The authors have nothing to disclose.

predicting the effectiveness of population replacement strategy using mathematical modeling

チャールズテイラーとジョンマーシャルは、人口置換戦略の有効性を評価するための数学的モデリングの有用性を説明する。洞察力は、計算モデルは、蚊の個体群動態とA. gambiae亜種を通じて、転移因子の拡散に関する情報を提供する方法に与えられます。野生に遺伝子組み換え蚊をリリースするの倫理的な問題について議論する。

Watch this Scientific Journal Video about Predicting the Effectiveness of Population Replacement Strategy Using Mathematical Modeling at JoVE.com

Predicting the Effectiveness of Population Replacement Strategy Using Mathematical Modeling

数理モデルを使用して人口置換戦略の有効性を予測

Charles Taylor and John Marshall explain the utility of mathematical modeling for evaluating the effectiveness of population replacement strategy.  ...

predicting-effectiveness-population-replacement-strategy-using

Universidad de Cartagena UDEC

Research

JoVE Journal

Biology

8.7K ビュー.  University of California, Los Angeles. チャールズテイラーとジョンマーシャルは、人口置換戦略の有効性を評価するための数学的モデリングの有用性を説明する。洞察力は、計算モデルは、蚊の個体群動態とA. gambiae亜種を通じて、転移因子の拡散に関する情報を提供する方法に与えられます。野生に遺伝子組み換え蚊をリリースするの倫理的な問題について議論する。

ビデオ: Predicting the Effectiveness of Population Replacement Strategy Using Mathematical Modeling

Population Replacement Strategies for Controlling Vector Populations and the Use of Wolbachia pipientis for Genetic Drive

In this video, Jason Rasgon discusses population replacement strategies to control vector-borne diseases such as malaria and dengue. "Population replacement" is the replacement of wild vector populations (that are competent to transmit pathogens) with those that are not competent to transmit pathogens. There are several theoretical strategies to accomplish this. One is to exploit the maternally-inherited symbiotic bacteria Wolbachia pipientis. Wolbachia is a widespread reproductive parasite that spreads in a selfish manner at the extent of its host's fitness. Jason Rasgon discusses, in detail, the basic biology of this bacterial symbiont and various ways to use it for control of vector-borne diseases.

In this interview, Jason Rasgon explains the concept of genetic drive and the characteristics of an effective gene drive system. The use of the endosymbiotic bacterium, Wolbachia pipientis, as a means to spread genes through mosquito populations, is hypothesized.

遺伝ドライブのための制御ベクトルの集団とボルバキアpipientisの使用のための人口置換戦略

In this video, Jason Rasgon discusses population replacement strategies to control vector-borne diseases such as malaria and dengue. "Population ...

生物学

Murine Colitis Modeling using Dextran Sulfate Sodium (DSS)

Colitis can occur from viral or bacterial infections, ischemic insult, or autoimmune disorders; most notably Ulcerative Colitis and the colonic variant of Crohn&rsquo;s Disease - Crohn&rsquo;s Colitis. Acute colitis may present with abdominal pain and distention, malabsorption, diarrhea, hematochezia and mucus in the stool. We are beginning to understand the complex interactions between the environment, genetics, and epithelial barrier dysfunction in Inflammatory Bowel Disease and animal models of colitis have been essential in advancing our understanding of this disease. One popular model involves supplementing the drinking water of mice with low-molecular weight Dextran Sodium Sulfate (DSS), resulting in epithelial damage and a robust inflammatory response in the colon lasting several days 1.Variations of this approach can be used to model acute injury, acute injury followed by repair, and repeated cycles of DSS interspersed with recovery modeling chronic inflammatory diseases 2. After a single four-day treatment of 3% DSS in drinking water, mice show signs of acute colitis including weight loss, bloody stools, and diarrhea. Mice are euthanized at the conclusion of the treatment course and at necropsy dissected colons are processed and can be 'Swiss rolled" 3 to allow microscopic analysis of the entire colon or infused with formalin as "sausages" to allow macroscopic analysis. Tissue is then embedded in paraffin, sectioned, and stained for histologic review.

Murine Colitis Modeling using Dextran Sulfate Sodium DSS

Dextran sulfate sodium (DSS) administered in the drinking water is an established murine inflammatory injury model of acute colitis. This protocol outlines the method for DSS treatment and the preparation of tissues.

デキストラン硫酸ナトリウム（DSS）を用いたマウス大腸炎モデル

Colitis can occur from viral or bacterial infections, ischemic insult, or autoimmune disorders; most notably Ulcerative Colitis and the colonic variant of ...

Cryopreserving and Recovering of Human iPS Cells using Complete KnockOut Serum Replacement Feeder-Free Medium

The discovery in 2006 that human and mouse fibroblasts could be reprogrammed to generate iPS cells 1-3 with qualities remarkably similar to embryonic stem cells has created a valuable new source of pluripotent cells for drug discovery, cell therapy, and basic research.
GIBCO media and reagents have been at the forefront of pluripotent stem cell research for years. Knockout DMEM supplemented with Knockout Serum Replacement is the media of choice for embryonic stem cell growth and now iPS cell culture 3-9. This gold standard media system can now be used for feeder-free culture with the addition of Knockout SR Growth Factor Cocktail.
Traditional human ES and iPS cell culture methods require the use of mouse or human fibroblast feeder layers, or feeder-conditioned medium. These culture methods are labor-intensive, hard to scale and it is difficult to maintain hiPS cells undifferentiated due to the undefined conditions. Invitrogen has developed Knockout SR Growth Factor Cocktail to allow you to easily transition your hiPS and hES cell cultures to feeder-free while still maintaining your use of Knockout SR.

This protocol describes the detailed procedure for cryopreserving human iPS cells in KnockOut SR cryopreservation medium and recovering these cells in complete KnockOut SR Feeder Free (KSR-FF) medium or feeder-based KnockOut SR medium.

完全ノックアウト血清代替のフィーダーを含まない培地を用いてヒトiPS細胞のCryopreservingおよびリカバリ

The discovery in 2006 that human and mouse fibroblasts could be reprogrammed to generate iPS cells 1-3 with qualities remarkably similar to embryonic stem ...

Using RNA-mediated Interference Feeding Strategy to Screen for Genes Involved in Body Size Regulation in the Nematode C. elegans

Double-strand RNA-mediated interference (RNAi) is an effective strategy to knock down target gene expression1-3. It has been applied to many model systems including plants, invertebrates and vertebrates. There are various methods to achieve RNAi in vivo4,5. For example, the target gene may be transformed into an RNAi vector, and then either permanently or transiently transformed into cell lines or primary cells to achieve gene knockdown effects; alternatively synthesized double-strand oligonucleotides from specific target genes (RNAi oligos) may be transiently transformed into cell lines or primary cells to silence target genes; or synthesized double-strand RNA molecules may be microinjected into an organism. Since the nematode C. elegans uses bacteria as a food source, feeding the animals with bacteria expressing double-strand RNA against target genes provides a viable strategy6. Here we present an RNAi feeding method to score body size phenotype. Body size in C. elegans is regulated primarily by the TGF- &beta; - like ligand DBL-1, so this assay is appropriate for identification of TGF-&beta; signaling components7. We used different strains including two RNAi hypersensitive strains to repeat the RNAi feeding experiments. Our results showed that rrf-3 strain gave us the best expected RNAi phenotype. The method is easy to perform, reproducible, and easily quantified. Furthermore, our protocol minimizes the use of specialized equipment, so it is suitable for smaller laboratories or those at predominantly undergraduate institutions.

Using RNA-mediated Interference Feeding Strategy to Screen for Genes Involved in Body Size Regulation in the Nematode C. elegans

We demonstrate how to use the RNAi feeding technique to knock down target genes and score body size phenotype in C. elegans. This method could be used for a large scale screen to identify potential genetic components of interest, such as those involved in body size regulation by DBL-1/TGF-&beta; signaling.

線虫における身体サイズ調節に関与する遺伝子をスクリーニングするための戦略を給餌RNA媒介干渉を用いた<em&gt; Cエレガンス</em

Double-strand RNA-mediated interference (RNAi) is an effective strategy to knock down target gene expression1-3. It has been applied to many model systems ...

In Vivo Modeling of the Morbid Human Genome using Danio rerio

Here, we present methods for the development of assays to query potentially clinically significant nonsynonymous changes using in vivo complementation in zebrafish. Zebrafish (Danio rerio) are a useful animal system due to their experimental tractability; embryos are transparent to enable facile viewing, undergo rapid development ex vivo, and can be genetically manipulated.1 These aspects have allowed for significant advances in the analysis of embryogenesis, molecular processes, and morphogenetic signaling. Taken together, the advantages of this vertebrate model make zebrafish highly amenable to modeling the developmental defects in pediatric disease, and in some cases, adult-onset disorders. Because the zebrafish genome is highly conserved with that of humans (~70% orthologous), it is possible to recapitulate human disease states in zebrafish. This is accomplished either through the injection of mutant human mRNA to induce dominant negative or gain of function alleles, or utilization of morpholino (MO) antisense oligonucleotides to suppress genes to mimic loss of function variants. Through complementation of MO-induced phenotypes with capped human mRNA, our approach enables the interpretation of the deleterious effect of mutations on human protein sequence based on the ability of mutant mRNA to rescue a measurable, physiologically relevant phenotype. Modeling of the human disease alleles occurs through microinjection of zebrafish embryos with MO and/or human mRNA at the 1-4 cell stage, and phenotyping up to seven days post fertilization (dpf). This general strategy can be extended to a wide range of disease phenotypes, as demonstrated in the following protocol. We present our established models for morphogenetic signaling, craniofacial, cardiac, vascular integrity, renal function, and skeletal muscle disorder phenotypes, as well as others.

In Vivo Modeling of the Morbid Human Genome using Danio rerio

Here, we present a systematic approach for developing physiologically relevant, sensitive and specific in vivo assays for interpreting variation in human pathology. Transient genetic manipulation via microinjection of WT and mutant human mRNA and morpholino (MO) antisense oligonucleotides harness the tractability of the developing zebrafish embryo to rapidly assay pathogenic mutations, especially, but not exclusively, in the context of human developmental disorders.

ゼブラフィッシュを用いた病的ヒトゲノムの in vivoモデルで

Here,  we present methods for the development of assays to query potentially clinically  significant nonsynonymous changes using in  vivo complementation ...

Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy

The MGM101 gene was identified 20 years ago for its role in the maintenance of mitochondrial DNA. Studies from several groups have suggested that the Mgm101 protein is involved in the recombinational repair of mitochondrial DNA. Recent investigations have indicated that Mgm101 is related to the Rad52-type recombination protein family. These proteins form large oligomeric rings and promote the annealing of homologous single stranded DNA molecules. However, the characterization of Mgm101 has been hindered by the difficulty in producing the recombinant protein. Here, a reliable procedure for the preparation of recombinant Mgm101 is described. Maltose Binding Protein (MBP)-tagged Mgm101 is first expressed in Escherichia coli. The fusion protein is initially purified by amylose affinity chromatography. After being released by proteolytic cleavage, Mgm101 is separated from MBP by cationic exchange chromatography. Monodispersed Mgm101 is then obtained by size exclusion chromatography. A yield of ~0.87 mg of Mgm101 per liter of bacterial culture can be routinely obtained. The recombinant Mgm101 has minimal contamination of DNA. The prepared samples are successfully used for biochemical, structural and single particle image analyses of Mgm101. This protocol may also be used for the preparation of other large oligomeric DNA-binding proteins that may be misfolded and toxic to bacterial cells.

The yeast mitochondrial nucleoid protein, Mgm101, is a Rad52-type recombination protein that forms large oligomeric rings. A protocol is described to prepare soluble recombinant Mgm101 using the Maltose Binding Protein (MBP)-tagging strategy coupled with cation exchange and size exclusion chromatography.

MBPベースタギング戦略によってMgm101組換えタンパク質の調製

The MGM101 gene was identified 20 years ago for its role in the maintenance of mitochondrial DNA. Studies from several groups have suggested that the ...

Use of MALDI-TOF Mass Spectrometry and a Custom Database to Characterize Bacteria Indigenous to a Unique Cave Environment (Kartchner Caverns, AZ, USA)

MALDI-TOF mass spectrometry has been shown to be a rapid and reliable tool for identification of bacteria at the genus and species, and in some cases, strain levels. Commercially available and open source software tools have been developed to facilitate identification; however, no universal/standardized data analysis pipeline has been described in the literature. Here, we provide a comprehensive and detailed demonstration of bacterial identification procedures using a MALDI-TOF mass spectrometer. Mass spectra were collected from 15 diverse bacteria isolated from Kartchner Caverns, AZ, USA, and identified by 16S rDNA sequencing. Databases were constructed in BioNumerics 7.1. Follow-up analyses of mass spectra were performed, including cluster analyses, peak matching, and statistical analyses. Identification was performed using blind-coded samples randomly selected from these 15 bacteria. Two identification methods are presented: similarity coefficient-based and biomarker-based methods. Results show that both identification methods can identify the bacteria to the species level.

Use of MALDI-TOF Mass Spectrometry and a Custom Database to Characterize Bacteria Indigenous to a Unique Cave Environment Kartchner Caverns, AZ, USA

This work details procedures for rapid identification of bacteria using MALDI-TOF MS. The identification procedures include spectrum acquisition, database construction, and follow up analyses. Two identification methods, similarity coefficient-based and biomarker-based methods, are presented.

MALDI-TOF質量分析およびカスタムデータベースを使用すると、ユニークな洞窟環境（カーチェナー洞窟、AZ、USA）を常在菌を特徴づけるために

MALDI-TOF mass spectrometry has been shown to be a rapid and reliable tool for identification of bacteria at the genus and species, and in some cases, ...

A Method for Selecting Structure-switching Aptamers Applied to a Colorimetric Gold Nanoparticle Assay

Small molecules provide rich targets for biosensing applications due to their physiological implications as biomarkers of various aspects of human health and performance. Nucleic acid aptamers have been increasingly applied as recognition elements on biosensor platforms, but selecting aptamers toward small molecule targets requires special design considerations. This work describes modification and critical steps of a method designed to select structure-switching aptamers to small molecule targets. Binding sequences from a DNA library hybridized to complementary DNA capture probes on magnetic beads are separated from nonbinders via a target-induced change in conformation. This method is advantageous because sequences binding the support matrix (beads) will not be further amplified, and it does not require immobilization of the target molecule. However, the melting temperature of the capture probe and library is kept at or slightly above RT, such that sequences that dehybridize based on thermodynamics will also be present in the supernatant solution. This effectively limits the partitioning efficiency (ability to separate target binding sequences from nonbinders), and therefore many selection rounds will be required to remove background sequences. The reported method differs from previous structure-switching aptamer selections due to implementation of negative selection steps, simplified enrichment monitoring, and extension of the length of the capture probe following selection enrichment to provide enhanced stringency. The selected structure-switching aptamers are advantageous in a gold nanoparticle assay platform that reports the presence of a target molecule by the conformational change of the aptamer. The gold nanoparticle assay was applied because it provides a simple, rapid colorimetric readout that is beneficial in a clinical or deployed environment. Design and optimization considerations are presented for the assay as proof-of-principle work in buffer to provide a foundation for further extension of the work toward small molecule biosensing in physiological fluids.

A protocol is provided to select structure-switching aptamers for small molecule targets based on a tunable stringency magnetic bead selection method. Aptamers selected with structure-switching properties are beneficial for assays that require a conformational change to signal the presence of a target, such as the described gold nanoparticle assay.

比色金ナノ粒子アッセイに適用される構造スイッチングアプタマーを選択するための方法

Small molecules provide rich targets for biosensing applications due to their physiological implications as biomarkers of various aspects of human health ...

A Strategy to Validate the Role of Callose-mediated Plasmodesmal Gating in the Tropic Response

The plant hormone auxin plays an important role in many growth and developmental processes, including tropic responses to light and gravity. The establishment of an auxin gradient is a key event leading to phototropism and gravitropism. Previously, polar auxin transport (PAT) was shown to establish an auxin gradient in different cellular domains of plants. However, Han et al. recently demonstrated that for proper auxin gradient formation, plasmodesmal callose-mediated symplasmic connectivity between the adjacent cells is also a critical factor. In this manuscript, the strategy to elucidate the role of particular genes, which can affect phototropism and gravitropism by altering the symplasmic connectivity through modulating plasmodesmal callose synthesis, is discussed. The first step is to screen aberrant tropic responses from 3-day-old etiolated seedlings of mutants or over-expression lines of a gene along with the wild type. This preliminary screening can lead to the identification of a range of genes functioning in PAT or controlling symplasmic connectivity. The second screening involves the sorting of candidates that show altered tropic responses by affecting symplasmic connectivity. To address such candidates, the movement of a symplasmic tracer and the deposition of plasmodesmal callose were examined. This strategy would be useful to explore new candidate genes that can regulate symplasmic connectivity directly or indirectly during tropic responses and other developmental processes.

This article describes the methods for screening the genes controlling plasmodesmal permeability and hence auxin gradient during tropic response. This includes the measurement of the degree of tropic response in hypocotyl of Arabidopsis thaliana and checking plasmodesmal permeability by 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) loading and finally callose level assessment.

トロピック応答におけるカロース媒介Plasmodesmalゲーティングの役割を検証するための戦略

The plant hormone auxin plays an important role in many growth and developmental processes, including tropic responses to light and gravity. The ...

Techniques to Induce and Quantify Cellular Senescence

In response to cellular stress or damage, proliferating cells can induce a specific program that initiates a state of long-term cell-cycle arrest, termed cellular senescence. Accumulation of senescent cells occurs with organismal aging and through continual culturing in vitro. Senescent cells influence many biological processes, including embryonic development, tissue repair and regeneration, tumor suppression, and aging. Hallmarks of senescent cells include, but are not limited to, increased senescence-associated &#946;-galactosidase activity (SA-&#946;-gal); p16INK4A, p53, and p21 levels; higher levels of DNA damage, including &#947;-H2AX; the formation of Senescence-associated Heterochromatin Foci (SAHF); and the acquisition of a Senescence-associated Secretory Phenotype (SASP), a phenomenon characterized by the secretion of a number of pro-inflammatory cytokines and signaling molecules. Here, we describe protocols for both replicative and DNA damage-induced senescence in cultured cells. In addition, we highlight techniques to monitor the senescent phenotype using several senescence-associated markers, including SA-&#946;-gal, &#947;-H2AX and SAHF staining, and to quantify protein and mRNA levels of cell cycle regulators and SASP factors. These methods can be applied to the assessment of senescence in various models and tissues.

Cellular senescence, the irreversible state of cell-cycle arrest, can be induced by various cellular stresses. Here, we describe protocols to induce cellular senescence and methods to assess markers of senescence.

誘導および定量化細胞老化するテクニック

In response to cellular stress or damage, proliferating cells can induce a specific program that initiates a state of long-term cell-cycle arrest, termed ...