The flagellar root apparatus, the microtubular system and associated organelles in the chrysophycean flagellate,Poterioochromonas malhamensis Peterfi (syn.Poteriochromonas stipitata Scherffel andOchromonas malhamensis pringsheim)

PROTOPLASMA ◽  
1977 ◽  
Vol 92 (1-2) ◽  
pp. 87-107 ◽  
Author(s):  
E. Schnepf ◽  
G. Deichgr�ber ◽  
G. R�derer ◽  
W. Herth
Keyword(s):  
Poterioochromonas Malhamensis ◽  
Microtubular System ◽  
Root Apparatus

Observations on the Fine Structure of the Eyespot and Associated Organelles in the Dinoflagellate Glenodinium Foliaceum

1969 ◽  
Vol 5 (2) ◽  
pp. 479-493 ◽  
Author(s):  
J. D. DODGE ◽  
R. M. CRAWFORD
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Lamellar Body ◽  
Ventral Side ◽  
Close Packing ◽  
Hexagonal Close Packing ◽  
Osmiophilic Granules ◽  
Algal Groups ◽  
Posterior Direction ◽  
Microtubular System

The eyespot of the marine dinoflagellate Glenodinium foliaceum is a flattened orange structure, more or less trapezoid in shape with an anterior hook-like projection. It is situated on the ventral side of the organism in the vicinity of the flagellar bases at the anterior end of the sulcus. In the electron microscope the eyespot is seen to contain two layers of osmiophilic granules 80-200 nm in diameter which usually show hexagonal close-packing. The eyespot is surrounded by a triple-membraned envelope and is not connected to any other organelle. Adjacent to the eyespot is a distinctive organelle termed the ‘lamellar body’. This consists of a stack of up to 50 flattened vesicles or disks, each 16 nm thick and about 750 nm wide, the whole being orientated in an antero-posterior direction. The lamellae are continuous, at the ends of the stack, with rough endoplasmic reticulum and are joined together by occasional bridges at their edges. The bases of the two flagella lie just ventral to the lamellar body and from them roots arise which pass by the eyespot and join the subthecal microtubular system. The eyespot of Glenodinium is unique both in structure and the presence of the associated lamellar body. It differs from eyespots which have been described from other algal groups and also from the more complex ocellus found in certain dinoflagellates belonging to the order Warnowiaceae. The method by which the eyespot functions is discussed and it is suggested that unidirectional stimuli could be perceived by shading of the lamellar body.

Cytoplasmic microtubular system implicated in de novo formation of a Rabl-like orientation of chromosomes in fission yeast

2001 ◽  
Vol 114 (13) ◽  
pp. 2427-2435 ◽  
Author(s):  
Bunshiro Goto ◽  
Koei Okazaki ◽  
Osami Niwa
Keyword(s):  
Fission Yeast ◽  
De Novo ◽  
Nuclear Periphery ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Limited Area ◽  
Cytoplasmic Microtubule ◽  
Random Arrangement ◽  
Triplex Structure ◽  
Microtubular System

Chromosomes are not packed randomly in the nucleus. The Rabl orientation is an example of the non-random arrangement of chromosomes, centromeres are grouped in a limited area near the nuclear periphery and telomeres are located apart from centromeres. This orientation is established during mitosis and maintained through subsequent interphase in a range of species. We report that a Rabl-like configuration can be formed de novo without a preceding mitosis during the transition from the sexual phase to the vegetative phase of the life cycle in fission yeast. In this process, each of the dispersed centromeres is often associated with a novel Sad1-containing body that is contacting a cytoplasmic microtubule laterally (Sad1 is a component of the spindle pole body (SPB)). The Sad1-containing body was colocalized with other known SPB components, Kms1 and Spo15 but not with Cut12, indicating that it represents a novel SPB-related complex. The existence of the triplex structure (centromere-microtubule-Sad1 body) suggests that the clustering of centromeres is controlled by a cytoplasmic microtubular system. Accordingly, when microtubules are destabilized, clustering is markedly reduced.

Isolation and evaluation of a novel strain of Chlorella sorokiniana that resists grazing by the predator Poterioochromonas malhamensis

2019 ◽  
Vol 38 ◽  
pp. 101429 ◽  
Author(s):  
Mingyang Ma ◽  
Chaojun Wei ◽  
Hongxia Wang ◽  
Cuicui Sha ◽  
Man Chen ◽  
...  
Keyword(s):  
Chlorella Sorokiniana ◽  
Poterioochromonas Malhamensis
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