In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

Q: Background: The Major Histocompatibility Complex (MHC) is a genomic region containing genes with crucial roles in immune responses. MHC class I and class II genes encode antigen-presenting molecules expressed on the cell surface. To counteract the high variability of pathogens, the MHC evolved into a region of considerable heterogeneity in its organization, number and extent of polymorphism. Studies of MHCs in different model species contribute to our understanding of mechanisms of immunity, diseases and their evolution. Camels are economically important domestic animals and interesting biomodels. Three species of Old World camels have been recognized: the dromedary (Camelus dromedarius), Bactrian camel (Camelus bactrianus) and the wild camel (Camelus ferus). Despite their importance, little is known about the MHC genomic region, its organization and diversity in camels. The objectives of this study were to identify, map and characterize the MHC region of Old World camelids, with special attention to genetic variation at selected class MHC II loci. Results: Physical mapping located the MHC region to the chromosome 20 in Camelus dromedarius. Cytogenetic and comparative analyses of whole genome sequences showed that the order of the three major sub-regions is "Centromere -Class II -Class III -Class I". DRA, DRB, DQA and DQB exon 2 sequences encoding the antigen binding site of the corresponding class II antigen presenting molecules showed high degree of sequence similarity and extensive allele sharing across the three species. Unexpectedly low extent of polymorphism with low numbers of alleles and haplotypes was observed in all species, despite different geographic origins of the camels analyzed. The DRA locus was found to be polymorphic, with three alleles shared by all three species. DRA and DQA sequences retrieved from ancient DNA samples of Camelus dromedarius suggested that additional polymorphism might exist. Conclusions: This study provided evidence that camels possess an MHC comparable to other mammalian species in terms of its genomic localization, organization and sequence similarity. We described ancient variation at the DRA locus, monomorphic in most species. The extent of molecular diversity of MHC class II genes seems to be substantially lower in Old World camels than in other mammalian species.

A: The major histocompatibility complex in Old World camelids and low polymorphism of its class II genes
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Q: Here we describe a novel endonuclease IV (Endo IV) based assay utilizing a substrate that mimics the abasic lesions that normally occur in doublestranded DNA. The three component substrate is characterized by single-stranded DNA target, an oligonucleotide probe, separated from a helper oligonucleotide by a one base gap. The oligonucleotide probe contains a non-fluorescent quencher at the 5 0 end and fluorophore attached to the 3 0 end through a special rigid linker. Fluorescence of the oligonucleotide probe is efficiently quenched by the interaction of terminal dye and quencher when not hybridized. Upon hybridization of the oligonucleotide probe and helper probe to their complementary target, the phosphodiester linkage between the rigid linker and the 3 0 end of the probe is efficiently cleaved, generating a fluorescent signal. In this study, the use of the Endo IV assay as a post-PCR amplification detection system is demonstrated. High sensitivity and specificity are illustrated using single nucleotide polymorphism detection.

A: A novel endonuclease IV post-PCR genotyping system
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Q: A rapid diagnostic method based on the melting curve SYBR Green I real-time PCR analysis was developed to detect and differentiate Newcastle disease virus (NDV) strains. Degenerated primers based on the cleavage site sequence of the F0 gene were designed to detect specific sequences characteristic of virulent and avirulent strains of NDV. Eighteen strains of NDV from four lineages were identified and grouped into virulent and avirulent strains. Peaks on the melting temperature graph with melting temperature values between 80.00 and 83.80 C were observed for lentogenic (avirulent) strains. T m values higher than 83.80 were observed for virulent (mesogenic and velogenic) strains. The detection limit of real-time PCR was 2 10 2 plasmid copies per reaction or 10 2 EID 50 for velogenic strains and 10 3 EID 50 for lentogenic strains. The results obtained in this study demonstrate the possible applications for melting curve real-time PCR analysis in laboratory practice for the diagnosis and differentiation of avirulent and virulent strains of Newcastle disease virus.

A:
Detection and differentiation of virulent and avirulent strains of Newcastle disease virus by real-time PCR
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