The Gram-negative aerobic coccobacillus Bordetella pertussis is one of the few exclusively human pathogens and the main causative agent of the respiratory infectious disease called pertussis, or whooping cough. Despite global vaccination programs, pertussis remains an important public-health burden and still accounts for over 100,000 infant deaths and over a dozen of millions of whooping cough cases every year. Substantial effort is devoted to studies on the mechanisms of action of virulence factors of B. pertussis, but the biology of interactions of B. pertussis with its human host remains largely underexplored. Evolution, genetics and adaptation of B. pertussis to the complex environment of human nasopharynx and the mechanisms enabling B. pertussis to overcome host innate and adaptive mucosal immune defenses, remain poorly understood. In such situations, unbiased exploratory omics approaches represent valuable tools for uncovering of unknown aspects of host-pathogen interactions and open the path to detailed analysis of virulence-underlying processes by mechanistic studies. In this thesis, I am presenting the results of three omics projects on B. pertussis biology that involved high-throughput proteomics. In the inital phosphoprotemics project, we analyzed the kinase signaling pathways hijacked...

As plastic pollution increases, top marine predators such as marine mammals are becoming increasingly susceptible to plastic particles and their additives. Plastic particles have been found in gastrointestinal tracts and scat of many marine mammals, and quantifying plastic pollution in those that are pelagic can provide insight into plastic pollution in mesopelagic ecosystems that are just beginning to be analyzed. Adapting well-developed laboratory techniques for microplastic (MP) isolation (i.e. density separation and chemical digestion), I isolated MPs from the scat of the deepest diving pinniped, the northern elephant seal (NES), and found that100% of scat samples (n=11) contained high counts of MPs compared to other pinnipeds. Further, as plastic particles move through the digestive tract and potentially translocate into the circulation, body cells may be exposed to these plastic particles. Nanoplastics (NPs;<1μm) have been shown to affect cell viability and redox homeostasis in fish and human cells, while the lipophilic additives bisphenol-a (BPA) and bisphenol-s (BPS) used in plastics production are known endocrine disruptors. However, the effects of plastics (NPs) and plastics additives (BPA and BPS) have not been well-studied in marine mammals. To assess the direct impacts of NPs on marine mammal cells, I exposed fibroblasts isolated from NES skin (n=6 experiments) to polystyrene NPs of two different sizes (0.05μm and 0.5μm) and concentrations (3.64x109 and 3.64x1010 particles/mL) and did not find consistent effects on morphology and viability. Cell viability, which was quantified by an MTT assay, decreased as a result of NP exposure in two experimental replicates, but these results were not reproducible. I found that NPs did not have consistent effects on the morphology or viability of NES fibroblasts, regardless of their size or concentration. Lastly, I examined the effects of plastic additives on the physiology of marine mammal blubber tissue, the primary energy depot and reservoir of lipophilic pollutants. Precision-cut NES blubber slices were exposed to BPA and BPS, alone and in combination with the lipolytic hormone epinephrine, and I assessed their effects on the blubber transcriptome. I found that while BPA and BPS treatments alone did not have a pronounced effect on gene expression, they altered the expression of several genes associated with lipid homeostasis and adipogenesis. These data suggest that NES likely ingest MPs and maybe physiologically affected by exposure to plastic particles and their associated contaminants.

The mortality rate is high for cancer patients and treatments are only efficient in a fraction of patients. To be able to cure more patients, new treatments need to be invented. Immunotherapy activates the immune system to fight against cancer and one treatment targets immune checkpoints. If more targets are found, more patients can be treated successfully. In this project, interactions between immune and cancer cells that drive tumour growth were investigated in an attempt to find new potential targets. This was achieved by creating a machine learning model that finds genes expressed in cells involved in tumour-driving interactions. Single-cell RNA sequencing and spatial transcriptomic data from breast cancer patients were utilised as well as single-cell RNA sequencing data from healthy patients. The tumour rate was based on the cumulative expression of G2/M genes. The G2/M related genes were excluded from the analysis since these were assumed to be cell cycle genes. The machine learning model was based on a supervised variational autoencoder architecture. By using this kind of architecture, it was possible to compress the input into a low dimensional space of genes, called a latent space, which was able to explain the tumour rate. Optuna hyperparameter optimizer framework was utilised to find the best combination of hyperparameters for the model. The model had a R2 score of 0.93, which indicated that the latent space was able to explain the growth rate 93% accurately. The latent space consisted of 20 variables. To find out which genes that were in this latent space, the correlation between each latent variable and each gene was calculated. The genes that were positively correlated or negatively correlated were assumed to be in the latent space and therefore involved in explaining tumour growth. Furthermore, the correlation between each latent variable and the growth rate was calculated. The up- and downregulated genes in each latent variable were kept and used for finding out the pathways for the different latent variables. Five of these latent variables were involved in immune responses and therefore these were further investigated. The genes in these five latent variables were mapped to cell types. One of these latent variables had upregulated immune response for positively correlated growth, indicating that immune cells were involved in promoting cancer progression. Another latent variable had downregulated immune response for negatively correlated growth. This indicated that if these genes would be upregulated instead, the tumour would be thriving. The genes found in these latent variables were analysed further. CD80, CSF1, CSF1R, IL26, IL7, IL34 and the protein NF-kappa-B were interesting finds and are known immune-modulators. These could possibly be used as markers for pro-tumour immunity. Furthermore, CSF1, CSF1R, IL26, IL34 and the protein NF-kappa-B could potentially be targeted in immunotherapy.

Durant le développement préimplantatoire, les défauts de ségrégation des chromosomes conduisent à l'héritage d'un nombre incorrect de chromosomes, connu sous le nom d'aneuploïdie, qui provoque l'infertilité. L’imagerie à intervalle du développement préimplantatoire est introduite pour sélectionner le meilleur embryon et des efforts sont en cours pour utiliser l'imagerie non invasive pour identifier les ovocytes euploïdes en métaphase-II comme prédicteur de la viabilité future de l'embryon. Il est déjà bien établi que les ovocytes de mammifères en métaphase-II subissent des mouvements cytoplasmiques stéréotypés qui peuvent être visualisés par imagerie non invasive à fond clair à intervalle, appelée « flux cytoplasmique ». Ici, nous avons émis l'hypothèse que le flux cytoplasmique pourrait être affecté par le statut de ploïdie de l'ovule et donc être un outil de sélection utile pour sélectionner les ovules euploïdes de manière non invasive. Nous avons développé des conditions pour générer des ovules euploïdes et aneuploïdes à partir du même bassin d'ovocytes sains. Nous avons ensuite utilisé la microscopie d'imagerie en temps réel DIC, permettant de visualiser et de mesurer le flux cytoplasmique sans manipulation de l'ovule. Les mouvements cytoplasmiques ont été liés au statut de ploïdie pour chaque ovule individuel par immunofluorescence. Nos résultats montrent qu'il n'y a pas de différence de flux cytoplasmique entre les ovules euploïdes et aneuploïdes. Nos données démontrent que l'état de la ploïdie n'a pas d'impact sur les mouvements cytoplasmiques, suggérant que l'utilisation d'une imagerie non invasive pour essayer de distinguer l'état de la ploïdie entre des ovocytes autrement sains sera difficile. / Chromosome segregation errors during early development lead to inheritance of incorrect number of chromosomes, known as aneuploidy, which causes infertility and birth defects. Time-lapse microscopy of preimplantation development is being widely introduced with the aim of selecting the best embryo and efforts to use non-invasive brightfield imaging to identify euploid oocytes at metaphase-II as a predictor of future embryo viability are underway. It is already well established that mammalian metaphase-II oocytes undergo stereotyped cytoplasmic movements that can be visualised by non-invasive brightfield timelapse imaging, termed “cytoplasmic flow”. Here, we hypothesised that this cytoplasmic flow might be affected by ploidy status of the egg and therefore be a useful selection tool to select euploid eggs non-invasively. To address this, we developed conditions to generate euploid and aneuploid eggs from the same pool of otherwise healthy oocytes. We then used DIC live-imaging microscopy, which allowed us to visualise and measure flow without any manipulation to the egg. Importantly, individual eggs were scored for their ploidy status by immunofluorescence, so that cytoplasmic movements could be related to ploidy on an egg-by-egg basis. Our results show that there is no difference in cytoplasmic flow between euploid and aneuploid eggs. Therefore, our data demonstrates that ploidy status does not impact biologically relevant stereotyped cytoplasmic movements, suggesting that using non-invasive imaging to try to distinguish ploidy status between otherwise healthy oocytes will be challenging.

Le rythme impressionnant auquel les technologies de séquençage progressent est alimenté par leur promesse de révolutionner les soins de santé et la recherche biomédicale. Le séquençage par nanopores est devenu une technologie attrayante pour résoudre des lacunes des technologies précédentes, mais aussi pour élargir nos connaissances sur le transcriptome en générant des lectures longues qui simplifient l’assemblage et la détection de grandes variations structurelles. Au cours du processus de séquençage, les nanopores mesurent les signaux de courant électrique représentant les bases (A, C, G, T) qui se déplacent à travers chaque nanopore. Tous les nanopores produisent simultanément des signaux qui peuvent être analysés en temps réel et traduits en bases par le processus d’appel de bases. Malgré la réduction du coût de séquençage et la portabilité des séquenceurs, le taux d’erreur de l’appel de base entrave leur mise en oeuvre dans la recherche biomédicale. Le but de ce mémoire est de classifier des séquences d’ARNm individuelles en différents groupes d’isoformes via l’élucidation de motifs communs dans leur signal brut. Nous proposons d’utiliser l’algorithme de déformation temporelle dynamique (DTW) pour l’alignement de séquences combiné à la technologie nanopore afin de contourner directement le processus d’appel de base. Nous avons exploré de nouvelles stratégies pour démontrer l’impact de différents segments du signal sur la classification des signaux. Nous avons effectué des analyses comparatives pour suggérer des paramètres qui augmentent la performance de classification et orientent les analyses futures sur les données brutes du séquençage par nanopores. / The impressive rate at which sequencing technologies are progressing is fueled by their promise to revolutionize healthcare and biomedical research. Nanopore sequencing has become an attractive technology to address shortcomings of previous technologies, but also to expand our knowledge of the transcriptome by generating long reads that simplify assembly and detection of large structural variations. During the sequencing process, the nanopores measure electrical current signals representing the bases (A, C, G, T) moving through each nanopore. All nanopores simultaneously produce signals that can be analyzed in real time and translated into bases by the base calling process. Despite the reduction in sequencing cost and the portability of sequencers, the base call error rate hampers their implementation in biomedical research. The aim of this project is to classify individual mRNA sequences into different groups of isoforms through the elucidation of common motifs in their raw signal. We propose to use the dynamic time warping (DTW) algorithm for sequence alignment combined with nanopore technology to directly bypass the basic calling process. We explored new strategies to demonstrate the impact of different signal segments on signal classification. We performed comparative analyzes to suggest parameters that increase classification performance and guide future analyzes on raw nanopore sequencing data.

The natural environments of organisms present a multitude of biotic and abiotic challenges that require both short-term ecological and long-term evolutionary responses. Though most environmental response studies have focused on effects at the ecosystem, community and organismal levels, the ultimate controls of these responses are located in the genome of the organism. Soil nematodes are highly responsive to, and display a wide variety of responses to changing environmental conditions, making them ideal models for the study of organismal interactions with their environment. In an attempt to examine responses to environmental stress (desiccation and freezing), genomic level analyses of gene expression during anhydrobiosis of the Antarctic nematode Plectus murrayi was undertaken. An EST library representative of the desiccation induced transcripts was established and the transcripts differentially expressed during desiccation stress were identified. The expressed genome of P. murrayi showed that desiccation survival in nematodes involves differential expression of a suite of genes from diverse functional areas, and constitutive expression of a number of stress related genes. My study also revealed that exposure to slow desiccation and freezing plays an important role in the transcription of stress related genes, improves desiccation and freezing survival of nematodes. Deterioration of traits essential for biological control has been recognized in diverse biological control agents including insect pathogenic nematodes. I studied the genetic mechanisms behind such deterioration using expression profiling. My results showed that trait deterioration of insect pathogenic nematode induces substantial overall changes in the nematode transcriptome and exhibits a general pattern of metabolic shift causing massive changes in metabolic and other processes. Finally, through field observations and molecular laboratory experiments the validity of the growth rate hypothesis in natural populations of Antarctic nematodes was tested. My results indicated that elemental stoichiometry influences evolutionary adaptations in gene expression and genome evolution. My study, in addition to providing immediate insight into the mechanisms by which multicellular animals respond to their environment, is transformative in its potential to inform other fundamental ecological and evolutionary questions, such as the evolution of life-history patterns and the relationship between community structure and ecological function in ecosystems.

Virtuellement toutes les plantes hébergent des champignons et des bactéries endosymbiontes (endophytes). Ces microorganismes façonnent le développement de leur hôte et peuvent inhiber des phytopathogènes. Au niveau moléculaire, les interactions plante-endophyte sont médiées par des molécules secrétées y compris des protéines et métabolites secondaires. Au cours des dernières années, la recherche d’endophytes a augmenté chez nombreux plantes, cependant chez les Ericaceae les endophytes ne sont pas bien connus. Alors, on s’est mis à investiguer les endophytes racinaires de la canneberge, une plante membre d’Ericaceae native de l’Amérique du Nord. On a échantillonné quatre plants provenant d’une ferme commerciale organique. Au total, 30 souches fongiques et 25 bactériens ont été isolés. Les bactéries Pseudomonas sp. EB212, Bacillus sp. EB213 et EB214; et les champignons Hyaloscypha sp. EC200, Pezicula sp. EC205 et Phialocephala sp. EC208 ont supprimé la croissance de cinq pathogènes de la canneberge, incluant Godronia cassandrae, un champignon causant la pourriture des fruits de la canneberge au Québec. EB213 a été capable de promouvoir légèrement la croissance de plantules de la canneberge. En performant des techniques microscopiques, on a constaté l’habileté de EC200, EC205 et EC208 à coloniser internement les racines des plantules de la canneberge. De plus, les génomes de ces champignons ont été séquencés, assemblés et annotés. Les analyses génomiques se sont concentrées sur les protéines secrétées et les groupes des gènes impliqués dans la biosynthèse (GGB). On a trouvé un large répertoire de gènes codant pour des enzymes qui métabolisent les carbohydrates et d’autres codant pour des protéases. Les deux groupes d’enzymes seraient utiles à dégrader de la matière organique pour libérer des nutriments. Aussi bien, ces enzymes pourraient faciliter la colonisation des racines de la plante hôte. De plus, on a prédit des nombreuses protéines effectrices qui assisteraient les endophytes à éviter l’activation du système immunitaire des plants. A noter que parmi les GGB inférés dans les génomes de EC200, EC205 et EC208, environ 90% ne sont pas caractérisés. Finalement, on a performé des analyses transcriptomiques pour élucider la réponse de EC200, EC205 et EC208 envers la présence de leur hôte, simulée par l’addition d’un extrait de canneberge au milieu de culture. Les conclusions majeures sont que les racines des plantes de la canneberge qui ont été échantillonnées sont dominées par des microorganismes avec l’habileté d’inhiber des phytopathogènes ; et que les génomes de EC200, EC205 et EC208 codent pour un grand répertoire de protéines qui pourraient être liées aux interactions plante-endophyte. / Virtually all plants host fungal and bacterial endosymbionts (endophytes). These microbes shape plant development and may inhibit phytopathogens. At the molecular level, plant-endophyte interactions are mediated by secreted compounds, including proteins and secondary metabolites. While endophytes are increasingly studied in diverse plants, little is known about their presence in Ericaceae. Therefore, we set out to investigate the root endophytes of cranberry, an ericacean member native to North America. We sampled endophytes from four plants grown on an organic farm. In total, 30 fungal and 25 bacterial strains were isolated and identified. A subset of these, notably Pseudomonas sp. EB212, Bacillus sp. EB213 and EB214; and fungi Hyaloscypha sp. EC200, Pezicula sp. EC205, and Phialocephala sp. EC208, were tested for their ability to suppress phytopathogens. Altogether, they inhibited five cranberry pathogens, including Godronia cassandrae, an important cranberry fruit-rot agent in Quebec. EB213 was the only endophyte that increased the biomass of cranberry seedlings. Using microscopy techniques, we confirmed the ability of EC200, EC205, and EC208 to colonize cranberry roots internally. The genomes of these fungi were sequenced, assembled and annotated. Genomic analyses focused on secreted proteins and biosynthetic gene clusters (BGCs). We found an extensive repertoire of carbohydrate-active enzymes and proteases that could assist in recycling organic nutrients, rendering them accessible to plants; these enzymes may also facilitate root colonization. In addition, effector proteins were predicted; these molecules may assist endophytes to escape the plant immune system and favour colonization. We inferred 139 biosynthetic gene clusters (BGCs) across the three examined fungi. Remarkably, the product of around 90% of BGCs are unknown. Finally, transcriptomic analyses were performed to determine how EC200, EC205 and EC208 respond to the presence of cranberry, simulated by the addition of cranberry extract in the culture medium. The two major conclusions of this work are that the roots of the sampled cranberry plants are dominated by endophytes with biocontrol abilities, and that EC200, EC205 and EC208 encode a broad repertoire of proteins that could be involved in plant-endophyte interactions.

Le sommeil est un comportement qui occupe un tiers de notre vie. L'horaire, la durée, et la qualité du sommeil sont contrôlés par deux processus principaux : la régulation homéostatique du sommeil et l’horloge qui synchronise les rythmes circadiens internes. EPHA4 est une molécule d'adhésion cellulaire qui régule la neurotransmission et qui est exprimée dans des régions cérébrales impliquées dans la régulation circadienne et du sommeil. De manière intéressante, le gène EphA4 contient des éléments régulateurs des facteurs de transcription circadiens et les souris Clock mutantes voient leur expression d’EphA4 modifiée. De plus, les souris EphA4 knockout (KO) ont des rythmes circadiens d’activité locomotrice anormaux, moins de sommeil paradoxal dans la période de lumière, et une distribution des oscillations cérébrales du sommeil modifiée sur un cycle de 24 heures. Par conséquent, et étant donné que EPHA4 est crucial pour le neurodéveloppement, il convient d’explorer si les phénotypes du sommeil/circadiens observés chez les souris EphA4 KO proviennent d'effets sur le développement ou des rôles d'EPHA4 dans la fonction neuronale adulte. Par ailleurs, les mécanismes de régulation transcriptionnelle d'EphA4 sont encore méconnus. Dans cette thèse, nous avons émis les hypothèses que i) l'expression du gène EphA4 ou de leurs ligands Éphrines (Efns) est régulée de manière circadienne ; et ii) que le modulateur de l’activité d’EPHA4 rhynchophylline (RHY) modifie le sommeil chez les souris adultes d'une manière qui ressemble au phénotype EphA4 KO. L'étude I montre que les facteurs de transcription de l’horloge (CLOCK/NPAS2 et BMAL1) activent la transcription via les éléments de réponse à l'ADN «boîtes E» trouvées dans les promoteurs putatifs d'EphA4, EfnB2 et EfnA3 in vitro. Cependant, les protéines EPHA4 et EFNB2 n’ont pas montré une oscillation circadienne dans le cortex préfrontal et les noyaux suprachiasmatiques (horloge principale) de souris. Dans le projet II, l'effet de RHY sur le sommeil a été étudié chez des souris mâles et femelles avec des enregistrements electroencéphalographiques. Nos données ont démontré que RHY prolonge le sommeil à onde lente, mais les effets sur le sommeil paradoxal dépendent de l’heure d’injection. RHY modifie aussi les oscillations cérébrales pendant l’éveil et le sommeil. Tous ces effets sont notablement plus marqués chez les femelles, ce qui souligne l’importance d’étudier les deux sexes lors des essais pharmacologiques. La transcriptomique spatiale cérébrale révèle que RHY modifie des transcrits liés à des réponses d’inflammation dans tout le cerveau, mais qu'elle affecte l'expression génique des neuropeptides associés à la régulation du sommeil et hypophysaires particulièrement dans l’hypothalamus. En outre, RHY affecte l'expression des gènes de la transcription/traduction de manière diffèrent selon l’heure d’injection. La première publication met en évidence que la régulation transcriptionnelle d’EphA4 et des Efns pourraient expliquer quelques-uns des phénotypes observés chez les souris KO. La deuxième publication démontre que RHY induit le sommeil chez la souris et souligne l’importance de caractériser des mécanismes inexplorés sous-jacents aux composés naturels. Décrire la régulation moléculaire du sommeil peut apporter des éclairages utiles pour la chronopharmacologie. / Sleep is a behavior which occupies a third of our lifetime. The schedule, the duration and the quality of sleep are controlled by two main processes: the homeostatic sleep regulation and the clock that synchronizes the internal circadian rhythm. EPHA4 is a cell adhesion molecule regulating neurotransmission and is expressed in brain centers regulating sleep and circadian rhythms. Interestingly, the EphA4 gene contains regulatory elements for circadian transcription factors, and Clock mutant mice have altered EphA4 expression. Moreover, EphA4 knockout mice (KO) have abnormal circadian rhythms of locomotor activity, less paradoxical sleep in the light period and altered sleep brain oscillations across the 24 hours. Given that EPHA4 is crucial for development, it should be investigated whether the sleep/circadian phenotypes observed in EphA4 KO originate from developmental effects or from roles of EPHA4 in adult neuronal function. Moreover, very little is known about the transcriptional regulation of EPHA4. Thus, the hypotheses of this thesis were that i) the gene expression of EphA4 or that of its ligands Ephrins (Efns) is regulated in a circadian manner; and ii) that the modulator of EPHA4 activity rhynchophylline (RHY) modifies sleep in adult mice in manners that resemble the EphA4 KO phenotype. Project I demonstrates that the clock transcription factors (CLOCK/NPAS2 et BMAL1) activate transcription via the DNA regulatory elements “E-boxes” found in the putative promoters of EphA4, EfnB2 and EfnA3 in vitro. Nevertheless, EPHA4 and EFNB2 proteins did not show a circadian oscillation in the mouse prefrontal cortex and suprachiasmatic nuclei (master clock). In project II, the effect of RHY on sleep was studied in male and female mice with electroencephalographic recordings. RHY extends slow wave sleep and effects on paradoxical sleep depended on the time-of-injection. RHY also modified the brain oscillations during wakefulness and sleep. Importantly, all these effects were larger in females, which highlights the need to consider both sexes in pharmacological studies. Brain spatial transcriptomics reveals that RHY modifies transcripts linked to inflammatory responses throughout the brain, while it affects transcripts linked to sleep regulation and pituitary responses particularly in the hypothalamus. Moreover, RHY affected the expression of genes for transcription/translation differently depending on the time of injection. The first publication underscores that the transcriptional regulation of EphA4 and Efns may underly some of the phenotypes observed in the KO mice. The second publication demonstrates that RHY induces sleep in mice, that it modifies brain activity associated to cognitive processes and highlights the importance of characterizing unexplored mechanisms of natural compounds. Describing the molecular regulation of sleep may provide useful insights for chronopharmacology.

Since the first human spaceflight in 1961, hundreds of humans have been in space. Microgravity and high radiation are the main spaceflight hazards. The space environment is known to impact several aspects of human health, such as bone density and cognitive performance. However, the effects of long­duration spaceflights on a cellular and molecular level, utilizing biosamples and multiomic approaches, is poorly studied. In this project, the method Spatial Transcriptomics has been utilized to compare brain tissue from the hippocampus region of mice that have been in space with a control group of mice that have stayed on Earth. Spatial Transcriptomics allow for the quantification of gene expression, while maintaining the spatial information of the transcriptome. The results of this study suggest that spaceflights cause mitochondrial stress.   This thesis work is part of a more extensive study in collaboration with NASA, and more studies will be conducted to investigate the effects of spaceflights further. If these findings are confirmed, medicines used on Earth to treat patients with mitochondrial dysfunction could increase the well­being of astronauts in space. / Sedan den första människan skickades till rymden år 1961, har hundratals astronauter lämnat jordens atmosfär.   De mest signifikanta hälsoriskerna i rymden är mikrogravitation och hög strålning och rymdmiljön har stor påverkan på oss. Exempelvis upplever astronauter ofta minskad benmassa och nedsatt kognitiv funktion. Men kunskapen kring hur människor påverkas av långtidresor i rymden är begränsad. Särskilt få experiment har genomförts på stora dataset från biologiska prover, på en molekylär och cellulär nivå. I detta projekt har genuttryck hos möss som varit i rymden jämförts med en kontrollgrupp av möss som stannat på jorden. Metoden Spatial Transcriptomics (ST) har använts för att undersöka vävnadssnitt från hippocampus i mushjärna. Med ST är det möjligt att undersöka RNA­molekyler och kartlägga deras position i vävnaden. Resultatet från denna studie indikerar att miljön i rymden leder till dysfunktion i mitokondrierna. Detta arbete är en del av en större studie i samarbete med NASA och fler experiment kommer genomföras för att undersöka hur vi påverkas av miljön i rymden. Om fler studier stödjer detta resultat, kan mediciner som använts på jorden för att behandla patienter med dysfunktion i mitokondrierna, användas i förebyggande syfte för astronauter.

La convergence, soit l'acquisition indépendante de phénotypes similaires, est un aspect intéressant de la diversité qui peut fournir des informations importantes sur la nature du changement évolutif. Dans les systèmes végétaux, les syndromes de pollinisation – combinaisons de traits floraux adaptés à leurs pollinisateurs – constituent de bons exemples de convergence se produisant sur les fleurs. Nous avons utilisé une approche globale incluant la morphologie cellulaire et la transcriptomique pour analyser la convergence de formes florales de deux syndromes de pollinisation trouvés dans les genres frères non Gesneria et Rhytidophyllum (Gesneriaceae), un groupe antillais qui contient environ 81 espèces avec différentes morphologies et stratégies de pollinisation variables dans leur degré de spécialisation écologique. Il a déjà été démontré que la forme des fleurs joue un rôle important dans l’évolution de ce groupe, qui présente de nombreuses transitions entre les stratégies de pollinisation. Nous avons testé la présence de convergence dans les forms de cellules de la corolle et dans l’expression des gènes de la corolle en utilisant (1) une analyse pour mesurer la forme des cellules de pétales matures à l’aide d’un modèle phylogénétique mixte et (2) une approche transcriptomique comparative combinant l'expression différentielle des gènes (DESEq2) et l'analyse de co-expression (WGCNA) de gènes exprimés dans certaines regions précises des pétales. Toutes les analyses ont pris en compte les relations phylogénétiques entre les espèces. Nous avons trouvé une anisotropie cellulaire convergente se produisant dans les régions distales des pétales au sein des espèces du même syndrome (forme). Nous avons également constaté une plus grande similarité dans les modèles d'expression génique entre les espèces d’un même syndrome qu'entre les espèces apparentées et avons produit une liste de 203 gènes potentiellement associés aux formes de fleurs convergentes. La convergence morphologique florale observée dans les syndromes de pollinisation des espèces étudiées se retrouve tant au niveau cellulaire qu'au niveau de l'expression. Les résultats présentés ici amplifient les informations de base sur la famille des Gesneriaceae pour les études futures sur la convergence et la forme florale dans le groupe. / Convergence, the independent acquisition of similar phenotypes, is an important aspect of diversity that can provide valuable insights about the nature of evolutionary change. In plants, pollination syndromes - combinations of floral traits adapted to their pollinators - make good examples of convergence occurring on flowers. We used a comprehensive approach that includes cell morphology and transcriptomics to analyze the floral shape convergence of two pollination syndromes found in the sister genera Gesneria and Rhytidophyllum (Gesneriaceae), an Antillean group that contains approximately 81 species with different morphologies and pollination strategies varying in their degree of ecological specialization. Flower shape has already been found to play an important role in the evolution of this group, which shows many transitions between pollination strategies. We tested convergence in the corolla cell shapes and in gene expression for the pollination syndromes using (1) cell measurement statistical analysis (Phylogenetic Mixed Model) of mature petals and (2) a comparative transcriptomic approach that combined differential gene expression (DESEq2) and co-expression analysis (WGCNA) in genes expressed in specific regions of the petals. All analyses took the phylogenetic relationships of the species into account. We found convergent cellular anisotropy occurring in the distal regions of the petals within species of the same syndrome (form). We also found greater similarity in gene expression patterns occurring among species of the same syndromes than between more closely related species and produced a list of 203 genes potentially associated with convergent flower forms. The floral morphological convergence observed in the pollination syndromes of the investigated species is paralleled both at the cellular and expression levels. The results shown here amplify the background information of the Gesneriaceae family for future studies of convergence and floral form in the group.