<i>M. xanthus</i> strains used in this study.

<p><i>M. xanthus</i> strains used in this study.</p

Regulation of lipid body production during <i>M. xanthus</i> fruiting body development.

<p>Mutants blocked in synthesis of proteins labeled in in black are deficient in lipid body synthesis (>40%). Those labeled in purple produce intermediate levels of lipid bodies (40–80%). Those in green produce near WT levels or higher (>80%). Red letters indicate developmental signals. Asg, A-signal; Csg, C-signal; Esg, E-signal.</p

<i>M. xanthus</i> fatty acid metabolic pathways were analyzed at the transcriptional level using available microarray data from developing cells [13].

<p>The pathway information and gene annotations were obtained from the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database. Genes that are down-regulated (≥1.5 fold), up-regulated (≥1.5 fold) or unchanged during development are shown in green, red, and black, respectively. Blue denotes genes that were not on the microarray. A dashed arrow between two compound names implies that the two names represent the same compound in different stages of polymerization or depolymerization.</p

Lipid body area correlates with cell length in developmental mutants.

<p>Lipid body production at 18<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099622#pone-0099622-t001" target="_blank">table 1</a>.</p

Lipid bodies are derived from membrane phospholipids.

<p><i>Myxococcus</i> cells were grown in the presence of palmitic acid alkyne (PA^alk) in A1 minimal medium and stained with Nile red. Click chemistry was used to attach Alexa Fluor 488 azide to PA^alk prior to visualization. Both Alex Fluor fatty acid and the Nile red stain are visible in membranes during vegetative growth (DK1622 0 h). The PA^alk was removed and cells were allowed to develop on TPM agar (DK1622 24 h). Labeled membrane lipids were incorporated into Nile red stained lipid bodies, seen in both channels and the merged images. In a strain deficient in lipid body production (LS3931), incorporation occurs into membrane lipids (LS3931 0 h) but not lipid bodies (LS3931 24 h). A <i>fadL</i> mutant (LS3125), defective in fatty acid uptake, is unable to incorporate PA^alk altogether. Wild-type cells grown in the absence of PA^alk then allowed to develop (DK1622^a 24 h) exhibit no fluorescence (bottom row, second panel) indicating little bleed through between channels. Scale bar is 10 µm.</p

Lipid body production in WT cells during development.

<p>(A) DK1622 cells stained with the lipophilic dye Nile red at times indicated during development. Phase (Left), fluorescence (Right). Bar is 10 µm. (B) Lipid bodies were quantified by measuring the average cross sectional area stained with Nile red using at least 30 cells (grey bars). Cell length was measured using phase contrast images of 30 randomly chosen cells (filled diamonds). At 48 h, the cells are a nearly equal mixture of long, peripheral rods and spherical myxospores.</p