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Liang J, Kang L, Michalak P, Sharakhov IV. Hybridization between Aedes aegypti and Aedes mascarensis mosquitoes leads to disruption of male sex determination. Commun Biol 2024; 7:886. [PMID: 39039226 PMCID: PMC11263339 DOI: 10.1038/s42003-024-06560-4] [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: 01/22/2024] [Accepted: 07/05/2024] [Indexed: 07/24/2024] Open
Abstract
Understanding the sex determination pathway and its disruptions in mosquitoes is critical for the effective control of disease vectors through genetic manipulations based on sex separation. When male hybrids of Aedes aegypti females and Ae. mascarensis males are backcrossed to Ae. aegypti females, a portion of the backcross progeny manifests as males with abnormal sexual differentiation. We discovered a significant correlation between pupal abnormalities and the feminization of subsequent adults exemplified by the relative abundance of ovarian and testicular tissues. All intersex individuals were genetic males as they expressed a male determining factor, Nix. Further, our analysis of the sex-specific splicing of doublesex and fruitless transcripts demonstrated the presence of both male and female splice variants indicating that sex determination is disrupted. A comparative transcriptomic analysis revealed similar expression levels of most female-associated genes in reproductive organs and carcasses between intersexual males and normal females. Moreover, intersexes had largely normal gene expression in testes but significant gene downregulation in male accessory glands when compared with normal males. We conclude that evolving hybrid incompatibilities between Ae. aegypti and Ae. mascarensis involve disruption of sex determination and are accompanied by changes in gene expression associated with sexual differentiation.
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Affiliation(s)
- Jiangtao Liang
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA, USA
- Fralin Life Science Institute, Virginia Polytechnic and State University, Blacksburg, VA, USA
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic and State University, Blacksburg, VA, USA
| | - Lin Kang
- Department of Biomedical Research, Edward Via College of Osteopathic Medicine, Monroe, LA, USA
- College of Pharmacy, University of Louisiana Monroe, Monroe, LA, USA
- Center for One Health Research, VA-MD College of Veterinary Medicine, Blacksburg, VA, USA
| | - Pawel Michalak
- Department of Biomedical Research, Edward Via College of Osteopathic Medicine, Monroe, LA, USA
- Center for One Health Research, VA-MD College of Veterinary Medicine, Blacksburg, VA, USA
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - Igor V Sharakhov
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA, USA.
- Fralin Life Science Institute, Virginia Polytechnic and State University, Blacksburg, VA, USA.
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic and State University, Blacksburg, VA, USA.
- Department of Genetics and Cell Biology, Tomsk State University, Tomsk, Russia.
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2
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David OG, Arce AV, Costa-da-Silva AL, Bellantuono AJ, DeGennaro M. Fertility decline in Aedes aegypti (Diptera: Culicidae) mosquitoes is associated with reduced maternal transcript deposition and does not depend on female age. JOURNAL OF MEDICAL ENTOMOLOGY 2024; 61:1064-1070. [PMID: 38757780 PMCID: PMC11239790 DOI: 10.1093/jme/tjae058] [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: 02/07/2024] [Revised: 04/02/2024] [Accepted: 04/25/2024] [Indexed: 05/18/2024]
Abstract
Female mosquitoes undergo multiple rounds of reproduction known as gonotrophic cycles (GC). A gonotrophic cycle spans the period from blood meal intake to egg laying. Nutrients from vertebrate host blood are necessary for completing egg development. During oogenesis, a female prepackages mRNA into her oocytes, and these maternal transcripts drive the first 2 h of embryonic development prior to zygotic genome activation. In this study, we profiled transcriptional changes in 1-2 h of Aedes aegypti (Diptera: Culicidae) embryos across 2 GC. We found that homeotic genes which are regulators of embryogenesis are downregulated in embryos from the second gonotrophic cycle. Interestingly, embryos produced by Ae. aegypti females progressively reduced their ability to hatch as the number of GC increased. We show that this fertility decline is due to increased reproductive output and not the mosquitoes' age. Moreover, we found a similar decline in fertility and fecundity across 3 GC in Aedes albopictus. Our results are useful for predicting mosquito population dynamics to inform vector control efforts.
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Affiliation(s)
- Olayinka G David
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Andrea V Arce
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Andre Luis Costa-da-Silva
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Anthony J Bellantuono
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Matthew DeGennaro
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
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3
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David OG, Sanchez KM, Arce AV, Costa-da-Silva AL, Bellantuono AJ, DeGennaro M. Fertility decline in female mosquitoes is regulated by the orco olfactory co-receptor. iScience 2023; 26:106883. [PMID: 37275523 PMCID: PMC10239028 DOI: 10.1016/j.isci.2023.106883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/23/2023] [Accepted: 05/11/2023] [Indexed: 06/07/2023] Open
Abstract
Female Aedes aegypti mosquitoes undergo multiple rounds of reproduction, known as gonotrophic cycles. These cycles span the period from blood meal intake to oviposition. Understanding how reproductive success is maintained across gonotrophic cycles allows for the identification of molecular targets to reduce mosquito population growth. Odorant receptor co-receptor (orco) encodes a conserved insect-specific transmembrane ion channel that complexes with tuning odorant receptors (ORs) to form a functional olfactory receptor. orco expression has been identified in the male and female mosquito germline, but its role is unclear. We report an orco-dependent, maternal effect reduction in fertility after the first gonotrophic cycle. This phenotype was removed by CRISPR-Cas9 reversion of the orco mutant locus. Eggs deposited by orco mutant females are fertilized but the embryos reveal developmental defects, reduced hatching, and changes in ion channel signaling gene transcription. We present an unexpected role for an olfactory receptor pathway in mosquito reproduction.
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Affiliation(s)
- Olayinka G. David
- Department of Biological Sciences & Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Kevin M. Sanchez
- Department of Biological Sciences & Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Andrea V. Arce
- Department of Biological Sciences & Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Andre Luis Costa-da-Silva
- Department of Biological Sciences & Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Anthony J. Bellantuono
- Department of Biological Sciences & Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Matthew DeGennaro
- Department of Biological Sciences & Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
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4
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Blondel L, Besse S, Rivard EL, Ylla G, Extavour CG. Evolution of a cytoplasmic determinant: evidence for the biochemical basis of functional evolution of the novel germ line regulator oskar. Mol Biol Evol 2021; 38:5491-5513. [PMID: 34550378 PMCID: PMC8662646 DOI: 10.1093/molbev/msab284] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Germ line specification is essential in sexually reproducing organisms. Despite their critical role, the evolutionary history of the genes that specify animal germ cells is heterogeneous and dynamic. In many insects, the gene oskar is required for the specification of the germ line. However, the germ line role of oskar is thought to be a derived role resulting from co-option from an ancestral somatic role. To address how evolutionary changes in protein sequence could have led to changes in the function of Oskar protein that enabled it to regulate germ line specification, we searched for oskar orthologs in 1,565 publicly available insect genomic and transcriptomic data sets. The earliest-diverging lineage in which we identified an oskar ortholog was the order Zygentoma (silverfish and firebrats), suggesting that oskar originated before the origin of winged insects. We noted some order-specific trends in oskar sequence evolution, including whole gene duplications, clade-specific losses, and rapid divergence. An alignment of all known 379 Oskar sequences revealed new highly conserved residues as candidates that promote dimerization of the LOTUS domain. Moreover, we identified regions of the OSK domain with conserved predicted RNA binding potential. Furthermore, we show that despite a low overall amino acid conservation, the LOTUS domain shows higher conservation of predicted secondary structure than the OSK domain. Finally, we suggest new key amino acids in the LOTUS domain that may be involved in the previously reported Oskar−Vasa physical interaction that is required for its germ line role.
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Affiliation(s)
- Leo Blondel
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Savandara Besse
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Emily L Rivard
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Guillem Ylla
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Cassandra G Extavour
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.,Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
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5
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Santos D, Gomes HF, Ribeiro L, Farias AB, Romeiro NC, da Fonseca RN, Nepomuceno-Silva JL, Moraes J. Inhibition of Aedes aegypti DNA topoisomerase II by etoposide: Impact on survival and morphology of larvae and pupae. Comp Biochem Physiol C Toxicol Pharmacol 2021; 247:109066. [PMID: 33930525 DOI: 10.1016/j.cbpc.2021.109066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 04/18/2021] [Accepted: 04/21/2021] [Indexed: 10/01/2022]
Abstract
DNA topoisomerase II enzymes maintain DNA stability during vital processes, such as genome replication, transcription and chromosomal segregation during mitosis and meiosis. In the present work, we analyzed functional aspects of the DNA topoisomerase II (AeTopII) enzyme of the mosquito Aedes aegypti. Here, we show that AeTopII mRNA is expressed at all stages of mosquito development. By in situ hybridization, we found that the AeTopII mRNA is concentrated along the ovarian follicular cells as well as in the region of the follicles. The observed expression profiles likely reflect increased topoisomerase II cellular requirements due to the intense ovarian growth and egg production following blood feeding in Ae. aegypti females. The drug etoposide, a classic inhibitor of topoisomerase II, was used for in vivo testing with 2nd stage larvae, in order to investigate the functional importance of this enzyme in Ae. aegypti survival and development. Inhibition of topoisomerase II activity with etoposide concentrations ranging from 10 to 200 μM did not leads to the immediate death of larvae. However, after 10 days of observation, etoposide treatments resulted in 30-40% decrease in survival, in a dose dependent manner, with persisting larvae and pupae presenting incomplete development, as well as morphological abnormalities. Also, approximately 50% of the treated larvae did not reach the pupal stage. Thus, we conclude that AeTopII is a vital enzyme in the development of Ae. aegypti and its sensitivity to inhibitors should be explored for potential chemical agents to be used in vector control.
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Affiliation(s)
- Daniele Santos
- Laboratório Integrado de Bioquímica Hatisaburo Masuda, NUPEM, Instituto de Biodiversidade e Sustentabilidade, Universidade Federal do Rio de Janeiro, Avenida São José Barreto, N° 764, Bairro, São José do Barreto, Macaé, RJ CEP: 27.965-045, Brazil
| | - Helga F Gomes
- Laboratório Integrado de Bioquímica Hatisaburo Masuda, NUPEM, Instituto de Biodiversidade e Sustentabilidade, Universidade Federal do Rio de Janeiro, Avenida São José Barreto, N° 764, Bairro, São José do Barreto, Macaé, RJ CEP: 27.965-045, Brazil
| | - Lupis Ribeiro
- Laboratório Integrado Ciências Morfofuncionais, NUPEM, Instituto de Biodiversidade e Sustentabilidade, Universidade Federal do Rio de Janeiro, Avenida São José Barreto, N° 764, Bairro, São José do Barreto, Macaé, RJ CEP: 27.965-045, Brazil
| | - André B Farias
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro CEP: 21941-909, Brazil; Laboratório Integrado de Computação Científica, Universidade Federal do Rio de Janeiro, Campus Macaé Professor Aloísio Teixeira, Avenida Aluízio da Silva Gomes, 50, CEP 27930-560, Granja dos Cavaleiros, Macaé, RJ, Brazil
| | - Nelilma C Romeiro
- Laboratório Integrado de Computação Científica, Universidade Federal do Rio de Janeiro, Campus Macaé Professor Aloísio Teixeira, Avenida Aluízio da Silva Gomes, 50, CEP 27930-560, Granja dos Cavaleiros, Macaé, RJ, Brazil
| | - Rodrigo Nunes da Fonseca
- Laboratório Integrado Ciências Morfofuncionais, NUPEM, Instituto de Biodiversidade e Sustentabilidade, Universidade Federal do Rio de Janeiro, Avenida São José Barreto, N° 764, Bairro, São José do Barreto, Macaé, RJ CEP: 27.965-045, Brazil
| | - José L Nepomuceno-Silva
- Laboratório Integrado de Bioquímica Hatisaburo Masuda, NUPEM, Instituto de Biodiversidade e Sustentabilidade, Universidade Federal do Rio de Janeiro, Avenida São José Barreto, N° 764, Bairro, São José do Barreto, Macaé, RJ CEP: 27.965-045, Brazil
| | - Jorge Moraes
- Laboratório Integrado de Bioquímica Hatisaburo Masuda, NUPEM, Instituto de Biodiversidade e Sustentabilidade, Universidade Federal do Rio de Janeiro, Avenida São José Barreto, N° 764, Bairro, São José do Barreto, Macaé, RJ CEP: 27.965-045, Brazil.
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Chae K, Valentin C, Jakes E, Myles KM, Adelman ZN. Novel synthetic 3'-untranslated regions for controlling transgene expression in transgenic Aedes aegypti mosquitoes. RNA Biol 2021; 18:223-231. [PMID: 34464234 DOI: 10.1080/15476286.2021.1971440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Transgenic technology for mosquitoes is now more than two decades old, and a wide array of control sequences have been described for regulating gene expression in various life stages or specific tissues. Despite this, comparatively little attention has been paid to the development and validation of other transgene-regulating elements, especially 3'-untranslated regions (3'UTRs). As a consequence, the same regulatory sequences are often used multiple times in a single transgene array, potentially leading to instability of transgenic effector genes. To increase the repertoire of characterized 3'UTRs available for genetics-based mosquito control, we generated fifteen synthetic sequences based on the base composition of the widely used SV40 3'UTR sequence, and tested their ability to contribute to the expression of reporter genes EGFP or luciferase. Transient transfection in mosquito cells identified nine candidate 3'UTRs that conferred moderate to strong gene expression. Two of these were engineered into the mosquito genome through CRISPR/Cas9-mediated site-specific insertion and compared to the original SV40 3'UTR. Both synthetic 3'UTRs were shown to successfully promote transgene expression in all mosquito life stages (larva, pupa and adults), similar to the SV40 3'UTR, albeit with differences in intensity. Thus, the synthetic 3'UTR elements described here are suitable for regulating transgene expression in Ae. aegypti, and provide valuable alternatives in the design of multi-gene cassettes. Additionally, the synthetic-scramble approach we validate here could be used to generate additional functional 3'UTR elements in this or other organisms.
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Affiliation(s)
- Keun Chae
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Collin Valentin
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Emma Jakes
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Kevin M Myles
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Zach N Adelman
- Department of Entomology, Texas A&M University, College Station, TX, USA
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7
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Yoon Y, Klomp J, Martin-Martin I, Criscione F, Calvo E, Ribeiro J, Schmidt-Ott U. Embryo polarity in moth flies and mosquitoes relies on distinct old genes with localized transcript isoforms. eLife 2019; 8:e46711. [PMID: 31591963 PMCID: PMC6783274 DOI: 10.7554/elife.46711] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 09/06/2019] [Indexed: 01/07/2023] Open
Abstract
Unrelated genes establish head-to-tail polarity in embryos of different fly species, raising the question of how they evolve this function. We show that in moth flies (Clogmia, Lutzomyia), a maternal transcript isoform of odd-paired (Zic) is localized in the anterior egg and adopted the role of anterior determinant without essential protein change. Additionally, Clogmia lost maternal germ plasm, which contributes to embryo polarity in fruit flies (Drosophila). In culicine (Culex, Aedes) and anopheline mosquitoes (Anopheles), embryo polarity rests on a previously unnamed zinc finger gene (cucoid), or pangolin (dTcf), respectively. These genes also localize an alternative transcript isoform at the anterior egg pole. Basal-branching crane flies (Nephrotoma) also enrich maternal pangolin transcript at the anterior egg pole, suggesting that pangolin functioned as ancestral axis determinant in flies. In conclusion, flies evolved an unexpected diversity of anterior determinants, and alternative transcript isoforms with distinct expression can adopt fundamentally distinct developmental roles.
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Affiliation(s)
- Yoseop Yoon
- Department of Organismal Biology and AnatomyUniversity of ChicagoChicagoUnited States
| | - Jeff Klomp
- Department of Organismal Biology and AnatomyUniversity of ChicagoChicagoUnited States
| | - Ines Martin-Martin
- Laboratory of Malaria and Vector ResearchNational Institute of Allergy and Infectious DiseasesRockvilleUnited States
| | - Frank Criscione
- Laboratory of Malaria and Vector ResearchNational Institute of Allergy and Infectious DiseasesRockvilleUnited States
| | - Eric Calvo
- Laboratory of Malaria and Vector ResearchNational Institute of Allergy and Infectious DiseasesRockvilleUnited States
| | - Jose Ribeiro
- Laboratory of Malaria and Vector ResearchNational Institute of Allergy and Infectious DiseasesRockvilleUnited States
| | - Urs Schmidt-Ott
- Department of Organismal Biology and AnatomyUniversity of ChicagoChicagoUnited States
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Bilinski SM, Jaglarz MK, Tworzydlo W. Organelle assemblages implicated in the transfer of oocyte components to the embryo: an insect perspective. CURRENT OPINION IN INSECT SCIENCE 2019; 31:1-7. [PMID: 31109662 DOI: 10.1016/j.cois.2018.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 05/09/2018] [Indexed: 06/09/2023]
Abstract
Besides reserve materials (yolk spheres, lipid droplets), ribosomes and various mRNA species, insect oocytes contain large easily morphologically recognizable organelle assemblages: the Balbiani body and the oosome (pole plasm). These assemblages are implicated in the transfer of oocyte components (mitochondria, polar granules) to the embryo that is to offspring. Here, we review present knowledge of morphology, morphogenesis, molecular composition and function/s of these assemblages. We discuss also the morphogenesis and presumed function of unconventional organelle assemblages, dormant stacks of endoplasmic reticulum, recently described in the oocytes and early embryos of a viviparous dermapteran, Hemimerus talpoides.
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Affiliation(s)
- Szczepan M Bilinski
- Department of Developmental Biology and Invertebrate Morphology, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Krakow, Poland.
| | - Mariusz K Jaglarz
- Department of Developmental Biology and Invertebrate Morphology, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Krakow, Poland
| | - Waclaw Tworzydlo
- Department of Developmental Biology and Invertebrate Morphology, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Krakow, Poland
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Kulkarni A, Extavour CG. The Cricket Gryllus bimaculatus: Techniques for Quantitative and Functional Genetic Analyses of Cricket Biology. Results Probl Cell Differ 2019; 68:183-216. [PMID: 31598857 DOI: 10.1007/978-3-030-23459-1_8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
All extant species are an outcome of nature's "experiments" during evolution, and hence multiple species need to be studied and compared to gain a thorough understanding of evolutionary processes. The field of evolutionary developmental biology (evo-devo) aspires to expand the number of species studied, because most functional genetic studies in animals have been limited to a small number of "traditional" model organisms, many of which belong to the same phylum (Chordata). The phylum Arthropoda, and particularly its component class Insecta, possesses many important characteristics that are considered favorable and attractive for evo-devo research, including an astonishing diversity of extant species and a wide disparity in body plans. The development of the most thoroughly investigated insect genetic model system to date, the fruit fly Drosophila melanogaster (a holometabolous insect), appears highly derived with respect to other insects and indeed with respect to most arthropods. In comparison, crickets (a basally branching hemimetabolous insect lineage compared to the Holometabola) are thought to embody many developmental features that make them more representative of insects. Here we focus on crickets as emerging models to study problems in a wide range of biological areas and summarize the currently available molecular, genomic, forward and reverse genetic, imaging and computational tool kit that has been established or adapted for cricket research. With an emphasis on the cricket species Gryllus bimaculatus, we highlight recent efforts made by the scientific community in establishing this species as a laboratory model for cellular biology and developmental genetics. This broad toolkit has the potential to accelerate many traditional areas of cricket research, including studies of adaptation, evolution, neuroethology, physiology, endocrinology, regeneration, and reproductive behavior. It may also help to establish newer areas, for example, the use of crickets as animal infection model systems and human food sources.
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Affiliation(s)
- Arpita Kulkarni
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Cassandra G Extavour
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
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10
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Ribeiro JMC, Martin-Martin I, Moreira FR, Bernard KA, Calvo E. A deep insight into the male and female sialotranscriptome of adult Culex tarsalis mosquitoes. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 95:1-9. [PMID: 29526772 PMCID: PMC5927831 DOI: 10.1016/j.ibmb.2018.03.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 02/20/2018] [Accepted: 03/01/2018] [Indexed: 06/09/2023]
Abstract
Previously, a Sanger-based sialotranscriptome analysis of adult female Culex tarsalis was published based on ∼2000 ESTs. During the elapsed 7.5 years, pyrosequencing has been discontinued and Illumina sequences have increased considerable in size and decreased in price. We here report an Illumina-based sialotranscriptome that allowed finding the missing apyrase from the salivary transcriptome of C. tarsalis, to determine several full-length members of the 34-62 kDa family, when a single EST has been found previously, in addition to identifying many salivary families with lower expression levels that were not detected previously. The use of multiple libraries including salivary glands and carcasses from male and female organisms allowed for an unprecedented insight into the tissue specificity of transcripts, and in this particular case permitting identification of transcripts putatively associated with blood feeding, when exclusive of female salivary glands, or associated with sugar feeding, when transcripts are found upregulated in both male and female glands.
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Affiliation(s)
- José M C Ribeiro
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, 12735 Twinbrook Parkway Room 2E32D, Rockville, MD, 20852, United States.
| | - Ines Martin-Martin
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, 12735 Twinbrook Parkway Room 2E32D, Rockville, MD, 20852, United States
| | - Fernando R Moreira
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Dr., Madison, WI, 53706, United States
| | - Kristen A Bernard
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Dr., Madison, WI, 53706, United States
| | - Eric Calvo
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, 12735 Twinbrook Parkway Room 2E32D, Rockville, MD, 20852, United States
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11
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Bilinski SM, Jaglarz MK, Tworzydlo W. The Pole (Germ) Plasm in Insect Oocytes. Results Probl Cell Differ 2017; 63:103-126. [PMID: 28779315 DOI: 10.1007/978-3-319-60855-6_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Animal germline cells are specified either through zygotic induction or cytoplasmic inheritance. Zygotic induction takes place in mid- or late embryogenesis and requires cell-to-cell signaling leading to the acquisition of germline fate de novo. In contrast, cytoplasmic inheritance involves formation of a specific, asymmetrically localized oocyte region, termed the germ (pole) plasm. This region contains maternally provided germline determinants (mRNAs, proteins) that are capable of inducing germline fate in a subset of embryonic cells. Recent data indicate that among insects, the zygotic induction represents an ancestral condition, while the cytoplasmic inheritance evolved at the base of Holometabola or in the last common ancestor of Holometabola and its sister taxon, Paraneoptera.In this chapter, we first describe subsequent stages of morphogenesis of the pole plasm and polar granules in the model organism, Drosophila melanogaster. Then, we present an overview of morphology and cytoarchitecture of the pole plasm in various holometabolan and paraneopteran insect species. Finally, we focus on phylogenetic hypotheses explaining the known distribution of two different strategies of germline specification among insects.
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Affiliation(s)
- Szczepan M Bilinski
- Department of Developmental Biology and Morphology of Invertebrates, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Krakow, Poland.
| | - Mariusz K Jaglarz
- Department of Developmental Biology and Morphology of Invertebrates, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Krakow, Poland
| | - Waclaw Tworzydlo
- Department of Developmental Biology and Morphology of Invertebrates, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Krakow, Poland
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12
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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.
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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.
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Quan H, Lynch JA. The evolution of insect germline specification strategies. CURRENT OPINION IN INSECT SCIENCE 2016; 13:99-105. [PMID: 27088076 PMCID: PMC4827259 DOI: 10.1016/j.cois.2016.02.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The establishment of the germline is essential for sexually reproducing organisms. In animals, there are two major strategies to specify the germline: maternal provision and zygotic induction. The molecular basis of the maternal provision mode has been well characterized in several model organisms (fly, frog, fish, and nematode), while that of the zygotic induction mode has mainly been studied in mammalian models such as the mouse. Shifts in germline determination modes occur unexpectedly frequently and many such shifts have occurred several times among insects. Given their general tractability and rapidly increasing genomic and genetic tools applicable to many species, the insects present a uniquely powerful model system for understanding major transitions in reproductive strategies, and developmental processes in general.
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Affiliation(s)
- Honghu Quan
- Department of Biological Sciences, University of Illinois at Chicago, United States
| | - Jeremy A Lynch
- Department of Biological Sciences, University of Illinois at Chicago, United States.
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14
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George P, Jensen S, Pogorelcnik R, Lee J, Xing Y, Brasset E, Vaury C, Sharakhov IV. Increased production of piRNAs from euchromatic clusters and genes in Anopheles gambiae compared with Drosophila melanogaster. Epigenetics Chromatin 2015; 8:50. [PMID: 26617674 PMCID: PMC4662822 DOI: 10.1186/s13072-015-0041-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/04/2015] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Specific genomic loci, termed Piwi-interacting RNA (piRNA) clusters, manufacture piRNAs that serve as guides for the inactivation of complementary transposable elements (TEs). The piRNA pathway has been accurately detailed in Drosophila melanogaster, while it remains poorly examined in other insects. This pathway is increasingly recognized as critical for germline development and reproduction. Understanding of the piRNA functions in mosquitoes could offer an opportunity for disease vector control by the reduction of their reproductive potential. RESULTS To analyze the similarities and differences in this pathway between Drosophila and mosquito, we performed an in-depth analysis of the genomic loci producing piRNAs and their targets in the African malaria vector Anopheles gambiae. We identified 187 piRNA clusters in the An. gambiae genome and 155 piRNA clusters in the D. melanogaster genome. We demonstrate that many more piRNA clusters in the mosquito compared with the fruit fly are uni-directionally transcribed and are located outside pericentromeric heterochromatin. About 11 % of the An. gambiae piRNA population map to gene transcripts. This is a noticeable increase compared with the ~6 % of the piRNA population mapped to genes in D. melanogaster. A subset of the piRNA-enriched genes in An. gambiae has functions related to reproduction and development. At least 24 and 65 % of the mapped piRNAs correspond to genomic TE sequences in An. gambiae and D. melanogaster, respectively. DNA transposons and non-LTR retrotransposons are more abundant in An. gambiae, while LTR retrotransposons are more abundant in D. melanogaster. Yet, piRNAs predominantly target LTR retrotransposons in both species, which may point to a distinct feature of these elements compared to the other classes of TEs concerning their silencing by the piRNA pathway. CONCLUSIONS Here, we demonstrate that piRNA-producing loci have more ubiquitous distribution in the An. gambiae genome than in the genome of D. melanogaster. Also, protein-coding genes have an increased role in production of piRNAs in the germline of this mosquito. Genes involved in germline and embryonic development of An. gambiae generate a substantial portion of piRNAs, suggesting a role of the piRNA pathway in the epigenetic regulation of the reproductive processes in the African malaria vector.
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Affiliation(s)
- Phillip George
- />Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
| | - Silke Jensen
- />Laboratoire Génétique, Reproduction, et Développement, Clermont Université, Université d’Auvergne, BP 38, 63001 Clermont-Ferrand, France
- />Institut National de la Santé et de la Recherche Médicale, U 1103, BP 38, 63001 Clermont-Ferrand, France
- />Centre National de Recherche Scientifique, UMR 6293, BP 38, 63001 Clermont-Ferrand, France
| | - Romain Pogorelcnik
- />Laboratoire Génétique, Reproduction, et Développement, Clermont Université, Université d’Auvergne, BP 38, 63001 Clermont-Ferrand, France
- />Institut National de la Santé et de la Recherche Médicale, U 1103, BP 38, 63001 Clermont-Ferrand, France
- />Centre National de Recherche Scientifique, UMR 6293, BP 38, 63001 Clermont-Ferrand, France
| | - Jiyoung Lee
- />The PhD Program in Genomics Bioinformatics and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
| | - Yi Xing
- />The PhD Program in Genomics Bioinformatics and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
| | - Emilie Brasset
- />Laboratoire Génétique, Reproduction, et Développement, Clermont Université, Université d’Auvergne, BP 38, 63001 Clermont-Ferrand, France
- />Institut National de la Santé et de la Recherche Médicale, U 1103, BP 38, 63001 Clermont-Ferrand, France
- />Centre National de Recherche Scientifique, UMR 6293, BP 38, 63001 Clermont-Ferrand, France
| | - Chantal Vaury
- />Laboratoire Génétique, Reproduction, et Développement, Clermont Université, Université d’Auvergne, BP 38, 63001 Clermont-Ferrand, France
- />Institut National de la Santé et de la Recherche Médicale, U 1103, BP 38, 63001 Clermont-Ferrand, France
- />Centre National de Recherche Scientifique, UMR 6293, BP 38, 63001 Clermont-Ferrand, France
| | - Igor V. Sharakhov
- />Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
- />The PhD Program in Genomics Bioinformatics and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
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15
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Reid WR, Zhang L, Liu N. Temporal Gene Expression Profiles of Pre Blood-Fed Adult Females Immediately Following Eclosion in the Southern House Mosquito Culex Quinquefasciatus. Int J Biol Sci 2015; 11:1306-13. [PMID: 26435696 PMCID: PMC4582154 DOI: 10.7150/ijbs.12829] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 07/28/2015] [Indexed: 01/08/2023] Open
Abstract
Prior to acquisition of the first host blood meal, the anautogenous mosquito Culex quinquefasciatus requires a period of time in order to prepare for the blood feeding and, later, vitellogenesis. In the current study, we conducted whole transcriptome analyses of adult female Culex mosquitoes to identify genes that may be necessary for both taking of the blood meal, and processing of the blood meal in adult female mosquitoes Cx. quinquefasciatus. We examined temporal expression of genes for the periods of post eclosion and prior to the female freely taking a blood meal. We further evaluated the temporal expression of certain genes for the periods after the taking of a blood meal to identify genes that may be necessary for both the taking of the blood meal, and the processing of the blood meal. We found that adult females required a minimum of 48 h post-eclosion before they freely took their first blood meal. We hypothesized that gene expression signatures were altered in the mosquitoes before blood feeding in preparation for the acquisition of the blood meal through changes in multiple gene expression. To identify the genes involved in the acquisition of blood feeding, we quantified the gene expression levels of adult female Cx. quinquefasciatus using RNA Seq throughout a pre-blooding period from 2 to 72 h post eclosion at 12 h intervals. A total of 325 genes were determined to be differentially-expressed throughout the pre-blooding period, with the majority of differentially-expressed genes occurring between the 2 h and 12 h post-eclosion time points. Among the up-regulated genes were salivary proteins, cytochrome P450s, odorant-binding proteins, and proteases, while the majority of the down-regulated genes were hypothetical or cuticular genes. In addition, Trypsin was found to be up-regulated immediately following blood feeding, while trypsin and chymotrypsin were up-regulated at 48h and 60h post blood-feeding, respectively, suggesting that these proteases are likely involved in the digestion of the blood meal. Overall, this study reviewed multiple genes that might be involved in the adult female competency for blood meal acquisition in mosquitoes.
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Affiliation(s)
- William R Reid
- 1. Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA ; 2. Current address: UDSA-ARS Center for Medical Veterinary and Agricultural Entomology, Mosquito and Fly Research Unit, Gainesville, FL 32608, USA
| | - Lee Zhang
- 3. Genomics Laboratory, Auburn University, Auburn, AL 36849, USA
| | - Nannan Liu
- 1. Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA
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Jeske M, Bordi M, Glatt S, Müller S, Rybin V, Müller CW, Ephrussi A. The Crystal Structure of the Drosophila Germline Inducer Oskar Identifies Two Domains with Distinct Vasa Helicase- and RNA-Binding Activities. Cell Rep 2015; 12:587-98. [PMID: 26190108 DOI: 10.1016/j.celrep.2015.06.055] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/25/2015] [Accepted: 06/15/2015] [Indexed: 12/31/2022] Open
Abstract
In many animals, the germ plasm segregates germline from soma during early development. Oskar protein is known for its ability to induce germ plasm formation and germ cells in Drosophila. However, the molecular basis of germ plasm formation remains unclear. Here, we show that Oskar is an RNA-binding protein in vivo, crosslinking to nanos, polar granule component, and germ cell-less mRNAs, each of which has a role in germline formation. Furthermore, we present high-resolution crystal structures of the two Oskar domains. RNA-binding maps in vitro to the C-terminal domain, which shows structural similarity to SGNH hydrolases. The highly conserved N-terminal LOTUS domain forms dimers and mediates Oskar interaction with the germline-specific RNA helicase Vasa in vitro. Our findings suggest a dual function of Oskar in RNA and Vasa binding, providing molecular clues to its germ plasm function.
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Affiliation(s)
- Mandy Jeske
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany; Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Matteo Bordi
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Sebastian Glatt
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Sandra Müller
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Vladimir Rybin
- Protein Expression and Purification Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Christoph W Müller
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
| | - Anne Ephrussi
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
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17
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Hu W, Criscione F, Liang S, Tu Z. MicroRNAs of two medically important mosquito species: Aedes aegypti and Anopheles stephensi. INSECT MOLECULAR BIOLOGY 2015; 24:240-52. [PMID: 25420875 PMCID: PMC4361387 DOI: 10.1111/imb.12152] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
MicroRNAs (miRNAs) are endogenous, single-stranded small RNAs that have important regulatory functions at the post-transcriptional level. In the present study, we characterize miRNAs in two divergent mosquito species, Aedes aegypti and Anopheles stephensi, through deep sequencing of small RNAs spanning all developmental stages. We discovered eight novel miRNAs in Ae. aegypti and 20 novel miRNAs in An. stephensi, which enabled the first systematic analysis of miRNA evolution in mosquitos. We traced the phylogenetic history of all miRNAs in both species and report a rate of 0.055-0.13 miRNA net gain per million years. Most novel miRNAs originate de novo. Duplications that produced miRNA clusters and families are more common in Ae. aegypti than in An. stephensi. We also identified arm-switch as a source of new miRNAs. Expression profile analysis identified mosquito-specific miRNAs that showed strong stage-specific expression in one or both lineages. For example, the aae-miR-2941/2946 family represents the most abundant maternally deposited and zygotically transcribed miRNAs in Ae. aegypti. miR-2943 is a highly expressed zygotic miRNA in both Ae. aegypti and An. stephensi. Such information provides the basis from which to study the function of these miRNAs in biology common to all mosquitos or unique to one particular lineage.
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Affiliation(s)
- W Hu
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA; Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, USA
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18
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Lin GW, Cook CE, Miura T, Chang CC. Posterior localization of ApVas1 positions the preformed germ plasm in the sexual oviparous pea aphid Acyrthosiphon pisum. EvoDevo 2014; 5:18. [PMID: 24855557 PMCID: PMC4030528 DOI: 10.1186/2041-9139-5-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 04/23/2014] [Indexed: 12/19/2022] Open
Abstract
Background Germline specification in some animals is driven by the maternally inherited germ plasm during early embryogenesis (inheritance mode), whereas in others it is induced by signals from neighboring cells in mid or late development (induction mode). In the Metazoa, the induction mode appears as a more prevalent and ancestral condition; the inheritance mode is therefore derived. However, regarding germline specification in organisms with asexual and sexual reproduction it has not been clear whether both strategies are used, one for each reproductive phase, or if just one strategy is used for both phases. Previously we have demonstrated that specification of germ cells in the asexual viviparous pea aphid depends on a preformed germ plasm. In this study, we extended this work to investigate how germ cells were specified in the sexual oviparous embryos, aiming to understand whether or not developmental plasticity of germline specification exists in the pea aphid. Results We employed Apvas1, a Drosophila vasa ortholog in the pea aphid, as a germline marker to examine whether germ plasm is preformed during oviparous development, as has already been seen in the viviparous embryos. During oogenesis, Apvas1 mRNA and ApVas1 protein were both evenly distributed. After fertilization, uniform expression of Apvas1 remained in the egg but posterior localization of ApVas1 occurred from the fifth nuclear cycle onward. Posterior co-localization of Apvas1/ApVas1 was first identified in the syncytial blastoderm undergoing cellularization, and later we could detect specific expression of Apvas1/ApVas1 in the morphologically identifiable germ cells of mature embryos. This suggests that Apvas1/ApVas1-positive cells are primordial germ cells and posterior localization of ApVas1 prior to cellularization positions the preformed germ plasm. Conclusions We conclude that both asexual and sexual pea aphids rely on the preformed germ plasm to specify germ cells and that developmental plasticity of germline specification, unlike axis patterning, occurs in neither of the two aphid reproductive phases. Consequently, the maternal inheritance mode implicated by a preformed germ plasm in the oviparous pea aphid becomes a non-canonical case in the Hemimetabola, where so far the zygotic induction mode prevails in most other studied insects.
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Affiliation(s)
- Gee-Way Lin
- Laboratory for Genetics and Development, Department of Entomology/Institute of Biotechnology, College of Bioresources and Agriculture, National Taiwan University, No. 27, Lane 113, Roosevelt Road, Sec. 4, Taipei 106, Taiwan ; Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, N10 W5, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
| | - Charles E Cook
- EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Toru Miura
- Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, N10 W5, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
| | - Chun-Che Chang
- Laboratory for Genetics and Development, Department of Entomology/Institute of Biotechnology, College of Bioresources and Agriculture, National Taiwan University, No. 27, Lane 113, Roosevelt Road, Sec. 4, Taipei 106, Taiwan ; Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei 100, Taiwan ; Genome and Systems Biology Degree Program, National Taiwan University, Taipei 106, Taiwan
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Marinotti O, Ngo T, Kojin BB, Chou SP, Nguyen B, Juhn J, Carballar-Lejarazú R, Marinotti PN, Jiang X, Walter MF, Tu Z, Gershon PD, James AA. Integrated proteomic and transcriptomic analysis of the Aedes aegypti eggshell. BMC DEVELOPMENTAL BIOLOGY 2014; 14:15. [PMID: 24707823 PMCID: PMC4234484 DOI: 10.1186/1471-213x-14-15] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 03/31/2014] [Indexed: 11/10/2022]
Abstract
Background Mosquito eggshells show remarkable diversity in physical properties and structure consistent with adaptations to the wide variety of environments exploited by these insects. We applied proteomic, transcriptomic, and hybridization in situ techniques to identify gene products and pathways that participate in the assembly of the Aedes aegypti eggshell. Aedes aegypti population density is low during cold and dry seasons and increases immediately after rainfall. The survival of embryos through unfavorable periods is a key factor in the persistence of their populations. The work described here supports integrated vector control approaches that target eggshell formation and result in Ae. aegypti drought-intolerant phenotypes for public health initiatives directed to reduce mosquito-borne diseases. Results A total of 130 proteins were identified from the combined mass spectrometric analyses of eggshell preparations. Conclusions Classification of proteins according to their known and putative functions revealed the complexity of the eggshell structure. Three novel Ae. aegypti vitelline membrane proteins were discovered. Odorant-binding and cysteine-rich proteins that may be structural components of the eggshell were identified. Enzymes with peroxidase, laccase and phenoloxidase activities also were identified, and their likely involvements in cross-linking reactions that stabilize the eggshell structure are discussed.
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Affiliation(s)
- Osvaldo Marinotti
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA.
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20
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Ahuja A, Extavour CG. Patterns of molecular evolution of the germ line specification gene oskar suggest that a novel domain may contribute to functional divergence in Drosophila. Dev Genes Evol 2014; 224:65-77. [DOI: 10.1007/s00427-013-0463-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 12/07/2013] [Indexed: 01/04/2023]
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21
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Criscione F, Qi Y, Saunders R, Hall B, Tu Z. A unique Y gene in the Asian malaria mosquito Anopheles stephensi encodes a small lysine-rich protein and is transcribed at the onset of embryonic development. INSECT MOLECULAR BIOLOGY 2013; 22:433-41. [PMID: 23683123 PMCID: PMC3700585 DOI: 10.1111/imb.12034] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In many organisms the Y chromosome initiates sex determination and regulates male fertility and mating behaviour. However, molecular characterization of Y genes is rare outside of a few model species because it is difficult to clone and analyse repeat-rich heterochromatic Y sequences. In insects, Y genes are only well characterized in a small number of Drosophila species. Here we report the discovery of GUY1 (gene unique to the Y), a gene unique to the Y chromosome in the Asian malaria mosquito, Anopheles stephensi, using an approach that compares Illumina sequences separately obtained from male and female genomic DNA. Experimental evidence confirmed that GUY1 is a single copy gene found only on the Y chromosome. GUY1 is transcribed at the very onset of zygotic transcription and encodes a small lysine-rich protein that forms two alpha helices and shows DNA-binding properties. Interestingly, three helix-loop-helix proteins are key factors that determine sex in the early embryo in Drosophila melanogaster. Single embryo analysis indicated that GUY1 is only transcribed in male embryos and that the GUY1 promoter is functional in the early embryos. GUY1 may be used as a paternally inherited molecular marker. Further investigation of GUY1 will contribute to the genetic approaches to control mosquito-borne diseases.
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Affiliation(s)
- F Criscione
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
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22
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Ewen-Campen B, Jones TEM, Extavour CG. Evidence against a germ plasm in the milkweed bug Oncopeltus fasciatus, a hemimetabolous insect. Biol Open 2013; 2:556-68. [PMID: 23789106 PMCID: PMC3683158 DOI: 10.1242/bio.20134390] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 03/01/2013] [Indexed: 01/23/2023] Open
Abstract
Primordial germ cell (PGC) formation in holometabolous insects like Drosophila melanogaster relies on maternally synthesised germ cell determinants that are asymmetrically localised to the oocyte posterior cortex. Embryonic nuclei that inherit this "germ plasm" acquire PGC fate. In contrast, historical studies of basally branching insects (Hemimetabola) suggest that a maternal requirement for germ line genes in PGC specification may be a derived character confined principally to Holometabola. However, there have been remarkably few investigations of germ line gene expression and function in hemimetabolous insects. Here we characterise PGC formation in the milkweed bug Oncopeltus fasciatus, a member of the sister group to Holometabola, thus providing an important evolutionary comparison to members of this clade. We examine the transcript distribution of orthologues of 19 Drosophila germ cell and/or germ plasm marker genes, and show that none of them localise asymmetrically within Oncopeltus oocytes or early embryos. Using multiple molecular and cytological criteria, we provide evidence that PGCs form after cellularisation at the site of gastrulation. Functional studies of vasa and tudor reveal that these genes are not required for germ cell formation, but that vasa is required in adult males for spermatogenesis. Taken together, our results provide evidence that Oncopeltus germ cells may form in the absence of germ plasm, consistent with the hypothesis that germ plasm is a derived strategy of germ cell specification in insects.
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Affiliation(s)
- Ben Ewen-Campen
- Department of Organismic and Evolutionary Biology, Harvard University , 16 Divinity Avenue, Cambridge, MA 02138 , USA
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Nguyen C, Andrews E, Le C, Sun L, Annan Z, Clemons A, Severson DW, Duman-Scheel M. Functional genetic characterization of salivary gland development in Aedes aegypti. EvoDevo 2013; 4:9. [PMID: 23497573 PMCID: PMC3599648 DOI: 10.1186/2041-9139-4-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 12/07/2012] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Despite the devastating global impact of mosquito-borne illnesses on human health, very little is known about mosquito developmental biology. In this investigation, functional genetic analysis of embryonic salivary gland development was performed in Aedes aegypti, the dengue and yellow fever vector and an emerging model for vector mosquito development. Although embryonic salivary gland development has been well studied in Drosophila melanogaster, little is known about this process in mosquitoes or other arthropods. RESULTS Mosquitoes possess orthologs of many genes that regulate Drosophila melanogaster embryonic salivary gland development. The expression patterns of a large subset of these genes were assessed during Ae. aegypti development. These studies identified a set of molecular genetic markers for the developing mosquito salivary gland. Analysis of marker expression allowed for tracking of the progression of Ae. aegypti salivary gland development in embryos. In Drosophila, the salivary glands develop from placodes located in the ventral neuroectoderm. However, in Ae. aegypti, salivary marker genes are not expressed in placode-like patterns in the ventral neuroectoderm. Instead, marker gene expression is detected in salivary gland rudiments adjacent to the proventriculus. These observations highlighted the need for functional genetic characterization of mosquito salivary gland development. An siRNA- mediated knockdown strategy was therefore employed to investigate the role of one of the marker genes, cyclic-AMP response element binding protein A (Aae crebA), during Ae. aegypti salivary gland development. These experiments revealed that Aae crebA encodes a key transcriptional regulator of the secretory pathway in the developing Ae. aegypti salivary gland. CONCLUSIONS The results of this investigation indicated that the initiation of salivary gland development in Ae. aegypti significantly differs from that of D. melanogaster. Despite these differences, some elements of salivary gland development, including the ability of CrebA to regulate secretory gene expression, are conserved between the two species. These studies underscore the need for further analysis of mosquito developmental genetics and may foster comparative studies of salivary gland development in additional insect species.
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Affiliation(s)
- Chilinh Nguyen
- University of Notre Dame, Notre Dame, Eck Institute for Global Health and Department of Biological Sciences, Notre Dame, IN 46556, USA.
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Telang A, Rechel JA, Brandt JR, Donnell DM. Analysis of ovary-specific genes in relation to egg maturation and female nutritional condition in the mosquitoes Georgecraigius atropalpus and Aedes aegypti (Diptera: Culicidae). JOURNAL OF INSECT PHYSIOLOGY 2013; 59:283-94. [PMID: 23238126 PMCID: PMC3596486 DOI: 10.1016/j.jinsphys.2012.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 11/23/2012] [Accepted: 11/27/2012] [Indexed: 05/09/2023]
Abstract
Analysis of the reproductive physiology of anautogenous mosquitoes at the molecular level is complicated by the simultaneity of ovarian maturation and the digestion of a blood meal. In contrast to anautogenous mosquitoes, autogenous female mosquitoes can acquire greater nutrient stores as larvae and exhibit higher ovarian production of ecdysteroids at adult eclosion. These features essentially replace the role of a blood meal in provisioning the first batch of eggs and initiating egg development. To gain insight into the process of ovary maturation we first performed a transcript analysis of the obligatory autogenous mosquito Georgecraigius atropalpus (formerly Ochlerotatus atropalpus). We identified ESTs using suppressive subtractive hybridization (SSH) of transcripts from ovaries at critical times during oogenesis in the absence of blood digestion. Preliminary expression studies of genes such as apolipophorin III (APO) and oxysterol binding protein (OSBP) suggested these genes might be cued to female nutritional status. We then applied our findings to the medically important anautogenous mosquito Aedes aegypti. RNAi-based analyses of these genes in Ae. aegypti revealed a reduction in APO transcripts leads to reduced lipid levels in carcass and ovaries and that OSBP may play a role in overall lipid and sterol homeostasis. In addition to expanding our understanding of mosquito ovarian development, the continued use of a comparative approach between autogenous and anautogenous species may provide novel intervention points for the regulation of mosquito egg production.
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Affiliation(s)
- Aparna Telang
- Department of Biology, University of Richmond, Richmond, VA 23173, USA.
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Juhn J, James AA. Hybridization in situ of salivary glands, ovaries, and embryos of vector mosquitoes. J Vis Exp 2012:3709. [PMID: 22781778 PMCID: PMC3476388 DOI: 10.3791/3709] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Mosquitoes are vectors for a diverse set of pathogens including arboviruses, protozoan parasites and nematodes. Investigation of transcripts and gene regulators that are expressed in tissues in which the mosquito host and pathogen interact, and in organs involved in reproduction are of great interest for strategies to reduce mosquito-borne disease transmission and disrupt egg development. A number of tools have been employed to study and validate the temporal and tissue-specific regulation of gene expression. Here, we describe protocols that have been developed to obtain spatial information, which enhances our understanding of where specific genes are expressed and their products accumulate. The protocol described has been used to validate expression and determine accumulation patterns of transcripts in tissues related to mosquito-borne pathogen transmission, such as female salivary glands, as well as subcellular compartments of ovaries and embryos, which relate to mosquito reproduction and development. The following procedures represent an optimized methodology that improves the efficiency of various steps in the protocol without loss of target-specific hybridization signals. Guidelines for RNA probe preparation, dissection of soft tissues and the general procedure for fixation and hybridization are described in Part A, while steps specific for the collection, fixation, pre-hybridization and hybridization of mosquito embryos are detailed in Part B.
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Affiliation(s)
- Jennifer Juhn
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA.
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Control of RNP motility and localization by a splicing-dependent structure in oskar mRNA. Nat Struct Mol Biol 2012; 19:441-9. [PMID: 22426546 DOI: 10.1038/nsmb.2257] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 01/07/2012] [Indexed: 11/08/2022]
Abstract
oskar RNA localization to the posterior pole of the Drosophila melanogaster oocyte requires splicing of the first intron and the exon junction complex (EJC) core proteins. The functional link between splicing, EJC deposition and oskar localization has been unclear. Here we demonstrate that the EJC associates with oskar mRNA upon splicing in vitro and that Drosophila EJC deposition is constitutive and conserved. Our in vivo analysis reveals that splicing creates the spliced oskar localization element (SOLE), whose structural integrity is crucial for ribonucleoprotein motility and localization in the oocyte. Splicing thus has a dual role in oskar mRNA localization: assembling the SOLE and depositing the EJC required for mRNA transport. The SOLE complements the EJC in formation of a functional unit that, together with the oskar 3' UTR, maintains proper kinesin-based motility of oskar mRNPs and posterior mRNA targeting.
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Behura SK, Haugen M, Flannery E, Sarro J, Tessier CR, Severson DW, Duman-Scheel M. Comparative genomic analysis of Drosophila melanogaster and vector mosquito developmental genes. PLoS One 2011; 6:e21504. [PMID: 21754989 PMCID: PMC3130749 DOI: 10.1371/journal.pone.0021504] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 05/30/2011] [Indexed: 11/18/2022] Open
Abstract
Genome sequencing projects have presented the opportunity for analysis of developmental genes in three vector mosquito species: Aedes aegypti, Culex quinquefasciatus, and Anopheles gambiae. A comparative genomic analysis of developmental genes in Drosophila melanogaster and these three important vectors of human disease was performed in this investigation. While the study was comprehensive, special emphasis centered on genes that 1) are components of developmental signaling pathways, 2) regulate fundamental developmental processes, 3) are critical for the development of tissues of vector importance, 4) function in developmental processes known to have diverged within insects, and 5) encode microRNAs (miRNAs) that regulate developmental transcripts in Drosophila. While most fruit fly developmental genes are conserved in the three vector mosquito species, several genes known to be critical for Drosophila development were not identified in one or more mosquito genomes. In other cases, mosquito lineage-specific gene gains with respect to D. melanogaster were noted. Sequence analyses also revealed that numerous repetitive sequences are a common structural feature of Drosophila and mosquito developmental genes. Finally, analysis of predicted miRNA binding sites in fruit fly and mosquito developmental genes suggests that the repertoire of developmental genes targeted by miRNAs is species-specific. The results of this study provide insight into the evolution of developmental genes and processes in dipterans and other arthropods, serve as a resource for those pursuing analysis of mosquito development, and will promote the design and refinement of functional analysis experiments.
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Affiliation(s)
- Susanta K. Behura
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Morgan Haugen
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
| | - Ellen Flannery
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Joseph Sarro
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Charles R. Tessier
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
| | - David W. Severson
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
| | - Molly Duman-Scheel
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
- * E-mail:
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Magnusson K, Mendes AM, Windbichler N, Papathanos PA, Nolan T, Dottorini T, Rizzi E, Christophides GK, Crisanti A. Transcription regulation of sex-biased genes during ontogeny in the malaria vector Anopheles gambiae. PLoS One 2011; 6:e21572. [PMID: 21738713 PMCID: PMC3128074 DOI: 10.1371/journal.pone.0021572] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 06/03/2011] [Indexed: 11/18/2022] Open
Abstract
In Anopheles gambiae, sex-regulated genes are responsible for controlling gender dimorphism and are therefore crucial in determining the ability of female mosquitoes to transmit human malaria. The identification and functional characterization of these genes will shed light on the sexual development and maturation of mosquitoes and provide useful targets for genetic control measures aimed at reducing mosquito fertility and/or distorting the sex ratio. We conducted a genome wide transcriptional analysis of sex-regulated genes from early developmental stages through adulthood combined with functional screening of novel gonadal genes. Our results demonstrate that the male-biased genes undergo a major transcription turnover starting from larval stages to adulthood. The male biased genes at the adult stage include a significant high number of unique sequences compared to the rest of the genome. This is in contrast to female-biased genes that are much more conserved and are mainly activated during late developmental stages. The high frequency of unique sequences would indicate that male-biased genes evolve more rapidly than the rest of the genome. This finding is particularly intriguing because A. gambiae is a strictly female monogamous species suggesting that driving forces in addition to sperm competition must account for the rapid evolution of male-biased genes. We have also identified and functionally characterized a number of previously unknown A. gambiae testis- and ovary-specific genes. Two of these genes, zero population growth and a suppressor of defective silencing 3 domain of the histone deacetylase co-repressor complex, were shown to play a key role in gonad development.
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Affiliation(s)
- Kalle Magnusson
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Antonio M. Mendes
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Nikolai Windbichler
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | | | - Tony Nolan
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Tania Dottorini
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Ermanno Rizzi
- Istituto di Tecnologie Biomediche, Consiglio Nazionale delle Ricerche, Milano, Italy
| | | | - Andrea Crisanti
- Department of Life Sciences, Imperial College London, London, United Kingdom
- * E-mail:
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Haugen M, Flannery E, Tomchaney M, Mori A, Behura SK, Severson DW, Duman-Scheel M. Semaphorin-1a is required for Aedes aegypti embryonic nerve cord development. PLoS One 2011; 6:e21694. [PMID: 21738767 PMCID: PMC3124551 DOI: 10.1371/journal.pone.0021694] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 06/08/2011] [Indexed: 12/30/2022] Open
Abstract
Although mosquito genome projects have uncovered orthologues of many known developmental regulatory genes, extremely little is known about mosquito development. In this study, the role of semaphorin-1a (sema1a) was investigated during vector mosquito embryonic ventral nerve cord development. Expression of sema1a and the plexin A (plexA) receptor are detected in the embryonic ventral nerve cords of Aedes aegypti (dengue vector) and Anopheles gambiae (malaria vector), suggesting that Sema1a signaling may regulate mosquito nervous system development. Analysis of sema1a function was investigated through siRNA-mediated knockdown in A. aegypti embryos. Knockdown of sema1a during A. aegypti development results in a number of nerve cord phenotypes, including thinning, breakage, and occasional fusion of the longitudinal connectives, thin or absent commissures, and general distortion of the nerve cord. Although analysis of Drosophila melanogaster sema1a loss-of-function mutants uncovered many similar phenotypes, aspects of the longitudinal phenotypes differed between D. melanogaster and A. aegypti. The results of this investigation suggest that Sema1a is required for development of the insect ventral nerve cord, but that the developmental roles of this guidance molecule have diverged in dipteran insects.
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Affiliation(s)
- Morgan Haugen
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
| | - Ellen Flannery
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Michael Tomchaney
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Akio Mori
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Susanta K. Behura
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - David W. Severson
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Molly Duman-Scheel
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- * E-mail:
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Lynch JA, Ozüak O, Khila A, Abouheif E, Desplan C, Roth S. The phylogenetic origin of oskar coincided with the origin of maternally provisioned germ plasm and pole cells at the base of the Holometabola. PLoS Genet 2011; 7:e1002029. [PMID: 21552321 PMCID: PMC3084197 DOI: 10.1371/journal.pgen.1002029] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 02/02/2011] [Indexed: 12/19/2022] Open
Abstract
The establishment of the germline is a critical, yet surprisingly evolutionarily labile, event in the development of sexually reproducing animals. In the fly Drosophila, germ cells acquire their fate early during development through the inheritance of the germ plasm, a specialized maternal cytoplasm localized at the posterior pole of the oocyte. The gene oskar (osk) is both necessary and sufficient for assembling this substance. Both maternal germ plasm and oskar are evolutionary novelties within the insects, as the germline is specified by zygotic induction in basally branching insects, and osk has until now only been detected in dipterans. In order to understand the origin of these evolutionary novelties, we used comparative genomics, parental RNAi, and gene expression analyses in multiple insect species. We have found that the origin of osk and its role in specifying the germline coincided with the innovation of maternal germ plasm and pole cells at the base of the holometabolous insects and that losses of osk are correlated with changes in germline determination strategies within the Holometabola. Our results indicate that the invention of the novel gene osk was a key innovation that allowed the transition from the ancestral late zygotic mode of germline induction to a maternally controlled establishment of the germline found in many holometabolous insect species. We propose that the ancestral role of osk was to connect an upstream network ancestrally involved in mRNA localization and translational control to a downstream regulatory network ancestrally involved in executing the germ cell program.
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Affiliation(s)
- Jeremy A Lynch
- Institute for Developmental Biology, University of Cologne, Cologne, Germany.
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Clemons A, Haugen M, Le C, Mori A, Tomchaney M, Severson DW, Duman-Scheel M. siRNA-mediated gene targeting in Aedes aegypti embryos reveals that frazzled regulates vector mosquito CNS development. PLoS One 2011; 6:e16730. [PMID: 21304954 PMCID: PMC3031613 DOI: 10.1371/journal.pone.0016730] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 12/25/2010] [Indexed: 01/03/2023] Open
Abstract
Although mosquito genome projects uncovered orthologues of many known developmental regulatory genes, extremely little is known about the development of vector mosquitoes. Here, we investigate the role of the Netrin receptor frazzled (fra) during embryonic nerve cord development of two vector mosquito species. Fra expression is detected in neurons just prior to and during axonogenesis in the embryonic ventral nerve cord of Aedes aegypti (dengue vector) and Anopheles gambiae (malaria vector). Analysis of fra function was investigated through siRNA-mediated knockdown in Ae. aegypti embryos. Confirmation of fra knockdown, which was maintained throughout embryogenesis, indicated that microinjection of siRNA is an effective method for studying gene function in Ae. aegypti embryos. Loss of fra during Ae. aegypti development results in thin and missing commissural axons. These defects are qualitatively similar to those observed in Dr. melanogaster fra null mutants. However, the Aa. aegypti knockdown phenotype is stronger and bears resemblance to the Drosophila commissureless mutant phenotype. The results of this investigation, the first targeted knockdown of a gene during vector mosquito embryogenesis, suggest that although Fra plays a critical role during development of the Ae. aegypti ventral nerve cord, mechanisms regulating embryonic commissural axon guidance have evolved in distantly related insects.
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Affiliation(s)
- Anthony Clemons
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
| | - Morgan Haugen
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
| | - Christy Le
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Akio Mori
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Michael Tomchaney
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - David W. Severson
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
| | - Molly Duman-Scheel
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, Indiana, United States of America
- * E-mail:
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32
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Malaria vector control: from past to future. Parasitol Res 2011; 108:757-79. [PMID: 21229263 DOI: 10.1007/s00436-010-2232-0] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 10/06/2010] [Indexed: 01/17/2023]
Abstract
Malaria is one of the most common vector-borne diseases widespread in the tropical and subtropical regions. Despite considerable success of malaria control programs in the past, malaria still continues as a major public health problem in several countries. Vector control is an essential part for reducing malaria transmission and became less effective in recent years, due to many technical and administrative reasons, including poor or no adoption of alternative tools. Of the different strategies available for vector control, the most successful are indoor residual spraying and insecticide-treated nets (ITNs), including long-lasting ITNs and materials. Earlier DDT spray has shown spectacular success in decimating disease vectors but resulted in development of insecticide resistance, and to control the resistant mosquitoes, organophosphates, carbamates, and synthetic pyrethroids were introduced in indoor residual spraying with needed success but subsequently resulted in the development of widespread multiple insecticide resistance in vectors. Vector control in many countries still use insecticides in the absence of viable alternatives. Few developments for vector control, using ovitraps, space spray, biological control agents, etc., were encouraging when used in limited scale. Likewise, recent introduction of safer vector control agents, such as insect growth regulators, biocontrol agents, and natural plant products have yet to gain the needed scale of utility for vector control. Bacterial pesticides are promising and are effective in many countries. Environmental management has shown sufficient promise for vector control and disease management but still needs advocacy for inter-sectoral coordination and sometimes are very work-intensive. The more recent genetic manipulation and sterile insect techniques are under development and consideration for use in routine vector control and for these, standardized procedures and methods are available but need thorough understanding of biology, ethical considerations, and sufficiently trained manpower for implementation being technically intensive methods. All the methods mentioned in the review that are being implemented or proposed for implementation needs effective inter-sectoral coordination and community participation. The latest strategy is evolution-proof insecticides that include fungal biopesticides, Wolbachia, and Denso virus that essentially manipulate the life cycle of the mosquitoes were found effective but needs more research. However, for effective vector control, integrated vector management methods, involving use of combination of effective tools, is needed and is also suggested by Global Malaria Control Strategy. This review article raises issues associated with the present-day vector control strategies and state opportunities with a focus on ongoing research and recent advances to enable to sustain the gains achieved so far.
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Juhn J, Naeem-Ullah U, Maciel Guedes BA, Majid A, Coleman J, Paolucci Pimenta PF, Akram W, James AA, Marinotti O. Spatial mapping of gene expression in the salivary glands of the dengue vector mosquito, Aedes aegypti. Parasit Vectors 2011; 4:1. [PMID: 21205315 PMCID: PMC3043528 DOI: 10.1186/1756-3305-4-1] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 01/04/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Aedes aegypti mosquitoes are the main vectors of dengue viruses to humans. Understanding their biology and interactions with the pathogen are prerequisites for development of dengue transmission control strategies. Mosquito salivary glands are organs involved directly in pathogen transmission to vertebrate hosts. Information on the spatial distribution of gene expression in these organs is expected to assist in the development of novel disease control strategies, including those that entail the release of transgenic mosquitoes with impaired vector competence. RESULTS We report here the hybridization in situ patterns of 30 transcripts expressed in the salivary glands of adult Ae. aegypti females. Distinct spatial accumulation patterns were identified. The products of twelve genes are localized exclusively in the proximal-lateral lobes. Among these, three accumulate preferentially in the most anterior portion of the proximal-lateral lobe. This pattern revealed a salivary gland cell type previously undescribed in Ae. aegypti, which was validated by transmission electron microscopy. Five distinct gene products accumulate in the distal-lateral lobes and another five localize in the medial lobe. Seven transcripts are found in the distal-lateral and medial lobes. The transcriptional product of one gene accumulates in proximal- and distal-lateral lobes. Seven genes analyzed by quantitative PCR are expressed constitutively. The most abundant salivary gland transcripts are those localized within the proximal-lateral lobes, while previous work has shown that the distal-lateral lobes are the most active in protein synthesis. This incongruity suggests a role for translational regulation in mosquito saliva production. CONCLUSIONS Transgenic mosquitoes with reduced vector competence have been proposed as tools for the control of dengue virus transmission. Expression of anti-dengue effector molecules in the distal-lateral lobes of Ae. aegypti salivary glands has been shown to reduce prevalence and mean intensities of viral infection. We anticipate greater efficiency of viral suppression if effector genes are expressed in all lobes of the salivary glands. Based on our data, a minimum of two promoters is necessary to drive the expression of one or more anti-dengue genes in all cells of the female salivary glands.
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Affiliation(s)
- Jennifer Juhn
- Department of Molecular Biology and Biochemistry, University of California, Irvine, USA
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Clemons A, Haugen M, Flannery E, Tomchaney M, Kast K, Jacowski C, Le C, Mori A, Simanton Holland W, Sarro J, Severson DW, Duman-Scheel M. Aedes aegypti: an emerging model for vector mosquito development. Cold Spring Harb Protoc 2010; 2010:pdb.emo141. [PMID: 20889691 DOI: 10.1101/pdb.emo141] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Blood-feeding mosquitoes, including the dengue and yellow fever vector Aedes aegypti, transmit many of the world's deadliest diseases. Such diseases have resurged in developing countries and pose clear threats for epidemic outbreaks in developed countries. Recent mosquito genome projects have stimulated interest in the potential for arthropod-borne disease control by genetic manipulation of vector insects. Targets of particular interest include genes that regulate development. However, although the Ae. aegypti genome project uncovered homologs of many known developmental regulatory genes, little is known of the genetic regulation of development in Ae. aegypti or other vector mosquitoes. This article provides an overview of the background, husbandry, and potential uses of Ae. aegypti as a model species. Methods for culturing, collecting and fixing developing tissues, analyzing gene and protein expression, and knocking down genes are permitting detailed analyses of the functions of developmental regulatory genes and the selective inhibition of such genes during Ae. aegypti development. This methodology, much of which is applicable to other mosquito species, is useful to both the comparative development and vector research communities.
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Affiliation(s)
- Anthony Clemons
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, South Bend, IN 46617, USA
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Analysis of expression in the Anopheles gambiae developing testes reveals rapidly evolving lineage-specific genes in mosquitoes. BMC Genomics 2009; 10:300. [PMID: 19580678 PMCID: PMC2713267 DOI: 10.1186/1471-2164-10-300] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Accepted: 07/06/2009] [Indexed: 11/10/2022] Open
Abstract
Background Male mosquitoes do not feed on blood and are not involved in delivery of pathogens to humans. Consequently, they are seldom the subjects of research, which results in a very poor understanding of their biology. To gain insights into male developmental processes we sought to identify genes transcribed exclusively in the reproductive tissues of male Anopheles gambiae pupae. Results Using a cDNA subtraction strategy, five male-specifically or highly male-biased expressed genes were isolated, four of which remain unannotated in the An. gambiae genome. Spatial and temporal expression patterns suggest that each of these genes is involved in the mid-late stages of spermatogenesis. Their sequences are rapidly evolving; however, two genes possess clear homologs in a wide range of taxa and one of these probably acts in a sperm motility control mechanism conserved in many organisms, including humans. The other three genes have no match to sequences from non-mosquito taxa, thus can be regarded as orphans. RNA in situ hybridization demonstrated that one of the orphans is transcribed in spermatids, which suggests its involvement in sperm maturation. Two other orphans have unknown functions. Expression analysis of orthologs of all five genes indicated that male-biased transcription was not conserved in the majority of cases in Aedes and Culex. Conclusion Discovery of testis-expressed orphan genes in mosquitoes opens new prospects for the development of innovative control methods. The orphan encoded proteins may represent unique targets of selective anti-mosquito sterilizing agents that will not affect non-target organisms.
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Rezende GL, Martins AJ, Gentile C, Farnesi LC, Pelajo-Machado M, Peixoto AA, Valle D. Embryonic desiccation resistance in Aedes aegypti: presumptive role of the chitinized serosal cuticle. BMC DEVELOPMENTAL BIOLOGY 2008; 8:82. [PMID: 18789161 PMCID: PMC2561029 DOI: 10.1186/1471-213x-8-82] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Accepted: 09/13/2008] [Indexed: 11/10/2022]
Abstract
Background One of the major problems concerning dengue transmission is that embryos of its main vector, the mosquito Aedes aegypti, resist desiccation, surviving several months under dry conditions. The serosal cuticle (SC) contributes to mosquito egg desiccation resistance, but the kinetics of SC secretion during embryogenesis is unknown. It has been argued that mosquito SC contains chitin as one of its components, however conclusive evidence is still missing. Results We observed an abrupt acquisition of desiccation resistance during Ae. aegypti embryogenesis associated with serosal cuticle secretion, occurring at complete germ band extension, between 11 and 13 hours after egglaying. After SC formation embryos are viable on dry for at least several days. The presence of chitin as one of the SC constituents was confirmed through Calcofluor and WGA labeling and chitin quantitation. The Ae. aegypti Chitin Synthase A gene (AaCHS1) possesses two alternatively spliced variants, AaCHS1a and AaCHS1b, differentially expressed during Ae. aegypti embryonic development. It was verified that at the moment of serosal cuticle formation, AaCHS1a is the sole variant specifically expressed. Conclusion In addition to the peritrophic matrix and exoskeleton, these findings confirm chitin is also present in the mosquito serosal cuticle. They also point to the role of the chitinized SC in the desiccation resistance of Ae. aegypti eggs. AaCHS1a expression would be responsible for SC chitin synthesis. With this embryological approach we expect to shed new light regarding this important physiological process related to the Ae. aegypti life cycle.
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Affiliation(s)
- Gustavo Lazzaro Rezende
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, FIOCRUZ and Laboratório de Entomologia, Instituto de Biologia do Exército, Rio de Janeiro, Brazil.
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Juhn J, Marinotti O, Calvo E, James AA. Gene structure and expression of nanos (nos) and oskar (osk) orthologues of the vector mosquito, Culex quinquefasciatus. INSECT MOLECULAR BIOLOGY 2008; 17:545-52. [PMID: 18828840 PMCID: PMC3721150 DOI: 10.1111/j.1365-2583.2008.00823.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The products of the maternal-effect genes, nanos (nos) and oskar (osk), are important for the development of germ cells in insects. Furthermore, these genes have been proposed as candidates for donating functional DNA regulatory sequences for use in gene drive systems to control transmission of mosquito-borne pathogens. The nos and osk genes of the cosmopolitan vector mosquito, Culex quinquefasciatus, encode proteins with domains common to orthologues found in other mosquitoes. Expression analyses support the conclusion that the role of these genes is conserved generally among members of the nematocera. Hybridization in situ analyses reveal differences in mRNA distribution in early embryos in comparison with the cyclorraphan, Drosophila melanogaster, highlighting a possible feature in the divergence of the clades each insect represents.
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Affiliation(s)
- J Juhn
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
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Abstract
Research on gene expression in mosquitoes is motivated by both basic and applied interests. Studies of genes involved in hematophagy, reproduction, olfaction, and immune responses reveal an exquisite confluence of biological adaptations that result in these highly-successful life forms. The requirement of female mosquitoes for a bloodmeal for propagation has been exploited by a wide diversity of viral, protozoan and metazoan pathogens as part of their life cycles. Identifying genes involved in host-seeking, blood feeding and digestion, reproduction, insecticide resistance and susceptibility/refractoriness to pathogen development is expected to provide the bases for the development of novel methods to control mosquito-borne diseases. Advances in mosquito transgenesis technologies, the availability of whole genome sequence information, mass sequencing and analyses of transcriptomes and RNAi techniques will assist development of these tools as well as deepen the understanding of the underlying genetic components for biological phenomena characteristic of these insect species.
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Affiliation(s)
- Xiao-Guang Chen
- Department of Parasitology, School of Public Health and Tropical Medicine, Southern Medical University, Guang Zhou, GD 510515, People's Republic of China
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Adelman ZN, Jasinskiene N, Onal S, Juhn J, Ashikyan A, Salampessy M, MacCauley T, James AA. nanos gene control DNA mediates developmentally regulated transposition in the yellow fever mosquito Aedes aegypti. Proc Natl Acad Sci U S A 2007; 104:9970-5. [PMID: 17548819 PMCID: PMC1891237 DOI: 10.1073/pnas.0701515104] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2007] [Indexed: 11/18/2022] Open
Abstract
Transposable elements (TEs) are proposed as a basis for developing drive systems to spread pathogen resistance genes through vector mosquito populations. The use of transcriptional and translational control DNA elements from genes expressed specifically in the insect germ line to mediate transposition offers possibilities for mitigating some of the concerns about transgene behavior in the target vector species and eliminating effects on nontarget organisms. Here, we describe the successful use of the promoter and untranslated regions from the nanos (nos) orthologous gene of the yellow fever mosquito, Aedes aegypti, to control sex- and tissue-specific expression of exogenously derived mariner MosI transposase-encoding DNA. Transgenic mosquitoes expressed transposase mRNA in abundance near or equal to the endogenous nos transcript and exclusively in the female germ cells. In addition, MosI mRNA was deposited in developing oocytes and localized and maintained at the posterior pole during early embryonic development. Importantly, four of five transgenic lines examined were capable of mobilizing a second MosI transgene into the mosquito genome, indicating that functional transposase was being produced. Thus, the nos control sequences show promise as part of a TE-based gene drive system.
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Affiliation(s)
- Zach N. Adelman
- Departments of *Molecular Biology and Biochemistry and
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | | | - Sedef Onal
- Departments of *Molecular Biology and Biochemistry and
| | - Jennifer Juhn
- Departments of *Molecular Biology and Biochemistry and
| | | | | | | | - Anthony A. James
- Departments of *Molecular Biology and Biochemistry and
- Microbiology and Molecular Genetics, University of California, Irvine, CA 92697; and
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