We have assessed the relationships between immune trait (antibody titers of Sheep red blood cell, SRBC; Avian influenza, AI; Newcastle disease, ND) and varieties of MHC B-LBHII Gene in local chicken breeds (Wenshang Barred chicken, LH; Laiwu Black chicken, LWH; and Jining Bairi chicken, BR). We selected 300 chickens randomly from the three indigenous chicken populations. The variations of MHC B-L BII gene were detected by directly DNA sequencing and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). The results indicated that there were about 19-22 nucleotide mutations in the three local breeds, which could affect 16-18 amino acid variations. Another results indicated that there was significantly relationship between seven to eight SNPs of the MHC B-LBII region and some immune traits (P < 0.05 or P < 0.01). Both locus G97A and locus T138A were found in the three species, which were significantly related to the antibodies of SRBC, ND and AI antibody titers (P < 0.05). Among them, the locus G97A was significantly associated with ND antibody titers (P < 0.05) in BR chicken, with SRBC antibody titers (P < 0.05) in LWH chicken, and with H9 antibody titers (P < 0.05) in LH chicken. Furthermore, locus T138A was significantly associated with H9 antibody titers in BR and LH chickens (P < 0.05). All those results suggest relationships among the different varieties of MHC B-LBII and immune traits in the three local breeds.
Animals ; Base Sequence ; Breeding ; Chickens ; genetics ; immunology ; Major Histocompatibility Complex ; genetics ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Polymorphism, Single-Stranded Conformational ; Sequence Analysis, DNA

BACKGROUND: China has the world's largest tea plantation area in the world. To sustain high yields of the tea, multiple pesticides are used on tea crops to control pests. Organophosphorus (OP) pesticides are among the most widely used types of agricultural pesticides in China. As tea is a significant potential source of exposure to pesticide residues, the public concern has increased in relation to pesticide residues found in tea in China. The aim of the study was to estimate cumulative dietary exposure to OP residues from tea infusion for Chinese tea consumers to determine whether exposure to OP residues from tea infusion is a cause of health concern for tea consumers in China. METHODS: OP residue data were obtained from the China National Monitoring Program on Food Safety (2013-2014), encompassing 1687 tea samples from 12 provinces. Tea consumption data were obtained from the China National Nutrient and Health Survey (2002), comprising 506 tea consumers aged 15-82 years. The transfer rates of residues from tea leaves into tea infusions were obtained from the literature. The relative potency factor (RPF) approach was used to estimate acute cumulative exposure to 20 OP residues from tea infusion using methamidophos as the index compound. Dietary exposure was calculated in a probabilistic way. RESULTS: For tea consumers, the mean and the 99.9th percentile (P99.9) of cumulative dietary exposure to OP residues from tea infusion equalled 0.08 and 1.08 μg/kg bw/d. When compared with the acute reference dose (ARfD), 10 μg/kg bw/d for methamidophos, this accounts for 0.8 and 10.8% of the ARfD. CONCLUSIONS Even when considering OP residues from vegetables, fruits and other foods, there are no health concerns based on acute dietary exposure to OP residues from tea infusion. However, it is necessary to strengthen the management of the OP pesticides used on tea in China to reduce the risk of chronic dietary exposure to OPs from tea infusion.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; China ; Dietary Exposure ; analysis ; Female ; Humans ; Male ; Middle Aged ; Organophosphorus Compounds ; analysis ; Pesticide Residues ; analysis ; Risk Assessment ; methods ; Tea ; chemistry ; Young Adult