scholarly journals Mapping on Sea-Star MHC Genes in Invertebrates

2021 ◽  
Vol 2 (2) ◽  
pp. 60-62
Author(s):  
Michel Leclerc ◽  
Loïc Baerlocher
Keyword(s):  
Class Ii ◽  
Class I ◽  
Sea Star ◽  
Asterias Rubens ◽  
Mhc Genes

MHC genes have been discovered in Echinodermata (Invertebrates containing 5 classes).2 classes (Ophuirids, Crinoïds) out of 5 possess HLA E, HLA B (Class I), HLADRB1, HLADQB1 (Class II). By the use of Mapping we identified 2 other MHC genes (Class II) in another Echinodermata: the sea star Asterias rubens (Asterids).

scholarly journals The Invertebrate Antibody

2021 ◽  
pp. 1-2
Keyword(s):  
Receptor Gene ◽  
Genomic Data ◽  
Class Ii ◽  
Fc Receptor ◽  
Class I ◽  
Sea Star ◽  
Mhc Genes ◽  
The Past

Introduction Many researchers don’t believe in our works: they speak we are wrong when we evoke the Invertebrate Antibody...BUT: Discussion We have discovered, in the past, the sea star lymphocytes ( B and T sea star lymphocytes : cf Fig 1,2) : these cells of 4-5µ in diameter are smaller than Vertebrate lymphocytes And ...We discovered recently the IPA (Invertebrate Primitive Antibody) with the sea star IGKAPPA gene with IG sites (Meta Gene 2013). Therefore genomic data assert the evidence of primitive antibody in Echinodermata. Furthermore, we find MHC genes class I and class II in 2019 and Fab gene, Fc receptor gene in these Invertebrates

scholarly journals Allelic diversity and patterns of selection at the major histocompatibility complex class I and II loci in a threatened shorebird, the Snowy Plover (Charadrius nivosus)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Medardo Cruz-López ◽  
Guillermo Fernández ◽  
Helen Hipperson ◽  
Eduardo Palacios ◽  
John Cavitt ◽  
...  
Keyword(s):  
Mhc Class I ◽  
Mhc Class Ii ◽  
Balancing Selection ◽  
Allelic Diversity ◽  
Class Ii ◽  
Class I ◽  
Mhc Genes ◽  
Snowy Plover ◽  
Snowy Plovers ◽  
Private Alleles

Abstract Background Understanding the structure and variability of adaptive loci such as the major histocompatibility complex (MHC) genes is a primary research goal for evolutionary and conservation genetics. Typically, classical MHC genes show high polymorphism and are under strong balancing selection, as their products trigger the adaptive immune response in vertebrates. Here, we assess the allelic diversity and patterns of selection for MHC class I and class II loci in a threatened shorebird with highly flexible mating and parental care behaviour, the Snowy Plover (Charadrius nivosus) across its broad geographic range. Results We determined the allelic and nucleotide diversity for MHC class I and class II genes using samples of 250 individuals from eight breeding population of Snowy Plovers. We found 40 alleles at MHC class I and six alleles at MHC class II, with individuals carrying two to seven different alleles (mean 3.70) at MHC class I and up to two alleles (mean 1.45) at MHC class II. Diversity was higher in the peptide-binding region, which suggests balancing selection. The MHC class I locus showed stronger signatures of both positive and negative selection than the MHC class II locus. Most alleles were present in more than one population. If present, private alleles generally occurred at very low frequencies in each population, except for the private alleles of MHC class I in one island population (Puerto Rico, lineage tenuirostris). Conclusion Snowy Plovers exhibited an intermediate level of diversity at the MHC, similar to that reported in other Charadriiformes. The differences found in the patterns of selection between the class I and II loci are consistent with the hypothesis that different mechanisms shape the sequence evolution of MHC class I and class II genes. The rarity of private alleles across populations is consistent with high natal and breeding dispersal and the low genetic structure previously observed at neutral genetic markers in this species.

LOSS OF POLYMORPHIC RESTRICTION FRAGMENTS OF CLASS I AND CLASS II MHC GENES IN A MALIGNANT MELANOMA

1986 ◽  
Vol 13 (2-3) ◽  
pp. 241-246 ◽  
Author(s):  
G. Angelini ◽  
G. Fossati ◽  
P. Radice ◽  
A. Longo ◽  
P. Piccioli ◽  
...  
Keyword(s):  
Malignant Melanoma ◽  
Class Ii ◽  
Class I ◽  
Restriction Fragments ◽  
Mhc Genes ◽  
Class Ii Mhc ◽  
Polymorphic Restriction

Determination of Distinction Odortypes by Mutation of Class I and Class II MHC Genes

1990 ◽  
pp. 62-64 ◽  
Author(s):  
K. Yamazaki ◽  
G. K. Beauchamp ◽  
L. Thomas ◽  
J. Bard ◽  
E. A. Boyse
Keyword(s):  
Class Ii ◽  
Class I ◽  
Mhc Genes ◽  
Class Ii Mhc

scholarly journals Major Histocompatibility Complex (MHC) Genes and Disease Resistance in Fish

2019 ◽  
Author(s):  
Takuya Yamaguchi ◽  
Johannes M. Dijkstra
Keyword(s):  
Disease Resistance ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Teleost Fish ◽  
Class Ii ◽  
Point Of View ◽  
Class I ◽  
Mhc Genes ◽  
Histocompatibility Complex ◽  
Genomic Regions

The basic pattern of MHC variation in fish, with MHC class I versus class II, and polymorphic classical versus nonpolymorphic nonclassical, is similar in fish and mammals. Nevertheless, in many or all teleost fishes, important differences with mammalian or human MHC were observed: (1) The allelic/haplotype diversification levels of classical MHC class I genes tend to be much higher than in mammals; (2) Teleost fish classical MHC class I and class II loci are not linked. The present article summarizes previous studies that performed quantitative trait loci (QTL) analysis for mapping differences in teleost fish disease resistance, and discusses them from MHC point of view. Overall, those studies suggest the possible importance of genomic regions including classical MHC class II and nonclassical MHC class I genes, whereas similar observations were not made for the genomic regions with the highly diversified classical MHC class I alleles. The present study is a review and discussion of the fish MHC situation.

Linkage of RXRB -like genes to class I and not to class II Mhc genes in the zebrafish

1998 ◽  
Vol 48 (2) ◽  
pp. 141-143 ◽  
Author(s):  
Rafael Gongora ◽  
Zofia Zaleska-Rutczynska ◽  
Kimitaka Takami ◽  
F. Figueroa ◽  
Jan Klein
Keyword(s):  
Class Ii ◽  
Class I ◽  
Mhc Genes ◽  
Class Ii Mhc

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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