Podcasts about transposon

Rosana Kapeller, CEO of Rome Therapeutics, and Marty Taylor, physician-scientist at Harvard Medical School, join Vineeta Agarwala, general partner, and Bryan Faust, investment partner at a16z Bio + Health.Together, they discuss Rosana and Marty's recent publication regarding a virus-like element in our genome known as LINE-1. LINE-1, part of our "dark genome," was ignored as junk DNA for years, but is increasingly recognized to contribute to the pathology of autoimmunity, cancer, neurodegeneration, and aging. Rosana and Marty discuss how the discovery was made as well as how Rome Therapeutics is developing a platform to target LINE-1 and other factors that are part of the "dark genome" for the treatment of disease.Additional reading:Structures, functions and adaptations of the human LINE-1 protein

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.07.11.548599v1?rss=1 Authors: Chavan, A., Skrutl, L., Uliana, F., Pfister, M., Burke, D. F., Braendle, F., Beltrao, P., Jagannathan, M. Abstract: The pericentromeric heterochromatin of eukaryotic chromosomes primarily consists of abundant non-coding repeats known as satellite DNA, which promote accurate chromosome segregation and genome stability. During interphase, sequence-specific satellite DNA-binding proteins cluster repeats from multiple chromosomes into foci known as chromocenters, which function to encapsulate the entire genome in a single nucleus. Despite the pivotal role of satellite DNA-binding proteins and chromocenters in cellular function, the proteins associated with these repetitive sequences remains incompletely characterized. Here, we use quantitative mass spectrometry to characterize the chromocenter-associated proteome in Drosophila embryos, ovaries and testes using two satellite DNA-binding proteins, D1 and Prod, as baits. We identify nearly 500 interactions, including known heterochromatin-associated proteins as well as proteins previously unlinked to satellite DNA or chromocenters. Among these interactions, we find that multiple components of the transposon-silencing piRNA pathway are associated with chromocenters. Strikingly, we reveal that proper satellite DNA clustering plays a role in transgenerational transposon repression, such that mothers with disrupted chromocenters give rise to progeny that exhibit transposon de-repression, germ cell loss and gonadal atrophy. Overall, our study highlights a novel link between satellite DNA repeats and transposon repression and lays the foundation for a more comprehensive understanding of satellite DNA function across tissues. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Vincent travels to Cornell University to speak with Cedric about his career and his research on mobile genetic elements such as transposons and endogenous viruses and how they have shaped the evolution of nearly all organisms. Hosts: Vincent Racaniello Guest: Cedric Feschotte Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Become a patron of TWiV! Links for this episode Feschotte laboratory Field guide to transposable elements (Ann Rev Genetics) Timestamps by Jolene. Thanks! Intro music is by Ronald Jenkees Send your virology questions and comments to twiv@microbe.tv

https://www.patreon.com/BMENEWS --- This episode is sponsored by · Anchor: The easiest way to make a podcast. https://anchor.fm/app Support this podcast: https://anchor.fm/nicholas-a-cusato/support

dessanをゲストに迎え、CRISPRの仕組みを利用した様々な技術や遺伝子回路、これからの発展について話しました。Show notes The Nobel Prize in Chemistry 2020…The Nobel Prize in Chemistry 2020 was awarded jointly to Emmanuelle Charpentier and Jennifer A. Doudna “for the development of a method for genome editing.” Scientifc Background on the Nobel Prize in Chemistry 2020 A TOOL FOR GENOME EDITING…ノーベル財団による詳細なCRISPR研究のレビュー、そしてなぜDoudnaとCharpentierの二人が受賞に値するのかについて説明している。 76. The Chimeric RNA, Researchat.fm…ゲノム編集についてdessanをゲストに迎えて話しました。 A Programmable Dual-RNA–Guided DNA Endonuclease in Adaptive Bacterial Immunity. Science 2012…CharpentierとDoudnaによるノーベル賞につながる論文の一つ。CRISPR–Cas9システムがこの論文によってその大枠が明らかにされた。 Multiplex Genome Engineering Using CRISPR/Cas Systems. Science 2013…Feng Zhang labによるヒト細胞におけるゲノム編集技術の報告。 RNA-Guided Human Genome Engineering via Cas9. Science 2012…George Church labによるヒト細胞におけるゲノム編集技術の報告も同時に掲載された。 First rounders: Feng Zhang (Podcast)…Feng Zhangが出演したNatute Biotechnologyのポッドキャスト。おすすめです。 26. Cool tech googlability, Researchat.fm…RNAを標的にできるCas13bについては、エピソード26で紹介しました。 Cas14 (crisp_bio)…“Cas14は、PAMに依存しないssDNA切断活性に加えて、PAMに依存するdsDNA切断活性も帯びている” CasX enzymes comprise a distinct family of RNA-guided genome editors. Nature 2019…CasX Transposon-encoded CRISPR–Cas systems direct RNA-guided DNA integration. Nature 2019…トランスポゾン型のCasシステムの報告。 RNA-programmed genome editing in human cells. eLife 2013…Doudna labによるヒト細胞におけるゲノム編集技術の報告。FengやChurchらよりも少しだけ遅かった。 Microhomology-mediated end-joining-dependent integration of donor DNA in cells and animals using TALENs and CRISPR/Cas9. Nature Communications 2014 Ep52. Split into a row Double Nicking by RNA-Guided CRISPR Cas9 for Enhanced Genome Editing Specificity. Cell 2013…Double nicking (2つのgRNAとCas9 nickase)によるより正確なゲノム編集方法が示された。 Genome-scale transcriptional activation by an engineered CRISPR-Cas9 complex. Nature 2015…Cas9を用いた転写の活性化手法。 Live visualization of chromatin dynamics with fluorescent TALEs. Nature Structural & Molecular Biology 2013 … TALENを用いた染色体の特定領域のイメージング方法 Dynamic Imaging of Genomic Loci in Living Human Cells by an Optimized CRISPR/Cas System. Cell 2013…dCas9-EGFPによる生細胞のイメージング技術。SpCas9の場合は、D10AとH840Aの２つの変異を入れることで、DNAに結合するが切断しないdead Cas9 (dCas9)として利用することができる。 Live cell imaging of low- and non-repetitive chromosome loci using CRISPR-Cas9. Nature Communications 2017…ガイドRNAにMS2 loopをたくさんつなげることで (14個!)、明るい輝点を得ることができる。 CRISPR-mediated live imaging of genome editing and transcription. Science 2019…こちらは蛍光標識したガイドRNAを利用した生細胞イメージング方法。 A protein tagging system for signal amplification in gene expression and fluorescence imaging. Cell 2014…Sun tagとCas9を用いたイメージング方法。 Split Green Fluorescent Proteins: Scope, Limitations, and Outlook…Split GFP Programmable RNA tracking in Live Cells with CRISPR/Cas9. Cell 2016…PAMmerによるSpCas9のmRNAイメージング CRISPR-Mediated Programmable 3D Genome Positioning and Nuclear Organization. Cell 2018 … CRISPR-GO：CRISPR技術、核内でのゲノム空間構造、ポッドキャスト内ではゲノム同士を寄せるという説明をしていましたが、今調べてみると特定のゲノム領域と核膜やカハール体への再配置ということでした。 Manipulation of nuclear architecture through CRISPR-mediated chromosomal looping. Nature Communications 2017 … こちらがCRISPRの仕組みを用いることで人工的に染色体内部にループを作成した論文。 Transcriptional repression mediated by repositioning of genes to the nuclear lamina. Nature 2008 … LacO-LacIの仕組みを用いることでゲノムの特定領域にLacO arrayを差し込み、核膜に局在させたLacIに結合させることである遺伝子領域を核膜側に誘導しようとした論文。最初にこの論文を読んだ時はそのアイデアにたまげました。 9. One-shot beautiful experiment (Researchat.fm)…人工的なDNA領域へ細胞内の情報（細胞系譜）を書き込む技術についてエピソード9で話しました。 CRISPR–Cas encoding of a digital movie into the genomes of a population of living bacteria. Nature 2017…George Churchらは、Cas1-Cas2システムによって馬の動画をバクテリアゲノム書き込み、それを読み出すことに成功した。 Multiplex recording of cellular events over time on CRISPR biological tape. Science 2017…コピー数の異なる2つのプラスミドをCas1-Cas2で取り込ませて、細胞内で人工的な時計のような仕組みを実現した。 Single-Nucleotide-Resolution Computing and Memory in Living Cells. Molecular Cell 2019…Tim Liu Labによる複雑な遺伝子回路の実現。DOMINOについては、プロモーター配列を標的にしているのではなくオペレーター配列でした。 Rewritable multi-event analog recording in bacterial and mammalian cells. Science 2018…David Liu labから報告されたガイドRNAによって連鎖する遺伝子回路（カスケード）の実現。 Terminal Deoxynucleotidyl Transferase, TdT…テンプレートに依存しないDNA合成を可能にする酵素。 Tandem fluorescent protein timers for in vivo analysis of protein dynamics. Nature Biotechnology 2012…GFP Timer Permanent genetic memory with >1-byte capacity. Nature Methods 2014 Continuous genetic recording with self-targeting CRISPR-Cas in human cells. Science 2016…自分で自分のガイドRNAを編集することで、理論的には無限に情報を書き込む方法が提案されたが、領域が壊れてしまう問題もある。 Ten Simple Rules to Win a Nobel Prize. ヘンリー・ブラッグ (Wikipedia) iPS細胞 (Wikipedia) 国境なき医師団 Human Genome Project Xiaowei Zhuang Expansion microscopy (Wikipedia) Renato Dulbecco (Wikipedia) Programmable RNA editing by recruiting endogenous ADAR using engineered RNAs. Nature Biotechnology 2019…LEAPER crisp_bio … 世界広しといえでも、これだけCRISPRの最新情報がまとまっているサイトはCRISP_BIOさんの他に世の中には存在しません。日本語でCRISPRの最先端情報を追える喜び。CRISP_BIOさん、いつもありがとうございます。 Editorial notes 1分でわかるとか無理なのですが、一方で言葉を尽くせばわかる可能性についても同時に信じておりますので…(soh) 思い出しながらどんどん話しているので、後から聞き返すと細部が間違っていたりしています。気になった方はshow notesをご参照ください。(dessan) いい感じのグルーヴがみられてよかったです。ポッドキャストやってきてよかったです。(tadasu) 最初に喋らんと出番が無くなる！と思ってこれまでの流れをまとめてみたんですが細かく色々ミスってました…(coela)

The Fellowship of the TWiM reveal that colorectal cancer-associated microbiota are associated with higher numbers of methylated genes in colonic mucosa, and identification of metabolites needed by the fire blight disease bacterium for virulence in apples. Become a patron of TWiM. Links for this episode: Colorectal cancer and the gut microbiome (PNAS) Fire blight (YouTube) Fire blight spreads north (NY Times) E. amylovora auxotrophs (Appl Environ Micro) Music used on TWiM is composed and performed by Ronald Jenkees and used with permission. Send your microbiology questions and comments to twim@microbe.tv

Bonjour à toutes et à tous, C'est Noël et nous vous avons préparé un épisode familial, à écouter au coin du feu ou au pied du sapin. Dans ce podcast, je vous conte deux histoires scientifiques pour enfants (à partir de 5 ans), dont le personnage central est l'ADN : l'ADN préfère l'ombre et Génie a une idée. Bien sûr, je reviens sur quelques explications qui vous aideront à mieux comprendre ces histoires, qui captiveront, j'en suis sûr, les adultes. Bonne écoute et Joyeux Noël !

The League of Extraordinary Virologists celebrate the eradication of wild poliovirus type 3, and consider the effectiveness of an influenza vaccine produced in insect cells, and how small RNAs are protecting the Koala germline from retroviral invasion. Hosts: Vincent Racaniello, Dickson Despommier, Alan Dove, Kathy Spindler, and Brianne Barker Subscribe (free): iTunes, Google Podcasts, RSS, email Become a patron of TWiV! Links for this episode Flublok (CDC) Adjuvant study of flu vaccines (NIH) Immunogenicity of quadrivalent Flublok (J Inf Dis) Monoclonal antibody response to Flublok (J Virol) Current flu vaccine recommendations (CDC) Double dose flu vaccine immunogenicity (Hum Vac Immunother) piRNA response on retroviral invasion of Koala genome (Cell) piRNAs rise to rescue Koalas (Cell) Image credit Letters read on TWiV 571 Timestamps by Jolene. Thanks! Weekly Science Picks Brianne - The Machinery of Life by David Goodsell Alan - Pomological watercolors Dickson - Wildlife Photographer of the Year Kathy - DiversifyMicrobiology  DiversifyImmunology and Marmot becomes fox food Vincent - Burnet A Life by Christopher Sexton Listener Picks Justin - Worm with three sexes Intro music is by Ronald Jenkees. Send your virology questions and comments to twiv@microbe.tv

The League of Extraordinary Virologists celebrate the eradication of wild poliovirus type 3, and consider the effectiveness of an influenza vaccine produced in insect cells, and how small RNAs are protecting the Koala germline from retroviral invasion. Hosts: Vincent Racaniello, Dickson Despommier, Alan Dove, Kathy Spindler, and Brianne Barker Subscribe (free): iTunes, Google Podcasts, RSS, email Become a patron of TWiV! Links for this episode Flublok (CDC) Adjuvant study of flu vaccines (NIH) Immunogenicity of quadrivalent Flublok (J Inf Dis) Monoclonal antibody response to Flublok (J Virol) Current flu vaccine recommendations (CDC) Double dose flu vaccine immunogenicity (Hum Vac Immunother) piRNA response on retroviral invasion of Koala genome (Cell) piRNAs rise to rescue Koalas (Cell) Image credit Letters read on TWiV 571 Timestamps by Jolene. Thanks! Weekly Science Picks Brianne - The Machinery of Life by David Goodsell Alan - Pomological watercolors Dickson - Wildlife Photographer of the Year Kathy - DiversifyMicrobiology  DiversifyImmunology and Marmot becomes fox food Vincent - Burnet A Life by Christopher Sexton Listener Picks Justin - Worm with three sexes Intro music is by Ronald Jenkees. Send your virology questions and comments to twiv@microbe.tv

Two recent scientific journal papers show what's possible when CRISPR moves from cutting DNA tool to a full-fledged platform -- expanding its toolkit for medicine across R&D, therapeutics, and diagnostics: "Transposon-encoded CRISPR-Cas systems direct RNA-guided DNA integration" in Nature -- by Sanne Klompe, Phuc Vo, Tyler Halpin-Healy, and Samuel Sternberg (of Columbia University) "RNA-guided DNA insertion with CRISPR-associated transposases" in Science -- by Jonathan Strecker, Alim Ladha, Zachary Gardner, Jonathan Schmid-burgk, Kira Makarova, Eugene Koonin, and Feng Zhang (of the Broad Institute) What do these two papers -- both about techniques for getting rid of the need to cut the genome to edit it -- make possible going forward, given the ongoing shift of biology becoming more like engineering? Where are we in the wave of the genome engineering "developer community" building on top of CRISPR with a constantly growing suite of programmable functionalities? a16z bio general partner Jorge Conde and bio deal team partner Andy Tran chat with Hanne Tidnam about these trends -- and these two papers -- in this short internal hallway-style conversation, part of our new a16z Journal Club series. This podcast is also part of our new a16z bio newsletter, which you can sign up for at a16z.com/subscribe

Hosts: Nels Elde and Vincent Racaniello Guest: Stephen Goff Nels joins Vincent in New York City to speak with Stephen Goff about transmissible clam cancers and the silencing of integrated retroviral genomes. Become a patron of TWiEVO A sixth modality of infectious disease (PLoS Path) Horizontal transmission of clam cancer (Cell) Transmissible bivalve cancers (Nature) Retrovirus transcriptional silencing (J Virol) Histones on retroviral DNA (Cell Host Micr) Image credit This episode is brought to you by Blue Apron. Blue Apron is the #1 fresh ingredient and recipe delivery service in the country. See what’s on the menu this week and get your first 3 meals free with your first purchase – WITH FREE SHIPPING – by going to blueapron.com/twie. Science Picks Nels - Mindsuckers Vincent - What is a species? Music on TWiEVO is performed by Trampled by Turtles Send your evolution questions and comments to twievo@microbe.tv

Hosts: Nels Elde and Vincent Racaniello Nels and Vincent reveal how introns - the parts of pre-mRNAs that are removed by splicing - were generated by DNA transposons in two different picoeukaryotes.   Become a patron of TWiEVO Introns from DNA transposons (Nature) Reverse transcription and integration lecture Image: Elde Lab Mobile Studios on location in Santa Fe, NM Letters read on TWiEVO 16 This episode is brought to you by Blue Apron. Blue Apron is the #1 fresh ingredient and recipe delivery service in the country. See what’s on the menu this week and get your first 3 meals free with your first purchase – WITH FREE SHIPPING – by going to blueapron.com/twie. Science Picks Nels - Did eukaryotes invent anything? (TWiM 144) Vincent - Virology course online Music on TWiEVO is performed by Trampled by Turtles Send your evolution questions and comments to twievo@microbe.tv

Hosts: Nels Elde and Vincent Racaniello Nels and Vincent review experiments showing that the replacement of a pale moth with a black one during the industrial revolution was caused by a transposable element.   Links for this episode Last experiment of Michael Majerus (Biol Lett) Moth melanism mutation is transposon (Nature) Image credit Letters read on TWiEVO 10 Science Picks Nels - Is Pokémon Go good for science? (one, two, three) Vincent - Seven Brief Lessons on Physics by Carlo Rovelli Music on TWiEVO is performed by Trampled by Turtles Send your evolution questions and comments to twievo@microbe.tv Become a patron of TWiEVO

Hosts: Vincent Racaniello, Dickson Despommier, Alan Dove, Rich Condit, and Kathy Spindler The TWiV teams reviews a MERS-coronavirus serosurvey and an outbreak in South Korea, and constraints on measles virus antigenic variation. Links for this episode Richard Elliott on TWiV 177 MERS-CoV outbreak, South Korea (ProMedMail) MERS-CoV serosurvey (Lancet Inf Dis) Biolabs in your backyard (USA Today) Constraints on measles virus antigenic variation (Cell Rep) Selection bias and bombers (John D. Cook) Virology (journal) Image credit: Cameron Moll Letters read on TWiV 340 Weekly Science Picks Dickson - Singapore Flower Dome  and Cloud ForestAlan - Rescuing biomedical researchKathy - The value of basic researchRich - Virology 60th Anniversary IssueVincent - Careers in virology: Science writing and journalism Listener Pick of the Week Pritesh - How T cells kill cancer cellsRamon - The power of herd immunity Send your virology questions and comments (email or mp3 file) to twiv@twiv.tv

Background: Pancreatic ductal adenocarcinoma (PDA) is a highly lethal cancer characterized by complex aberrant genomes. A fundamental goal of current studies is to identify those somatic events arising in the variable landscape of PDA genomes that can be exploited for improved clinical outcomes. Methods: We used DNA content flow sorting to identify and purify tumor nuclei of PDA samples from 50 patients. The genome of each sorted sample was profiled by oligonucleotide comparative genomic hybridization and targeted resequencing of STAG2. Transposon insertions within STAG2 in a KRAS(G12D)-driven genetically engineered mouse model of PDA were screened by RT-PCR. We then used a tissue microarray to survey STAG2 protein expression levels in 344 human PDA tumor samples and adjacent tissues. Univariate Kaplan Meier analysis and multivariate Cox Regression analysis were used to assess the association of STAG2 expression relative to overall survival and response to adjuvant therapy. Finally, RNAi-based assays with PDA cell lines were used to assess the potential therapeutic consequence of STAG2 expression in response to 18 therapeutic agents. Results: STAG2 is targeted by somatic aberrations in a subset (4%) of human PDAs. Transposon-mediated disruption of STAG2 in a KRAS(G12D) genetically engineered mouse model promotes the development of PDA and its progression to metastatic disease. There was a statistically significant loss of STAG2 protein expression in human tumor tissue (Wilcoxon-Rank test) with complete absence of STAG2 staining observed in 15 (4.3%) patients. In univariate Kaplan Meier analysis nearly complete STAG2 positive staining (> 95% of nuclei positive) was associated with a median survival benefit of 6.41 months (P = 0.031). The survival benefit of adjuvant chemotherapy was only seen in patients with a STAG2 staining of less than 95% (median survival benefit 7.65 months; P = 0.028). Multivariate Cox Regression analysis showed that STAG2 is an independent prognostic factor for survival in pancreatic cancer patients. Finally, we show that RNAi-mediated knockdown of STAG2 selectively sensitizes human PDA cell lines to platinum-based therapy. Conclusions: Based on these iterative findings we propose that STAG2 is a clinically significant tumor suppressor in PDA.

This episode: "Selfish" jumping gene is actually helpful for its host plant's resistance to disease! Download Episode (5.56 MB, 6 minutes)Show notes:News item/Journal Paper Other interesting stories: Gut microbes may make difference in autoimmunity between males and females Helpful fungal symbiont prevents growth of toxin-producing fungi in potatoes (paper) Modified soil bacteria could treat parasite infections (paper) Mothers transfer good bacteria to babies through breastmilk Pollution-degrading bacteria are more common than was known Post questions or comments here or email to bacteriofiles at gmail dot com. Thanks for listening! Subscribe at iTunes, check out the show at Twitter or Facebook

Thu, 16 May 2013 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/16319/ https://edoc.ub.uni-muenchen.de/16319/1/Elmer_Anna_K.pdf Elmer, Anna Katharina ddc:540, ddc:500, Fakultät für Chemie und Pharmazie

Tue, 26 Mar 2013 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/16940/ https://edoc.ub.uni-muenchen.de/16940/1/Mirkovic-Hoesle_Milijana.pdf Mirkovic-Hösle, Milijana ddc:540, ddc:500, Fakultät

This Week in Virology and Futures in Biotech join together in a science mashup to talk about a virophage at the origin of DNA transposons, and unintended spread of a recombinant retrovirus.

Human cytomegalovirus is a ubiquitous human pathogen, causing disease in the immunocompromised host. Most of its ORFs have not been well studied due to a limited host range and slow growth of HCMV in cultured cells. MCMV, a natural pathogen isolated from mice, constitutes the most amenable animal model for human β-herpesviruses. To date most of its approximately 200 genes have an unknown function. For the analysis of these genes straightforward mutagenesis methods are necessary. With the cloning of herpesviruses as an infectious bacterial artificial chromosome a novel approach of mutagenesis has been established. Herpesviruses are now accessible to the tools of bacterial genetics. Since then site-directed mutagenesis by homologous recombination using linear DNA fragments and random transposon BAC mutagenesis have been introduced to delineate the functions of viral ORFs. The purpose of this work was to analyze two members of the US 22 gene homolog family, genes m139 and m142, with site-directed mutagenesis. Members of this family are conserved in all herpesviruses and mostly have unknown functions. Transposon mutants showed a macrophage phenotype for m139, whereas m142 was possibly essential for viral replication. Genes m139-m141 and m142-m143 have complex transcriptional regions and have 3´-coterminal transcripts. The insertion of a 3-kb large transposon could destabilize the upstream transcripts. Site-directed mutants of genes m139 and m142, where only the start codon is deleted, should not influence transcript stability and permit confirmation of the results obtained with transposon mutagenesis. Targeted mutants of MCMV BAC were constructed for ORF m139 (ΔATG-m139) and m142 (ΔATG-m142, ΔATG-m142/FRT) by homologous recombination using linear DNA fragments. Mutant ΔATG-m139 showed attenuated growth in peritoneal macrophages. This mutant, with the first two ATGs deleted, expressed a truncated protein of 61 kDa. Gene m139 seems to act in cooperation with genes m140 and m141 on the protein level. The site-directed MCMV BAC mutant of ORF m142 on the other hand could not reconstitute viral progeny in eukaryotic cells. The ORF of m142 was inserted an ectopic position and viral progeny was reconstituted with this revertant. Thus, it was shown that gene m142 is essential for viral replication. Further analysis of nonessential and essential genes of cytomegalovirus will be needed to understand CMV viral pathology and to develop vaccines for herpesvirus infection and vectors for gene therapy.

Im Rahmen der vorliegenden Doktorarbeit wurde zum ersten Mal die Keimbahn eines Käfers erfolgreich genetisch transformiert. Der von uns zu diesem Zweck in Zusammenarbeit mit Ernst Wimmer entwickelte Transformationsmarker 3xP3-EGFP hat inzwischen sein Potential als spezies-unabhängiges Markergen auch in weiteren Invertebraten-Spezies unter Beweis gestellt und damit das Spektrum transformierbarer Taxa beträchtlich erweitert. In Tribolium konnten Transformationsereignisse mit 3xP3-EGFP für drei verschiedene Transposons - Hermes, Minos und piggyBac - erzielt werden. Die Effizienz betrug dabei 1,4% (Hermes), 11,4% (Minos) bzw. 56% (piggyBac) der fertilen G0 und gehört damit zu den höchsten Werten, die in der Literatur für Insekten berichtet wurden. Bei Minos konnte die Effizienz durch die Verwendung von Transposase mRNA statt einem DNA Helper-Plasmid weiter auf 32,4% gesteigert werden. Für piggyBac und Minos wurde ferner in Zusammenarbeit mit anderen Labors gezeigt, daß es sich bei den meisten Transposoninsertionen um unabhängige Einzelintegrationen handelt, die auf verschiedene Chromosomen verteilt sind und stabil weitervererbt werden. Die Größe zusätzlich transferierter Fremd-DNA kann dabei bei piggyBac mindestens bis zu 9,5 kb betragen. Schließlich konnte noch ein piggyBac Element durch Helperinjektion mit einer Rate von 28,1% remobilisiert werden. Zusammen mit der Anfälligkeit für enhancer trap Effekte können daher mit diesem System alle relevanten Transposon-basierenden Techniken zur funktionellen Genomanalyse angewandt werden. Als erste praktische Anwendung wurden D. melanogaster Sequenzen für anteriore und posteriore mRNA-Lokalisierung (bicoid-3’UTR und oskar-3’UTR), sowie ein bicoid-abhängiger Minimalpromotor in Tribolium eingeführt. Allerdings konnten durch diese Ansätze keine Komponenten oder Mechanismen eines ggf. konservierten maternalen Systems nachgewiesen werden. Ein Konstrukt mit 5,2 kb der upstream Sequenzen von Tc’hunchback mit lacZ als Reportergen war hingegen in der Lage, das endogene hunchback-Muster größtenteils nachzubilden. Das frühere Ergebnis von Christian Wolff mit Tc’hunchback in Drosophila, wonach dieses Fragment alle wesentlichen regulatorischen Elemente enthält, konnte daher in transgenen Käfern bestätigt werden. Zusätzlich zu dem als sehr riskant eingestuften Transformations-Projekt wurde parallel ein weiteres Projekt durchgeführt, die Analyse der homöotischen Mutanten wurm und überlänge. In beiden Mutanten ist vor allem die Identität der posterioren Segmente ab A9 verändert. In wurm sind die Segmente A9-A11 nach A8 transformiert und die telsonalen Anhänge Urogomphi und Pygopodien fehlen. In überlänge ist nur A9 wie A8 ausgebildet und demzufolge nicht mit dem Telson fusioniert. Es fehlen nur die Urogomphi. überlänge bildet zusätzlich ein ektopisches Stigma im ersten thorakalen Segment. Es wurde gezeigt, daß es sich bei den betroffenen Genen um zwei verschiedene Loci handelt, die beide nicht im homöotischen Komplex liegen. Obwohl der Phänotyp von wurm weitgehend der RNAi-Phänokopie von Abdominal-B entspricht, konnte also keiner dieser beiden Loci einem bekannten Hox-Gen zugeordnet werden. Als mögliches Kandidatengen für diese Loci wurde daher das Tribolium-Homolog des regionsspezifischen homöotischen Gens spalt kloniert. Die Expression von spalt entspricht weitgehend der von Dm’spalt, mit einer anterioren und einer posterioren Domäne, einer dorsalen Expression an den seitlichen Rändern des Keimstreifs, sowie einem komplexen Muster im Nervensystem. Mit Hilfe der kürzlich entwickelten Technik der parentalen RNAi wurde die Funktion dieses Gens untersucht. In sal–– Phänokopien finden sich, wie in Drosophila, anteriore und posteriore Veränderungen von Segmentidentitäten. So wird das abdominale Segment A9 in Richtung anteriore abdominale Segmente transformiert. Dadurch tritt ein zusätzliches Stigma auf und die Pygopodien gehen verloren, das Segment fusioniert aber weiterhin mit dem Telson. Im Gegensatz zu Drosophila wird aber anterior nicht das Labium verändert, sondern die Identität der Maxille wird partiell in Richtung Mandibel transformiert: statt dem Enditen der Maxille wird ein mandibel-ähnlicher Zahn gebildet. Damit kommt offenbar auch spalt nicht als Locus in Frage, der in wurm oder überlänge seine Funktion verloren hat. Möglicherweise spielen diese beiden Loci eine Rolle als den HOX-Genen übergeordnete regulatorische Gene, oder als Co-Faktor von Abd-B. Damit sind wurm und überlänge als interessante (und aus Drosophila nicht bekannte) Spieler im homöotischen System der Insekten identifiziert, was weitere Untersuchungen als sehr lohnend erscheinen läßt. Vor allem aber hat dieses Teilprojekt die Evolution des spalt-Gens erhellt, das in weniger abgeleiteten Insekten offenbar eine essentielle Rolle bei der Spezifizierung von Mandibel versus Maxille spielt. Diese Funktion ist in Drosophila vermutlich im Zuge der Reduktion der Mandibel verloren gegangen.