HLA-DR4 can be subdivided serologically into two specificities, DR4.1 and DR4.2, using well-defined monospecific alloantisera used in the 11th International Histocompatibility Workshop. In this study, a total of 1095 random DR4-positive individuals from several ethnic groups were tested first for serotype DR4.1/4.2 and then for DRB1*04 alleles using polymerase chain reaction (PCR) followed by sequence-specific oligonucleotide probe hybridization (SSOPH). An almost 100% correlation between samples testing positive for DR4.1 and the presence of alanine at position 74 was observed, while samples testing positive for DR4.2 correlated with the presence of glutamic acid at position 74. DRB1*04 alleles 0401, 0402, 0404, 0405, 0408, 0409 and 0410 are aligned in functional groups which coincide with the serological subtype of DR4.1. DRB1*04 alleles 0403, 0406, 0407 and 0411 coincide with subtype DR4.2. Amino acid substitutions at positions 57, 71 and 86 indicate other significant variations between alleles within the serological subgroup of DR4.1 and define five minor subgroups. The serologic and oligonucleotide allelic subgroups are in turn correlated with recognized cellular Dw antigens. While sequence data provide evidence of structural differences, data on cellular antigens support a functional association between these designated groups and their significance in transplantation and GVHD. Testing results are categorized by ethnic group in order to establish frequency data for donor selection criteria.

The objective of this study was to analyze the effects of single and combined genotypes of MC4R and POU1F1 genes in Chinese well-known indigenous chicken (Langshan chicken) population. Genetic variants within MC4R gene and POU1F1 gene were screened through PCR-SSCP and DNA sequencing methods. A C/T mutation at nt 944 in MC4R gene (NC_006089.2:g. 944C>T) and a G/A mutation at nt 3109 in POU1F1 gene (NC_006088.2:g. 3109 G>A) were identified. Associations between the mutations of the two genes with two production traits were analyzed. The results showed that, at MC4R locus, individuals with BB and AB genotypes had highly significantly higher body weight at 16 weeks (p < 0.01) than did those with the AA genotype. And, individuals within AA and AB genotypes had significantly higher egg numbers at 300 days (p < 0.05). At POU1F1 locus, individuals with CD genotype had higher body weight at 16 weeks and egg numbers at 300 days (p < 0.05). Furthermore, combined genotypes from these two loci were found to be associated with egg numbers at 300 days (p < 0.05). The individuals within combined genotype AB/CD had higher egg production. Therefore, variations identified within the MC4R and POU1F1genes are suitable for future use in identifying chickens with the genetic potential of higher body weight and reproductive traits, at least in the population of Langshan chickens.

HLA-DR, -DQ specificities were determined by PCR amplification with SSOP in 4560 individuals: Caucasoid Americans (CA), African Americans (AA), Chinese Americans (ChA), Native Americans (NA) and Xiamen Chinese (XC). DR2 subtypes were compared amongst the five ethnic populations. The DRB1*1501-DRB5*0101 haplotype was found to be the most frequent in all populations except African Americans, in which DRB1*1503-DRB5*0101 was the predominant haplotype, accounting for 65% of DR2 subtypes. In contrast to Caucasoid Americans, the DRB1*1602 is strongly associated with the DRB5*0101 allele in Chinese populations. The presence of DRB5*0203 and DRB1*1602-DRB5*0101 haplotypes in Chinese populations, especially in Xiamen Chinese, suggests that various DR2 haplotypes may be generated via multiple gene conversion events together with point mutations and reciprocal recombination. The strong DR and DQ associations are found in DRB1*1501/DQB1*0602 (66.22%) for CA, DRB1*1503/DQB1*0602 (56.58%) for AA, DRB1*1501/DQB1*0602 (30.20%) and DRB1*1602/DQB1*0502 (15.76%) for ChA, DRB1* 1501/DQB1*0602 (41.55%) and DRB1*1602/DQB1*0301 (40.25%) for NA, and DRB1*1501/DQB1*0602 (30.26%) and DRB1*1602/DQB1*0502 (25.81%) for XC.

Since mutations on POU1F1 gene possibly resulted in deficiency of growth hormone (GH), prolactin (PRL), thyroid-stimulating hormone (TSH) and pituitary specific transcription factor-1 (POU1F1), this study revealed the polymorphism of cattle POU1F1-HinfI locus and analyzed the distribution of alleles on eight cattle breeds including five indigenous Chinese cattle and three crossbred cattle breeds. The PCR-RFLP analysis showed that allele B was the dominant allele. The frequencies of allele B varied from 0.535 to 0.868. Further study, distributions of genotypic and allelic frequencies at this locus were found to be significantly different among populations based on a x 2-test (p B0.05), suggesting that the breed factor significantly affected the molecular genetic character of POU1F1 gene. The genetic diversity analysis revealed that these populations had a wide spectrum of genetic diversity in cattle POU1F1-HinfI locus. In addition, the relationship between the polymorphism of POU1F1 gene and milk production traits in Chinese Holsteins was also analyzed. The effects of POU1F1 gene on milk yield, fat percent, pre somatic cell count, somatic cell count and somatic cell score were not homogeneous(p !0.05). And, POU1F1 gene had homogeneous effect on protein percent (p B0.05). Protein percent of individuals with genotype AB was higher than those with BB.