Fig. 2: Convergent loss of cellular dimorphic traits within Caulobacteraceae.
a Lifecycle of Caulobacter crescentus, showcasing the obligate motile-to-sessile (swarmer-to-stalked) cell differentiation that precedes reproduction, as well as the obligate generation of motile offspring through asymmetric cell division. Schematic representation of cellular levels of the intracellular signaling molecule cyclic diguanylate (c-di-GMP) is indicated in purple in the lower bar, highlighting the surge in c-di-GMP levels that drives cell differentiation126. b Presence and absence of genes involved in chemotaxis (mcp and genes with che, cle, and mot names), flagellar motility (genes with fla, flb, flg, flh, fli, and flm names), type IV tight-adherence pilus (T4P; pilA, tadD, and genes with cpa names), holdfast (genes with hfa and hfs names), and cell developmental regulation, as annotated by KEGG KOs (dark gray; from eggNOG-mapper95) and using the reciprocal best blast hit (RBH) algorithm against the C. crescentus CB15 proteome (blue). The total numbers of genes investigated for each functional category are indicated (n). For genera and families, the average presence and absence is shown with linear color gradients. Five outgroup Alphaproteobacteria are included to highlight the broader conservation of genes. The labels of the cell developmental genes have been colored as follows. Purple: master cell cycle regulators; red: absent from both lineages lacking flagellar genes; yellow: absent from both lineages lacking flagellar genes and their close relatives; and gray: remaining regulators. See Supplementary Data 4 and 5a–f for the full dataset, including gene names and functional annotations. c Simplified schematic summary of C. crescentus cell development regulation, showcasing positive and negative regulatory interactions. Developmental regulators are color-coded as in (b). Direct binders of cyclic diguanylate (c-di-GMP) are highlighted with purple text. CckA is displayed in its phosphatase state (*). For simplicity, temporal aspects are disregarded, and most of the specific genes controlled by CtrA, CcrM, DnaA, and GcrA are not indicated. Based on refs. 7,40,41,42,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144.
