scholarly journals Polymorphism in the major histocompatibility complex (MHC class II B) genes of the Rufous-backed Bunting (Emberiza jankowskii)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2917 ◽  
Author(s):  
Dan Li ◽  
Keping Sun ◽  
Yunjiao Zhao ◽  
Aiqing Lin ◽  
Shi Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Major Histocompatibility Complex ◽  
Mhc Class Ii ◽  
Nucleotide Diversity ◽  
Environmental Changes ◽  
Major Histocompatibility ◽  
High Genetic Diversity ◽  
Exon 2 ◽  
Histocompatibility Complex ◽  
Segregating Sites

Genetic diversity is one of the pillars of conservation biology research. High genetic diversity and abundant genetic variation in an organism may be suggestive of capacity to adapt to various environmental changes. The major histocompatibility complex (MHC) is known to be highly polymorphic and plays an important role in immune function. It is also considered an ideal model system to investigate genetic diversity in wildlife populations. The Rufous-backed Bunting (Emberiza jankowskii) is an endangered species that has experienced a sharp decline in both population and habitat size. Many historically significant populations are no longer present in previously populated regions, with only three breeding populations present in Inner Mongolia (i.e., the Aolunhua, Gahaitu and Lubei557 populations). Efforts focused on facilitating the conservation of the Rufous-backed Bunting (Emberiza jankowskii) are becoming increasingly important. However, the genetic diversity ofE. jankowskiihas not been investigated. In the present study, polymorphism in exon 2 of the MHCIIB ofE. jankowskiiwas investigated. This polymorphism was subsequently compared with a related species, the Meadow Bunting (Emberiza cioides). A total of 1.59 alleles/individual were detected inE. jankowskiiand 1.73 alleles/individual were identified inE.cioides. The maximum number of alleles per individual from the threeE. jankowskiipopulations suggest the existence of at least three functional loci, while the maximum number of alleles per individual from the threeE. cioidespopulations suggest the presence of at least four functional loci. Two of the alleles were shared between theE. jankowskiiandE. cioides. Among the 12 unique alleles identified inE. jankowskii, 10.17 segregating sites per allele were detected, and the nucleotide diversity was 0.1865. Among the 17 unique alleles identified inE. cioides, eight segregating sites per allele were detected, and the nucleotide diversity was 0.1667. Overall, compared to other passerine birds, a relatively low level of MHC polymorphism was revealed inE. jankowskii, which was similar to that inE. cioides. Positive selection was detected by PAML/SLAC/FEL analyses in the region encoding the peptide-binding region in both species, and no recombination was detected. Phylogenetic analysis showed that the alleles fromE. jankowskiiandE. cioidesbelong to the same clade and the two species shared similar alleles, suggesting the occurrence of a trans-species polymorphism between the twoEmberizaspecies.

Genetic diversity at the Major Histocompatibility Complex class II DZB gene, and geographical distribution of alleles, in platypuses in a Tasmanian river catchment.

2019 ◽  
Vol 40 (2) ◽  
pp. 241-250
Author(s):  
J.W. Macgregor ◽  
C. Holyoake ◽  
S. Munks ◽  
J.H. Connolly ◽  
I.D. Robertson ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Major Histocompatibility Complex ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Major Histocompatibility ◽  
Island Populations ◽  
Low Genetic Diversity ◽  
Histocompatibility Complex ◽  
Wildlife Populations ◽  
River Catchments

Genetic diversity at loci concerned with fitness is an important part of the ability of a wild population to adapt to changes in its environment, including climatic events, disease and pollution. Research into the effects of genetic diversity on the impacts of disease on wildlife populations has focussed on genes of the major histocompatibility complex (MHC). This study investigated the genetic diversity at the MHC class II DZB gene, as well as the distribution of alleles of the same gene, for platypuses Ornithorhynchus anatinus in the Seabrook Creek Catchment in northwest Tasmania. This study detected 10 previously identified alleles and two previously unreported alleles at the MHC Class II DZB locus in 18 platypuses from the Seabrook Creek Catchment. An additional sequence isolated from two individuals was consistent with a pseudogene. Alleles were reasonably well distributed geographically through the catchment, but there was evidence of a degree of isolation at one site. Consistent with evidence that smaller wildlife populations have relatively low genetic diversity, and that there is relatively slow gene flow between river catchments, the observed genetic diversity at the MHC Class II locus was lower than those in larger previously studied river catchments but higher than those in two island populations. Consequently, this population of platypuses may have a limited capacity to respond to new infectious challenges, such as the fungal disease mucormycosis.

scholarly journals Turkey humoral and cell-mediated immune responses to a Newcastle viscerotropic vaccine and its association with major histocompatibility complex.

2019 ◽  
Vol 22 (1) ◽  
pp. 26-40
Author(s):  
H. Al-Karagoly ◽  
G. Nikbakht ◽  
M. Hassanzadeh ◽  
T. Tolouei
Keyword(s):  
Major Histocompatibility Complex ◽  
Immune Responses ◽  
Mhc Class Ii ◽  
Cellular Response ◽  
Class Ii ◽  
Secretory Iga ◽  
Enzyme Linked Immunosorbent Assay ◽  
Major Histocompatibility ◽  
Exon 2 ◽  
Histocompatibility Complex

Immune responses to vaccines are mainly influenced by the nature of vaccines and host variation in response to vaccination. In this study we aimed to investigate turkey humoral and cell-mediated immune responses to a Newcastle viscerotropic vaccine and its association with major histocompatibility complex (MHC). Turkeys were vaccinated with Villegas–Glisson/University of Georgia (VG/GA) attenuated vaccine against Newcastle disease. The stimulation index of lymphocyte proliferation and antigen-specific local secretory IgA responses in bile, duodenum, ileum, as well as serum IgY and IgA responses were analysed by enzyme-linked immunosorbent assay. The turkey MHC class II B locus was selected as candidate gene for detection of associations with cellular and humoral immune responses. Significant differences were observed between both cellular and humoral responses of vaccinated and unvaccinated groups. A significant positive correlation was also found between ND specific IgY and ND specific IgA titres in serum, intestine (duodenum and ileum) and trachea. Moreover, the correlation between specific IgA titres in ileum and specific bile, duodenum and trachea was positively significant. High resolution melting analysis (HRM) was used to genotype MHC class II B exon 2. Eight melting profiles (A-G) were identified, among which, profile G showed a significant association with cellular response. The profile B revealed significant association with total IgA titres in serum and ileum. These findings help our understanding of the association of turkey MHC types with immune responses. Further correlation analysis between serum and mucosal antibody titres demonstrated that the levels of IgY and IgA in serum can give an impression about the levels of secretory IgA and situation of mucosal immunity. Based on the significant effects, ND specific IgY in serum appears to be a promising indirect marker for specific IgA in serum and trachea.

Hae III locus at Major Histocompatibility Complex (MHC) class II region hints duplicated DQA genes in Indian mithun (Bos frontalis)

2016 ◽  
Author(s):  
S K Niranjan ◽  
D. S. Gonge ◽  
S. K. Mishra ◽  
R. K . Singh ◽  
S Kumar ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Gene Duplication ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Major Histocompatibility ◽  
Exon 2 ◽  
Heterozygous Condition ◽  
Colony Pcr ◽  
Histocompatibility Complex ◽  
Pcr Rflp

In bovines, duplication of major histocompatibility complex (MHC) class II DQ genes increase the advantage of high genetic polymorphism in the region multifold to produce better immune response and population fitness. In this study, the DQA gene duplication was explored at MHC class II locus in mithun (Bos frontalis, Bofr), a unique bovine of North-East region of India. A 776 nucleotide long genomic region encompassing hyper-variable exon 2 of Bofr-DQA was amplified in 79 mithuns and digested with Hae III restriction enzyme for PCR-RFLP analysis. The analysis revealed some of the restriction patterns, which were carrying the total fragment size of the alleles aggregating more than a heterozygous condition. Colony PCR-RFLP of clones of mithun DQA by Hinf I enzyme revealed a total of three DQA alleles in single PCR product. The RFLP of direct PCR and clone (colony) PCR products indicated the amplification of three DQA alleles at a time, suggesting duplication of the DQA locus in mithun. Further, the RFLP based typing of mithun DQA locus revealed the presence of five different DQA1 and DQA2 alleles in different combinations during duplication in mithun population. The duplication of DQA, carrying both DQA1 and DQA2 alleles gene was found to be present in nearly half of the mithun population. In mithun, similar to other bovines, DQA gene duplication may have much importance in creating more and diversified MHC class II molecules, thus conferring an advantage to bind with a more number of pathogenic antigens.

scholarly journals Genetic diversity, evolution and selection in the major histocompatibility complex DRB and DQB loci in the family Equidae

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Marie Klumplerova ◽  
Petra Splichalova ◽  
Jan Oppelt ◽  
Jan Futas ◽  
Aneta Kohutova ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Major Histocompatibility Complex ◽  
Positive Selection ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Depth Analysis ◽  
The Family ◽  
Antigen Presenting

Abstract Background The mammalian Major Histocompatibility Complex (MHC) is a genetic region containing highly polymorphic genes with immunological functions. MHC class I and class II genes encode antigen-presenting molecules expressed on the cell surface. The MHC class II sub-region contains genes expressed in antigen presenting cells. The antigen binding site is encoded by the second exon of genes encoding antigen presenting molecules. The exon 2 sequences of these MHC genes have evolved under the selective pressure of pathogens. Interspecific differences can be observed in the class II sub-region. The family Equidae includes a variety of domesticated, and free-ranging species inhabiting a range of habitats exposed to different pathogens and represents a model for studying this important part of the immunogenome. While equine MHC class II DRA and DQA loci have received attention, the genetic diversity and effects of selection on DRB and DQB loci have been largely overlooked. This study aimed to provide the first in-depth analysis of the MHC class II DRB and DQB loci in the Equidae family. Results Three DRB and two DQB genes were identified in the genomes of all equids. The genes DRB2, DRB3 and DQB3 showed high sequence conservation, while polymorphisms were more frequent at DRB1 and DQB1 across all species analyzed. DQB2 was not found in the genome of the Asiatic asses Equus hemionus kulan and E. h. onager. The bioinformatic analysis of non-zero-coverage-bases of DRB and DQB genes in 14 equine individual genomes revealed differences among individual genes. Evidence for recombination was found for DRB1, DRB2, DQB1 and DQB2 genes. Trans-species allele sharing was identified in all genes except DRB1. Site-specific selection analysis predicted genes evolving under positive selection both at DRB and DQB loci. No selected amino acid sites were identified in DQB3. Conclusions The organization of the MHC class II sub-region of equids is similar across all species of the family. Genomic sequences, along with phylogenetic trees suggesting effects of selection as well as trans-species polymorphism support the contention that pathogen-driven positive selection has shaped the MHC class II DRB/DQB sub-regions in the Equidae.

Genetic Diversity in Exon 2 of the Major Histocompatibility Complex Class II DQB1 Locus in Nigerian Goats

2013 ◽  
Vol 51 (11-12) ◽  
pp. 954-966 ◽  
Author(s):  
Abdulmojeed Yakubu ◽  
Adebowale E. Salako ◽  
Marcos De Donato ◽  
Michael I. Takeet ◽  
Sunday O. Peters ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
Class Ii ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Exon 2 ◽  
Histocompatibility Complex

Detection of Polymorphisms in the exon 2 region of the DRB3 gene in Naqu yaks

2018 ◽  
Author(s):  
Luo-Bu Danjiu ◽  
Tian-Wu An ◽  
Wang-Dui Basang ◽  
Yan-Bin Zhu ◽  
Shi-Cheng He ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Nucleotide Diversity ◽  
Haplotype Diversity ◽  
Nucleotide Polymorphism ◽  
High Genetic Diversity ◽  
Single Nucleotide ◽  
Exon 2 ◽  
Environmental Suitability ◽  
Histocompatibility Complex ◽  
The Status

In the present study, the second exon of the DRB3 gene of the major histocompatibility complex (MHC) from 94 Naqu yaks was amplified and sequenced, and its variation and phylogeny of nucleotides and haplotypes were analyzed. The results showed that 71 single-nucleotide polymorphism (SNPs) were identified, and 147 haplotypes were reconstructed. The average number of nucleotide differences was 16.80965, the nucleotide diversity was 0.05982, and the haplotype diversity was 0.9964. In addition, fewer haplotypes of exon 2 of DRB3 were shared among different ecotype strains, and a large number of privatized haplotypes (93.2%) were observed. Based on the results of the present study, the high genetic diversity of Naqu yaks could reflect their epidemic history and geographical distribution. In addition, the abundant diversity in the MHC region was estimated not only to enhance the current understanding of the status of genetic diversity for the conservation of Naqu yaks but also to improve the relative environmental suitability and disease-resistant breeding of these animals.

scholarly journals Relationship between invariant chain expression and major histocompatibility complex class II transport into early and late endocytic compartments.

1993 ◽  
Vol 177 (3) ◽  
pp. 583-596 ◽  
Author(s):  
P Romagnoli ◽  
C Layet ◽  
J Yewdell ◽  
O Bakke ◽  
R N Germain
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Endocytic Pathway ◽  
Invariant Chain ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Late Endosomes ◽  
Early Endosomes ◽  
Endocytic Compartments

Invariant chain (Ii), which associates with major histocompatibility complex (MHC) class II molecules in the endoplasmic reticulum, contains a targeting signal for transport to intracellular vesicles in the endocytic pathway. The characteristics of the target vesicles and the relationship between Ii structure and class II localization in distinct endosomal subcompartments have not been well defined. We demonstrate here that in transiently transfected COS cells expressing high levels of the p31 or p41 forms of Ii, uncleaved Ii is transported to and accumulates in transferrin-accessible (early) endosomes. Coexpressed MHC class II is also found in this same compartment. These early endosomes show altered morphology and a slower rate of content movement to later parts of the endocytic pathway. At more moderate levels of Ii expression, or after removal of a highly conserved region in the cytoplasmic tail of Ii, coexpressed class II molecules are found primarily in vesicles with the characteristics of late endosomes/prelysosomes. The Ii chains in these late endocytic vesicles have undergone proteolytic cleavage in the lumenal region postulated to control MHC class II peptide binding. These data indicate that the association of class II with Ii results in initial movement to early endosomes. At high levels of Ii expression, egress to later endocytic compartments is delayed and class II-Ii complexes accumulate together with endocytosed material. At lower levels of Ii expression, class II-Ii complexes are found primarily in late endosomes/prelysosomes. These data provide evidence that the route of class II transport to the site of antigen processing and loading involves movement through early endosomes to late endosomes/prelysosomes. Our results also reveal an unexpected ability of intact Ii to modify the structure and function of the early endosomal compartment, which may play a role in regulating this processing pathway.

scholarly journals CD1 and Major Histocompatibility Complex II Molecules Follow a Different Course during Dendritic Cell Maturation

2003 ◽  
Vol 14 (8) ◽  
pp. 3378-3388 ◽  
Author(s):  
Nicole N. van der Wel ◽  
Masahiko Sugita ◽  
Donna M. Fluitsma ◽  
Xaiochun Cao ◽  
Gerty Schreibelt ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Major Histocompatibility Complex ◽  
Dendritic Cell ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Dendritic Cell Maturation ◽  
Cell Maturation ◽  
Major Histocompatibility ◽  
Mhc Molecules ◽  
Histocompatibility Complex

The maturation of dendritic cells is accompanied by the redistribution of major histocompatibility complex (MHC) class II molecules from the lysosomal MHC class II compartment to the plasma membrane to mediate presentation of peptide antigens. Besides MHC molecules, dendritic cells also express CD1 molecules that mediate presentation of lipid antigens. Herein, we show that in human monocyte-derived dendritic cells, unlike MHC class II, the steady-state distribution of lysosomal CD1b and CD1c isoforms was unperturbed in response to lipopolysaccharide-induced maturation. However, the lysosomes in these cells underwent a dramatic reorganization into electron dense tubules with altered lysosomal protein composition. These structures matured into novel and morphologically unique compartments, here termed mature dendritic cell lysosomes (MDL). Furthermore, we show that upon activation mature dendritic cells do not lose their ability of efficient clathrin-mediated endocytosis as demonstrated for CD1b and transferrin receptor molecules. Thus, the constitutive endocytosis of CD1b molecules and the differential sorting of MHC class II from lysosomes separate peptide- and lipid antigen-presenting molecules during dendritic cell maturation.

scholarly journals MPYS, a Novel Membrane Tetraspanner, Is Associated with Major Histocompatibility Complex Class II and Mediates Transduction of Apoptotic Signals

2008 ◽  
Vol 28 (16) ◽  
pp. 5014-5026 ◽  
Author(s):  
Lei Jin ◽  
Paul M. Waterman ◽  
Karen R. Jonscher ◽  
Cindy M. Short ◽  
Nichole A. Reisdorph ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class Ii ◽  
Cell Activation ◽  
Cytoplasmic Tail ◽  
Class Ii ◽  
Antigenic Peptides ◽  
Major Histocompatibility ◽  
Mhc Ii ◽  
Histocompatibility Complex ◽  
Death Signals

ABSTRACT Although the best-defined function of type II major histocompatibility complex (MHC-II) is presentation of antigenic peptides to T lymphocytes, these molecules can also transduce signals leading alternatively to cell activation or apoptotic death. MHC-II is a heterodimer of two transmembrane proteins, each containing a short cytoplasmic tail that is dispensable for transduction of death signals. This suggests the function of an undefined MHC-II-associated transducer in signaling the death response. Here we describe a novel plasma membrane tetraspanner (MPYS) that is associated with MHC-II and mediates its transduction of death signals. MPYS is unusual among tetraspanners in containing an extended C-terminal cytoplasmic tail (∼140 amino acids) with multiple embedded signaling motifs. MPYS is tyrosine phosphorylated upon MHC-II aggregation and associates with inositol lipid and tyrosine phosphatases. Finally, MHC class II-mediated cell death signaling requires MPYS-dependent activation of the extracellular signal-regulated kinase signaling pathway.

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