Putative Meiotic Toolkit in the Dinoflagellate Prorocentrum cordatum: Additional Evidence for Sexual Process from Transcriptome

2021 ◽  
Author(s):  
Mariia A. Berdieva ◽  
Ilya A. Pozdnyakov ◽  
Vera O. Kalinina ◽  
Sergei O. Skarlato
Keyword(s):  
Sexual Process

SEXUALITY IN ASCOBOLUS STERCORARIUS. II. PRELIMINARY EXPERIMENTS ON VARIOUS ASPECTS OF THE SEXUAL PROCESS

1957 ◽  
Vol 44 (5) ◽  
pp. 436-443 ◽  
Author(s):  
George Bistis
Keyword(s):  
Sexual Process

Sexual processes in the kinetoplastida

Parasitology ◽  
1983 ◽  
Vol 86 (4) ◽  
pp. 29-57 ◽  
Author(s):  
A. Tait
Keyword(s):  
Drug Resistance ◽  
Genetic Exchange ◽  
Sexual Cycle ◽  
Drug Resistant ◽  
Sexual Process ◽  
Experimental Approaches ◽  
Well Differentiated ◽  
Sexual Processes ◽  
Open Question

SUMMARYThe commonly held view that the kinetoplastida, and in particular trypanosomes, are asexual is largely derived from the principle that an organism is asexual until proved sexual. If the basis for this view is examined in detail, it largely arises from the lack of morphologically distinguishable gametes, the difficulties encountered in visualizing chromosomes and a few experiments, using drug-resistant stocks, in which no recombination between stocks could be demonstrated. While it is clear that these organisms are able to reproduce asexually, the existence of a sexual cycle was, until recently, an entirely open question. The early work strongly suggests that any sexual process (in the species examined extensively at the morphological level) does not involve classical well-differentiated gametes and so must involve fusion of morphologically very similar cells. These findings taken together with the inability to visualize chromosomes and thereby identify meiosis, mean that classical methods are unable to detect any sexual process even if it did occur. This review examines the evidence provided by the experimental approaches which have been applied recently to the question of kinetoplastid sexuality. These approaches include isoenzyme studies and the analysis of possible genetic exchange by the use of selective markers (e.g. drug resistance). The results which these techniques have produced make it clear that the kinetoplastid protozoans cannot be regarded as a totally asexual group of organisms.

scholarly journals Transmission of a genetic trait through total conjugation in a hypotrich ciliateParaurostyla weissei. Genetic basis of the multi-left-marginal mutant

1985 ◽  
Vol 46 (3) ◽  
pp. 263-271 ◽  
Author(s):  
Maria Jerka-Dziadosz ◽  
Bozena Dubielecka
Keyword(s):  
Genetic Basis ◽  
Single Gene ◽  
Phenotypic Change ◽  
Wild Type ◽  
Genetic Trait ◽  
Mendelian Segregation ◽  
Cell Cycles ◽  
Slow Growth Rate ◽  
Sexual Process ◽  
Aberrant Phenotype

SUMMARYThe genetic basis of slow growth rate and aberrations in the ciliary pattern was studied in the multi-left-marginal variant ofParaurostyla weissei. The 3:1 segregation in F2 sibling crosses and 1:1 segregation in test crosses indicate that the aberrant phenotype is controlled by a recessive allele at a single gene locus termedmlm. The phenotypic change from wild type tomlmtakes place about 5–8 cell cycles after conjugation. The study established that total conjugation inP. weisseiis a true sexual process in which meiosis, fertilization and Mendelian segregation occur.

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.

Fusion-inhibiting monoclonal antibodies and their relevant antigens in relation to sexual process of Dictyostelium discoideum

1992 ◽  
Vol 49 (2) ◽  
pp. 63-68 ◽  
Author(s):  
Kazuhiro Aiba ◽  
Hideko Urushihara ◽  
Kaichiro Yanagisawa
Keyword(s):  
Monoclonal Antibodies ◽  
Dictyostelium Discoideum ◽  
Sexual Process

scholarly journals Morphogenesis of the Ciliature During Sexual Process of Conjugation in the Ciliated Protist Euplotes raikovi

2021 ◽  
Vol 7 ◽  
Author(s):  
Usman Asghar ◽  
Yong Chi ◽  
Yunyi Gao ◽  
Borong Lu ◽  
Yaohan Jiang ◽  
...  
Keyword(s):  
De Novo ◽  
Anterior Part ◽  
Posterior Part ◽  
Marine Species ◽  
Ventral Side ◽  
Fragmentation Pattern ◽  
Morphogenetic Process ◽  
Stable Pattern ◽  
Sexual Process ◽  
Euplotes Raikovi

Morphogenesis is an important process that widely occurs in almost all the organisms, including the ciliated protists. Ciliates are a large group of single-celled eukaryotes that can reproduce asexually (e.g., binary fission) and perform sexual process (e.g., conjugation). Morphogenesis happens in both asexual reproduction and sexual process in ciliates and the reorganization during conjugation is more complex. However, studies of morphogenesis focusing on conjugation are very limited. Here we studied the morphogenetic process during conjugation in the marine species Euplotes raikovi Agamaliev, 1966. The results indicate that: (1) the ciliature in the ventral side reorganizes twice during sexual process, i.e., conjugational and postconjugational reorganization; (2) the adoral zone of membranelles (AZM) is generated de novo in a pouch beneath the cortex during both reorganizations, with the anterior part generated during the first reorganization, while the posterior part formed during the second reorganization; (3) the frontoventral-transverse (FVT) cirri anlagen are formed de novo in both processes with the fragmentation pattern of 2:2:3:3:2; (4) one left marginal cirrus is generated de novo during both reorganizations; and (5) the dorsal ciliature remains intact during the whole process, except that the two caudal cirri originate from the end of the right-most two dorsal kineties during both reorganizations. Comparisons of the morphogenetic process during conjugation demonstrate a considerably stable pattern within Euplotes while the patterns vary dramatically among different ciliate groups.

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.

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