[Polymorphism of the Full-Length mRNA Sequences of MNS blood group-related genes GYPA, GYPB and GYPE].

OBJECTIVE: The characteristics of the full-length mRNA sequences of MNS blood group-related genes GYPA, GYPB and GYPE were analyzed to understand the polymorphism of MNS blood group genes. METHODS: Anticoagulated blood within 24 h from 500 unpaid blood donors (8 ml each) were randomly selected, and MN, Ss and Mia blood types were identified by serological methods. 5 samples with different combinations of MNS and Mia blood types were randomly selected from 500 samples, and peripheral blood mononuclear cells (PBMC) were isolated by density gradient centrifugation, then total mRNA was extracted. cDNA was prepared by using the reverse transcription kit. The target fragments were amplified by nested PCR, and the full-length mRNA sequences of GYPA, GYPB and GYPE were sequenced after gel cutting and recycling, and the base sequences were analyzed by Oligo 6.0 software. RESULTS: The MN, Ss and Mia phenotypes were detected by serological methods, and there were differences in agglutination intensity of red blood cells (RBC) and anti-Mia serum between different individuals. The full-length mRNA sequences of GYPA, GYPB and GYPE genes in 5 samples of different phenotype combinations were detected. The exon-6 was completely deleted from the GYPA mRNA in 1 sample, and the full-length of GYPA mRNA in the other 4 samples were complete. The exon-2 was completely deleted from the GYPB mRNA in 2 samples, with Mia blood type negative. 2 samples showed complete full-length of GYPB mRNA, with Mia blood type positive. There was base substitution in exon-5 of GYPB mRNA in 1 sample. The full-length of GYPE mRNA was intact in 5 samples. CONCLUSION: MNS blood group related-genes have obvious polymorphism, and the detection of full-length mRNA sequence lays a foundation for the analysis of GYPA, GYPB and GYPE gene structure and in-depth study of MNS blood group antigen expression.

Functional network connectivity changes in children with attention-deficit hyperactivity disorder: A resting-state fMRI study.

The study aimed to investigate the pathologic mechanism of functional brain regions in attention-deficit hyperactivity disorder (ADHD) patients through making comparisons of normal and ADHD children from the perspective of the network nodes of brain network and the intensity of functional connection between bilateral of hemispheres by resting-state functional magnetic resonance imaging (fMRI). Thirty-five ADHD and forty-two children were examined by resting-state functional magnetic resonance imaging (fMRI) scans. Data analysis was done via the degree centrality (DC) and voxel-mirrored homotopic connectivity (VMHC) approaches. Compared with healthy subjects, the ADHD group exhibited significantly decreased DC values in the right posterior cingulate gyrus, left medial superior frontal gyrus, right inferior parietal gyrus, right middle frontal gyrus, left superior frontal gyrus and right superior frontal gyrus. Children with ADHD also exhibited some areas with increased DC values compared with healthy children. These regions included the cerebellar anterior lobe, right middle occipital cortex, left middle cingulate gyrus and right middle cingulate gyrus. VMHC analysis all revealed positive activation in a range of brain regions when comparing ADHD and normal children, suggesting that the VMHC scores of children with ADHD were higher in the bilateral superior frontal lobe, bilateral middle occipital lobe, and bilateral cerebellar anterior lobes. This work provides a new approach for examining the neural mechanisms underlying ADHD, demonstrating that the DC and VMHC methods enabled more comprehensive analysis that can be cross-checked.

An ancient balanced polymorphism in a regulatory region of human major histocompatibility complex is retained in Chinese minorities but lost worldwide.

The coding regions of many of the major histocompatibility complex (MHC) (human leukocyte antigen [HLA] in humans) molecules are believed to be subject to balancing selection. But it is less certain whether the regulatory regions of such coding sequences are also subject to the same type of selection. Here, we studied the polymorphism of the regulatory regions of the HLA-DPA1 and HLA-DPB1 genes among ethnic minorities in southwestern China. Phylogenetic analysis revealed two deep clades >10 million years old. There is almost complete linkage disequilibrium between the regulatory and coding regions of HLA-DPA1, which hints at coadaptive balancing selection on the entire region. Thus, the molecular mechanism of balancing selection in MHC may involve expression modulation in addition to coding-region polymorphisms. Although the frequency of clade II is >30% in some ethnic minorities, it decreases to <5% among southern Han Chinese and vanishes among Europeans. As suspected, some ancient balanced polymorphisms, lost in major populations, still exist in isolated ethnicities. These isolated populations may thus contribute disproportionately to the total diversity of modern humans.