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 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.

scholarly journals A unique sequence of the NZW I-E beta chain and its possible contribution to autoimmunity in the (NZB x NZW)F1 mouse.

1989 ◽  
Vol 170 (3) ◽  
pp. 971-984 ◽  
Author(s):  
J Schiffenbauer ◽  
D M McCarthy ◽  
N R Nygard ◽  
S L Woulfe ◽  
D K Didier ◽  
...  
Keyword(s):  
Amino Acid ◽  
Early Death ◽  
Class Ii ◽  
Base Change ◽  
Unique Sequence ◽  
Chain Reaction ◽  
S Haplotype ◽  
Severe Renal Disease ◽  
Single Base Change ◽  
Polymerase Chain

The (NZB x NZW)F1 mouse strain develops a syndrome of accelerated autoimmunity including severe renal disease and early death. Evidence suggests that class II molecules play a central role in this process. Previous studies have suggested that the NZW strain contributes at least one gene to the development of accelerated autoimmunity that is linked to the H-2 complex, and antibodies to murine class II molecules have been used to ameliorate disease in (NZB x NZW)F1 mice. We therefore wished to sequence the class II molecules from NZW mice to identify any unique sequences that may contribute to disease development. We constructed oligonucleotide primers corresponding to the 5' and 3' regions of the second exon of class II genes from a variety of haplotypes, and used these primers in a polymerase chain reaction to sequence the second exon of the NZW I-A alpha, I-A beta, and I-E beta genes. We report that the second exons of NZW I-A alpha, I-A beta, and I-E alpha are identical to their counterparts of the previously sequenced u haplotype, and that the second exon of NZW I-E beta is identical to its counterpart from u except for a single base change that results in a substitution of arginine for threonine at amino acid 72. This base and amino acid are identical to those found at the same positions in the s haplotype.

scholarly journals Cross-incompatibility and self-incompatibility: unrelated phenomena in wild and cultivated potatoes?

Botany ◽  
2018 ◽  
Vol 96 (1) ◽  
pp. 33-45 ◽  
Author(s):  
Juan Federico Maune ◽  
Elsa Lucila Camadro ◽  
Luis Ernesto Erazzú
Keyword(s):  
Germplasm Conservation ◽  
Solanum Chacoense ◽  
Molecular Evidence ◽  
Self Incompatibility ◽  
S Locus ◽  
S Haplotype ◽  
Family Level ◽  
Sib Families ◽  
Cultivated Potatoes ◽  
The Individual

Knowledge of internal hybridization barriers is relevant for germplasm conservation and utilization. The two pre-zygotic barriers are pollen–pistil self-incompatibility (SI) and cross-incompatibility (CI). To ascertain whether SI and CI were phenotypically related phenomena in potatoes, extensive intra- and interspecific, both intra- and interploidy breeding relationships were established, without previous assumptions on the compatibility behavior of the studied germplasm. Pollen–pistil relationships were analyzed at the individual genotype/accession/family level. In two seasons, 828 intra- and interspecific genotypic combinations were performed, using accessions of the wild potatoes Solanum chacoense Bitter (2n = 2x = 24), S. gourlayi Hawkes (2n = 2x = 24; 2n = 4x = 48), and S. spegazzinii Bitter (2n = 2x = 24), full-sibling (hereinafter “full-sib”) families (2n = 2x = 24) within/between the latter two diploids, and S. tuberosum L. (2n = 4x = 48) cultivars. Pollen–pistil incompatibility occurred in the upper first third of the style (I1/3) in all selfed diploids. In both the intra- and interspecific combinations, the most frequent relationship was compatibility, followed by I1/3, but incompatibility also occurred in the stigma and the style (middle third and bottom third). We observed segregation for these relationships in full-sib families, and unilateral and bilateral incompatibility in reciprocal crosses between functional SI genotypes. Cross-incompatibility in potatoes is, apparently, controlled by genes independent of the S-locus or its S-haplotype recognition region (although molecular evidence is needed to confirm it), with segregation even within accessions.

scholarly journals Characterization of a Common S Haplotype BnS-6 in the Self-Incompatibility of Brassica napus

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2186
Author(s):  
Zhiquan Liu ◽  
Bing Li ◽  
Yong Yang ◽  
Changbin Gao ◽  
Bin Yi ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Genetic Locus ◽  
Recognition System ◽  
Inbred Lines ◽  
The Self ◽  
Self Incompatibility ◽  
S Locus ◽  
S Haplotype ◽  
Self Compatibility

Self-incompatibility (SI) is a pollen-stigma recognition system controlled by a single and highly polymorphic genetic locus known as the S-locus. The S-locus exists in all Brassica napus (B. napus, AACC), but natural B. napus accessions are self-compatible. About 100 and 50 S haplotypes exist in Brassica rapa (AA) and Brassica oleracea (CC), respectively. However, S haplotypes have not been detected in B. napus populations. In this study, we detected the S haplotype distribution in B. napus and ascertained the function of a common S haplotype BnS-6 through genetic transformation. BnS-1/BnS-6 and BnS-7/BnS-6 were the main S haplotypes in 523 B. napus cultivars and inbred lines. The expression of SRK in different S haplotypes was normal (the expression of SCR in the A subgenome affected the SI phenotype) while the expression of BnSCR-6 in the C subgenome had no correlation with the SI phenotype in B. napus. The BnSCR-6 protein in BnSCR-6 overexpressed lines was functional, but the self-compatibility of overexpressed lines did not change. The low expression of BnSCR-6 could be a reason for the inactivation of BnS-6 in the SI response of B. napus. This study lays a foundation for research on the self-compatibility mechanism and the SI-related breeding in B. napus.

scholarly journals S-RNase proteins: functional studies of the 120kDa glycoprotein and SRNase oligomerization

2005 ◽  
Author(s):  
◽  
Charles Nathan Hancock
Keyword(s):  
Nicotiana Alata ◽  
Self Incompatibility ◽  
S Locus ◽  
Transmitting Tract ◽  
Functional Studies ◽  
S Haplotype ◽  
S Factor ◽  
Self Association ◽  
Incompatible Cross ◽  
F Box Protein

Flowering plants control fertilization through pollen-pistil interactions. Self-incompatibility (SI) is a well-studied pollen-pistil interaction that promotes cross-pollination. SI is controlled by a multi-haplotype locus called the S-locus. In Nicotiana alata, S-RNase is a product of the S-locus and regulates specificity in the pistil, while S-locus F-box protein (SLF) controls specificity in the pollen. The interaction between S-RNase and SLF determines whether the pollination is compatible or incompatible. In an incompatible cross, the ribonuclease activity of S-RNase inhibits pollen tube growth. Genetic experiments indicate that, in addition to S-RNase and SLF, non-S-factors are also required for SI. S-RNase binding proteins represent potential non-S-factors required for SI. Using affinity chromatography, we found that S-RNase selfassociates and three homologous stylar glycoproteins - the 120kDa glycoprotein (120K), N. alata pistil extensin-like protein III (NaPELP III), and N. alata transmitting tract specific glycoprotein (NaTTS) - bind directly to S-RNase. I studied the oligomerization of S-RNase in detail and found that self-association is dependent on S-haplotype and buffer conditions. I determined that the components of the S-RNase complex account for 30% of soluble pistil protein. 120K is the most likely candidate for a non-S-factor because it enters the cytoplasm of growing pollen tubes and shows polymorphism when SI and self-compatible Nicotiana species are compared. To test its role in SI, I suppressed 120K expression using RNAi. Suppressing 120K caused a breakdown of SI, confirming that it functions in SI.

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.

Comparative Study on Mitogen Activated Protein Kinase of Plasmodium Species by Using in silico Method

2012 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Mohd Fakharul Zaman Raja Yahya ◽  
Hasidah Mohd Sidek
Keyword(s):  
Amino Acid ◽  
In Silico ◽  
Nuclear Export ◽  
Nuclear Export Signal ◽  
Plasmodium Species ◽  
Mitogen Activated Protein Kinase ◽  
Multiple Sequence ◽  
Wide Range ◽  
Mitogen Activated Protein ◽  
Human Plasmodium

Malaria parasites, Plasmodium can infect a wide range of hosts including humans and rodents. There are two copies of mitogen activated protein kinases (MAPKs) in Plasmodium, namely MAPK1 and MAPK2. The MAPKs have been studied extensively in the human Plasmodium, P. falciparum. However, the MAPKs from other Plasmodium species have not been characterized and it is therefore the premise of presented study to characterize the MAPKs from other Plasmodium species-P. vivax, P. knowlesi, P. berghei, P. chabaudi and P.yoelli using a series of publicly available bioinformatic tools. In silico data indicates that all Plasmodium MAPKs are nuclear-localized and contain both a nuclear localization signal (NLS) and a Leucine-rich nuclear export signal (NES). The activation motifs of TDY and TSH were found to be fully conserved in Plasmodium MAPK1 and MAPK2, respectively. The detailed manual inspection of a multiple sequence alignment (MSA) construct revealed a total of 17 amino acid stack patterns comprising of different amino acids present in MAPKJ and MAPK2 respectively, with respect to rodent and human Plasmodia. It is proposed that these amino acid stack patterns may be useful in explaining the disparity between rodent and human Plasmodium MAPKs. 

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