Genetic analysis of mating type differentiation in Paramecium tetraurelia. III. A mutation restricted to mating typeE and affecting the determination of mating type

1981 ◽  
Vol 2 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Yves Brygoo ◽  
A. M. Keller
Keyword(s):  
Genetic Analysis ◽  
Mating Type ◽  
Paramecium Tetraurelia

scholarly journals GENETIC ANALYSIS OF MATING TYPE DIFFERENTIATION IN PARAMECIUM TETRAURELIA. II. ROLE OF THE MICRONUCLEI IN MATING-TYPE DETERMINATION

Genetics ◽  
1980 ◽  
Vol 94 (4) ◽  
pp. 951-959
Author(s):  
Y Brygoo ◽  
T M Sonneborn ◽  
A M Keller ◽  
R V Dippell ◽  
M V Schneller
Keyword(s):  
Genetic Analysis ◽  
Mating Type ◽  
Cytoplasmic Inheritance ◽  
Mating Types ◽  
Paramecium Tetraurelia ◽  
Macronuclear Development ◽  
Cytoplasmic Factors ◽  
Determining Factors

ABSTRACT The two complementary mating types, 0 and E, of Paramecium tetrauretia are normally inherited cytoplasmically. This property has generally been interpreted to indicate the presence of cytoplasmic factors that determine macronuclear differentiation towards 0 or E . In these macronuclear-cytoplasmic interactions, the micronuclei were held to be unbiased and the determination to be established in the course of macronuclear development. In order to ascertain whether the micronuclei were actually neutral, amicronucleate clones were needed and a method to produce them was developed. In crosses between amicronucleate clones and normal micronucleate clones, we have observed regular deviations from cytoplasmic inheritance: the commonest deviation is that most 0 amicronucleate cells become E when they receive a micronucleus from an E partner. The data can be interpreted by assuming that the micronuclei are predetermined and that the apparent "cytoplasmic" inheritance of the two mating types is due, in E cells, to E-determining factors present in the cytoplasm and in the nucleus; and, in 0 cells, to 0-determining factors present only or mainly in the nucleus.

scholarly journals A Mendelian Mutation Affecting Mating-Type Determination Also Affects Developmental Genomic Rearrangements in Paramecium tetraurelita

Genetics ◽  
1996 ◽  
Vol 143 (1) ◽  
pp. 191-202 ◽  
Author(s):  
Eric Meyer ◽  
Anne-Marie Keller
Keyword(s):  
Mating Type ◽  
Maternal Inheritance ◽  
Germ Line ◽  
Molecular Model ◽  
Genomic Rearrangements ◽  
Paramecium Tetraurelia ◽  
Wild Type ◽  
Genetic Context ◽  
Pleiotropic Mutation

Abstract In Paramecium tetraurelia, mating type is determined during the differentiation of the somatic macronucleus from a zygotic nucleus genetically competent for both types, O and E. Determination of the developing macronucleus is controlled by the parental macronucleus through an unknown mechanism resulting in the maternal inheritance of mating types. The pleiotropic mutation mtFE affects macronuclear differentiation. Determination for E is constitutive in mutant homozygotes; a number of unrelated mutant characters are also acquired during development. We have examined the possibility that the mutation causes a defect in the developmental rearrangements of the germ-line genome. We show that the excision of an IES (internal eliminated sequence) interrupting the coding sequence of a surface antigen gene is impaired in the mutant, resulting in an alternative macronuclear version of the gene. Once established, the excision defect is indefinitely transmitted across sexual generations in the cytoplasmic lineage, even in a wild-type genetic context. Thus, the processes of mating-type determination and excision of this IES, in addition to their common sensitivity to the mtFE mutation, show a similar maternal inheritance of developmental alternatives in wild-type cells, suggesting a molecular model for mating-type determination.

scholarly journals GENETIC ANALYSIS OF MATING-TYPE DIFFERENTIATION IN PARAMECIUM TETRAURELIA

Genetics ◽  
1977 ◽  
Vol 87 (4) ◽  
pp. 633-653
Author(s):  
Yves Brygoo
Keyword(s):  
Genetic Analysis ◽  
Mating Type ◽  
Geographical Origin ◽  
Cytoplasmic Inheritance ◽  
Mating Types ◽  
Paramecium Tetraurelia ◽  
Wild Type ◽  
Cytoplasmic Factors ◽  
Nuclear Change

ABSTRACT Whereas each of the two complementary mating types, O and E, of Paramecium tetraulrelia normally shows cytoplasmic inheritance, an abnormal heredity of mating type was observed in the progeny of crosses between two stocks of different geographical origin of Paramecium tetraurelia(stock 51 and stock 32). The modified pattern of mating-type inheritance was shown to result from the interaction of the two wild-type alleles at the locus mtD (mtD51 and mtD32), leading to a new differentiated state O*, different from the normal O and E states observed in both stock 51 and stock 32 cells. The genetic analysis of O* clones showed that the O* phenotype involves both a new heritable cytoplasmic state and possibly a nuclear change which can be transmitted through conjugation and segregates in a Mendelian fashion. All the data can be interpreted if the assumption is made that mating-type determination is achieved only by the commitment or noncommitment to the expression of mating-type E, and that this commitment may simply reflect the activation or nonactivation of the locus mtD, under the influence of one or two "cytoplasmic factors" including the product of the gene mtD itself.

Sampling, Preservation and Counting of Samples II: Zooplankton

2017 ◽  
Author(s):  
Peter H. Wiebe ◽  
Ann Bucklin ◽  
Mark Benfield
Keyword(s):  
Genetic Analysis ◽  
High Speed ◽  
Morphological Analysis ◽  
Taxonomic Composition ◽  
Sampling Techniques ◽  
Sample Analysis ◽  
Sample Preservation ◽  
The Past ◽  
Plankton Collection

This chapter reviews traditional and new zooplankton sampling techniques, sample preservation, and sample analysis, and provides the sources where in-depth discussion of these topics is addressed. The net systems that have been developed over the past 100+ years, many of which are still in use today, can be categorized into eight groups: non-opening/closing nets, simple opening/closing nets, high-speed samplers, neuston samplers, planktobenthos plankton nets, closing cod-end samplers, multiple net systems, and moored plankton collection systems. Methods of sample preservation include preservation for sample enumeration and taxonomic morphological analysis, and preservation of samples for genetic analysis. Methods of analysis of zooplankton samples include determination of biomass, taxonomic composition, and size by traditional methods; and genetic analysis of zooplankton samples.

scholarly journals Propagation of Pistacia lentiscus var. Chia Genotypes and Determination of Their Ornamental Traits Combined with a Genetic Analysis Using ISSR Markers

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 205
Author(s):  
Stefanos Kostas ◽  
Stefanos Hatzilazarou ◽  
Elias Pipinis ◽  
Anastasios Vasileiadis ◽  
Panagiotis Magklaras ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Germination Rate ◽  
Leaf Traits ◽  
Issr Markers ◽  
Pistacia Lentiscus ◽  
Natural Habitats ◽  
Indolebutyric Acid ◽  
Single Male ◽  
Asexual Propagation

Pistacia lentiscus L. is a dioecious shrub or small tree with high drought resistance, native in the entire Mediterranean basin. The variety ‘Chia’ (mastic tree) is cultivated for the production of mastic gum (a resin produced after wounding of the trunks and thick branches) in the Island of Chios (Greece), but it also has a significant ornamental value. In the present study, ten male and ten female genotypes of P. lentiscus var. Chia from the natural habitats of Chios were selected and examined with respect to the rooting efficiency of their shoot cuttings. The germination ability of the seeds was also tested. The 20 plants were morphologically described, mainly with respect to traits related to their ornamental value. Furthermore, leaves were collected from the 20 genotypes, from which genomic DNA (gDNA) was isolated, followed by amplification of gDNA fragments using the polymerase chain reaction (PCR) and inter simple sequence repeat (ISSR) primers. This was done aiming both at the determination of their genetic distance and the establishment of possible correlations between the amplified bands and certain morphological traits. The results of the study showed that there were differences among the genotypes for both methods of propagation. Regarding the rooting of the shoot cuttings, the best genotype was 8M (cv. ‘Psilophyllos’), achieving a rooting rate of 62.5% in winter with the application of indolebutyric acid (potassium salt of IBA), while regarding the seed germination capacity the genotype 2F exhibited the highest germination rate (57%). Genetic analysis using ISSRs separated the plants into four groups, one group consisting of male genotypes, one of the female genotypes, one consisting of members from both genders and a fourth containing a single male genotype. The genetic analysis of the male genotypes only produced a dendrogram showing the cultivars clustering in three different groups. Regardless of the genetic analysis, it seems that there were correlations between the ISSR markers and the leaf traits and also the gender and the asexual propagation. These correlations can assist future breeding programs of P. lentiscus var. Chia.

scholarly journals Phenotypic and Genetic Analysis of “Chameleon,” a Paramecium Mutant With an Enhanced Sensitivity to Magnesium

Genetics ◽  
1997 ◽  
Vol 146 (3) ◽  
pp. 871-880
Author(s):  
Robin R Preston ◽  
Jocelyn A Hammond
Keyword(s):  
Genetic Analysis ◽  
Single Locus ◽  
Behavioral Analysis ◽  
Paramecium Tetraurelia ◽  
Wild Type ◽  
Ion Conductance ◽  
Membrane Excitation ◽  
Enhanced Sensitivity ◽  
Electrophysiological Analysis ◽  
Mutant Strains

Three mutant strains of Paramecium tetraurelia with an enhanced sensitivity to magnesium have been isolated. These new “Chameleon” mutants result from partial- or codominant mutations at a single locus, Cha. Whereas the wild type responded to 5 mm Mg2+ by swimming backward for 10–15 sec, Cha mutants responded with ∼30 sec backward swimming. Electrophysiological analysis suggested that this behavior may be caused by slowing in the rate at which a Mg2+-specific ion conductance deactivates following membrane excitation. This would be consistent with an observed increase in the sensitivity of Cha mutants to nickel poisoning, since Ni2+ is also able to enter the cell via this pathway. More extensive behavioral analysis showed that Cha cells also overresponded to Na+, but there was no evidence for a defect in intracellular Ca2+ homeostasis that might account for a simultaneous enhancement of both the Mg2+ and Na+ conductances. The possibility that the Cha locus may encode a specific regulator of the Mg2+- and Na+-permeabilities is considered.

Genetic analysis of segregation distortion of mating-type factors in Lentinula edodes

2005 ◽  
Vol 15 (8) ◽  
pp. 684-688
Author(s):  
Cheng Shuiming ◽  
Lin Fanxue ◽  
Xu Xuefeng ◽  
Li Anzheng ◽  
Lin Fangcan
Keyword(s):  
Genetic Analysis ◽  
Mating Type ◽  
Segregation Distortion ◽  
Lentinula Edodes

Physical and physiological components of the graviresponses of wild-type and mutant Paramecium Tetraurelia

2000 ◽  
Vol 203 (6) ◽  
pp. 1059-1070 ◽  
Author(s):  
U. Nagel ◽  
H. Machemer
Keyword(s):  
Swimming Speed ◽  
Sedimentation Rates ◽  
Paramecium Tetraurelia ◽  
Wild Type ◽  
Centre Of Gravity ◽  
In The Wild ◽  
Type Population ◽  
G Value ◽  
Mutant Cells

Wild-type and the morphological mutant kin 241 of Paramecium tetraurelia showed improved orientation away from the centre of gravity (negative gravitaxis) when accelerations were increased from 1 to 7 g. Gravitaxis was more pronounced in the mutant. A correlation between the efficiency of orientation and the applied g value suggests a physical basis for gravitaxis. Transiently enhanced rates of reversal of the swimming direction coincided with transiently enhanced gravitaxis because reversals occurred more often in downward swimmers than in upward swimmers. The results provide evidence of a physiological modulation of gravitaxis by means of the randomizing effect of depolarization-dependent swimming reversals. Gravity bimodally altered propulsion rates of wild-type P. tetraurelia so that sedimentation was partly antagonized in upward and downward swimmers (negative gravikinesis). In the mutant, only increases in propulsion were observed, although the orientation-dependent sensitivity of the gravikinetic response was the same as in the wild-type population. Observed swimming speed and sedimentation rates in the wild-type and mutant cells were linearly related to acceleration, allowing the determination of gravikinesis as a linear (and so far non-saturating) function of gravity.

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