PMC

An enlarged polymerase is more sensitive to PcG repression. (A) Drawing comparing wild-type T7RNAP and Goliath polymerase. (B) Pattern of Goliath polymerase protein in the CNS Goliath line in a germ band retracted embryo. The location of Goliath polymerase was detected with a monoclonal antibody to β-galactosidase. PS5, the anterior limit of bx enhancer activity, is indicated with a bracket. (C) Transcription by Goliath polymerase on the 4× T7 promoters in the bx control region in a germ band retracted embryo. Transcription by Goliath is blocked anterior to PS5. (D) Transcription by Goliath polymerase in an extra sex combs mutant embryo (esc²/esc¹⁰, maternal and zygotic null). The repression in anterior segments is lost. (E to H) T7RNAP versus Goliath polymerase as shown by expression of the polymerases with the Gal4-UAS system. A ubiquitous Gal4 source (line 32B) was used to drive polymerase expression. All embryos are in the germ band extended stage. (E) Goliath polymerase protein pattern marked with an antibody to β-galactosidase. (F) Transcription by T7RNAP on the 4× T7 promoters in the bx control region. Transcription appears unaffected by the PcG. (G) Transcription by Goliath polymerase. Transcription is repressed by the PcG anterior to PS5. (H) Transcription by Goliath polymerase in a Polycomb mutant (zygotic null). Repression in the anterior segments is lost.

(a) Sites investigated by the authors and others from published data. (b–e) Locations of mature goliath catfishes by species. Figure was created by authors with ArcGIS for Desktop Advanced 10.2, MapPublisher 9.6 tool inside Adobe Illustrator CC, and Adobe Illustrator CC, 2.0.

Cell wall analysis of Goliath cells. (A) Goliath cells stained for exposed β-glucan (Fc-Dectin), mannan (concanavalin A), exposed (WGA) and total (Calcofluor White) chitin and compared with normal yeast cells. Scale bar represents 5 μm. (B) Mean fluorescence intensities of respective cell wall components for Goliath cells and normal yeast cells as determined by flow cytometry represented as a bar graph. Data were obtained from three independent experiments and normalized by cell size (C), error bars represent standard deviation and p-values were calculated by t-test. A significant increase in mean fluorescence intensity of WGA was observed Goliath cells as compared to normal yeast cells. (^∗P ≤ 0.05, ^∗∗P ≤ 0.01, ^∗∗∗P ≤ 0.0001). (C) Increase in cell size determined using flow cytometry by measuring forward scatter (FSC) intensities of Goliath cells (blue) and normal yeast cells (red) (n > 10000). A shift in FCS peak shows that Goliath cells are significantly larger than normal yeast cells. Mean FCS intensities were compared to determine fold increase in cell size. Based on the FCS intensities, C. albicans Goliath cells exhibit a 3.3-fold increase in size as compared to normal yeasts. Note that relative to cell size, only chitin exposure is relative higher for Goliath cells vs. control yeasts.