#PAGE_PARAMS# #ADS_HEAD_SCRIPTS# #MICRODATA#

Neuron-Specific Feeding RNAi in and Its Use in a Screen for Essential Genes Required for GABA Neuron Function


Forward genetic screens are important tools for exploring the genetic requirements for neuronal function. However, conventional forward screens often have difficulty identifying genes whose relevant functions are masked by pleiotropy. In particular, if loss of gene function results in sterility, lethality, or other severe pleiotropy, neuronal-specific functions cannot be readily analyzed. Here we describe a method in C. elegans for generating cell-specific knockdown in neurons using feeding RNAi and its application in a screen for the role of essential genes in GABAergic neurons. We combine manipulations that increase the sensitivity of select neurons to RNAi with manipulations that block RNAi in other cells. We produce animal strains in which feeding RNAi results in restricted gene knockdown in either GABA-, acetylcholine-, dopamine-, or glutamate-releasing neurons. In these strains, we observe neuron cell-type specific behavioral changes when we knock down genes required for these neurons to function, including genes encoding the basal neurotransmission machinery. These reagents enable high-throughput, cell-specific knockdown in the nervous system, facilitating rapid dissection of the site of gene action and screening for neuronal functions of essential genes. Using the GABA-specific RNAi strain, we screened 1,320 RNAi clones targeting essential genes on chromosomes I, II, and III for their effect on GABA neuron function. We identified 48 genes whose GABA cell-specific knockdown resulted in reduced GABA motor output. This screen extends our understanding of the genetic requirements for continued neuronal function in a mature organism.


Vyšlo v časopise: Neuron-Specific Feeding RNAi in and Its Use in a Screen for Essential Genes Required for GABA Neuron Function. PLoS Genet 9(11): e32767. doi:10.1371/journal.pgen.1003921
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.pgen.1003921

Souhrn

Forward genetic screens are important tools for exploring the genetic requirements for neuronal function. However, conventional forward screens often have difficulty identifying genes whose relevant functions are masked by pleiotropy. In particular, if loss of gene function results in sterility, lethality, or other severe pleiotropy, neuronal-specific functions cannot be readily analyzed. Here we describe a method in C. elegans for generating cell-specific knockdown in neurons using feeding RNAi and its application in a screen for the role of essential genes in GABAergic neurons. We combine manipulations that increase the sensitivity of select neurons to RNAi with manipulations that block RNAi in other cells. We produce animal strains in which feeding RNAi results in restricted gene knockdown in either GABA-, acetylcholine-, dopamine-, or glutamate-releasing neurons. In these strains, we observe neuron cell-type specific behavioral changes when we knock down genes required for these neurons to function, including genes encoding the basal neurotransmission machinery. These reagents enable high-throughput, cell-specific knockdown in the nervous system, facilitating rapid dissection of the site of gene action and screening for neuronal functions of essential genes. Using the GABA-specific RNAi strain, we screened 1,320 RNAi clones targeting essential genes on chromosomes I, II, and III for their effect on GABA neuron function. We identified 48 genes whose GABA cell-specific knockdown resulted in reduced GABA motor output. This screen extends our understanding of the genetic requirements for continued neuronal function in a mature organism.


Zdroje

1. JohnsonNM, BehmCA, TrowellSC (2005) Heritable and inducible gene knockdown in C. elegans using Wormgate and the ORFeome. Gene 359: 26–34 doi:10.1016/j.gene.2005.05.034

2. EspositoG, Di SchiaviE, BergamascoC, BazzicalupoP (2007) Efficient and cell specific knock-down of gene function in targeted C. elegans neurons. Gene 395: 170–176 doi:10.1016/j.gene.2007.03.002

3. YochemJ, HermanRK (2003) Investigating C. elegans development through mosaic analysis. Development 130: 4761–4768 doi:10.1242/dev.00701

4. TimmonsL, FireA (1998) Specific interference by ingested dsRNA. Nature 395: 854–854 doi:10.1038/27579

5. FraserAG, KamathRS, ZipperlenP, Martinez-CamposM, SohrmannM, et al. (2000) Functional genomic analysis of C. elegans chromosome I by systematic RNA interference. Nature 408: 325–330 doi:10.1038/35042517

6. KamathRS, AhringerJ (2003) Genome-wide RNAi screening in Caenorhabditis elegans. Methods 30: 313–321.

7. RualJ-F, CeronJ, KorethJ, HaoT, NicotA-S, et al. (2004) Toward improving Caenorhabditis elegans phenome mapping with an ORFeome-based RNAi library. Genome Res 14: 2162–2168 doi:10.1101/gr.2505604

8. WinstonWM, MolodowitchC, HunterCP (2002) Systemic RNAi in C. elegans requires the putative transmembrane protein SID-1. Science 295: 2456–2459 doi:10.1126/science.1068836

9. FeinbergEH, HunterCP (2003) Transport of dsRNA into cells by the transmembrane protein SID-1. Science 301: 1545–1547 doi:10.1126/science.1087117

10. ShihJD, HunterCP (2011) SID-1 is a dsRNA-selective dsRNA-gated channel. RNA 17: 1057–1065 doi:10.1261/rna.2596511

11. TabaraH, SarkissianM, KellyWG, FleenorJ, GrishokA, et al. (1999) The rde-1 gene, RNA interference, and transposon silencing in C. elegans. Cell 99: 123–132.

12. QadotaH, InoueM, HikitaT, KöppenM, HardinJD, et al. (2007) Establishment of a tissue-specific RNAi system in C. elegans. Gene 400: 166–173 doi:10.1016/j.gene.2007.06.020

13. CalixtoA, ChelurD, TopalidouI, ChenX, ChalfieM (2010) Enhanced neuronal RNAi in C. elegans using SID-1. Nature Methods 7: 554–559 doi:10.1038/nmeth.1463

14. KamathRS, Martinez-CamposM, ZipperlenP, FraserAG, AhringerJ (2001) Effectiveness of specific RNA-mediated interference through ingested double-stranded RNA in Caenorhabditis elegans. Genome Biol 2: RESEARCH0002 doi:10.1186/gb-2000-2-1-research0002

15. TimmonsL, CourtDL, FireA (2001) Ingestion of bacterially expressed dsRNAs can produce specific and potent genetic interference in Caenorhabditis elegans. Gene 263: 103–112 doi:10.1016/S0378-1119(00)00579-5

16. AsikainenS, VartiainenS, LaksoM, NassR, WongG (2005) Selective sensitivity of Caenorhabditis elegans neurons to RNA interference. Neuroreport 16: 1995–1999.

17. WangD, KennedyS, ConteDJr, KimJK, GabelHW, et al. (2005) Somatic misexpression of germline P granules and enhanced RNA interference in retinoblastoma pathway mutants. Nature 436: 593–597 doi:10.1038/nature04010

18. KimJK, GabelHW, KamathRS, TewariM, PasquinelliA, et al. (2005) Functional Genomic Analysis of RNA Interference in C. elegans. Science 308: 1164–1167 doi:10.1126/science.1109267

19. JoseAM, SmithJJ, HunterCP (2009) Export of RNA silencing from C. elegans tissues does not require the RNA channel SID-1. Proc Natl Acad Sci USA 106: 2283–2288 doi:10.1073/pnas.0809760106

20. SpiethJ, BrookeG, KuerstenS, LeaK, BlumenthalT (1993) Operons in C. elegans: polycistronic mRNA precursors are processed by trans-splicing of SL2 to downstream coding regions. Cell 73: 521–532.

21. Frøkjær-JensenC, Wayne DavisM, HopkinsCE, NewmanBJ, ThummelJM, et al. (2008) Single-copy insertion of transgenes in Caenorhabditis elegans. Nature Genetics 40: 1375–1383 doi:10.1038/ng.248

22. McIntireSL, ReimerRJ, SchuskeK, EdwardsRH, JorgensenEM (1997) Identification and characterization of the vesicular GABA transporter. Nature 389: 870–876 doi:10.1038/39908

23. BirdDM, RiddleDL (1989) Molecular cloning and sequencing of ama-1, the gene encoding the largest subunit of Caenorhabditis elegans RNA polymerase II. Mol Cell Biol 9: 4119–4130.

24. JinY, JorgensenE, HartwiegE, HorvitzHR (1999) The Caenorhabditis elegans gene unc-25 encodes glutamic acid decarboxylase and is required for synaptic transmission but not synaptic development. J Neurosci 19: 539–548.

25. BamberBA, BegAA, TwymanRE, JorgensenEM (1999) The Caenorhabditis elegans unc-49 locus encodes multiple subunits of a heteromultimeric GABA receptor. J Neurosci 19: 5348–5359.

26. MaruyamaIN, BrennerS (1991) A phorbol ester/diacylglycerol-binding protein encoded by the unc-13 gene of Caenorhabditis elegans. Proc Natl Acad Sci USA 88: 5729–5733.

27. NonetML, SaifeeO, ZhaoH, RandJB, WeiL (1998) Synaptic transmission deficits in Caenorhabditis elegans synaptobrevin mutants. J Neurosci 18: 70–80.

28. VashlishanAB, MadisonJM, DybbsM, BaiJ, SieburthD, et al. (2008) An RNAi screen identifies genes that regulate GABA synapses. Neuron 58: 346–361 doi:10.1016/j.neuron.2008.02.019

29. HammarlundM, DavisWS, JorgensenEM (2000) Mutations in beta-spectrin disrupt axon outgrowth and sarcomere structure. J Cell Biol 149: 931–942.

30. HammarlundM, JorgensenEM, BastianiMJ (2007) Axons break in animals lacking beta-spectrin. J Cell Biol 176: 269–275 doi:10.1083/jcb.200611117

31. NassR, HallDH, MillerDM3rd, BlakelyRD (2002) Neurotoxin-induced degeneration of dopamine neurons in Caenorhabditis elegans. Proc Natl Acad Sci USA 99: 3264–3269 doi:10.1073/pnas.042497999

32. SulstonJ, DewM, BrennerS (1975) Dopaminergic neurons in the nematode Caenorhabditis elegans. J Comp Neurol 163: 215–226 doi:10.1002/cne.901630207

33. SawinER, RanganathanR, HorvitzHR (2000) C. elegans Locomotory Rate Is Modulated by the Environment through a Dopaminergic Pathway and by Experience through a Serotonergic Pathway. Neuron 26: 619–631 doi:10.1016/S0896-6273(00)81199-X

34. LintsR, EmmonsSW (1999) Patterning of dopaminergic neurotransmitter identity among Caenorhabditis elegans ray sensory neurons by a TGFbeta family signaling pathway and a Hox gene. Development 126: 5819–5831.

35. ChaseDL, PepperJS, KoelleMR (2004) Mechanism of extrasynaptic dopamine signaling in Caenorhabditis elegans. Nat Neurosci 7: 1096–1103 doi:10.1038/nn1316

36. KaplanJM, HorvitzHR (1993) A dual mechanosensory and chemosensory neuron in Caenorhabditis elegans. Proc Natl Acad Sci USA 90: 2227–2231.

37. LeeRY, SawinER, ChalfieM, HorvitzHR, AveryL (1999) EAT-4, a homolog of a mammalian sodium-dependent inorganic phosphate cotransporter, is necessary for glutamatergic neurotransmission in caenorhabditis elegans. J Neurosci 19: 159–167.

38. HartAC, SimsS, KaplanJM (1995) Synaptic code for sensory modalities revealed by C. elegans GLR-1 glutamate receptor. Nature 378: 82–85 doi:10.1038/378082a0

39. MaricqAV, PeckolE, DriscollM, BargmannCI (1995) Mechanosensory signalling in C. elegans mediated by the GLR-1 glutamate receptor. Nature 378: 78–81 doi:10.1038/378078a0

40. AlfonsoA, GrundahlK, DuerrJS, HanHP, RandJB (1993) The Caenorhabditis elegans unc-17 gene: a putative vesicular acetylcholine transporter. Science 261: 617–619.

41. AlfonsoA, GrundahlK, McManusJR, AsburyJM, RandJB (1994) Alternative Splicing Leads to Two Cholinergic Proteins in Caenorhabditis elegans. Journal of Molecular Biology 241: 627–630 doi:10.1006/jmbi.1994.1538

42. ShayeDD, GreenwaldI (2011) OrthoList: a compendium of C. elegans genes with human orthologs. PLoS ONE 6: e20085 doi:10.1371/journal.pone.0020085

43. LiuQ, HollopeterG, JorgensenEM (2009) Graded synaptic transmission at the Caenorhabditis elegans neuromuscular junction. Proc Natl Acad Sci USA 106: 10823–10828 doi:10.1073/pnas.0903570106

44. BrennerS (1974) The genetics of Caenorhabditis elegans. Genetics 77: 71–94.

45. Frøkjær-JensenC, DavisMW, AilionM, JorgensenEM (2012) Improved Mos1-mediated transgenesis in C. elegans. Nature Methods 9: 117–118 doi:10.1038/nmeth.1865

46. YochemJ, GuT, HanM (1998) A new marker for mosaic analysis in Caenorhabditis elegans indicates a fusion between hyp6 and hyp7, two major components of the hypodermis. Genetics 149: 1323–1334.

47. MelloCC, KramerJM, StinchcombD, AmbrosV (1991) Efficient gene transfer in C.elegans: extrachromosomal maintenance and integration of transforming sequences. EMBO J 10: 3959–3970.

48. SchindelinJ, Arganda-CarrerasI, FriseE, KaynigV, LongairM, et al. (2012) Fiji: an open-source platform for biological-image analysis. Nature Methods 9: 676–682 doi:10.1038/nmeth.2019

Štítky
Genetika Reprodukčná medicína

Článok vyšiel v časopise

PLOS Genetics


2013 Číslo 11
Najčítanejšie tento týždeň
Najčítanejšie v tomto čísle
Kurzy

Zvýšte si kvalifikáciu online z pohodlia domova

Aktuální možnosti diagnostiky a léčby litiáz
nový kurz
Autori: MUDr. Tomáš Ürge, PhD.

Všetky kurzy
Prihlásenie
Zabudnuté heslo

Zadajte e-mailovú adresu, s ktorou ste vytvárali účet. Budú Vám na ňu zasielané informácie k nastaveniu nového hesla.

Prihlásenie

Nemáte účet?  Registrujte sa

#ADS_BOTTOM_SCRIPTS#