Osteoblasts are considered as a major factor contributing to bone development and mineralization, however, few studies have been done to establish and evaluate the primary cultured tibial osteoblast model of broiler chicks.  Therefore, in the present study, two experiments were conducted to establish and evaluate the primary cultured tibial osteoblast model of broiler chicks.  In experiment 1, osteoblasts were isolated from the tibia of one-day-old Arbor Acre male broiler chicks using the explant method and identified through the cell morphology, alkaline phosphatase (ALP) and alizarin red staining.  Experiment 2 was carried out to evaluate the vitality and mineralization of primary cultured tibial osteoblasts of broilers on days 4, 8, 12, 16, 20, 24, 28 and 32 after incubation, respectively.  The results from experiment 1 demonstrated that primary cultured tibial osteoblasts of broilers showed a spindle-shaped, triangular or polygonal morphology.  More than 95% of the cells were stained blue-black after ALP staining, and mineralized nodules were formed after 4 days of continuous incubation.  in experiment 2, lactate dehydrogenase (LDH) activity stayed at a relatively stabilized level although incubation time affected (P=0.0012) it during the whole culture period.  Additionally, incubation time affected (P≤0.0001) the number and proportion of the area of mineralized nodules.  They increased linearly and quadratically (P<0.04) with the increase of incubation time, and remained at a stabilized level from 24 to 32 days of incubation.  The estimates of the optimal incubation time were 17 and 26 days based on the best fitted broken-line or quadratic models (P<0.0001) of the number and proportion of the area of mineralized nodules, respectively.  These results indicate that the primary cultured tibial osteoblast model of broilers has been established successfully by the explant method, and it showed typical osteoblast morphology and characteristics of ALP activity and mineralization, and could maintain a relatively stabilized vitality from 4 to 32 days of incubation; and the optimal incubation time of primary tibial osteoblasts was 17 to 26 days.  Therefore, it could be used to further study the underlying mechanisms of bone development and mineralization of broiler chicks.

The aim of the study was to investigate whether phosphorus (P) transporters, type IIb sodium-dependent phosphate cotransporter (NaP-IIb) and inorganic phosphate transporter 2 (PiT2), were directly involved in P absorption across primary cultured duodenal epithelial cell monolayers of chick embryos.  The siRNAs against NaP-IIb or PiT2 were designed, synthesized and transfected into primary cultured duodenal epithelial cells of chick embryos.  Then, the inhibitory efficiency of siRNAs against NaP-IIb or PiT2 was analyzed, and the most efficacious siRNAs were selected to be used for subsequent P absorption experiments.  Briefly, primary cultured duodenal epithelial cells of chick embryos were transfected with either NaP-IIb or PiT2 siRNAs and grown in confluent monolayers on transwell plates.  The untransfected or transfected cell monolayers were then incubated in an uptake medium containing 0 or 0.25 mmol L^–1 of P as KH₂PO₄ to measure the P absorption across duodenal epithelial cell monolayers.  The results showed that among the siRNAs designed, si-1372 and si-890 were demonstrated to be the most effective in inhibiting the NaP-IIb and PiT2 expressions, respectively.  Supplemental P increased (P=0.065) the protein abundance of PiT2 and enhanced (P<0.0001) P absorption in primary cultured duodenal epithelial cell of chick embryos.  Furthermore, NaP-IIb silencing decreased (P=0.07) P absorption across duodenal epithelial cell monolayers, while PiT2 silencing had no effect (P=0.345).  It is concluded that the NaP-IIb, but not PiT2, might be directly involved in the P absorption of chick duodenal epithelial cells.

The bone morphogenetic protein (BMP) and mitogen-activated protein kinase (MAPK) signaling pathways play an important role in regulation of bone formation and development, however, it remains unclear that the effect of dietary different levels of non-phytate phosphorus (NPP) on these signaling pathways and their correlations with bone phosphorus (P) retention and bone development in broilers.  Therefore, this experiment was conducted to investigate the effect of dietary P supplementation on BMP and MAPK signaling pathways and their correlations with bone P retention and bone development in broilers.  A total of 800 one-day-old Arbor Acres male broilers were randomly allotted to 1 of 5 treatments with 8 replicates in a completely randomized design.  The 5 treatments of dietary NPP levels were 0.15, 0.25, 0.35, 0.45 and 0.55% or 0.15, 0.22, 0.29, 0.36 and 0.43% for broilers from 1 to 21 days of age or 22 to 42 days of age, respectively.  The results showed that extracellular signal-regulated kinase 1 (ERK1) mRNA expression in the tibia of broilers on days 14 and 28, phosphorylated-ERK1 (p-ERK1) on day 14, and BMP2 protein expression on days 28 and 42 decreased linearly (P<0.04), while c-Jun N-terminal kinase 1 (JNK1) mRNA expression on day 42 increased linearly (P<0.02) with the increase of dietary NPP level.  At 14 days of age, total P accumulation in tibia ash (TP_TA), bone mineral concentration (BMC), bone mineral density (BMD), bone breaking strength (BBS) and tibia ash were negatively correlated (r=–0.726 to –0.359, P<0.05) with ERK1 and JNK1 mRNA as well as p-ERK1; tibia alkaline phosphatase (ALP) and bone gal protein (BGP) were positively correlated (r=0.405 to 0.665, P<0.01) with ERK1 mRNA and p-ERK1.  At 28 days of age, TP_TA, BMC, BMD, BBS and tibia ash were negatively correlated (r=–0.518 to –0.370, P<0.05) with ERK1 mRNA and BMP2 protein, while tibia ALP was positively correlated (r=0.382 to 0.648, P<0.05) with them.  The results indicated that TP_TA, BMC, BMD, BBS or tibia ash had negative correlations, while tibia ALP and BGP had positive correlations with ERK1 and JNK1 mRNAs, BMP2 protein and p-ERK1, suggesting that bone P retention and bone development might be regulated by BMP and MAPK signaling pathways in broiler chickens.

Cuticular wax plays an important role in protecting land plant against biotic and abiotic stresses.  Cuticular wax production on plant surface is often visualized by a characteristic glaucous appearance.  This study identified quantitative trait loci (QTLs) for wheat (Triticum aestivum L.) flag leaf glaucousness (FLG) using a high-density genetic linkage map developed from a recombinant inbred line (RIL) population derived from the cross Heyne×Lakin by single-seed descent.  The map consisted of 2 068 single nucleotide polymorphism (SNP) markers and 157 simple sequence repeat (SSR) markers on all 21 wheat chromosomes and covered a genetic distance of 2 381.19 cM, with an average marker interval of 1.07 cM. Two additive QTLs for FLG were identified on chromosomes 3AL and 2DS with the increasing FLG allele contributed from Lakin.  The major QTL on 3AL, QFlg.hwwgr-3AL, explained 17.5–37.8% of the phenotypic variation in different environments.  QFlg.hwwgr-3AL was located in a 4.4-cM interval on chromosome 3AL that was flanked by two markers IWA1831 and IWA8374.  Another QTL for FLG on 2DS, designated as QFlg.hwwgr-2DS which was identified only in Yangling in 2014 (YL14), was flanked by IWA1939 and Xgwm261 and accounted for 11.3% of the phenotypic variation for FLG.  QFlg.hwwgr-3AL and QFlg.hwwgr-2DS showed Additive×Environment (AE) interactions, explaining 3.5 and 4.4% of the phenotypic variance, respectively.  Our results indicated that different genes/QTLs may contribute different scores of FLG in a cultivar and that the environment may play a role in FLG.

Avian influenza (AI), caused by the influenza A virus, has been a global concern for public health. AI outbreaks not only impact the poultry production, but also give rise to a risk in food safety caused by viral contamination of poultry products in the food supply chain. Distinctions in AI outbreak between strains H5N1 and H7N9 indicate that early detection of the AI virus in poultry is crucial for the effective warning and control of AI to ensure food safety. Therefore, the establishment of a poultry surveillance system for food safety by early detection is urgent and critical. In this article, methods to detect AI virus, including current methods recommended by the World Health Organization (WHO) and the World Organisation for Animal Health (Office International des Epizooties, OIE) and novel techniques not commonly used or commercialized are reviewed and evaluated for feasibility of use in the poultry surveillance system. Conventional methods usually applied for the purpose of AI diagnosis face some practical challenges to establishing a comprehensive poultry surveillance program in the poultry supply chain. Diverse development of new technologies can meet the specific requirements of AI virus detection in various stages or scenarios throughout the poultry supply chain where onsite, rapid and ultrasensitive methods are emphasized. Systematic approaches or integrated methods ought to be employed according to the application scenarios at every stage of the poultry supply chain to prevent AI outbreaks.