WordNet

of the transmission gear causing backward movement in a motor vehicle; "in reverse gear"
a relation of direct opposition; "we thought Sue was older than Bill but just the reverse was true" (同)contrary, opposite
the gears by which the motion of a machine can be reversed (同)reverse gear
the side of a coin or medal that does not bear the principal design (同)verso
(American football) a running play in which a back running in one direction hands the ball to a back running in the opposite direction
an unfortunate happening that hinders or impedes; something that is thwarting or frustrating (同)reversal, setback, blow, black_eye
pertaining to or referring to origin; "genetic history reconstructs the origins of a literary work"
of or relating to the science of genetics; "genetic research" (同)genetical
a lapel on a womans garment; turned back to show the reverse side (同)revere
turned inside out and resewn; "the reversed collar looked as good as new"
the branch of biology that studies heredity and variation in organisms (同)genetic science

PrepTutorEJDIC

(位置・方向・順序などにおいて)『逆の』;裏側の』 / 逆に動かす(動く),バックの / 〈U〉《the reverse》(…の)『反対』,『逆』《+『of』+『名』(『wh』‐節)》》 / 〈U〉《the reverse》(貨幣・メダルなどの)『裏側』,(一般に)(…の)裏面《+『of』+『名』》 / 〈C〉(運命などの)逆転,不運 / 〈U〉後退[装置],逆転[装置] / …‘を'『逆にする』,反対にする;…‘を'裏返す / 〈機械など〉‘を'逆転させる,逆方向に動かす / 〈判決など〉‘を'取り消す,破棄する / (ダンスで)逆に回る / 〈機械などが〉逆方向に動く
（フランス語）(えりの)裏出し,折り返し
逆にした,反対の,裏返のし;取り消された
遺伝学

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/03/22 04:27:15」(JST)

wiki en

[Wiki en表示]

Avian Flu vaccine development by Reverse Genetics techniques. Courtesy: National Institute of Allergy and Infectious Diseases

Reverse genetics is an approach to discover the function of a gene by analyzing the phenotypic effects of specific gene sequences obtained by DNA sequencing. This investigative process proceeds in the opposite direction of so-called forward genetic screens of classical genetics. Simply put, while forward genetics seeks to find the genetic basis of a phenotype or trait, reverse genetics seeks to find what phenotypes arise as a result of particular genetic sequences.

Automated DNA sequencing generates large volumes of genomic sequence data relatively rapidly. Many genetic sequences are discovered in advance of other, less easily obtained, biological information. Reverse genetics attempts to connect a given genetic sequence with specific effects on the organism.

Techniques used in reverse genetics[edit]

To learn the influence a sequence has on phenotype, or to discover its biological function, researchers can engineer a change or disruption in the DNA. After this change has been made a researcher can look for the effect of such alterations in the whole organism. There are several different methods of reverse genetics that have proved useful:

Directed deletions and point mutations[edit]

Site-directed mutagenesis is a sophisticated technique that can either change regulatory regions in the promoter of a gene or make subtle codon changes in the open reading frame to identify important amino residues for protein function.

Wild-type Physcomitrella patens (A) and Knockout mosses (B-D): Deviating phenotypes induced in gene-disruption library transformants. Physcomitrella wild-type and transformed plants were grown on minimal Knop medium to induce differentiation and development of gametophores. For each plant, an overview (upper row; scale bar corresponds to 1 mm) and a close-up (bottom row; scale bar equals 0.5 mm) are shown. A: Haploid wild-type moss plant completely covered with leafy gametophores and close-up of wild-type leaf. B–D: Different mutants.^[1]

Alternatively, the technique can be used to create null alleles so that the gene is not functional. For example, deletion of a gene by gene targeting (gene knockout) can be done in some organisms, such as yeast, mice and moss. Unique among plants, in Physcomitrella patens, gene knockout via homologous recombination to create knockout moss (see figure) is nearly as efficient as in yeast.^[2] In the case of the yeast model system directed deletions have been created in every non-essential gene in the yeast genome.^[3] In the case of the plant model system huge mutant libraries have been created based on gene disruption constructs.^[4] In gene knock-in, the endogenous exon is replaced by an altered sequence of interest.^[5]

In some cases conditional alleles can be used so that the gene has normal function until the conditional allele is activated. This might entail ‘knocking in’ recombinase sites (such as lox or frt sites) that will cause a deletion at the gene of interest when a specific recombinase (such as CRE, FLP) is induced. Cre or Flp recombinases can be induced with chemical treatments, heat shock treatments or be restricted to a specific subset of tissues.

Another technique that can be used is TILLING. This is a method that combines a standard and efficient technique of mutagenesis with a chemical mutagen such as ethyl methanesulfonate (EMS) with a sensitive DNA-screening technique that identifies point mutations in a target gene.

Gene silencing[edit]

The discovery of gene silencing using double stranded RNA, also known as RNA interference (RNAi), and the development of gene knockdown using Morpholino oligos, have made disrupting gene expression an accessible technique for many more investigators. This method is often referred to as a gene knockdown since the effects of these reagents are generally temporary, in contrast to gene knockouts which are permanent.

RNAi creates a specific knockout effect without actually mutating the DNA of interest. In C. elegans, RNAi has been used to systematically interfere with the expression of most genes in the genome. RNAi acts by directing cellular systems to degrade target messenger RNA (mRNA).

While RNA interference relies on cellular components for efficacy (e.g. the Dicer proteins, the RISC complex) a simple alternative for gene knockdown is Morpholino antisense oligos. Morpholinos bind and block access to the target mRNA without requiring the activity of cellular proteins and without necessarily accelerating mRNA degradation. Morpholinos are effective in systems ranging in complexity from cell-free translation in a test tube to in vivo studies in large animal models.

Interference using transgenes[edit]

A molecular genetic approach is the creation of transgenic organisms that overexpress a normal gene of interest. The resulting phenotype may reflect the normal function of the gene.

Alternatively it is possible to overexpress mutant forms of a gene that interfere with the normal (wildtype) gene's function. For example, over-expression of a mutant gene may result in high levels of a non-functional protein resulting in a dominant negative interaction with the wildtype protein. In this case the mutant version will out compete for the wildtype proteins partners resulting in a mutant phenotype.

Other mutant forms can result in a protein that is abnormally regulated and constitutively active (‘on’ all the time). This might be due to removing a regulatory domain or mutating a specific amino residue that is reversibly modified (by phosphorylation, methylation, or ubiquitination). Either change is critical for modulating protein function and often result in informative phenotypes......

References[edit]

^ Egener et al. BMC Plant Biology 2002 2:6 doi:10.1186/1471-2229-2-6
^ Reski R (1998). "Physcomitrella and Arabidopsis: the David and Goliath of reverse genetics". Trends Plant Sci 3 (6): 209–210. doi:10.1016/S1360-1385(98)01257-6.
^ Winzeler, EA; et al. (1999). "Functional characterization of the Saccharomyces cervisiae genome by precise deletion and parallel analysis". Science 285 (5429): 901–6. doi:10.1126/science.285.5429.901. PMID 10436161. Cite uses deprecated parameters (help)
^ Schween G, Egener T, Fritzkowsky D, Granado J, Guitton M-C, Hartmann N, Hohe A, Holtorf H, Lang D, Lucht JM, Reinhard C, Rensing SA, Schlink K, Schulte J, R Reski (2005). "Large-scale analysis of 73329 Physcomitrella plants transformed with different gene disruption libraries: Production parameters and mutant phenotypes". Plant Biology 7 (3): 228–237. doi:10.1055/s-2005-837692. PMID 15912442.
^ Manis, John P., M.D. (December 13, 2007). "Knock Out, Knock In, Knock Down — Genetically Manipulated Mice and the Nobel Prize" (PDF). New England Journal of Medicine (Waltham, MA, USA: Massachusetts Medical Society) 357 (24): 2426–2429. doi:10.1056/NEJMp0707712. ISSN 1533-4406. OCLC 34945333. Retrieved December 26, 2011.

External links[edit]

From the National Institute of Allergy and Infectious Diseases (NIAID) site:
- Reassortment vs Reverse Genetics
- Reverse Genetics: Building Flu Vaccines Piece by Piece
From the National Center for Biotechnology Information (NCBI) site:
- Neumann G, Hatta M, Kawaoka Y (2003). "Reverse genetics for the control of avian influenza". Avian Dis. 47 (3 Suppl): 882–7. doi:10.1637/0005-2086-47.s3.882. PMID 14575081.
- Neumann G, Fujii K, Kino Y, Kawaoka Y (November 2005). "An improved reverse genetics system for influenza A virus generation and its implications for vaccine production". Proc. Natl. Acad. Sci. U.S.A. 102 (46): 16825–9. doi:10.1073/pnas.0505587102. PMC 1283806. PMID 16267134.
- Ozaki H, Govorkova EA, Li C, Xiong X, Webster RG, Webby RJ (February 2004). "Generation of high-yielding influenza A viruses in African green monkey kidney (Vero) cells by reverse genetics". J. Virol. 78 (4): 1851–7. doi:10.1128/JVI.78.4.1851-1857.2004. PMC 369478. PMID 14747549.

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 外陰部異常を有する幼児の評価 evaluation of the infant with ambiguous genitalia
2. 虚血性脳卒中の病態生理 pathophysiology of ischemic stroke
3. 血友病患者における第VIIIおよび第IX因子阻害物質 factor viii and factor ix inhibitors in patients with hemophilia
4. ベンゾジアゼピンの中毒および離脱 benzodiazepine poisoning and withdrawal
5. ワルファリンおよびその他のビタミンK拮抗剤の治療使用 therapeutic use of warfarin and other vitamin k antagonists

English Journal

A common polymorphism in pre-microRNA-146a is associated with lung cancer risk in a Korean population.

Jeon HS, Lee YH, Lee SY, Jang JA, Choi YY, Yoo SS, Lee WK, Choi JE, Son JW, Kang YM, Park JY.SourceDepartment of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Dong In 2Ga 101, Daegu 700-422, South Korea; Lung Cancer Center, Kyungpook National University Medical Center, 807, Hoguk-ro, Buk-gu, Daegu 702-210, South Korea. Electronic address: jeonh@knu.ac.kr.
Gene.Gene.2014 Jan 15;534(1):66-71. doi: 10.1016/j.gene.2013.10.014. Epub 2013 Oct 19.
INTRODUCTION: MicroRNAs (miRs) play important roles in the development and progression of human cancers. MiR-146a down-regulates epidermal growth factor receptor and the nuclear factor-κB regulatory kinase interleukin-1 receptor-associated kinase 1 genes that play important roles in lung carcinogen
PMID 24144839

A fisheye view on lymphangiogenesis.

van Impel A, Schulte-Merker S.SourceHubrecht Institute, KNAW and UMC Utrecht, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands.
Advances in anatomy, embryology, and cell biology.Adv Anat Embryol Cell Biol.2014;214:153-65. doi: 10.1007/978-3-7091-1646-3_12.
Zebrafish have been widely used to study vasculogenesis and angiogenesis, and the vascular system is one of the most intensively studied organ systems in teleosts. It is a little surprising, therefore, that the development of the zebrafish lymphatic network has only been investigated in any detail f
PMID 24276893

Novel approaches in melanoma prevention and therapy.

Grimaldi AM, Cassidy PB, Leachmann S, Ascierto PA.SourceUnit of Melanoma, Immunotherapy and Innovative Therapies, Istituto Nazionale per lo Studio e la Cura dei Tumori Fondazione G. Pascale, Via Mariano Semmola, 80131, Naples, Italy.
Cancer treatment and research.Cancer Treat Res.2014;159:443-55. doi: 10.1007/978-3-642-38007-5_25.
The incidence of cutaneous melanoma has risen at a rate significantly higher than that for other malignancies. This increase persists despite efforts to educate the public about the dangers of excess exposure to UV radiation from both the sun and tanning beds. Melanoma affects a relatively younger p
PMID 24114495

Japanese Journal

Genetic Organization of Two Types of Flounder Warm-Temperature Acclimation-Associated 65-kDa Protein and Their Gene Expression Profiles

KIM Young-Ok,PARK Eun-Mi,MOON Ji Young [他]
Bioscience, Biotechnology, and Biochemistry 77(10), 2065-2072, 2013-10
NAID 40019851020

Genetic engineering of rotaviruses by reverse genetics

Komoto Satoshi,Taniguchi Koki
Microbiology and immunology 57(7), 479-486, 2013-07
NAID 40019719032

A New High-Speed Droplet-Real-Time Polymerase Chain Reaction Method Can Detect Bovine Respiratory Syncytial Virus in Less than 10 Min

UEHARA Masayuki,MATSUDA Kazuyuki,SUGANO Mitsutoshi,HONDA Takayuki
Journal of Veterinary Medical Science, 2013
… Therefore, we developed a new genetic-based method called droplet-real-time PCR, which can detect bovine respiratory syncytial virus (BRSV) within 10 min. Our droplet-real-time PCR markedly reduced the reaction time of reverse transcription-PCR while maintaining the same sensitivity as conventional real-time PCR, and it can be used as a rapid assay for detection of BRSV. …
NAID 130003382395