018-3220-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The Asian malaria mosquito, Anopheles stephensi, is a major urban malaria vector in the Middle East and on the Indian subcontinent. Early zygotic transcription, which marks the maternal-to-zygotic transition, has not been systematically studied in An. stephensi or any other Anopheles mosquitoes. Improved understanding of early embryonic gene expression in An. stephensi will facilitate genetic and evolutionary studies and help with the development of novel control strategies for this important disease vector. RESULTS We obtained RNA-seq data in biological triplicates from four early An. stephensi embryonic time points. Using these data, we identified 70 and 153 pure early zygotic genes (pEZGs) under stringent and relaxed conditions, respectively. We show that these pEZGs are enriched in functional groups related to DNA-binding transcription regulators, cell cycle modulators, proteases, transport, and cellular metabolism. On average these pEZGs are shorter and have less introns than other An. stephensi genes. Some of the pEZGs may arise de novo while others have clear non-pEZG paralogs. There is no or very limited overlap between An. stephensi pEZGs and Drosophila melanogaster or Aedes aegypti pEZGs. Interestingly, the upstream region of An. stephensi pEZGs lack significant enrichment of a previously reported TAGteam/VBRGGTA motif found in the regulatory region of pEZGs in D. melanogaster and Ae. aegypti. However, a GT-rich motif was found in An. stephensi pEZGs instead. CONCLUSIONS We have identified a number of pEZGs whose predicted functions and structures are consistent with their collective roles in the degradation of maternally deposited components, activation of the zygotic genome, cell division, and metabolism. The pEZGs appear to rapidly turn over within the Dipteran order and even within the Culicidae family. These pEZGs, and the shared regulatory motif, could provide the promoter or regulatory sequences to drive gene expression in the syncytial or early cellular blastoderm, a period when the developing embryo is accessible to genetic manipulation. In addition, these molecular resources may be used to achieve sex separation of mosquitoes for sterile insect technique.
Collapse
Affiliation(s)
- Yang Wu
- Department of Pathogen Biology, School of Public Health, Southern Medical, University, Guangzhou, Guangdong, 510515, People's Republic of China.,Department of Biochemistry, Engel Hall, Blacksburg, VA, 24061, USA.,Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Wanqi Hu
- Department of Biochemistry, Engel Hall, Blacksburg, VA, 24061, USA.,Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - James K Biedler
- Department of Biochemistry, Engel Hall, Blacksburg, VA, 24061, USA.,Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Xiao-Guang Chen
- Department of Pathogen Biology, School of Public Health, Southern Medical, University, Guangzhou, Guangdong, 510515, People's Republic of China.
| | - Zhijian Jake Tu
- Department of Biochemistry, Engel Hall, Blacksburg, VA, 24061, USA. .,Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, 24061, USA.
| |
Collapse
|
7
|
Molecular tools and genetic markers for the generation of transgenic sexing strains in Anopheline mosquitoes. Parasit Vectors 2018; 11:660. [PMID: 30583738 PMCID: PMC6304780 DOI: 10.1186/s13071-018-3207-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Malaria is a serious global health burden, affecting more than 200 million people each year in over 90 countries, predominantly in Africa, Asia and the Americas. Since the year 2000, a concerted effort to combat malaria has reduced its incidence by more than 40%, primarily due to the use of insecticide-treated bednets, indoor residual spraying and artemisinin-based combination drug therapies. Nevertheless, the cost of control is expected to nearly triple over the next decade and the current downward trend in disease transmission is threatened by the rise of resistance to drugs and insecticides. Novel strategies that are sustainable and cost-effective are needed to help usher in an era of malaria elimination. The most effective strategies thus far have focussed on control of the mosquito vector. The sterile insect technique (SIT) is a potentially powerful strategy that aims to suppress mosquito populations through the unproductive mating of wild female mosquitoes with sterile males that are released en masse. The technique and its derivatives are currently not appropriate for malaria control because it is difficult to sterilise males without compromising their ability to mate, and because anopheline males cannot be easily separated from females, which if released, could contribute to disease transmission. Advances in genome sequencing technologies and the development of transgenic techniques provide the tools necessary to produce mosquito sexing strains, which promise to improve current malaria-control programs and pave the way for new ones. In this review, the progress made in the development of transgenic sexing strains for the control of Anopheles gambiae, a major vector of human malaria, is discussed.
Collapse
|
8
|
Abstract
Background Aedes aegypti is an important mosquito vector that transmits arboviruses that cause devastating diseases including Zika, dengue fever, yellow fever and chikungunya. Improved understanding of gene regulation in the early development of Ae. aegypti will facilitate genetic studies and help the development of novel control strategies of this important disease vector. Results In this study, we demonstrated through transgenic assays that the promoter of an endogenous early zygotic gene KLC2 could drive gene expression in the syncytial blastoderm and early cellular blastoderm, which is a stage that the developing germline and the rest of embryo are accessible to genetic manipulation. An unexpected expression of the reporter gene in transgenic male testes was also observed. Further analysis confirmed the expression of the endogenous KLC2 in the testes, which was not detected in the previous RNA sequencing data. Conclusions Our finding provided a new promoter element that can be used in future genetic studies and applications in Ae. aegypti. Moreover, our transgenic reporter assays showed that cautions are needed when interpreting RNA sequencing data as transient or tissue-specific transcription may go undetected by RNAseq. Electronic supplementary material The online version of this article (10.1186/s13071-018-3210-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Wanqi Hu
- Department of Biochemistry, Virginia Tech, 303 Fralin, Blacksburg, VA, 24061, USA.,Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Zhijian Jake Tu
- Department of Biochemistry, Virginia Tech, 303 Fralin, Blacksburg, VA, 24061, USA. .,Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, 24061, USA.
| |
Collapse
|
9
|
Criscione F, Qi Y, Tu Z. GUY1 confers complete female lethality and is a strong candidate for a male-determining factor in Anopheles stephensi. eLife 2016; 5. [PMID: 27644420 PMCID: PMC5061544 DOI: 10.7554/elife.19281] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/12/2016] [Indexed: 12/02/2022] Open
Abstract
Despite their importance in sexual differentiation and reproduction, Y chromosome genes are rarely described because they reside in repeat-rich regions that are difficult to study. Here, we show that Guy1, a unique Y chromosome gene of a major urban malaria mosquito Anopheles stephensi, confers 100% female lethality when placed on the autosomes. We show that the small GUY1 protein (56 amino acids in length) causes female lethality and that males carrying the transgene are reproductively more competitive than their non-transgenic siblings under laboratory conditions. The GUY1 protein is a primary signal from the Y chromosome that affects embryonic development in a sex-specific manner. Our results have demonstrated, for the first time in mosquitoes, the feasibility of stable transgenic manipulation of sex ratios using an endogenous gene from the male-determining chromosome. These results provide insights into the elusive M factor and suggest exciting opportunities to reduce mosquito populations and disease transmission. DOI:http://dx.doi.org/10.7554/eLife.19281.001 Much like humans, Anopheles mosquitoes have a pair of sex chromosomes that determine whether they are male or female: females have two X chromosomes, while males have an X and a Y. Genetic evidence has indicated that there is a dominant male-determining factor on the Y chromosome that acts as a master switch to cause mosquitoes to develop into males. Mosquitoes that lack a Y chromosome, and hence the male-determining factor, therefore develop into the default female sex. Because only female mosquitoes feed on blood and transmit disease-causing microbes – including those that cause malaria – there is strong interest in identifying the male-determining factor. Introducing this gene into females could allow mosquito sex ratios to be manipulated towards the harmless non-biting males. In 2013, a study of male Anopheles stephensi mosquitoes identified a gene called Guy1 that is only found on the Y chromosome. Criscione et al. – who were involved in the 2013 study – now show that female A. stephensi mosquitoes die when the Guy1 gene is placed on their non-sex chromosomes. Further investigation confirmed that the protein produced from the Guy1 gene kills the females. This protein is an initiating signal that affects embryonic development in a sex-specific manner, making it a strong candidate to be the male determining factor in A. stephensi. This is consistent with previous reports in which the master switches of sex determination could be manipulated to kill specific sexes in fruit flies and nematode worms. Criscione et al. also found that males that carry the inserted Guy1 gene on their non-sex chromosomes – and so could potentially pass it on to both male and female offspring – are reproductively more competitive than their non-modified siblings under laboratory conditions. As the resulting female offspring would not survive, it is thus feasible, in principle, to genetically manipulate the sex ratio of the mosquitoes. A future challenge will be to identify how the protein encoded by the Guy1 gene acts to kill female mosquitoes. This knowledge will help to investigate the feasibility of using genetically modified mosquitoes to reduce Anopheles populations in order to control malaria. DOI:http://dx.doi.org/10.7554/eLife.19281.002
Collapse
Affiliation(s)
- Frank Criscione
- Department of Biochemistry, Virginia Tech, Blacksburg, United States
| | - Yumin Qi
- Department of Biochemistry, Virginia Tech, Blacksburg, United States
| | - Zhijian Tu
- Department of Biochemistry, Virginia Tech, Blacksburg, United States
| |
Collapse
|
10
|
Krzywinska E, Dennison NJ, Lycett GJ, Krzywinski J. A maleness gene in the malaria mosquito Anopheles gambiae. Science 2016; 353:67-9. [PMID: 27365445 DOI: 10.1126/science.aaf5605] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 06/01/2016] [Indexed: 12/22/2022]
Abstract
The molecular pathways controlling gender are highly variable and have been identified in only a few nonmammalian model species. In many insects, maleness is conferred by a Y chromosome-linked M factor of unknown nature. We have isolated and characterized a gene, Yob, for the M factor in the malaria mosquito Anopheles gambiae Yob, activated at the beginning of zygotic transcription and expressed throughout a male's life, controls male-specific splicing of the doublesex gene. Silencing embryonic Yob expression is male-lethal, whereas ectopic embryonic delivery of Yob transcripts yields male-only broods. This female-killing property may be an invaluable tool for creation of conditional male-only transgenic Anopheles strains for malaria control programs.
Collapse
Affiliation(s)
| | - Nathan J Dennison
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK. Department of Life Sciences, Imperial College, South Kensington Campus, London SW7 2AZ, UK
| | - Gareth J Lycett
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Jaroslaw Krzywinski
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK. Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
| |
Collapse
|
11
|
|
12
|
Hall AB, Papathanos PA, Sharma A, Cheng C, Akbari OS, Assour L, Bergman NH, Cagnetti A, Crisanti A, Dottorini T, Fiorentini E, Galizi R, Hnath J, Jiang X, Koren S, Nolan T, Radune D, Sharakhova MV, Steele A, Timoshevskiy VA, Windbichler N, Zhang S, Hahn MW, Phillippy AM, Emrich SJ, Sharakhov IV, Tu ZJ, Besansky NJ. Radical remodeling of the Y chromosome in a recent radiation of malaria mosquitoes. Proc Natl Acad Sci U S A 2016; 113:E2114-23. [PMID: 27035980 PMCID: PMC4839409 DOI: 10.1073/pnas.1525164113] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Y chromosomes control essential male functions in many species, including sex determination and fertility. However, because of obstacles posed by repeat-rich heterochromatin, knowledge of Y chromosome sequences is limited to a handful of model organisms, constraining our understanding of Y biology across the tree of life. Here, we leverage long single-molecule sequencing to determine the content and structure of the nonrecombining Y chromosome of the primary African malaria mosquito, Anopheles gambiae We find that the An. gambiae Y consists almost entirely of a few massively amplified, tandemly arrayed repeats, some of which can recombine with similar repeats on the X chromosome. Sex-specific genome resequencing in a recent species radiation, the An. gambiae complex, revealed rapid sequence turnover within An. gambiae and among species. Exploiting 52 sex-specific An. gambiae RNA-Seq datasets representing all developmental stages, we identified a small repertoire of Y-linked genes that lack X gametologs and are not Y-linked in any other species except An. gambiae, with the notable exception of YG2, a candidate male-determining gene. YG2 is the only gene conserved and exclusive to the Y in all species examined, yet sequence similarity to YG2 is not detectable in the genome of a more distant mosquito relative, suggesting rapid evolution of Y chromosome genes in this highly dynamic genus of malaria vectors. The extensive characterization of the An. gambiae Y provides a long-awaited foundation for studying male mosquito biology, and will inform novel mosquito control strategies based on the manipulation of Y chromosomes.
Collapse
Affiliation(s)
- Andrew Brantley Hall
- The Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Philippos-Aris Papathanos
- Section of Genomics and Genetics, Department of Experimental Medicine, University of Perugia, 06132 Perugia, Italy; Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Atashi Sharma
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Changde Cheng
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556; Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
| | - Omar S Akbari
- Department of Entomology, Riverside Center for Disease Vector Research, Institute for Integrative Genome Biology, University of California, Riverside, CA 92521
| | - Lauren Assour
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, IN 46556
| | - Nicholas H Bergman
- National Biodefense Analysis and Countermeasures Center, Frederick, MD 21702
| | - Alessia Cagnetti
- Section of Genomics and Genetics, Department of Experimental Medicine, University of Perugia, 06132 Perugia, Italy
| | - Andrea Crisanti
- Section of Genomics and Genetics, Department of Experimental Medicine, University of Perugia, 06132 Perugia, Italy; Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Tania Dottorini
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Elisa Fiorentini
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Roberto Galizi
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jonathan Hnath
- National Biodefense Analysis and Countermeasures Center, Frederick, MD 21702
| | - Xiaofang Jiang
- The Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Sergey Koren
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892
| | - Tony Nolan
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Diane Radune
- National Biodefense Analysis and Countermeasures Center, Frederick, MD 21702
| | - Maria V Sharakhova
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; Laboratory of Evolutionary Cytogenetics, Tomsk State University, Tomsk 634050, Russia
| | - Aaron Steele
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, IN 46556
| | - Vladimir A Timoshevskiy
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Nikolai Windbichler
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Simo Zhang
- School of Informatics and Computing, Indiana University, Bloomington, IN 47405
| | - Matthew W Hahn
- School of Informatics and Computing, Indiana University, Bloomington, IN 47405; Department of Biology, Indiana University, Bloomington, IN 47405
| | - Adam M Phillippy
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892
| | - Scott J Emrich
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556; Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, IN 46556
| | - Igor V Sharakhov
- The Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; Laboratory of Evolutionary Cytogenetics, Tomsk State University, Tomsk 634050, Russia;
| | - Zhijian Jake Tu
- The Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Nora J Besansky
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556; Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556;
| |
Collapse
|
13
|
Adelman ZN, Tu Z. Control of Mosquito-Borne Infectious Diseases: Sex and Gene Drive. Trends Parasitol 2016; 32:219-229. [PMID: 26897660 DOI: 10.1016/j.pt.2015.12.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 12/01/2015] [Accepted: 12/04/2015] [Indexed: 01/23/2023]
Abstract
Sterile male releases have successfully reduced local populations of the dengue vector, Aedes aegypti, but challenges remain in scale and in separating sexes before release. The recent discovery of the first mosquito male determining factor (M factor) will facilitate our understanding of the genetic programs that initiate sexual development in mosquitoes. Manipulation of the M factor and possible intermediary factors may result in female-to-male conversion or female killing, enabling efficient sex separation and effective reduction of target mosquito populations. Given recent breakthroughs in the development of CRISPR-Cas9 reagents as a source of gene drive, more advanced technologies at driving maleness, the ultimate disease refractory phenotype, become possible and may represent efficient and self-limiting methods to control mosquito populations.
Collapse
Affiliation(s)
- Zach N Adelman
- Department of Entomology, Virginia Tech, Blacksburg, VA, USA; Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, USA.
| | - Zhijian Tu
- Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, USA; Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA.
| |
Collapse
|
14
|
Salvemini M, Arunkumar KP, Nagaraju J, Sanges R, Petrella V, Tomar A, Zhang H, Zheng W, Saccone G. De novo assembly and transcriptome analysis of the Mediterranean fruit fly Ceratitis capitata early embryos. PLoS One 2014; 9:e114191. [PMID: 25474564 PMCID: PMC4256415 DOI: 10.1371/journal.pone.0114191] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 11/05/2014] [Indexed: 01/04/2023] Open
Abstract
The agricultural pest Ceratitis capitata, also known as the Mediterranean fruit fly or Medfly, belongs to the Tephritidae family, which includes a large number of other damaging pest species. The Medfly has been the first non-drosophilid fly species which has been genetically transformed paving the way for designing genetic-based pest control strategies. Furthermore, it is an experimentally tractable model, in which transient and transgene-mediated RNAi have been successfully used. We applied Illumina sequencing to total RNA preparations of 8–10 hours old embryos of C. capitata, This developmental window corresponds to the blastoderm cellularization stage. In summary, we assembled 42,614 transcripts which cluster in 26,319 unique transcripts of which 11,045 correspond to protein coding genes; we identified several hundreds of long ncRNAs; we found an enrichment of transcripts encoding RNA binding proteins among the highly expressed transcripts, such as CcTRA-2, known to be necessary to establish and, most likely, to maintain female sex of C. capitata. Our study is the first de novo assembly performed for Ceratitis capitata based on Illumina NGS technology during embryogenesis and it adds novel data to the previously published C. capitata EST databases. We expect that it will be useful for a variety of applications such as gene cloning and phylogenetic analyses, as well as to advance genetic research and biotechnological applications in the Medfly and other related Tephritidae.
Collapse
Affiliation(s)
- Marco Salvemini
- Department of Biology, University of Naples Federico II, Naples, Italy
| | | | | | - Remo Sanges
- Stazione Zoologica "Anton Dohrn", Naples, Italy
| | - Valeria Petrella
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Archana Tomar
- Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
| | - Hongyu Zhang
- State Key Laboratory of Agricultural Microbiology and Institute of Urban and Horticultural Pests, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Weiwei Zheng
- State Key Laboratory of Agricultural Microbiology and Institute of Urban and Horticultural Pests, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Giuseppe Saccone
- Department of Biology, University of Naples Federico II, Naples, Italy
| |
Collapse
|
15
|
Jiang X, Peery A, Hall AB, Sharma A, Chen XG, Waterhouse RM, Komissarov A, Riehle MM, Shouche Y, Sharakhova MV, Lawson D, Pakpour N, Arensburger P, Davidson VLM, Eiglmeier K, Emrich S, George P, Kennedy RC, Mane SP, Maslen G, Oringanje C, Qi Y, Settlage R, Tojo M, Tubio JMC, Unger MF, Wang B, Vernick KD, Ribeiro JMC, James AA, Michel K, Riehle MA, Luckhart S, Sharakhov IV, Tu Z. Genome analysis of a major urban malaria vector mosquito, Anopheles stephensi. Genome Biol 2014; 15:459. [PMID: 25244985 PMCID: PMC4195908 DOI: 10.1186/s13059-014-0459-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 09/03/2014] [Indexed: 12/24/2022] Open
Abstract
Background Anopheles stephensi is the key vector of malaria throughout the Indian subcontinent and Middle East and an emerging model for molecular and genetic studies of mosquito-parasite interactions. The type form of the species is responsible for the majority of urban malaria transmission across its range. Results Here, we report the genome sequence and annotation of the Indian strain of the type form of An. stephensi. The 221 Mb genome assembly represents more than 92% of the entire genome and was produced using a combination of 454, Illumina, and PacBio sequencing. Physical mapping assigned 62% of the genome onto chromosomes, enabling chromosome-based analysis. Comparisons between An. stephensi and An. gambiae reveal that the rate of gene order reshuffling on the X chromosome was three times higher than that on the autosomes. An. stephensi has more heterochromatin in pericentric regions but less repetitive DNA in chromosome arms than An. gambiae. We also identify a number of Y-chromosome contigs and BACs. Interspersed repeats constitute 7.1% of the assembled genome while LTR retrotransposons alone comprise more than 49% of the Y contigs. RNA-seq analyses provide new insights into mosquito innate immunity, development, and sexual dimorphism. Conclusions The genome analysis described in this manuscript provides a resource and platform for fundamental and translational research into a major urban malaria vector. Chromosome-based investigations provide unique perspectives on Anopheles chromosome evolution. RNA-seq analysis and studies of immunity genes offer new insights into mosquito biology and mosquito-parasite interactions. Electronic supplementary material The online version of this article (doi:10.1186/s13059-014-0459-2) contains supplementary material, which is available to authorized users.
Collapse
|
16
|
Hall AB, Timoshevskiy VA, Sharakhova MV, Jiang X, Basu S, Anderson MAE, Hu W, Sharakhov IV, Adelman ZN, Tu Z. Insights into the preservation of the homomorphic sex-determining chromosome of Aedes aegypti from the discovery of a male-biased gene tightly linked to the M-locus. Genome Biol Evol 2014; 6:179-91. [PMID: 24398378 PMCID: PMC3914700 DOI: 10.1093/gbe/evu002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The preservation of a homomorphic sex-determining chromosome in some organisms without transformation into a heteromorphic sex chromosome is a long-standing enigma in evolutionary biology. A dominant sex-determining locus (or M-locus) in an undifferentiated homomorphic chromosome confers the male phenotype in the yellow fever mosquito Aedes aegypti. Genetic evidence suggests that the M-locus is in a nonrecombining region. However, the molecular nature of the M-locus has not been characterized. Using a recently developed approach based on Illumina sequencing of male and female genomic DNA, we identified a novel gene, myo-sex, that is present almost exclusively in the male genome but can sporadically be found in the female genome due to recombination. For simplicity, we define sequences that are primarily found in the male genome as male-biased. Fluorescence in situ hybridization (FISH) on A. aegypti chromosomes demonstrated that the myo-sex probe localized to region 1q21, the established location of the M-locus. Myo-sex is a duplicated myosin heavy chain gene that is highly expressed in the pupa and adult male. Myo-sex shares 83% nucleotide identity and 97% amino acid identity with its closest autosomal paralog, consistent with ancient duplication followed by strong purifying selection. Compared with males, myo-sex is expressed at very low levels in the females that acquired it, indicating that myo-sex may be sexually antagonistic. This study establishes a framework to discover male-biased sequences within a homomorphic sex-determining chromosome and offers new insights into the evolutionary forces that have impeded the expansion of the nonrecombining M-locus in A. aegypti.
Collapse
|
17
|
Medusa: a novel gene drive system for confined suppression of insect populations. PLoS One 2014; 9:e102694. [PMID: 25054803 PMCID: PMC4108329 DOI: 10.1371/journal.pone.0102694] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Accepted: 06/23/2014] [Indexed: 01/03/2023] Open
Abstract
Gene drive systems provide novel opportunities for insect population suppression by driving genes that confer a fitness cost into pest or disease vector populations; however regulatory issues arise when genes are capable of spreading across international borders. Gene drive systems displaying threshold properties provide a solution since they can be confined to local populations and eliminated through dilution with wild-types. We propose a novel, threshold-dependent gene drive system, Medusa, capable of inducing a local and reversible population crash. Medusa consists of four components - two on the X chromosome, and two on the Y chromosome. A maternally-expressed, X-linked toxin and a zygotically-expressed, Y-linked antidote results in suppression of the female population and selection for the presence of the transgene-bearing Y because only male offspring of Medusa-bearing females are protected from the effects of the toxin. At the same time, the combination of a zygotically-expressed, Y-linked toxin and a zygotically-expressed, X-linked antidote selects for the transgene-bearing X in the presence of the transgene-bearing Y. Together these chromosomes create a balanced lethal system that spreads while selecting against females when present above a certain threshold frequency. Simple population dynamic models show that an all-male release of Medusa males, carried out over six generations, is expected to induce a population crash within 12 generations for modest release sizes on the order of the wild population size. Re-invasion of non-transgenic insects into a suppressed population can result in a population rebound; however this can be prevented through regular releases of modest numbers of Medusa males. Finally, we outline how Medusa could be engineered with currently available molecular tools.
Collapse
|
18
|
Site-specific genetic engineering of the Anopheles gambiae Y chromosome. Proc Natl Acad Sci U S A 2014; 111:7600-5. [PMID: 24821795 DOI: 10.1073/pnas.1404996111] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Despite its function in sex determination and its role in driving genome evolution, the Y chromosome remains poorly understood in most species. Y chromosomes are gene-poor, repeat-rich and largely heterochromatic and therefore represent a difficult target for genetic engineering. The Y chromosome of the human malaria vector Anopheles gambiae appears to be involved in sex determination although very little is known about both its structure and function. Here, we characterize a transgenic strain of this mosquito species, obtained by transposon-mediated integration of a transgene construct onto the Y chromosome. Using meganuclease-induced homologous repair we introduce a site-specific recombination signal onto the Y chromosome and show that the resulting docking line can be used for secondary integration. To demonstrate its utility, we study the activity of a germ-line-specific promoter when located on the Y chromosome. We also show that Y-linked fluorescent transgenes allow automated sex separation of this important vector species, providing the means to generate large single-sex populations. Our findings will aid studies of sex chromosome function and enable the development of male-exclusive genetic traits for vector control.
Collapse
|
19
|
McDermott GP, Do D, Litterst CM, Maar D, Hindson CM, Steenblock ER, Legler TC, Jouvenot Y, Marrs SH, Bemis A, Shah P, Wong J, Wang S, Sally D, Javier L, Dinio T, Han C, Brackbill TP, Hodges SP, Ling Y, Klitgord N, Carman GJ, Berman JR, Koehler RT, Hiddessen AL, Walse P, Bousse L, Tzonev S, Hefner E, Hindson BJ, Cauly TH, Hamby K, Patel VP, Regan JF, Wyatt PW, Karlin-Neumann GA, Stumbo DP, Lowe AJ. Multiplexed Target Detection Using DNA-Binding Dye Chemistry in Droplet Digital PCR. Anal Chem 2013; 85:11619-27. [PMID: 24180464 DOI: 10.1021/ac403061n] [Citation(s) in RCA: 137] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Geoffrey P. McDermott
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Duc Do
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Claudia M. Litterst
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Dianna Maar
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | | | - Erin R. Steenblock
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Tina C. Legler
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Yann Jouvenot
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Samuel H. Marrs
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Adam Bemis
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Pallavi Shah
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Josephine Wong
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Shenglong Wang
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - David Sally
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Leanne Javier
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Theresa Dinio
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Chunxiao Han
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Timothy P. Brackbill
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Shawn P. Hodges
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Yunfeng Ling
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Niels Klitgord
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - George J. Carman
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Jennifer R. Berman
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Ryan T. Koehler
- VerdAscend Sciences, West Linn, Oregon, 97068, United States
| | - Amy L. Hiddessen
- Purigen Biosystems, Inc., Alviso, California 95002, United States
| | - Pramod Walse
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Luc Bousse
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Svilen Tzonev
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Eli Hefner
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | | | - Thomas H. Cauly
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Keith Hamby
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Viresh P. Patel
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - John F. Regan
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - Paul W. Wyatt
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | - George A. Karlin-Neumann
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| | | | - Adam J. Lowe
- The
Digital Biology Center, Bio-Rad Laboratories, Inc., 5731 West Las Positas
Boulevard, Pleasanton, California 94566, United States
| |
Collapse
|