Coordination mechanism of cell and cyanelle division in the glaucophyte alga Cyanophora sudae.

In unicellular algae with a single chloroplast, two mechanisms coordinate cell and chloroplast division: the S phase-specific expression of chloroplast division genes and the permission of cell cycle progression from prophase to metaphase by the onset of chloroplast division. This study investigated whether a similar mechanism exists in a unicellular alga with multiple chloroplasts using the glaucophyte alga Cyanophora sudae, which contains four chloroplasts (cyanelles). Cells with eight cyanelles appeared after the S phase arrest with a topoisomerase inhibitor camptothecin, suggesting that the mechanism of S phase-specific expression of cyanelle division genes was conserved in this alga.

Cis-acting elements involved in the G2/M-phase-specific transcription of the cyclin B gene in the unicellular alga Cyanidioschyzon merolae.

M-specific activator (MSA) cis-acting elements have been determined to be involved in the regulation of G2/M-phase-specific transcription in spermatophytes. In this study, the involvement of MSA-core elements in G2/M-phase-specific transcription was examined in the unicellular red alga Cyanidioschyzon merolae. In the C.

ESCRT Machinery Mediates Cytokinetic Abscission in the Unicellular Red Alga .

In many eukaryotes, cytokinesis proceeds in two successive steps: first, ingression of the cleavage furrow and second, abscission of the intercellular bridge. In animal cells, the actomyosin contractile ring is involved in the first step, while the endosomal sorting complex required for transport (ESCRT), which participates in various membrane fusion/fission events, mediates the second step. Intriguingly, in archaea, ESCRT is involved in cytokinesis, raising the hypothesis that the function of ESCRT in eukaryotic cytokinesis descended from the archaeal ancestor.

Reduction in Recurrence Rate by Combining Modified Hotz Procedure With Epicanthoplasty to Treat Congenital Epiblepharon.

Aim: To determine whether patients with congenital lower lid epiblepharon treated with a modified Hotz procedure combined with epicanthoplasty have a decreased recurrence rate.

Patients And Methods: Patients with epiblepharon of the lower eyelid corrected using a modified Hotz method between 2007 and 2017 were evaluated retrospectively by chart review to determine rates of complications and recurrence as well as whether the Hotz method was combined with epicanthoplasty. The recurrence rates for patients treated with the Hotz method alone or in combination with epicanthoplasty were compared.

Day/Night Separation of Oxygenic Energy Metabolism and Nuclear DNA Replication in the Unicellular Red Alga .

The transition from G to S phase and subsequent nuclear DNA replication in the cells of many species of eukaryotic algae occur predominantly during the evening and night in the absence of photosynthesis; however, little is known about how day/night changes in energy metabolism and cell cycle progression are coordinated and about the advantage conferred by the restriction of S phase to the night. Using a synchronous culture of the unicellular red alga , we found that the levels of photosynthetic and respiratory activities peak during the morning and then decrease toward the evening and night, whereas the pathways for anaerobic consumption of pyruvate, produced by glycolysis, are upregulated during the evening and night as reported recently in the green alga Inhibition of photosynthesis by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) largely reduced respiratory activity and the amplitude of the day/night rhythm of respiration, suggesting that the respiratory rhythm depends largely on photosynthetic activity. Even when the timing of G/S-phase transition was uncoupled from the day/night rhythm by depletion of retinoblastoma-related (RBR) protein, the same patterns of photosynthesis and respiration were observed, suggesting that cell cycle progression and energy metabolism are regulated independently.