The effect of sodium thiosulfate in a culture medium on the sexual reproduction of three species of Bacillariophyta

2021 ◽  
pp. 10-14
Author(s):  
Svetlana L. Polykova ◽  
Nickolai A. Davidovich ◽  
Olga I. Davidovich ◽  
Yuliia A. Podunai
Keyword(s):  
Sexual Reproduction ◽  
Culture Medium ◽  
Sodium Thiosulfate ◽  
Marine Water ◽  
Sexual Process ◽  
Clonal Cultures

It was studied the effect of sulfur in the form of sodium thiosulfate pentahydrate on the capability of clonal cultures of Pleurosigma sp., Toxarium undulatum, Pseudo-nitzschia calliantha to interbreed successfully and produce fertile offspring if they were cultivated in artificially prepared marine water (ESAW medium). Differences in the time of the beginning of the sexual process and the intensity of its passage for clones contained on ESAW with the addition of sodium thiasulfate and in the absence of it are shown.

scholarly journals Modification of the ESAW culture medium used for cultivation of marine diatoms

2018 ◽  
Vol 3 (2) ◽  
pp. 73-80 ◽  
Author(s):  
S. L. Polyakova ◽  
O. I. Davidovich ◽  
Yu. A. Podunay ◽  
N. A. Davidovich
Keyword(s):  
Growth Rate ◽  
Culture Medium ◽  
Sodium Thiosulfate ◽  
Fold Increase ◽  
Ammonium Citrate ◽  
Practical Reasons ◽  
Algae Growth ◽  
Clonal Cultures ◽  
Ferrous Ammonium ◽  
Pennate Diatoms

Experiments with clonal cultures of four pennate diatoms Haslea karadagensis, H. ostrearia, Pleurosigma sp. and Pseudo-nitzschia cf. seriata revealed that adding of sodium thiosulfate to the culture medium resulted in increase of algae growth rate. The highest, approximately two-fold, increase of the growth rate was observed in Pseudo-nitzschia cf. seriata, a member of the genus including toxicogenous species. Dependence of the algae growth rate on concentration of sodium thiosulfate was studied; optimal concentrations providing the highest growth rate were determined. Addition of ferrous-ammonium citrate or replacement of ferric chloride with ferrous-ammonium citrate did not affect the growth rate of the diatoms studied. For practical reasons, it is useful to prepare culture medium with the salinity of 36 ‰. Modified recipe of the ESAW medium is given.

scholarly journals Salinity optima for vegetative growth and sexual reproduction of the diatom Toxarium undulatum

2020 ◽  
Vol 5 (1) ◽  
pp. 20-28
Author(s):  
N. A. Davidovich ◽  
O. I. Davidovich
Keyword(s):  
Sexual Reproduction ◽  
Black Sea ◽  
Salinity Tolerance ◽  
Vegetative Growth ◽  
Sea Water ◽  
The Black Sea ◽  
Crimean Peninsula ◽  
Wide Range ◽  
Clonal Cultures ◽  
Oceanic Species

Distribution of diatom algae is limited by their tolerance to environmental factors. Although a genus Toxarium has been evolving for more than 100 million years, it is represented by only two species. Toxarium undulatum is widely spread in tropical and subtropical seas, and it can be also found in the Black Sea, the salinity of which is twice lower than the oceanic one. Ecological and psychological characteristics research of this species is of great interest in terms of its relationship to salinity. T. undulatum clonal cultures were sampled in the Donuzlav Lake connected to the Black Sea (southwest of the Crimean Peninsula) and on Gran Canaria coast (Canary Islands archipelago). Experiments on the salinity tolerance limits showed, that the Black Sea clones were viable in a range of at least 30 ‰ (12 to 42 ‰). The same wide range of salinity tolerance with slightly higher values was observed among oceanic clones of this species. Optima of vegetative growth and sexual reproduction were determined. Optima of the Black Sea clones appeared to be 27.8 and 27.2 ‰, respectively, which was significantly higher than salinity observed in population habitat. Similar higher optima of vegetative growth and sexual reproduction, compared with those salinity values, at which natural population developed, were observed for a number of other Black Sea diatoms, which proved their oceanic (Mediterranean) origin. It was concluded that T. undulatum, along with other species, began to populate the Black Sea basin about seven thousand years ago after Mediterranean Sea water started to flow into the freshened Novoevksinsky Sea-Lake through the Bosporus Strait. However, the evolution rate did not allow bringing physiological and ecological characteristics of the species studied into full agreement with environmental conditions. Oceanic origin is evidently seen in its physiological reactions to salinity. Possibility of speciation due to settlement of the Black Sea with oceanic species is discussed.

Environmental Effects Upon Reproduction of a Mushroom-infesting Cecid Fly, Mycophila speyeri (Barnes) (Diptera: Ceciodomyiidae)

1965 ◽  
Vol 97 (12) ◽  
pp. 1318-1323 ◽  
Author(s):  
Shiu-Ling Chung ◽  
Robert Snetsinger
Keyword(s):  
Sexual Reproduction ◽  
Environmental Effects ◽  
Culture Medium ◽  
Strain Differences ◽  
Growing Media ◽  
Time Required

AbstractMycophila speyeri Barnes is presently the most important mushroom-infesting cecid fly in Pennsylvania. Larval paedogenesis is the main means of reproduction (used by this species). Adult cecid fiies and sexual reproduction arc rarely observed in mushroom growing houses. The higher temperatures of spawn-run (70 ° to 75 °F.) are very favorable to paedogenetic reproduction of M. speyeri. Under these conditions, a generation is completed in about one week and about ten daughter-larvae per mother-larva are produced. The quantity of malt in the culture medium, the age of the spawn, and strain differences in spawn also play roles in the length of a generation and the number of young produced by a mother-larva. The lower temperatures (55 ° to 60 °F.), normal during mushroom cropping, approximately triple the time required to complete a generation. Prevention of cecid infestations during the spawn-run and sanitation to prevent spread, once larvae are present, are important considerations in the control of M. speyeri. Adult cecid flies occur only when populations become crowded on old growing media.

Induction of conjugation in Mougeotia

1989 ◽  
Vol 67 (7) ◽  
pp. 2217-2218 ◽  
Author(s):  
H. Stabenau ◽  
W. Säftel
Keyword(s):  
Sexual Reproduction ◽  
Growth Medium ◽  
Nitrogen Supply ◽  
Sexual Process ◽  
University Of Göttingen ◽  
The University

The alga Mougeotia, strain 164.80, from the algae collection of the University of Göttingen, can be stimulated into sexual reproduction by decreasing the concentration of nitrate in the growth medium from 10−2 to 10−3 M. This effect could not be observed at any other concentration. To initiate the sexual process, cultures were illuminated with an intensity of 550 foot candles. Aeration of the cultures was absolutely necessary. Conjugation started 6 or 9 days after limitation of the nitrogen supply, depending on the CO2 content in the aeration mixture. From the characteristics observed during conjugation, strain 164.80 was identified to be Mougeotia scalaris Hassall.

Cortical positioning and the fate of oral structures during the sexual process in amicronucleate homopolar tandems of Paramecium

Development ◽  
1988 ◽  
Vol 102 (3) ◽  
pp. 587-594
Author(s):  
S.F. Ng
Keyword(s):  
Sexual Reproduction ◽  
Cell Lines ◽  
Low Frequency ◽  
Positional Information ◽  
Binary Fission ◽  
Transient Growth ◽  
Paramecium Tetraurelia ◽  
Growth Depression ◽  
Sexual Process

Paramecium tetraurelia normally resorbs the pre-existing oral apparatus (and develops a new one) during sexual reproduction. Violation of this rule was found in amicronucleate cell lines. These cell lines generated chains of two cells (homopolar tandems) at a low frequency, as a result of incomplete binary fission during a transient growth depression period following emicronucleation. In autogamous chains, the proter resorbed the pre-existing oral structures, while some of the ospisthes retained them. The oral structures in the opisthes of the chains were unusually close to the opisthes' anterior end. The ectopic location of these oral structures might account for their retention, formally understood in terms of the theory of positional information. It is suggested that nongenic factors, likely involving components of the rigid cortical matrix, are involved in the fixation of positional values.

Sexual reproduction of Entomoneis cf. paludosa (Bacillariophyta)

2019 ◽  
pp. 194-196
Author(s):  
Yulia A. Podunay ◽  
Nickolai A. Davidovich ◽  
Olga I. Davidovich
Keyword(s):  
Life Cycle ◽  
Sexual Reproduction ◽  
Pennate Diatom ◽  
Sexual Process

Sexual reproduction and the life cycle of the marine pennate diatom Entomoneis cf. paludosa are described. The reproduction in this species is characterized by morphological and behavioral isogamy. Two gametangia are involved in the sexual process, each of which produces two gametes.

Effects of Nutrition on Mild Steel Corrosion by Sulfate Reducing Bacteria under Aerobic Environment

2015 ◽  
Vol 814 ◽  
pp. 625-630
Author(s):  
Dong Xia Duan ◽  
Cun Guo Lin ◽  
Guang Zhou Liu ◽  
Ping Yao
Keyword(s):  
Mild Steel ◽  
Culture Medium ◽  
Iron Sulfide ◽  
Steel Corrosion ◽  
Sulfate Reducing Bacteria ◽  
Marine Water ◽  
Sulfate Reducing ◽  
Mild Steel Corrosion ◽  
Artificial Biofilm ◽  
Reducing Bacteria

Sulfate reducing bacteria (SRB) are traditionally considered as anaerobic organism. In this paper, the potential of sulfate reducing bacteria to cause mild steel corrosion under aerobic situation was investigated. Natural biopolymer agar and sulfate reducing bacteria cells were used to produce artificial biofilm. Micro-sensors were used to investigate the microenvironment in artificial biofilm. Environmental scanning electron microscopy and energy dispersive spectroscopy were used to study mild steel corrosion covered by artificial biofilm. The results indicated that SRB could grow and reduce sulfate both in suspension and in biofilm. The hydrogen sulfide produced by SRB and mild steel corrosion were influenced by the nutrients in the environment. The concentration of H2S in SRB biofilm exposed to culture medium was as twenty times as that exposed to marine water. The main corrosion product of mild steel in culture medium was iron sulfide, whereas the main product of mild steel in marine water was iron oxide.

scholarly journals Estimation of the propensity for sexual selection in a cyclical parthenogen

2020 ◽  
Author(s):  
David Duneau ◽  
Florian Altermatt ◽  
Jean-Baptiste Ferdy ◽  
Frida Ben-Ami ◽  
Dieter Ebert
Keyword(s):  
Sexual Selection ◽  
Sexual Reproduction ◽  
Sperm Competition ◽  
Indirect Evidence ◽  
Sperm Length ◽  
Cyclical Parthenogenesis ◽  
Single Female ◽  
Sexual Process ◽  
Different Populations ◽  
Firm Evidence

AbstractCyclical parthenogenesis is a widespread reproductive strategy in which organisms go through one or multiple rounds of clonal reproduction before sexual reproduction. Because sexual reproduction is typically less common than parthenogenesis in populations of the planktonic cladoceran Daphnia magna, it is not frequently studied. Here we examine the sexual process of D. magna and its relation to sexual selection in Daphnia rockpool populations by observing natural mating in these shallow habitats where sex generally occurs throughout the summer. Although microsatellite markers were found to reveal no evidence of disassortative mating or, thus, of inbreeding avoidance, body length and infection status did reveal assortative mating, suggesting sexual selection to act. When two males mated with a single female, the larger male was observed to remain longer, possibly giving it an advantage in sperm competition. Indirect evidence points at the brood pouch as the likely site of fertilization and thus, sperm competition. Sperm length was as variable within ejaculates as it was among males from different populations. Our data provide firm evidence that sexual selection is present in this species, most likely manifesting itself through a combination of female choice and male–male competition.

Elimination of altered karyotypes by sexual reproduction preserves species identity

Genome ◽  
2007 ◽  
Vol 50 (5) ◽  
pp. 517-524 ◽  
Author(s):  
Henry H.Q. Heng
Keyword(s):  
Genetic Diversity ◽  
Sexual Reproduction ◽  
Cancer Cells ◽  
Evolutionary Biology ◽  
Genetic Recombination ◽  
Deleterious Mutations ◽  
Species Identity ◽  
Sexual Process ◽  
Controlled Reproduction ◽  
Chromosome Level

Resolving the persistence of sexual reproduction despite its overwhelming costs (known as the paradox of sex) is one of the most persistent challenges of evolutionary biology. In thinking about this paradox, the focus has traditionally been on the evolutionary benefits of genetic recombination in generating offspring diversity and purging deleterious mutations. The similarity of pattern between evolution of organisms and evolution among cancer cells suggests that the asexual process generates more diverse genomes owing to less controlled reproduction systems, while sexual reproduction generates more stable genomes because the sexual process can serve as a mechanism to “filter out” aberrations at the chromosome level. Our reinterpretation of data from the literature strongly supports this hypothesis. Thus, the principal consequence of sexual reproduction is the reduction of drastic genetic diversity at the genome or chromosome level, resulting in the preservation of species identity rather than the provision of evolutionary diversity for future environmental challenges. Genetic recombination does contribute to genetic diversity, but it does so secondarily and within the framework of the chromosomally defined genome.

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