Chloroplast Abnormalities Seen in a Pale Green Mutant of Chlamydomonas reinhardtii

1971 ◽  
Vol 29 ◽  
pp. 350-351
Author(s):  
Nancy J. Symmes ◽  
Ellen C. Weaver
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
High Efficiency ◽  
Life Support ◽  
Photosynthetic Capacity ◽  
Wild Type ◽  
Space Flights ◽  
Manned Space ◽  
Pale Green ◽  
Green Mutant

In the search for life support systems for possible long term manned space flights one must, at some point, investigate photosynthetic systems, and hence the interest in green algae with their ease of care, rapid growth rates, and high efficiency of energy conversion. With the present restriction of weight it would be most advantageous to find an organism with a maximum photosynthetic capability.A pale green mutant Ac 29 of Chlamydomonas reinhardtii (obtained from Professor Wilbur Ebersold, UCLA) has been studied which has four times the photosynthetic capacity at high light intensities on a chlorophyll basis as the wild type (as based on measurements of CO2 uptake and O2 evolution). In order to try to find some basis for the differences in photosynthetic capacity, comparisons were made between wild type (strain 21gr, obtained from Ruth Sager, Hunter College) and mutant at both the ultrastructural and chemical levels.

Dosimetric complex for long-term manned space flights

1992 ◽  
Vol 20 (1) ◽  
pp. 7-11
Author(s):  
Yu. Akatov ◽  
E.E. Kovalev ◽  
V.A. Sakovich ◽  
S. Deme ◽  
I. Fehér ◽  
...  
Keyword(s):  
Space Flights ◽  
Manned Space ◽  
Manned Space Flights

scholarly journals EFFECT OF CHANNEL DEPTH ON YIELD OF SWEET POTATOES GROWN HYDROPONICALLY

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 856b-856
Author(s):  
C. Morris ◽  
D. Mortley ◽  
P. Loretan ◽  
C. Bonsi ◽  
W. Hill
Keyword(s):  
Sweet Potato ◽  
Life Support ◽  
Storage Root ◽  
Life Support System ◽  
Storage Roots ◽  
Channel Depth ◽  
Sweet Potatoes ◽  
Manned Space ◽  
Manned Space Missions

The potential of the sweet potato as a food source for future long-term manned space missions is being evaluated for the National Aeronautics and Space Administration's (NASA) Controlled Ecological Life Support System (CELSS) Program. Several experiments have shown that the sweet potato can be grown hydroponically. However, an evaluation of the NASA fan-shaped Biomass Production Chamber (BPC) channel was initiated to determine if channel depths influenced the yield of hydroponically grownsweet potatoes. Three channel depths were studied, 5 cm (2 in) standard NASA BPC channel, 10 cm (4 in) channel and 15 cm (6 in) channel. The experiment consisted of one replication. The results show that channel depth does effect the yield of storage roots. The 15 cm depth channel provided the most consistent yield with all channels having significantly different fresh storage root yields in the replicate.

scholarly journals Motility in multicellular Chlamydomonas reinhardtii (Chlamydomonadales, Chlorophyceae)

2017 ◽  
Author(s):  
Margrethe Boyd ◽  
Fran Rosenzweig ◽  
Matthew Herron
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Radiant Energy ◽  
Culture Conditions ◽  
Wild Type ◽  
Unicellular Alga ◽  
Trade Off ◽  
Directional Movement ◽  
Volvocine Algae ◽  
History Of

AbstractThe advent of multicellularity was a watershed event in the history of life, yet the transition from unicellularity to multicellularity is not well understood. Multicellularity opens up opportunities for innovations in intercellular communication, cooperation, and specialization, which can provide selective advantages under certain ecological conditions. The unicellular alga Chlamydomonas reinhardtii has never had a multicellular ancestor yet it is closely related to the volvocine algae, a clade containing taxa that range from simple unicells to large, specialized multicellular colonies. Simple multicellular structures have been observed to evolve in C. reinhardtii in response to predation or to settling rate-based selection. Structures formed in response to predation consist of individual cells grouped within a shared transparent extracellular matrix. Evolved isolates form such structures obligately under culture conditions in which their wild type ancestors do not, indicating that newly-evolved multicellularity is heritable. C. reinhardtii is capable of photosynthesis, and possesses an eyespot and two flagella with which it moves towards or away from light in order to optimize input of radiant energy. Motility contributes to C. reinhardtii fitness because it allows cells or colonies to achieve this optimum. Utilizing phototaxis to assay motility, we determined that newly evolved multicellular strains do not exhibit significant directional movement, even though the flagellae of their constituent unicells are present and active. In C. reinhardtii the first steps towards multicellularity in response to predation appear to result in a trade-off between motility and differential survivorship, a trade-off that must overcome by further genetic change to ensure the long-term success of the new multicellular organism.

scholarly journals Modeling the influence of heavy ion beams on neurogenesis and functioning of hippocampal neural networks

2019 ◽  
Vol 204 ◽  
pp. 04007
Author(s):  
Elena Kolesnikova ◽  
Aleksandr Bugay
Keyword(s):  
Neural Networks ◽  
Heavy Ion ◽  
Hippocampal Neurogenesis ◽  
Space Flights ◽  
Radiation Induced ◽  
Manned Space ◽  
Induced Changes ◽  
Pattern Encoding ◽  
Manned Space Flights

Radiation-induced impairment of hippocampal neurogenesis is one of serious factors associated with cognitive detriments after radiation therapy of brain cancers and realization of long-term manned space flights. The goal of this study is to develop a mathematical model describing radiation-induced changes in cellular populations participating in neurogenesis and how these alterations worsen the processing of information by hippocampus. Modeling results have demonstrated that heavy ions may cause non-reversible suppression of neurogenesis, which is followed by failure of pattern encoding and retrieval by hippocampal neural networks.

Sign in / Sign up

Export Citation Format

Share Document