scholarly journals Phenotypic conversion of mating type specificity induced by transplantation of macronucleoplasm in Paramecium caudatum

1994 ◽  
Vol 63 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Manabu Hori ◽  
Mihoko Takahashi
Keyword(s):  
Genetic Analysis ◽  
Mating Type ◽  
Null Allele ◽  
Gene Dosage ◽  
The Other ◽  
Paramecium Caudatum ◽  
Specific Expression ◽  
Classical Genetic ◽  
Transplantation Technique

SummaryAccording to the classical genetic analysis in Paramecium caudatum by Tsukii & Hiwatashi (1983), the E mating type of each syngen is expressed when the cell bears alleles specific for syngen at the Mt locus. The O mating type is expressed when cells are homozygous for the null allele, mt, at the Mt locus. In such mt/mt cells the O syngen specificity is determined by alleles at two other loci called MA and MB. Inthe study reported here, macronucleoplasmic transplantation technique was used to test the above hypothesis. When macronucleoplasm of type E3 (mating type E of syngen 3) was injected into a macronucleus of type O12 (mating type O of syngen 12), some recipients changed to type E of the donor syngen but some others changed to type E of the recipient syngen. Thus, syngen specificity of donor macronucleoplasm controlling type E was converted into that of the recipients, even though the latter has no gene that controls type E. When this transformant expressing type E of the recipiexnt syngen was re-injected back into E of the other syngen, the expression of the converted mating type in some way continued in the recipient. This suggests that syngen specificity of gene Mt of the donor was changed to that of the recipients by intersyngenic transplantation of macronucleoplasm. We also obtained results suggesting that the gene dosage ratio of Mt to mt or Mt to MA and MB may be important for syngen specific expression of type E.

scholarly journals ISOLATION AND GENETIC ANALYSIS OF MUTANT STRAINS OF CHLAMYDOMONAS REINHARDI DEFECTIVE IN GAMETIC DIFFERENTIATION

Genetics ◽  
1976 ◽  
Vol 82 (2) ◽  
pp. 169-186
Author(s):  
Ursula W Goodenough ◽  
Carol Hwang ◽  
Howard Martin
Keyword(s):  
Genetic Analysis ◽  
Cell Fusion ◽  
Mating Type ◽  
Normal Growth ◽  
The Other ◽  
Genetic Dissection ◽  
Structural Studies ◽  
Tetrad Analysis ◽  
Mating Structure ◽  
Mutant Strains

ABSTRACT Impotent mutant strains of Chlamydomonas reinhardi, mating-type (mt) plus, are described that have normal growth and motility but fail to differentiate into normal gametes. Procedures for their isolation and their genetic analysis are described. Five of the imp strains (imp-2, imp-5, imp-6, imp-7, and imp-8) exhibit no flagellar agglutination when mixed with mt  - or mt  + gametes; these strains have been induced to form rare zygotes with mt  - gametes and the mutations are shown to be unlinked to the mt locus (with the possible exception of imp-7). Two of the strains (imp-3 and imp-4) carry leaky mutations that affect cell fusion; neither mutation is found by tetrad analysis to be linked to mt or to the other. Cells of the imp-1 strain agglutinate well with mt  - gametes and active agglutination continues for up to 48 hours, but cell fusion occurs only very rarely. Analysis of these rare zygotes indicates that imp-1 is closely linked to the mt  + locus, and fine-structural studies reveal that imp-1gametes produce a mutant mating structure involved in zygotic cell fusion. The development of sexuality in C. reinhardi therefore appears amenable to genetic dissection.

scholarly journals GENES CONTROLLING MATING-TYPE SPECIFICITY IN PARAMECIUM CAUDATUM: THREE LOCI REVEALED BY INTERSYNGENIC CROSSES

Genetics ◽  
1983 ◽  
Vol 104 (1) ◽  
pp. 41-62
Author(s):  
Yuuji Tsukii ◽  
Koichi Hiwatashi
Keyword(s):  
Genetic Analysis ◽  
Mating Type ◽  
Pair Formation ◽  
High Fertility ◽  
Mating Types ◽  
Paramecium Caudatum ◽  
Multiple Alleles ◽  
Behavioral Marker ◽  
Species Pairs ◽  
Recessive Homozygote

ABSTRACT In mating interactions in Paramecium caudatum, initial mating agglutination is strictly mating-type specific, but subsequent conjugating pair formation is not mating-type specific. Using this nonspecificity of pair formation, intersyngenic (intersibling species) pairs were induced by mixing four mating types of two different syngens. To distinguish intersyngenic pairs from intrasyngenic ones, the behavioral marker CNR (Takahashi 1979) was mainly used. Clones of intersyngenic hybrids showed high fertility and thus made feasible a genetic analysis of syngenic specificity of mating type. The syngenic specificities of E (even) mating types were found to be controlled by co-dominant multiple alleles at the Mt locus, and those of O (odd) mating types by interactions of co-dominant multiple alleles at two loci, MA and MB. Clones of heterozygotes express dual mating types. Mt is epistatic to MA and MB, and thus O mating types can be expressed only in the recessive homozygote (mt/mt) at the Mt locus. In addition, at least one allele each at the MA and MB loci must have a common syngen specificity for the expression of O types. Thus, when MA is homozygous for one syngen and MB is homozygous for another syngen, no mating type is expressed.

scholarly journals Comparative regulomics supports pervasive selection on gene dosage following whole genome duplication

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gareth B. Gillard ◽  
Lars Grønvold ◽  
Line L. Røsæg ◽  
Matilde Mengkrog Holen ◽  
Øystein Monsen ◽  
...  
Keyword(s):  
Genome Evolution ◽  
Whole Genome Duplication ◽  
Genome Stability ◽  
Genome Duplication ◽  
Gene Dosage ◽  
Whole Genome ◽  
Specific Expression ◽  
Tissue Specific ◽  
Genome Doubling ◽  
Expression Evolution

Abstract Background Whole genome duplication (WGD) events have played a major role in eukaryotic genome evolution, but the consequence of these extreme events in adaptive genome evolution is still not well understood. To address this knowledge gap, we used a comparative phylogenetic model and transcriptomic data from seven species to infer selection on gene expression in duplicated genes (ohnologs) following the salmonid WGD 80–100 million years ago. Results We find rare cases of tissue-specific expression evolution but pervasive expression evolution affecting many tissues, reflecting strong selection on maintenance of genome stability following genome doubling. Ohnolog expression levels have evolved mostly asymmetrically, by diverting one ohnolog copy down a path towards lower expression and possible pseudogenization. Loss of expression in one ohnolog is significantly associated with transposable element insertions in promoters and likely driven by selection on gene dosage including selection on stoichiometric balance. We also find symmetric expression shifts, and these are associated with genes under strong evolutionary constraints such as ribosome subunit genes. This possibly reflects selection operating to achieve a gene dose reduction while avoiding accumulation of “toxic mutations”. Mechanistically, ohnolog regulatory divergence is dictated by the number of bound transcription factors in promoters, with transposable elements being one likely source of novel binding sites driving tissue-specific gains in expression. Conclusions Our results imply pervasive adaptive expression evolution following WGD to overcome the immediate challenges posed by genome doubling and to exploit the long-term genetic opportunities for novel phenotype evolution.

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

scholarly journals Genetics of Differences in Pheromonal Hydrocarbons Between Drosophila melanogaster and D. simulans

Genetics ◽  
1996 ◽  
Vol 143 (1) ◽  
pp. 353-364 ◽  
Author(s):  
Jerry A Coyne
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Dimorphism ◽  
Genetic Analysis ◽  
Species Difference ◽  
The Other ◽  
Chromosome 3 ◽  
Apparent Effect ◽  
The Third ◽  
Hydrocarbon Profile ◽  
The Right

Abstract Females of Drosophila melanogaster and its sibling species D. simulans have very different cuticular hydrocarbons, with the former bearing predominantly 7,11-heptacosadiene and the latter 7-tricosene. This difference contributes to reproductive isolation between the species. Genetic analysis shows that this difference maps to only the third chromosome, with the other three chromosomes having no apparent effect. The D. simulans alleles on the left arm of chromosome 3 are largely recessive, allowing us to search for the relevant regions using D. melanogaster deficiencies. At least four nonoverlapping regions of this arm have large effects on the hydrocarbon profile, implying that several genes on this arm are responsible for the species difference. Because the right arm of chromosome 3 also affects the hydrocarbon profile, a minimum of five genes appear to be involved. The large effect of the third chromosome on hydrocarbons has also been reported in the hybridization between D. simulans and its closer relative D. sechellia, implying either an evolutionaly convergence or the retention in D. sechllia of an ancestral sexual dimorphism.

The HML mating-type cassette of Saccharomyces cerevisiae is regulated by two separate but functionally equivalent silencers

1989 ◽  
Vol 9 (11) ◽  
pp. 4621-4630
Author(s):  
D J Mahoney ◽  
J R Broach
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Binding Sites ◽  
The Other ◽  
Functional Domains ◽  
Gene Products ◽  
Cis Acting ◽  
Full Expression ◽  
Mating Type Genes ◽  
Chromosome Iii

Mating-type genes resident in the silent cassette HML at the left arm of chromosome III are repressed by the action of four SIR gene products, most likely mediated through two cis-acting sites located on opposite sides of the locus. We showed that deletion of either of these two cis-acting sites from the chromosome did not yield any detectable derepression of HML, while deletion of both sites yielded full expression of the locus. In addition, each of these sites was capable of exerting repression of heterologous genes inserted in their vicinity. Thus, HML expression is regulated by two independent silencers, each fully competent for maintaining repression. This situation was distinct from the organization of the other silent locus, HMR, at which a single silencer served as the predominant repressor of expression. Examination of identifiable domains and binding sites within the HML silencers suggested that silencing activity can be achieved by a variety of combinations of various functional domains.

Genetic Analysis of a Null‐Allele for Lipoxygenase‐2 in Soybean 1

Crop Science ◽  
1986 ◽  
Vol 26 (3) ◽  
pp. 460-463 ◽  
Author(s):  
C. S. Davies ◽  
N. C. Nielsen
Keyword(s):  
Genetic Analysis ◽  
Null Allele

scholarly journals MUTATIONS INCREASING ASEXUAL PLASMODIUM FORMATION IN PHYSARUM POLYCEPHALUM

Genetics ◽  
1977 ◽  
Vol 87 (3) ◽  
pp. 401-420
Author(s):  
Paul N Adler ◽  
Charles E Holt
Keyword(s):  
Life Cycle ◽  
Mating Type ◽  
Physarum Polycephalum ◽  
The Other ◽  
Type Allele ◽  
Cold Sensitive ◽  
The One

ABSTRACT Rare plasmodia formed in clones of heterothallic amoebae were analyzed in a search for mutations affecting plasmodium formation. The results show that the proportion of mutants varies with both temperature (18°, 26° or 30°) and mating-type allele (mt1, mt2, mt3, mt4). At one extreme, only one of 33 plasmoida formed by mt2 amoebae at 18° is mutant. At the other extreme, three of three plasmodia formed by mt1 amoebae at 30° are mutant. The mutant plasmodia fall into two groups, the GAD (greater asexual differentiation) mutants and the ALC (amoebaless life cycle) mutants. The spores of GAD mutants give rise to amoebae that differentiate into plasmodia asexually at much higher frequencies than normal heterothallic amoebae. Seven of eight gad mutations analyzed genetically are linked to mt and one (gad-12) is not. The gad-12 mutation is expressed in strains with different alleles of mt. The frequency of asexual plasmodium formation is heat sensitive in some (e.g., mt3 gad-11), heat-insensitive in two (mt2 gad-8 and mt2 gad-9) and cold-sensitive in one (mt1 gad-12) of twelve GAD mutants analyzed phenotypically. The spores of ALC mutants give rise to plasmodia directly, thereby circumventing the amoebal phase of the life cycle. Spores from five of the seven ALC mutants give rise to occasional amoebae, as well as plasmodia. The amoebae from one of the mutants carry a mutation (alc-1) that is unlinked to mt and is responsible for the ALC phenotype in this mutant. Like gad-12, alc-1 is expressed with different mt alleles. Preliminary observations with amoebae from the other four ALC mutants suggest that two are similar to the one containing alc-1; one gives rise to revertant amoebae, and one gives rise to amoebae carrying an alc mutation and a suppressor of the mutation.

scholarly journals Functional analysis of mutations of murine chromosome 17 with the use of tertiary trisomy.

Genetics ◽  
1991 ◽  
Vol 127 (4) ◽  
pp. 781-788
Author(s):  
A Ruvinsky ◽  
A Agulnik ◽  
S Agulnik ◽  
M Rogachova
Keyword(s):  
Functional Analysis ◽  
Gene Dosage ◽  
Tail Length ◽  
Proximal Region ◽  
The Other ◽  
Chromosome 17 ◽  
Recessive Mutations ◽  
T Complex ◽  
Functional Nature ◽  
Morphogenetic Effects

Abstract Analysis of the functional nature of mutations can be based on comparisons of their manifestation in organisms with a deletion or duplication of a particular chromosome segment. With the use of reciprocal translocation T(16;17)43H, it is feasible to produce mice with tertiary trisomy of the proximal region of chromosome 17. The mutations on chromosome 17 we tested included brachyury (T), hairpin tail (Thp), kinky (Fuki), quaking (qk), tufted (tf), as well as tct (t complex tail interaction), and tcl (t complex lethal) that are specific to t haplotypes. The set of dominant and recessive mutations was assigned to two groups: one obligatory, manifesting itself in the phenotype independently of the number of normal alleles in di- and trisomics, and the other facultative, phenotypically manifesting itself depending upon the dosage of mutant alleles. A model was derived from analysis of the interaction of the T and Thp mutations with t haplotypes. It seeks to explain the morphogenetic effects of the mutations observed in mice of different genotypes. The tir gene is postulated to reside on chromosome 17 within its framework. It is suggested that the gene dosage ratio at the tir and tct loci determines tail length.

scholarly journals Genome-wide analysis of CrRLK1L genes and their expression profiling during fiber development in cotton

2020 ◽  
Author(s):  
Dongyun Zuo ◽  
Javaria Ashraf ◽  
Hailiang Cheng ◽  
Shang Liu ◽  
Youping Zhang ◽  
...  
Keyword(s):  
Stress Responses ◽  
Plant Immunity ◽  
Fiber Development ◽  
The Other ◽  
Element Analysis ◽  
Specific Expression ◽  
Group Iii ◽  
Group I ◽  
Genome Wide ◽  
Specific Expression Pattern

Abstract Background: Catharanthus roseus receptor-like kinase 1-like (CrRLK1Ls) proteins play important roles in cell growth, plant morphogenesis, reproduction, hormone signaling, plant immunity and stress responses in Arabidopsis. However, not much information is available about their functions during cotton fiber development.Results: We identified a total of 125, 73 and 71 full-length putative CrRLK1L genes in G. hirsutum, G. arboreum and G. raimondii, which are much greater than that of the other plants. The phylogenetic and gene structure analysis divided the cotton CrRLK1L genes into six major groups, among which only group I and II contained AtCrRLK1Ls of Arabidopsis, suggesting that other groups (group III-VI) were expanded by gene duplication during cotton evolution. Genome collinearity analysis revealed that half of the At02 genes in G. hirsutum derived from A02 of G. arboreum, while the other half (GhCrRLK1L6 and GhCrRLK1L7) originated from Dt03 and Dt02 of G. raimondii, indicating segmental duplication between noncorresponding chromosomes during polyploidization of G. hirsutum. In addition, expression and cis-element analysis revealed that only 22 GhCrRLK1Ls showed specific expression pattern during fiber development which are mainly due to the presence of binding sites for NAC, MYB and WRKY transcription factors.Conclusions: This study provides a strong foundation to further explore the molecular mechanism of CrRLK1L genes during fiber development in upland cotton.

Sign in / Sign up

Export Citation Format

Share Document