Drouetiella fasciculata Mai et al.

Mai T., Johansen J.R., Pietrasiak N., Bohunicka M., Martin M.P. Revision of the Synechococcales (Cyanobacteria) through recognition of four families including Oculatellaceae fam. nov. and Trichocoleaceae fam. nov. and six new genera containing 14 species // Phytotaxa, 2018. V. 365. N. 1. P. 1-59. https://doi.org/10.11646/phytotaxa.365.1.1

Diagnosis:―D.fasciculata is phenotypically distinct from other Drouetiella species due to its bright blue-green color and fasciculation of trichomes. The V3 helix has identical sequence and structure to D. hepatica in nucleotides 1–8 on the 5’ strand and their complement on the 3’ strand (Fig. 8e); however, in general it is distinctive in length and sequence from all other species (Table 6). The percent dissimilarity between the ITS region of this species and the other taxa is >25%

Description:—Colony bright blue green, composed of fasciculated (Fig. 15a) and solitary filaments, growing into the agar. Filaments long, without false branching, frequently slightly coiled and entangled (Figs. 15b–c), 2.7–
3.2 μm wide. Sheath firm, usually attached to trichome, occasionally distinct, clear, up to 1.3 μm wide. Trichomes not constricted at the cross-walls, with necridia, lacking meristematic zones, with cell division occurring throughout
trichome, 1.5–2.4 (3.0) μm wide. Hormogonia rare (Fig. 15d). Cells longer than wide, occasionally isodiametric after division, with peripheral thylakoids, with one large or two smaller central granules, 3.1–4.4 (5.4) μm long (Figs.
15e–f). End cells untapered, rounded (Fig. 15g). D1-D1’ 65 nucleotides long, with a 3’ unilateral bulge of 7 nucleotides (5’-CAACCCA-3’), and several internal loops in the mid-helix region at positions 8–9/49–50 and 15–16/43–44, with the largest bilateral bulge at position 21–24/34–38 immediately subtending the terminal loop by a 5’-GC:GC-3’ clamp (Fig. 6h). Box B helix 39 nucleotides long, with a basal bulge at position 5/34–35 and one unpaired adenine residue at position 9 on the 5’ strand (Fig. 7g). V2 helix 11 nucleotides long, with a 5-nucleotide terminal loop, having sequence 5’-AAUAU-3’ (Fig. 8e). V3 helix 51 nucleotides long, with one basal unpaired guanine residue at position 46 of the 3’ strand, and one large bilateral bulge at position 9–12/39–42. Terminal loop sequence 5’-UUGC-3’ (Fig. 9h).