Salmonella enterica, serovar Enteritidis (S. Enteritidis), an important zoonotic foodborne pathogen, can affect the microbiota of the chicken intestine and cause many enteric diseases, such as acute gastroenteritis. The gut microbiota contributes to the development and function of the host immune system and competes with pathogenic microbes. The interaction between S. Enteritidis and the host cecal microbiota is still not fully understood. We investigated the microbiome composition in both treated and control groups through 16S ribosomal RNA (rRNA) gene sequencing at 1, 3, 7, 14, 21, 28, and 35 days post-S. Enteritidis inoculation (dpi) in the current study. Chao1 richness and Shannon diversity significantly increased with chicken development in both the treated and control groups (P < 0.05). The Chao1 index was significantly lower in the treated group than that in the control group at 14 dpi (P < 0.05). Phyla Proteobacteria and Firmicutes were most dominant at 1 and 3 dpi. S. Enteritidis inoculation influenced cecal microbiota mainly at 7 and 14 dpi. S. Enteritidis inoculation significantly altered the relative abundance of 18 genera at different time points (P < 0.05) with relative abundance significantly changed after 14 dpi. The abundance of those genera changed dramatically between 28 and 35 dpi in the treated group compared to control group. Positive correlations existed between Bacillus and Blautia and between Coprococcus and Flavonifractor following S. Enteritidis inoculation. Our results indicated that both development and S. Enteritidis have effect on chicken cecal microbiota profiles. S. Enteritidis inoculation in young chicks influences the cecal microbiota mainly at 7 and 14 dpi. The cecal microbiota exhibited immunity to S. Enteritidis inoculation at 28 dpi. These findings will provide basic knowledge of the role that chicken cecal microbiota play in response to S. Enteritidis inoculation.

Salmonella enterica serovar Enteritidis (SE) is a food-borne pathogen and of great threat to human health through consuming the contaminated poultry products. MicroRNAs (miRNAs) play an important role in different biological activities and have been shown to regulate the innate immunity in the bacterial infection. The objective of this study is to identify miRNAs associated with SE infection in laying chicken cecum. Average number of reads of three libraries constructed from infected and non-infected chickens was 12,476,156 and 10,866,976, respectively. There were 598 miRNAs including 194 potential novel miRNAs identified in which 37 miRNAs were significantly differentially expressed between infected and non-infected chickens. In total, 2897 unique target genes regulated by differentially expressed miRNAs were predicted, in which, 841 genes were uniquely regulated by up-regulated miRNAs (G1), 636 genes were uniquely regulated by down-regulated miRNAs (G2), and 1420 were co-regulated by both up and down- regulated miRNAs (G3). There were 118, 73 and 178 GO (Gene ontology) BP (Biological process) terms significantly enriched in G1, G2 and G3 groups, respectively. More immune-related GO BP terms than metabolism-related terms were found in G1. Expression of 12 immune-related genes of four differentially expressed miRNAs was detected through qRT-PCR. The regulatory direction of gga-miR-1416-5p, gga-miR-1662, and gga-miR-34a-5p were opposite with the target genes of TLR21, BCL10, TLR1LA, NOTCH2 and THBS1, respectively. The miRNAs contribute to the response to SE infection at the onset of egg laying through regulating the homeostasis between metabolism and immunity. The gga-miR-125b-5p, gga-miR-34a-5p, gga-miR-1416-5p and gga-miR-1662 could play an important role in SE infection through regulating their target genes. The finding herein will pave the foundation for the studies of microRNA regulation in SE infection in laying hens.

A compact, low-loss, optical power splitter based on inverse tapers is proposed and fabricated on a silicon-on-insulator platform. High efficiency mode evolution between the fundamental mode of the input waveguide and the super mode of the output waveguides is realized using optimized tapers. A $1\times 4$ splitter with insertion loss lower than 0.4 dB and uniformity better than 0.68 dB in a wavelength range from 1510 to 1550 nm are demonstrated within a footprint of only $\sim 75{\mathrm{\mu m}}^2$. These properties are very promising for ultrahigh density photonic integration applications.

: Background: Salmonella enterica serovar Enteritidis (SE) is one of the food-borne pathogenic bacteria, which affects poultry production and poses severe threat to human health. The correlation of immune system and metabolism in chicken after SE inoculation is important but not clear. In the current study, we identified the expression of immune and energy metabolism related genes using quantitative PCR to evaluate the correlation between immune system and energy metabolism against SE inoculation in Jining Bairi chicken. Results: ATP5G1, ATP5G3 and ND2 were significantly up-regulated at 1 dpi (day post inoculation), and ATP5E, ATP5G1, ATP5G3 were significantly down-regulated at 7 dpi (P < 0.05). IL-8 and IL-1β were significantly down-regulated at 1 dpi, IL-8 and IL-18 were significantly down-regulated at 3 dpi, IL-8 and BCL10 were significantly up-regulated at 7 dpi (P < 0.05). Conclusions: These findings indicate that the correlation between immune and energy metabolism related genes gradually change with time points post SE inoculation, from one homeostasis to an opposite homeostasis with 3 dpi as a turning point. These results will pave the foundation for the relationship between immune system and energy metabolism in the response to SE inoculation in chicken.

Circular RNAs (circRNAs) are a class of endogenous noncoding RNA, which is different from linear RNA. CircRNA is an RNA molecule with a closed loop structure formed by reverse splicing. CircRNAs have been studied in several organisms, however, the circRNAs associated with the response to Salmonella enterica serovar Enteritidis (SE) inoculation in chickens are still unclear. In the current study, Jining Bairi chickens were inoculated with SE. CircRNAs involved in the response to SE inoculation were identified through next-generation sequencing. Our results showed that there were 5,118 circRNAs identified in the control and treated groups. There were 62 circRNAs significantly differentially expressed following SE inoculation. Functional classification revealed that those significantly differentially expressed circRNAs were associated with immune system process, rhythmic process and signaling following SE inoculation. CircRNAs NC_006091.4: 65510578|65515090, NC_006099.4: 16132825|16236906, and NC_006099.4: 15993284|16006290 play important roles in the response to SE inoculation. The findings in the current study provide evidence that circRNA alterations are involved in the response to SE inoculation in the chicken.

All female vertebrates develop a pair of ovaries except for birds, in which only the left gonad develops into an ovary, whereas the right gonad regresses. Previous studies found that the transcription factor Paired-Like Homeodomain 2 (PITX2), a key mediator for left/right morphogenesis in vertebrates, was also implicated in asymmetric gonadal development in chickens. In this study, we systematically screened and validated the signaling pathways that could be targeted by Pitx2 to control unilateral gonad development. Integrated chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) analyses indicated that Pitx2 directly binds to the promoters of genes encoding neurotransmitter receptors and leads to left-biased expression of both serotonin and dopamine receptors. Forcibly activating serotonin receptor 5-Hydroxytryptamine Receptor 1B (HTR1B) signaling could induce ovarian gene expression and cell proliferation to partially rescue the degeneration of the right gonad. In contrast, inhibiting serotonin signaling could block the development of the left gonad. These findings reveal a PITX2–HTR1B genetic pathway that guides the left-specific ovarian growth in chickens. We also provided new evidence showing neurotransmitters stimulate the growth of nonneuronal cells during the early development of reproductive organs well before innervation.