the hla class ii genes of human major histocompatibility complex (mhc) exhibit an extensive degree of genetic polymorphism. this region subdivides into four sub-regions dp, do, dq, and dr. there are five different dr haplotypes that all contain a highly polymorphic allele called hla-drb1. in most recent studies, the association between hla-drb1 and a large number of diseases such as multiple sc...

Sequence comparisons of seven distinct MHC class I cDNA clones revealed that feline class I molecules have a remarkable similarity to human HLA genes in their organization of functional domains as well as in the nonrandom partitioning of genetic variability according to the functional constraints ascribed to different regions of the MHC molecule. The distribution of the pattern of sequence poly...

Background: The high polymorphism in the human leukocyte antigen (HLA) genes can be used as an identity of individuals to compare with other populations. This extreme polymorphism in the HLA system is accountable for the differences in alleles and haplotypes among ethnic groups, populations, and the inhabitants of many regions. Objective: To define the frequency of HLA alleles and haplotypes am...

The major histocompatibility complex (MHC) is a multigene family that mediates the host immune response by helping T lymphocytes to recognize and respond to foreign antigens. The high degree of polymorphism and a quick turnover of the genetic loci make the evolution of MHC genes an intriguing subject of study. To understand the evolutionary pattern of this multigene family, we studied the phylo...

The major histocompatibility complex (MHC) hosts the most polymorphic genes ever described in vertebrates. The MHC triggers the adaptive branch of the immune response, and its extraordinary variability is considered an evolutionary consequence of pathogen pressure. The last few years have witnessed the characterization of the MHC multigene family in a large diversity of bird species, unraveling...

The common marmoset (Callithrix jacchus) is a New World primate species that is highly susceptible to fatal infections caused by various strains of bacteria. We present here a first step in the molecular characterization of the common marmoset's Mhc class II genes by nucleotide sequence analysis of the polymorphic exon 2 segments. For this study, genetic material was obtained from animals bred ...

One of the key features of major histocompatibility complex (MHC) genes is the frequent occurrence of trans-species polymorphism, that is 'the passage of allelic lineages from ancestral to descendant species' (Klein et al. 2007). Selectively maintained ancestral polymorphism may, however, be hard to distinguish from introgression of MHC alleles between hybridizing species (Fig. 1). In this issu...

DNA polymorphism within diacylglycerol transferase 2 (DGAT2) / monoacyl glycerol transferases 2 (MOGAT2), leptin and butyrophilin genes were analysed using PCR-SSCP in Murrah buffalo. The single strand conformation polymorphism (SSCP) analysis of amplified gene fragment in exon 5 of MOGAT2, exon 3 of leptin and intron 1 of butyrophilin gene revealed different patterns. A, B and C showed the fol...

Population-level studies using the major histocompatibility complex (Mhc) have linked specific alleles with specific diseases, but data requirements are high and the power to detect disease association is low. A novel use of Mhc population surveys involves mapping allelic substitutions onto the inferred structural molecular model to show functional differentiation related to local selective pre...