University of Zagreb. Faculty of Science. Department of Biology.
Abstract
Links between ontogeny and phylogeny in animals have been discussed for more than two
centuries. With the uprising of molecular biology and bioinformatics, several studies have
revealed the presence of the phylogeny-ontogeny correlation on molecular level in
developmental transcriptomes of eukaryotic clades with complex multicellularity. These
findings open a possibility to test the phylogeny-ontogeny correlation in more basal organisms,
with more obscure development and multicellularity characteristics. Using time-resolved
transcriptome and proteome profiles, this study showed that Bacillus subtilis biofilm ontogeny
correlates with the evolutionary measures through recapitulation pattern, in a way that
evolutionary younger and more diverged genes were increasingly expressed towards the later
timepoints of the biofilm growth. Molecular and morphological signatures also revealed that
biofilm growth is highly regulated and organized into discrete ontogenetic stages. Together,
this suggests that the biofilm formation in Bacillus subtilis is a true developmental process
comparable to organismal development in animals, plants and fungiKorelacija između filogenije i ontogenije životinja je predmet rasprave među znanstvenicima
od početka 19. stoljeća. Razvojem molekularne biologije i bioinformatike te analizama
transkriptoma razvojnih stadija, uočena je prisutnost korelacije filogenije i ontogenije na
molekularnoj razini u eukariotskim evolucijskim granama sa složenom višestaničnosti. Ova
saznanja potaknula su nas da testiramo korelaciju filogenije i ontogenije u bazalnim
organizmima s nejasnim razvojnim i višestaničnim karakteristikama. Analizom
transkriptomskih i proteomskih podataka, pokazali smo da ontogenija Bacillus subtilis
biofilmova korelira s evolucijskim mjerama u obliku rekapitulacijskog profila, odnosno
evolucijski mlađi i divergentniji geni su sve više eksprimirani prema kasnijim stadijima rasta
biofilma. Dodatne molekularne analize pokazale su da je rast biofilma reguliran i organiziran u
jasno odvojene stadije ontogenije. Zaključno, rezultati pokazuju da je rast Bacillus subtilis
biofilmova istinski razvojni proces usporediv s razvojem životinja, biljaka i gljiva