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Beijing You Chicken, a valuable local chicken breed from Beijing, China, was once listed as an endangered breed. From the point of view of conservation, the preservation of this breed is an important task for the local researchers. Semen cryopreservation is a popular method to maintain valuable species. However, during cryopreservation, semen is susceptible to oxidative damage. Melatonin is a potent antioxidant and free radical scavenger, so it has been selected to improve the efficiency of sperm cryopreservation. In this study, the chicken semen was treated with different concentrations of melatonin in the cryopreservation solution. The results showed that melatonin at concentrations of 10−3 M and 10−5 M significantly improved sperm progressive motility and total motility, respectively, compared to the control (P < 0.05). Melatonin at 10−3 M also significantly improved the plasma membrane and acrosome integrity of spermatozoa compared to the control. The mechanisms are that melatonin significantly reduces the level of ROS and preserves sperm mitochondrial membrane potential. Most importantly, the melatonin-treated cryopreserved chicken sperm after artificial insemination significantly increased the hatching rate of chicks compared to the control (p < 0.05). The results show that melatonin has a positive effect on the quality of the cryopreserved spermatozoa. These results provide the theoretical and practical basis for using melatonin to improve Beijing You Chicken conservation, and they may also be applicable to poultry as a whole. [ABSTRACT FROM AUTHOR]

Piao chicken, a Chinese indigenous rumpless chicken breed, lacks pygostyle, caudal vertebra, uropygial gland and tail feathers. The rumplessness in Piao chicken presents an autosomal dominant inheritance pattern. However, the molecular genetic mechanisms underlying the rumplessness in Piao chicken remains unclear. In this study, whole-genome resequencing was performed for 146 individuals from 10 chicken breeds, including 9 tailed chicken breeds and Piao rumpless breed. Tailbone CT scan for Piao chickens and WL chickens, revealed that some Piao chicken tails were normal in number, and for a few Piao chickens tail length and tail bone numbers were between the rumpless and the normal tailed chickens. The results showed that the rumpless phenotype has not been completely fixed in Piao chicken breed. Using selection signature analysis and structural variation detection, we found a 4174 bp deletion located in the upstream region of IRX1 gene on chromosome 2 related to rumpless phenotype. Structural variation genotyping showed that the deletion was present in all 32 rumpless Piao chickens (del/del, wild/del) and absent from all 112 tailed chickens included in the dataset for the other 9 breeds and 2 tailed Piao chickens (wild/wild). In summary, all rumpless Piao chickens tested here carry this deletion mutation, to show a complete linkage association with rumplessness trait. We suggested that the 4174 bp deletion could be causative for rumpless phenotype in Piao chicken since this is the only mutation to show the complete linkage disequilibrium with rumplessness on whole genome level across all of 146 chickens from the 10 breeds. This study could facilitate a better understanding of the genetic characteristics of Piao chicken. • Piao chicken structural variation detection. • In Piao Chicken, a deletion variant was found to be associated with rumpless. • This study could facilitate a better understanding of tail degeneration in chicken. [ABSTRACT FROM AUTHOR]

Under the pressure of natural and artificial selection, domestic animals, including chickens, have evolved unique mechanisms of genetic adaptations such as high-altitude adaptation, hot and arid climate adaptation, and desert adaptation. Here, we investigated the genetic basis of cold tolerance in chicken by integrating whole-genome and transcriptome sequencing technologies. Genome-wide comparative analyses of 118 chickens living in different latitudes showed 46 genes and several pathways that may be involved in cold adaptation. The results of the functional enrichment analysis of differentially expressed genes proved the important role of metabolic pathways and immune-related pathways in cold tolerance in chickens. The subsequent integration of whole genome and transcriptome sequencing technology further identified six genes — dnah5 (dynein axonemal heavy chain 5), ptgs2 (prostaglandin-endoperoxide synthase 2), inhba (inhibin beta A subunit), irx2 (iroquois homeobox 2), ensgalg00000054917 , and ensgalg00000046652 — requiring more detailed studies. In addition, we also discovered different allele frequency distributions of five SNPs (single nucleotide polymorphisms) within ptgs2 and nine SNPs within dnah5 in chickens in different latitudes, suggesting strong selective pressure of these two genes in chickens. We provide a novel insight into the genetic adaptation in chickens to cold environments, and provide a reference for evaluating and developing adaptive chicken breeds in cold environments. • The genetic basis of cold tolerance in indigenous chickens long-living in the cold environment were explored. • Two important genes associated with cold tolerance were identified. • Provide a precious source for evaluating and developing adaptive chicken breeds to face climate change. [ABSTRACT FROM AUTHOR]

In this paper, a fan-out device for multicore fiber (MCF) based on capillary bridge self-assembly fabrication method is proposed. The relation among the coupling errors (including transverse misalignment, longitudinal misalignment, and angle misalignment), refractive-index match and the coupling efficiency is analyzed in theory and simulation, and the transverse misalignment and angle misalignment are found to be the main factors affecting coupling efficiency. Then, a fan-out for a four-cores MCF is fabricated by using capillary-bridge force self-assembly of the UV adhesive, the coupling process of fan-out for four-cores MCF, consisting of transverse alignment, longitudinal alignment and tilt alignment, is demonstrated through the coupling of one core to the coupling of two cores, until the coupling efficiencies of all cores are the maximum. At last, the coupling loss of the packaged fan-out in the 1.55 μm spectral region is measured, and the actual coupling loss of all cores is less than 1.25 dB. [ABSTRACT FROM AUTHOR]

Abstract: We previously show the expression of transient receptor potential vanilloid 1 (TRPV1) in primary synoviocytes from collagen-induced arthritis (CIA) rats. Capsaicin and lowered extracellular pH from 7.4 to 5.5 induce cell death through TRPV1-mediated Ca2+ entry and reactive oxygen species (ROS) production. However, under the pathological condition in rheumatoid arthritis, the synovial fluid is acidified to a moderate level (about pH 6.8). In the present study, we examined the effects of pH 6.8 on the TRPV1-mediated cell death. Our finding is different or even opposite from what was observed at pH 5.5. We found that the moderate extracellular acidification (from pH 7.4 to 6.8) inhibited the capsaicin-induced Ca2+ entry through attenuating the activity of TRPV1. In the mean time, it triggered a phospholipse C (PLC)-related Ca2+ release from intracellular stores. The nuclear translocation of NF-κB was found at pH 6.8, and this also depends on PLC activation. Moreover, the capsaicin-evoked massive ROS production and cell death were depressed at pH 6.8, both of which are dependent on the activation of PLC and NF-κB. Taken together, these results suggested that the moderate extracellular acidification inhibited the capsaicin-induced synoviocyte death through regulating Ca2+ mobilization, activating NF-κB nuclear translocation and depressing ROS production. [Copyright &y& Elsevier]