Linear Dominance Relationship among Four Class-II S Haplotypes in Pollen is Determined by the Expression of SP11 in Brassica Self-Incompatibility

2003 ◽  
Vol 44 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Tomohiro Kakizaki ◽  
Yoshinobu Takada ◽  
Akiko Ito ◽  
Go Suzuki ◽  
Hiroshi Shiba ◽  
...  
Keyword(s):  
Class Ii ◽  
Self Incompatibility ◽  
Dominance Relationship

scholarly journals Intrahaplotype Polymorphism at the Brassica S Locus

Genetics ◽  
2001 ◽  
Vol 159 (2) ◽  
pp. 811-822
Author(s):  
Christine Miege ◽  
Véronique Ruffio-Châble ◽  
Mikkel H Schierup ◽  
Didier Cabrillac ◽  
Christian Dumas ◽  
...  
Keyword(s):  
Class Ii ◽  
The Self ◽  
Self Incompatibility ◽  
Receptor Kinase ◽  
S Locus ◽  
S Haplotype

Abstract The S locus receptor kinase and the S locus glycoproteins are encoded by genes located at the S locus, which controls the self-incompatibility response in Brassica. In class II self-incompatibility haplotypes, S locus glycoproteins can be encoded by two different genes, SLGA and SLGB. In this study, we analyzed the sequences of these genes in several independently isolated plants, all of which carry the same S haplotype (S2). Two groups of S2 haplotypes could be distinguished depending on whether SRK was associated with SLGA or SLGB. Surprisingly, SRK alleles from the two groups could be distinguished at the sequence level, suggesting that recombination rarely occurs between haplotypes of the two groups. An analysis of the distribution of polymorphisms along the S domain of SRK showed that hypervariable domains I and II tend to be conserved within haplotypes but to be highly variable between haplotypes. This is consistent with these domains playing a role in the determination of haplotype specificity.

Expression level of the SLG gene is not correlated with the self-incompatibility phenotype in the class II S haplotypes of Brassica oleracea

1995 ◽  
Vol 27 (5) ◽  
pp. 1003-1014 ◽  
Author(s):  
Thierry Gaude ◽  
Mireille Rougier ◽  
Philippe Heizmann ◽  
David J. Ockendon ◽  
Christian Dumas
Keyword(s):  
Brassica Oleracea ◽  
Class Ii ◽  
The Self ◽  
Expression Level ◽  
Self Incompatibility ◽  
Slg Gene

scholarly journals Genetic and Molecular Characterization of a Self-Compatible Brassica rapa Line Possessing a New Class II S Haplotype

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2815
Author(s):  
Bing Li ◽  
Xueli Zhang ◽  
Zhiquan Liu ◽  
Lulin Wang ◽  
Liping Song ◽  
...  
Keyword(s):  
Amino Acid ◽  
De Novo ◽  
Class Ii ◽  
Transcriptional Level ◽  
Self Incompatibility ◽  
S Locus ◽  
Multiple Sequence ◽  
Pak Choi ◽  
New Class ◽  
S Haplotype

Most flowering plants have evolved a self-incompatibility (SI) system to maintain genetic diversity by preventing self-pollination. The Brassica species possesses sporophytic self-incompatibility (SSI), which is controlled by the pollen- and stigma-determinant factors SP11/SCR and SRK. However, the mysterious molecular mechanism of SI remains largely unknown. Here, a new class II S haplotype, named BrS-325, was identified in a pak choi line ‘325’, which was responsible for the completely self-compatible phenotype. To obtain the entire S locus sequences, a complete pak choi genome was gained through Nanopore sequencing and de novo assembly, which provided a good reference genome for breeding and molecular research in B. rapa. S locus comparative analysis showed that the closest relatives to BrS-325 was BrS-60, and high sequence polymorphism existed in the S locus. Meanwhile, two duplicated SRKs (BrSRK-325a and BrSRK-325b) were distributed in the BrS-325 locus with opposite transcription directions. BrSRK-325b and BrSCR-325 were expressed normally at the transcriptional level. The multiple sequence alignment of SCRs and SRKs in class II S haplotypes showed that a number of amino acid variations were present in the contact regions (CR II and CR III) of BrSCR-325 and the hypervariable regions (HV I and HV II) of BrSRK-325s, which may influence the binding and interaction between the ligand and the receptor. Thus, these results suggested that amino acid variations in contact sites may lead to the SI destruction of a new class II S haplotype BrS-325 in B. rapa. The complete SC phenotype of ‘325’ showed the potential for practical breeding application value in B. rapa.

scholarly journals Classification and Identification of S-haplotypes Using PCR-RFLP and Measuring the Self-incompatibility Activity in Radish (Raphanus sativus L.)

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1113C-1113
Author(s):  
Su-Hyoung Park ◽  
Ki-Taek Kim ◽  
Sun-Hyoung Lim ◽  
Moo-Kyoung Yoon ◽  
Soo-Seong Lee ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Seed Set ◽  
Class Ii ◽  
Class I ◽  
Ratio Analysis ◽  
Self Incompatibility ◽  
Strong Activity ◽  
Flower Pollination ◽  
Pcr Rflp ◽  
Polymerase Chain

Self-incompatibility (SI) in Brassicaceae vegetables prevents self-pollination by recognizing self-pollens and rejecting them at the stigmatic surfaces. The S-haplotypes of 47 hybrid radish cultivars that are commercially available in Korea were classified and identified using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Twelve kinds of S-haplotypes were identified from the cultivars: S1, S8, S11, S17, S18, S30, and S31 haplotypes in class-I S-haplotype and S4, S5, S13, S21, and S26 haplotypes in class-II S-haplotypes. Even though the class-II S-haplotypes are supposed to exhibit weak and/or leaky SI activity, the class-II S-haplotypes showed the same allele frequency of class-I S-haplotypes in 38 fully classified commercial cultivars. The SI activity was examined using the pollen tube germination test, flower pollination test, and the seed set ratio analysis. The pollen tube test showed low correlation (R2 = 0.13) with the flower pollination test, a conventional method. The results of seed set ratio analysis varied from 0% to 159%, and thus could distinguish the weak and strong SI activity clearly and showed high correlation with the flower pollination test (R2 = 0.69). The seed set ratios of the cultivars possessing the class-I/class-I, class-I/class-II, and class-II/class-II genotypes were 0.6%, 17.4%, and 38.1%, respectively. Among the eight class-II/class-II cultivars, three cultivars showed strong SI activity. The SI activity of the S4S17, S5S8, and S4S26 genotypes varied among cultivars, but the S1S17, S5S17, and S8S26 genotypes showed constant strong, intermediate, and strong activity, respectively, among the cultivars. Results indicate that the SI activity of Brassicaceae vegetables depends not only on the S-haplotypes, but also on the genetic background of cultivars.

scholarly journals Evolutionary Dynamics of Self-Incompatibility Alleles in Brassica

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 351-359 ◽  
Author(s):  
Marcy K Uyenoyama
Keyword(s):  
Evolutionary Dynamics ◽  
Low Frequency ◽  
Pollen Grains ◽  
Evolutionary Model ◽  
Class Ii ◽  
Class I ◽  
Self Incompatibility ◽  
S Locus ◽  
Single Class ◽  
And Function

Abstract Self-incompatibility in Brassica entails the rejection of pollen grains that express specificities held in common with the seed parent. In Brassica, pollen specificity is encoded at the multipartite S-locus, a complex region comprising many expressed genes. A number of species within the Brassicaceae express sporophytic self-incompatibility, under which individual pollen grains bear specificities determined by one or both S-haplotypes of the pollen parent. Classical genetic and nucleotide-level analyses of the S-locus have revealed a dichotomy in sequence and function among S-haplotypes; in particular, all class I haplotypes show dominance over all class II haplotypes in determination of pollen specificity. Analysis of an evolutionary model that explicitly incorporates features of the Brassica system, including the class dichotomy, indicates that class II haplotypes may invade populations at lower rates and decline to extinction at higher rates than class I haplotypes. This analysis suggests convergence to an evolutionarily persistent state characterized by the maintenance in high frequency of a single class II haplotype together with many class I haplotypes, each in low frequency. This expectation appears to be consistent with empirical observations of high frequencies of relatively few distinct recessive haplotypes.

Electron microscopy analysis of degenerating pancreatic ß cells in transgenic mice expressing the MHC Class I antigen Dd

1990 ◽  
Vol 48 (3) ◽  
pp. 548-549
Author(s):  
T. A. Stewart ◽  
D. Liggitt ◽  
S. Pitts ◽  
L. Martin ◽  
M. Siegel ◽  
...  
Keyword(s):  
Type I Diabetes ◽  
Disease Process ◽  
Class Ii ◽  
Class I ◽  
Type I ◽  
Aberrant Expression ◽  
Mhc Molecules ◽  
Endogenous Insulin ◽  
Class Ii Mhc ◽  
Ifn Γ

Insulin-dependant (Type I) diabetes mellitus (IDDM) is a metabolic disorder resulting from the lack of endogenous insulin secretion. The disease is thought to result from the autoimmune mediated destruction of the insulin producing ß cells within the islets of Langerhans. The disease process is probably triggered by environmental agents, e.g. virus or chemical toxins on a background of genetic susceptibility associated with particular alleles within the major histocompatiblity complex (MHC). The relation between IDDM and the MHC locus has been reinforced by the demonstration of both class I and class II MHC proteins on the surface of ß cells from newly diagnosed patients as well as mounting evidence that IDDM has an autoimmune pathogenesis. In 1984, a series of observations were used to advance a hypothesis, in which it was suggested that aberrant expression of class II MHC molecules, perhaps induced by gamma-interferon (IFN γ) could present self antigens and initiate an autoimmune disease. We have tested some aspects of this model and demonstrated that expression of IFN γ by pancreatic ß cells can initiate an inflammatory destruction of both the islets and pancreas and does lead to IDDM.

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