Em eucariotos, o DNA é organizado juntamente com histonas em um complexo nucleoproteico conhecido como cromatina, cuja unidade fundamental corresponde aos nucleossomos. A cromatina apresenta-se de duas maneiras: eucromatina, região estruturalmente menos condensada e, portanto, mais facilmente transcrita, e heterocromatina, região muito condensada e transcricionalmente silenciosa. Na forma de eucromatina, o acesso dos fatores de transcrição a regiões de DNA livres de nucleossomos é facilitado, enquanto que na forma de heterocromatina os fatores de transcrição não conseguem acessar o DNA para ativar ou reprimir a expressão gênica inferindo, assim, que o grau de compactação da cromatina interfere na regulação da expressão gênica e que o nucleossomo atua como silenciador gênico. Neste contexto, os objetivos foram identificar, mapear e caracterizar regiões em eucromatina na musculatura esquelética de bovinos da raça Nelore. As análises foram realizadas em relação ao músculo Longissimus dorsi pela técnica Assay for Transposase-Accessible Chromatin (ATAC-Seq), capaz de isolar regiões livres de nucleossomos a partir do mecanismo enzimático de transposição. A fim de otimizar o protocolo dessa metodologia para tecido muscular, foram testadas concentrações de 50 mil, 75 mil e 100 mil núcleos tratados com transposase. Destes, foram encontrados 6.811, 11.121 e 11.473 picos de eucromatina, respectivamente, e 6.212 regiões de cromatina aberta foram coincidentes nas três amostras. A associação entre regiões eucromáticas, expressão gênica e gordura intrasmuscular foi confirmada a partir da análise de sobreposição com transcriptional start sites (TSS), genes expressos em músculo esquelético, genes diferencialmente expressos (GDE) para gordura intramuscular e regiões de expression quantitative trait loci (eQTL) de tecido muscular reforçando, assim, o potencial regulatório das regiões de eucromatina. / In eukaryotes, DNA is organized along with histones in nucleoproteins complexes known as chromatin, which has nucleosomes as their fundamental unit. Chromatin exists in two forms: euchromatin, corresponding to a lightly condensed structure and an easily transcribed region, and heterochromatin, a highly condensed and transcriptionally silent region. In euchromatin form, transcription factors have free access to nucleosome-depleted DNA regions, while in heterochromatin the transcription factors can not access the DNA for activate or repress genic expression, which suggests that the chromatin compaction degree interferes with regulation of gene expression and that nucleosomes act as gene silencer. In this context, the aims of the present project were to identify, map and characterize euchromatin regions in the skeletal musculature of Nellore cattle. Analyzes were performed considering the muscle Longissimus dorsi using Assay for Transposase-Accessible Chromatin technique (ATAC-Seq), which isolates nucleosome-depleted regions throught transposition enzymatic mechanism. Differente transposase-treated nuclei concentrations were tested: 50 thousand, 75 thousand and 100 thousand. From these, 6.811, 11.121, and 11.473 euchromatin peaks were found, respectively, and 6.212 open chromatin regions were coincident among them. The association between euchromatic regions, gene expression and intrasmuscular fat was confirmed from the overlap analysis with transcriptional start sites (TSS), genes expressed in skeletal muscle, differentially expressed genes (GDE) for intramuscular fat and regions of expression quantitative trait loci (eQTL) of muscle tissue, reinforcing the regulatory potential of the euchromatin regions.

Em eucariotos, o DNA é organizado juntamente com histonas em um complexo nucleoproteico conhecido como cromatina, cuja unidade fundamental corresponde aos nucleossomos. A cromatina apresenta-se de duas maneiras: eucromatina, região estruturalmente menos condensada e, portanto, mais facilmente transcrita, e heterocromatina, região muito condensada e transcricionalmente silenciosa. Na forma de eucromatina, o acesso dos fatores de transcrição a regiões de DNA livres de nucleossomos é facilitado, enquanto que na forma de heterocromatina os fatores de transcrição não conseguem acessar o DNA para ativar ou reprimir a expressão gênica inferindo, assim, que o grau de compactação da cromatina interfere na regulação da expressão gênica e que o nucleossomo atua como silenciador gênico. Neste contexto, os objetivos foram identificar, mapear e caracterizar regiões em eucromatina na musculatura esquelética de bovinos da raça Nelore. As análises foram realizadas em relação ao músculo Longissimus dorsi pela técnica Assay for Transposase-Accessible Chromatin (ATAC-Seq), capaz de isolar regiões livres de nucleossomos a partir do mecanismo enzimático de transposição. A fim de otimizar o protocolo dessa metodologia para tecido muscular, foram testadas concentrações de 50 mil, 75 mil e 100 mil núcleos tratados com transposase. Destes, foram encontrados 6.811, 11.121 e 11.473 picos de eucromatina, respectivamente, e 6.212 regiões de cromatina aberta foram coincidentes nas três amostras. A associação entre regiões eucromáticas, expressão gênica e gordura intrasmuscular foi confirmada a partir da análise de sobreposição com transcriptional start sites (TSS), genes expressos em músculo esquelético, genes diferencialmente expressos (GDE) para gordura intramuscular e regiões de expression quantitative trait loci (eQTL) de tecido muscular reforçando, assim, o potencial regulatório das regiões de eucromatina. / In eukaryotes, DNA is organized along with histones in nucleoproteins complexes known as chromatin, which has nucleosomes as their fundamental unit. Chromatin exists in two forms: euchromatin, corresponding to a lightly condensed structure and an easily transcribed region, and heterochromatin, a highly condensed and transcriptionally silent region. In euchromatin form, transcription factors have free access to nucleosome-depleted DNA regions, while in heterochromatin the transcription factors can not access the DNA for activate or repress genic expression, which suggests that the chromatin compaction degree interferes with regulation of gene expression and that nucleosomes act as gene silencer. In this context, the aims of the present project were to identify, map and characterize euchromatin regions in the skeletal musculature of Nellore cattle. Analyzes were performed considering the muscle Longissimus dorsi using Assay for Transposase-Accessible Chromatin technique (ATAC-Seq), which isolates nucleosome-depleted regions throught transposition enzymatic mechanism. Differente transposase-treated nuclei concentrations were tested: 50 thousand, 75 thousand and 100 thousand. From these, 6.811, 11.121, and 11.473 euchromatin peaks were found, respectively, and 6.212 open chromatin regions were coincident among them. The association between euchromatic regions, gene expression and intrasmuscular fat was confirmed from the overlap analysis with transcriptional start sites (TSS), genes expressed in skeletal muscle, differentially expressed genes (GDE) for intramuscular fat and regions of expression quantitative trait loci (eQTL) of muscle tissue, reinforcing the regulatory potential of the euchromatin regions.

Afin d’initier la transcription par l’ARN Polymérase II, la chromatine est modifiée par des coactivateurs, dont certains catalysent des modifications post-traductionnelles des queues des histones. La protéine GCN5 est une enzyme qui possède une activité histone acétyltransférase (HAT). Elle fait partie du complexe coactivateur SAGA, qui acétyle les histones H3. Or, il existe un second complexe HAT contenant GCN5 : le complexe ATAC, mis en évidence chez la drosophile. Chez l’homme en revanche, l’existence d’un tel complexe n’avait pas encore été démontrée au début de ma thèse.L’objectif de ma thèse a consisté tout d’abord en la purification et la caractérisation du complexe HAT ATAC chez l’homme. Puis, j’ai cherché à comprendre le fonctionnement et la spécificité d’action du complexe ATAC, par rapport au complexe SAGA.Dans une première partie, j’ai ainsi pu montrer que GCN5 fait partie d’un second complexe chez l’homme, le complexe ATAC. La composition en sous-unités du complexe ATAC a été déterminée et l’activité de ce dernier sur les histones étudiée. Nous avons pu démontrer que, comme hSAGA, hATAC acétyle les histones in vitro et in vivo, et préférentiellement la lysine 14 de l’histone H3. Chez les vertébrés, un paralogue de GCN5, PCAF peut se substituer à GCN5 dans les complexes ATAC ou SAGA.Par la suite, j’ai poursuivi la caractérisation de ces complexes HAT afin de comprendre le rôle des enzymes au sein des complexes et leurs fonctions. Pour cela, j’ai voulu comprendre le rôle des sous-unités, comment elles influencent l’activité de l’enzyme, et ainsi identifier les protéines qui permettent la spécificité de hATAC par rapport à hSAGA. / In order to initiate the transcription by the RNA polymerase II, chromatin needs to be modified by coactivators. Some of these coactivators are histone post-translational modifying complexes. GCN5 is a histone acetyltransferase enzyme (HAT), which can acetylate the histones. This enzyme is found in a multiproteic complex named SAGA. Recently, a second HAT complex containing GCN5 was discovered: ATAC, in drosophila. At the beginning of my thesis, the existence of such complex in human was not shown.My thesis objectives were then to identify and characterize an ATAC complex in human cells. In a first part, we purified and identified the composition in subunits of human ATAC. Then we studied the activity and specificity of ATAC on histone substrates, compared to SAGA. Next, we were wondering how the subunits of the two HAT complexes could play a role on the regulation of the activity of the enzyme GCN5, in order to understand the histone specificity of ATAC and SAGA.

In dieser Arbeit wurde die Expression von XCR1 in B6XCR1lacZ+/+ Reporter Mäusen charakterisiert, die β-Galaktosidase unter der Kontrolle des XCR1-Promotors exprimieren. In Gewebeschnitten konnten wir zeigen, dass eine starke XCR1-Expression nur in lymphatischen Organen wie Milz, Lymphknoten und Thymus nachweisbar ist. In der Milz fanden sich XCR1+ Zellen vor allem in der Marginal Zone, aber auch in der roten Pulpa und der T-Zell-Zone. Durchflusszytometrische Analysen zeigten, dass XCR1 in der Milz ausschließlich von dendritischen Zellen DZ exprimiert wird, hauptsächlich von der CD8+DZ Subpopulation aber auch von einer Minderheit der CD4−CD8−DZ. In vivo migrierten diese XCR1+ Zellen nach Applikation von chemotaktischen oder inflammatorischen Substanzen: Die Injektion sowohl einer ATAC-sezernierenden Zelllinie als auch von LPS lösten nach 3-9 h eine Translokation der XCR1+Zellen in die T-Zell-Zone der Milz aus. Untersuchungen der Phagozytose-Aktivität ergaben, dass nur XCR1+CD8+DZ, aber keine anderen DZ Subpopulationen, injizierte allogene Zellen aufnahmen, und dass eine Transfektion dieser Zellen mit ATAC diese Phagozytose signifikant verstärkte. Daher konnten wir allogene Zellen, die intrazellulär Ovalbumin OVA exprimierten, für die selektive Applikation von Antigen auf XCR1+DZ verwenden. Diese selektive Antigen-Applikation induzierte eine starke antigenspezifische zytotoxische Antwort von endogenen T-Zellen, ohne dass es zur Produktion von OVA-spezifischen Antikörpern kam. In Abwesenheit von ATAC war diese endogene zytotoxische Aktivität verringert. Durch adoptivem Transfer und Aktivierung von Wildtyp- oder ATAC-defizienten OVA-spezifischen transgenen CD8+TZellen konnten wir bestätigen, dass ATAC für die Erzeugung einer optimalen zytotoxischen Antwort benötigt wird. Die selektive Applikation von Antigen auf CD8+DZ stellt daher eine vielversprechende Strategie dar, um optimierte Vakzinierungs-Ansätze für die Auslösung einer zytotoxischen Immunantwort zu entwickeln / The G protein-coupled receptor XCR1 has been described as the sole receptor for the chemokine ATAC. As contradictory data were published on the expression pattern of XCR1, its role in the immune system has not yet been defined. In this work, expression of XCR1 was characterized in B6.XCR1 lacZ+/+ reporter mice which express β galactosidase under the control of the XCR1 promoter. In tissue sections, strong expression of XCR1 was only detected in lymphoid organs like spleen, lymph nodes and thymus. In the spleen, XCR1+ cells were mainly found in the marginal zones, but also in the red pulp and the T cell zones. Flow cytometric analysis demonstrated exclusive expression of XCR1 on DC, mainly on the CD8+ DC subset, but also on a minority of CD4− CD8− DC. In vivo, these XCR1+ cells migrated in response to chemotactic or inflammatory stimuli: application of either an ATAC-expressing cell line or LPS induced within 3 9 h the translocation of XCR1+ cells to the T cell area of the spleen. When tested for phagocytic capacity, XCR1+ CD8+ DC, but not other DC subsets, specifically took up injected allogeneic cells, and transfection of these cells with ATAC significantly enhanced their endocytosis by XCR1+ CD8+ DC. Thus, we could employ allogeneic cells expressing OVA intracellularly to target antigen selectively to XCR1+ DC. This antigen targeting induced a strong antigen-specific cytotoxic response by endogenous T cells without a generation of OVA-specific antibodies. In the absence of ATAC, the endogenous cytotoxic activity was markedly diminished. Adoptive transfer and activation of wild type or ATAC-deficient OVA-specific CD8+ transgenic T cells confirmed that ATAC is required for the generation of an optimal cytotoxic response. Targeting of antigen to CD8+ DC via XCR1 may thus be a promising strategy for the development of new vaccination approaches aimed at optimizing the induction of cytotoxic T cells.

Les complexes acétyltransférases (HAT), SAGA et ATAC, sont des régulateurs de la transcription des gènes. Cependant, peu d’études ont été menées sur la dynamique de ces complexes au niveau cellulaire et sur les mécanismes régulant leur assemblage. Au cours de mes travaux de thèse, j’ai utilisé des approches d’imagerie sur cellules vivantes, afin de déterminer la mobilité de ces complexes en comparaison avec celle d’autres régulateurs transcriptionnels. Les résultats ont montré que les sous-unités de SAGA et ATAC interagissent de manière transiente avec la chromatine. En complément, nous avons montré que les sous-unités spécifiques de SAGA et ATAC (ADA2b et ADA2a) ont des propriétés dynamique intracellulaire différentes et que GCN5, affecte la distribution d’ADA2a. Des analyses protéomique menées sur le comportement de ces protéines au niveau endogène, ont permis de montrer que les voies d’assemblage de ces deux complexes étaient différentes au niveau cytoplasmique et nucléaire. / Human SAGA and ATAC, are histone acetyltransferase (HAT) containing complexes that share a set of subunits and facilitate RNA polymerase II (Pol II) transcription. Little is known for the dynamics of the complexes in living cells and the regulation of their assembly. In this work, we used live-cell imaging to characterise the mobility of the two complexes and compare it with other actors of Pol II transcription. All tested ATAC and SAGA subunits exhibit very transient interactions with chromatin, a property that explains certain aspects of the function of the complexes. Moreover, we showed that overexpressed ATAC- and SAGA-specific HAT-module subunits (ADA2a and ADA2b respectively) have different intracellular dynamics and that the abundance of the shared subunit GCN5, affects the distribution of ADA2a. Quantitative proteomic analysis expanded our findings on endogenous proteins and provided evidence that the cytoplasmic and nuclear assembly pathways of SAGA and ATAC are different.

Cis-regulatorische Elemente wie Promotoren und Enhancer, die die Regulation der Transkription von Genen steuern, befinden sich in Regionen des dekondensierten Chromatins. DNase-seq und ATAC-seq sind weit verbreitete Verfahren, um solche offenen Chromatinregionen genomweit zu untersuchen. Die einzel-Nukleotid-Auflösung von DNase-seq wurde des Weiteren genutzt, um Transkriptionsfaktor-Bindungsstellen (TFBS) in regulatorischen Regionen durch TF-Footprinting zu bestimmen. Kürzlich durchgeführte Studien haben jedoch gezeigt, dass DNase I einen Sequenzbias aufweist, welcher nachteilige Auswirkungen auf die Footprinting-Effizienz hat. Auch wurden das Footprinting und die Auswirkungen des Sequenzbias auf ATAC-seq noch nicht umfassend untersucht. In dieser Arbeit nehme ich einen systematischen Vergleich der beiden Methoden vor und zeige, dass die beiden Methoden unterschiedliche Sequenzbiases haben und korrigiere diese protokollspezifischen Biases beim Footprinting. Der Einfluss von Bias-Korrekturen der Footprinting Ergebnisse ist für DNase-seq größer als für ATAC-seq, und Footprinting mit DNase-seq führt zu besseren Ergebnissen in unserer Datensätze. Trotz dieser Unterschiede zeige ich, dass die Integration replizierter Experimente die Ableitung von qualitativ hochwertigen Footprints ermöglicht, wobei die beiden Techniken weitgehend übereinstimmen. Diese Techniken werden ferner eingesetzt, um die cis-regulatorischen Elemente zu charakterisieren, die die Embryogenese der Fruchtfliege Drosophila melanogaster bestimmen. Durch die Verwendung von Embryonen die sich im richtigen Entwicklungsstadium befinden, sowie gewebespezifischer Kernsortierung mit offenem Chromatin-Profiling können zeitlich und gewebespezifisch aufgelöste vermeintliche cis-regulatorische Elemente definiert werden. Zusammengenommen demonstrieren diese Analysen die Fähigkeit der offenen Chromatin-Profilierung und der Computeranalyse zur Aufklärung der Mechanismen der Genregulation. / Cis-regulatory elements such as promoters and enhancers, that govern transcriptional gene regulation, reside in regions of open chromatin. DNase-seq and ATAC-seq are broadly used methods to assay open chromatin regions genome-wide. The single nucleotide resolution of DNase-seq has been further exploited to infer transcription factor binding sites (TFBS) in regulatory regions through TF footprinting. However, recent studies have demonstrated the sequence bias of DNase I and its adverse effects on footprinting efficiency. Furthermore, footprinting and the impact of sequence bias have not been extensively studied for ATAC-seq. In this thesis, I undertake a systematic comparison of the two methods and demonstrate that the two methods have distinct sequence biases and correct for these protocol-specific biases when performing footprinting. The impact of bias correction on footprinting performance is greater for DNase-seq than for ATAC-seq, and footprinting with DNase-seq leads to better performance in our datasets. Despite these differences, I show that integrating replicate experiments allows the inference of high-quality footprints, with substantial agreement between the two techniques. These techniques are further employed to characterize the cis-regulatory elements governing the embryogenesis of a complex organism, the fruit fly Drosophila melanogaster. Combining tight staging of embryos and tissue-specific nuclear sorting with open chromatin profiling, enables the definition of temporally and tissue-specifically resolved putative cis-regulatory elements. Taken together, these analyses demonstrate the power of open chromatin profiling and computational analysis in elucidating the mechanisms of transcriptional gene regulation.

Afin d'initier la transcription par l'ARN Polymérase II, la chromatine est modifiée par des coactivateurs, dont certains catalysent des modifications post-traductionnelles des queues des histones. La protéine GCN5 est une enzyme qui possède une activité histone acétyltransférase (HAT). Elle fait partie du complexe coactivateur SAGA, qui acétyle les histones H3. Or, il existe un second complexe HAT contenant GCN5 : le complexe ATAC, mis en évidence chez la drosophile. Chez l'homme en revanche, l'existence d'un tel complexe n'avait pas encore été démontrée au début de ma thèse.L'objectif de ma thèse a consisté tout d'abord en la purification et la caractérisation du complexe HAT ATAC chez l'homme. Puis, j'ai cherché à comprendre le fonctionnement et la spécificité d'action du complexe ATAC, par rapport au complexe SAGA.Dans une première partie, j'ai ainsi pu montrer que GCN5 fait partie d'un second complexe chez l'homme, le complexe ATAC. La composition en sous-unités du complexe ATAC a été déterminée et l'activité de ce dernier sur les histones étudiée. Nous avons pu démontrer que, comme hSAGA, hATAC acétyle les histones in vitro et in vivo, et préférentiellement la lysine 14 de l'histone H3. Chez les vertébrés, un paralogue de GCN5, PCAF peut se substituer à GCN5 dans les complexes ATAC ou SAGA.Par la suite, j'ai poursuivi la caractérisation de ces complexes HAT afin de comprendre le rôle des enzymes au sein des complexes et leurs fonctions. Pour cela, j'ai voulu comprendre le rôle des sous-unités, comment elles influencent l'activité de l'enzyme, et ainsi identifier les protéines qui permettent la spécificité de hATAC par rapport à hSAGA.

Haematopoietic stem cells (HSCs) maintain the vertebrate blood system throughout life. Exploiting their clinical potential requires a thorough understanding of the natural origins of the HSCs. They first arise from the haemogenic endothelium (HE), located in the main embryonic artery, the dorsal aorta. Our understanding of the genetic mechanisms underlying HE specification remains incomplete, but one of the crucial transcription factors is Gata2. We found that a conserved enhancer of zebrafish gata2a gene (i4 enhancer) is active in vivo specifically in endothelial cells, including the HE. To unravel the function of gata2a in specifying the HSCs, we have targeted the i4 enhancer with CRISPR/Cas9, generating the first reported genomic deletion of an endogenous cis-regulatory region in zebrafish. Deletion of the i4 enhancer leads to a decrease in endothelial gata2a expression and a concomitant transient decrease in the number of HSCs. This is marked by an early decrease in the expression of gata2b, a gata2a paralogue previously shown to be required for the initiation of the haematopoietic programme. Our results suggest non-redundant roles of both zebrafish gata2 paralogues in programming of HSCs, providing insights into different roles of GATA2 throughout the programming of HSCs. We also confirmed the previously reported loss of HSCs upon MO-mediated knockdown of lmo4a, associated with increased gata2a expression in HE. We validated the increase in gata2a levels in TALEN-generated lmo4a mutants. To identify the links between lmo4a, gata2a and the HE programming, we have profiled the transcriptome of lmo4a-deficient endothelial cells, including the HE. Our results suggest that Lmo4a may be a global regulator of the transcriptional programming of the HE. Moreover, Wnt signalling pathway may regulate gata2a downstream of lmo4a. This provides novel insights into the gene regulatory network orchestrating the generation of HSCs in the embryo.

Droplet-based microfluidics is a powerful tool permitting massive-scale single-cell analysis in pico-/nano-liter water-in-oil droplets. It has been integrated into various library preparation techniques to accomplish high-throughput scRNA-seq, scDNA-seq, scATAC-seq, scChIP-seq, as well as scMulti-omics-seq. These advanced technologies have been providing unique and novel insights into both normal differentiation and disease development at single-cell level. In this thesis, we develop four new droplet-based tools for single-cell omics profiling. First, the developed Drop-BS is the first droplet-based platform to construct single-cell bisulfite sequencing libraries for DNA methylome profiling and allows production of BS library of 2,000-10,000 single cells within 2 d. We applied the technology to separately profile mixed cell lines, mouse brain tissues, and human brain tissues to reveal cell type heterogeneity. Second, the new Drop-ChIP platform only requires two steps of droplet generation to achieve multiple steps of reactions in droplets such as single-cell lysis, chromatin fragmentation, ChIP, and barcoding. Third, we aim to establish a droplet-based platform to accomplish high-throughput full-length RNA-seq (Drop-full-seq), which both current tube-based and droplet-based methods cannot realize. Last, we constructed an in-house droplet-based tool to assist single-cell ATAC-seq library preparation (Drop-ATAC), which provided a low-cost and facile protocol to conduct scATAC-seq in laboratories without the expensive instrument. / Doctor of Philosophy / Microfluidics is a collection of techniques to manipulate fluids in the micrometer scale. One of microfluidic techniques is called "droplet-based microfluidics". It can manipulate (i.e., generate, merge, sort, split, etc) pico-/nano-liter of water-in-oil droplets. First, since the water phase is separated by the continuous oil phase, these droplets are discrete and individual reactors. Second, droplet-based microfluidics can achieve highly parallel manipulation of thousands to millions of droplets. These two advantages make droplet-based microfluidics an ideal tool to perform single-cell assays. Over the past 10 years, various droplet-based platforms have been developed to study single-cell transcriptome, genome, epigenome, as well as multi-ome. To expand droplet-based tools for single-cell analysis, we aim to develop four novel platforms in this thesis. First, Drop-BS, by integrating droplet generation and droplet fusion techniques, can achieve high-throughput single-cell bisulfite sequencing library preparation. It can generate 10,000 single-cell BS libraries within 2 days which is difficult to achieve for conventional library preparation in tubes/microwells. Second, we developed a novel and facile Drop-ChIP platform to prepare single-cell ChIP-seq library. It is easy to operate since it only requires two steps of droplet generation. It also generates higher quality of data compared to previous work. In addition, we are working on the development and characterization of the other two droplet-based tools to achieve full-length single-cell RNA-seq and single-cell ATAC-seq.

Mänsklig utforskning av månen och Mars innebär stora utmaningar för människans fysiologi och hälsa på grund av de unika miljöfaktorer som följer av långvariga rymduppdrag. Rymdbiologiska experiment har blivit ett viktigt verktyg för att studera effekterna som mikrogravitation och rymdstrålning har på levande organismer, i syfte att förstå och minska dessa utmaningar. Sådana experiment ger forskarna möjlighet att få insikt i rymduppdragens inverkan på människans fysiologi och utveckla strategier för att motverka eventuella skadliga effekter. Dessutom ger rymdbiologiska experiment möjlighet att öka vår förståelse av grundläggande biologiska processer, inklusive mikrogravitationens effekter på celldifferentiering och vävnadsregeneration, med potentiella tillämpningar för både rymdforskning och för att förbättra människors hälsa på jorden. Särskilt studier av mikrogravitationens effekter på hjärncellerna har potentiella konsekvenser för neurodegenerativa sjukdomar som Alzheimers och Parkinsons sjukdom. Genom att analysera data som genererats från hjärnor hos möss som skickats ut i rymden med en ny R-mjukvara, ArchR, är det möjligt att belysa de mekanismer som ligger till grund för förändringar i hjärnans funktion och beteende hos astronauter under långvariga rymduppdrag. Genom att förstå dessa mekanismer kan man utveckla nya terapeutiska metoder för att behandla eller till och med förebygga dessa sjukdomstillstånd. Fortsatta investeringar i rymdbiologisk forskning är avgörande för att garantera säkerheten och framgången för framtida, långvariga rymdforskningsuppdrag för människor. Genom att integrera avancerad teknik, t.ex. användning av spatiell transkriptomik eller sekvensering med encellsupplösning, kan en omfattande förståelse av komplexa biologiska system tolkas. De potentiella fördelarna med rymdbiologisk forskning sträcker sig längre än till att bara förstå effekterna av rymdfärder på människans fysiologi, med konsekvenser för grundläggande biologiska processer och behandling av en rad neurologiska sjukdomar. / Human exploration of the Moon and Mars poses significant challenges to human physiology and health due to the unique environmental factors that accompany long-duration space missions. Space biology experiments have emerged as an essential tool for studying the effects of microgravity and space radiation on living organisms, in order to understand and mitigate these challenges. Such experiments provide researchers with the opportunity to gain insights into the impacts of prolonged exposure to outer space on human physiology, and develop strategies to counteract any harmful effects. Additionally, space biology experiments offer the potential to enhance our understanding of fundamental biological processes, including the effects of microgravity on cell differentiation and tissue regeneration, with potential applications for both space exploration and improving human health on Earth. Previous research indicated the regulation of similar biomarkers, studying the effects of microgravity on brain cells could offer valuable insights into the potential impact on neurodegenerative conditions such as Alzheimer’s and Parkinson’s diseases. By analyzing data generated from the brains of mice that have been sent to space with a new R-software tool called ArchR, it is possible to elucidate the mechanisms underlying changes in brain function and behavior in astronauts during long-duration space missions. Understanding these mechanisms can inform the development of new therapeutic approaches to treating or even preventing these conditions. Continued investment in space biology research is critical to ensuring the safety and success of future long-term human space exploration missions. By integrating advanced technologies, such as the use of spatial transcriptomics or sequencing at the single-cell resolution, comprehensive understanding of complex biological systems can be interpreted. The potential benefits of space biology research extend beyond just understanding the effects of spaceflight on human physiology, with implications for fundamental biological processes and the treatment of a range of neurological diseases.