TY - JOUR
T1 - Division of cell nuclei, mitochondria, plastids, and microbodies mediated by mitotic spindle poles in the primitive red alga Cyanidioschyzon merolae
AU - Imoto, Yuuta
AU - Fujiwara, Takayuki
AU - Yoshida, Yamato
AU - Kuroiwa, Haruko
AU - Maruyama, Shinichiro
AU - Kuroiwa, Tsuneyoshi
N1 - Funding Information:
This work was supported by grants from the Scientific Research on Priority Areas (no.19207004 to T.K.), the Frontier Project “Adaptation and Evolution of Extremophiles” from the Ministry of Education, Culture, Sports, Science and Technology of Japan, and by the program for the Promotion of Basic Search Activities for Innovative Biosciences (PROBRAIN, to T.K.). We have no financial relationship with the organization that sponsored this research.
PY - 2010/5
Y1 - 2010/5
N2 - To understand the cell cycle, we must understand not only mitotic division but also organelle division cycles. Plant and animal cells contain many organelles which divide randomly; therefore, it has been difficult to elucidate these organelle division cycles. We used the primitive red alga Cyanidioschyzon merolae, as it contains a single mitochondrion and plastid per cell, and organelle division can be highly synchronized by a light/dark cycle. We demonstrated that mitochondria and plastids multiplied by independent division cycles (organelle G1, S, G2 and M phases) and organelle division occurred before cell-nuclear division. Additionally, organelle division was found to be dependent on microtubules as well as cell-nuclear division. We have observed five stages of microtubule dynamics: (1) the microtubule disappears during the G1 phase; (2) α-tubulin is dispersed within the cytoplasm without forming microtubules during the S phase; (3) α-tubulin is assembled into spindle poles during the G2 phase; (4) polar microtubules are organized along the mitochondrion during prophase; and (5) mitotic spindles in cell nuclei are organized during the M phase. Microfluorometry demonstrated that the intensity peak of localization of α-tubulin changed in the order to spindle poles, mitochondria, spindle poles, and central spindle area, but total fluorescent intensity did not change remarkably throughout mitotic phases suggesting that division and separation of the cell nucleus and mitochondrion is mediated by spindle pole bodies. Inhibition of microtubule organization induced cell-nuclear division, mitochondria separation, and division of a single membrane-bound microbody, suggesting that similar to cell-nuclear division, mitochondrion separation and microbody division are dependent on microtubules.
AB - To understand the cell cycle, we must understand not only mitotic division but also organelle division cycles. Plant and animal cells contain many organelles which divide randomly; therefore, it has been difficult to elucidate these organelle division cycles. We used the primitive red alga Cyanidioschyzon merolae, as it contains a single mitochondrion and plastid per cell, and organelle division can be highly synchronized by a light/dark cycle. We demonstrated that mitochondria and plastids multiplied by independent division cycles (organelle G1, S, G2 and M phases) and organelle division occurred before cell-nuclear division. Additionally, organelle division was found to be dependent on microtubules as well as cell-nuclear division. We have observed five stages of microtubule dynamics: (1) the microtubule disappears during the G1 phase; (2) α-tubulin is dispersed within the cytoplasm without forming microtubules during the S phase; (3) α-tubulin is assembled into spindle poles during the G2 phase; (4) polar microtubules are organized along the mitochondrion during prophase; and (5) mitotic spindles in cell nuclei are organized during the M phase. Microfluorometry demonstrated that the intensity peak of localization of α-tubulin changed in the order to spindle poles, mitochondria, spindle poles, and central spindle area, but total fluorescent intensity did not change remarkably throughout mitotic phases suggesting that division and separation of the cell nucleus and mitochondrion is mediated by spindle pole bodies. Inhibition of microtubule organization induced cell-nuclear division, mitochondria separation, and division of a single membrane-bound microbody, suggesting that similar to cell-nuclear division, mitochondrion separation and microbody division are dependent on microtubules.
KW - Cyanidioschyzon merolae
KW - Microbody division
KW - Microtubule
KW - Mitochondrion division
KW - Organelle cell cycle
KW - Spindle pole
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U2 - 10.1007/s00709-010-0107-y
DO - 10.1007/s00709-010-0107-y
M3 - Article
C2 - 20148273
AN - SCOPUS:77951498392
VL - 241
SP - 63
EP - 74
JO - Protoplasma
JF - Protoplasma
SN - 0033-183X
IS - 1
ER -