Mai T., Johansen J.R., Pietrasiak N., Bohunická 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. Vol. 365 (1): 001-059.
Colony dark olive-green, hairy, spreading radially, flat and mucilaginous or mounded. Filaments long or short, frequently irregularly bent due to uneven cell division along filament (Fig. 11a–d), false branched
(Fig. 11e), sometimes loosely coiled to form irregular nodules (Fig. 11d), 2.0–3.3–(3.7) µm wide. Sheath firm, colorless, usually attached to trichome, occasionally widened (Fig. 11h), up to 1.7 µm wide. Trichomes constricted at indistinctly visible cross-walls, cell division along trichomes often irregular, producing cells with variable shape and width (Figs. 11g–k), with necridia, 1.9–2.8 µm wide in young trichomes, 2.4–3.5 µm wide in actively dividing trichomes. Hormogonia few-celled (Figs. 11h–k). Cells occasionally isodiametric (1.7–2.6 µm long), shorter than wide in meristematic regions (1.1–1.7 µm long), often with a large central granule. End cells typically rounded, but sometimes elongated and/or irregularly shaped (Fig. 11k). D1-D1’ helix similar to that of P. bostrychoides in structure and sequence, 87 nucleotides long, with basal 3’ side loop of 9 unpaired nucleotides (5’-UCAUCCCAA-3’), opposed on the 5’ strand by a single unpaired cytosine residue, with mid-helix region with two unpaired adenine residues at position 14–15, several internal loops at position
32–33/48–49 and 22–25/56–60. Terminal loop having sequence 5’-GAAA-3’ (Fig. 6b). Box B helix 36 nucleotides long, bearing 4 nucleotides at terminal loop, and one 5’-A/C-3’ mismatch at position 5/32 (Fig. 7b). V2 helix 24 nucleotides long, with terminal loop of 4 nucleotides (Fig. 8b). V3 helix 96 nucleotides long, with several internal loops at positions 5–6/92, 10–14/86–88, 18/81–82 and 36–37/62–63, and two mismatches of 5’-G/A-3’ and 5’-A/G-3’ at positions 24/75 and 29/70 respectively. Terminal loop having sequence 5’-GUAA-3’ (Fig. 9b).
