X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/chloroplast13.git/blobdiff_plain/c3bc9b78abb7c8a25cd497b8d4b80f0ba8b8edb3..c4e790fc4e8c0442d8ffa296055c2407238ce291:/intro.tex diff --git a/intro.tex b/intro.tex index e69de29..ddb2fcb 100644 --- a/intro.tex +++ b/intro.tex @@ -0,0 +1,26 @@ +Identifying core genes is important to understand evolutionary and +functional phylogenies. Therefore, in this work we present methods to +build a genes content evolutionary tree. More precisely, we focus on +the following questions considering a collection of 99~chloroplasts +annotated from NCBI \cite{Sayers01012011} and Dogma \cite{RDogma}: how +can we identify the best core genome and what is the evolutionary +scenario of these chloroplasts.\\ +Chloroplast (such as mitochondria) are fondamental key elements in +living organisms history. Indeed, chlorplast in Eucaryotes are organites responsible for +photosynthesis. Photosynthesis is the main way to produce organic matter +from mineral matter, using solar energy. Consequently photosynthetic +organisms are at the base of most ecosystems trophic chains and +photosynthesis in eucaryotes allowed a great speciation in the lineage +(to a great biodiversity). From an ecological point of view, +photosynthetic organisms are at the origin of the presence of dioxygen +in the atmosphere (allowing extant life) and are the main source of mid- +to long term carbon stockage (using atmospheric CO2, important in the +context of climate change). Chloroplast found in Eucaryots have an endosymbiotic origin, meaning +that they are a fusion of a photosynthetic bacteria (Cyanobacteria) and +a eucaryotic cell (enable to produce organic matter = heterotrophic). +This fusion or First Endiosymbiosis ended in a Great diversification of +a lineage comprising Red Algae, Green Algae and Land Plants (terrestrial). +Several Second Enbiosymbioses occurred then: two involving a Red +Algae and other heterotrophic eucaryotes and giving birth to both Brown +Algae and Dinoflagellates lineages; another involving a Green Algae and +a heterotrophic eucaryot and giving birth to Euglens. \ No newline at end of file