Toll-like receptor 5-mediated IL-17C expression in intestinal epithelial cells enhances epithelial host defense against F4+ ETEC infection

International audienceAbstractEnterotoxigenic Escherichia coli (ETEC) are an important cause of post-weaning diarrhea (PWD) in piglets. The IL-17 cytokine family is well known to play important roles in the host defense against bacterial infections at the mucosa. Previously, we reported the potential role of IL-17A in clearing an ETEC infection in piglets. IL-17C, another member of the IL-17 family, is highly expressed in the intestinal epithelium, however, its role during an ETEC infection is still unclear. In this study, we demonstrate that F4+ ETEC induce IL-17C mRNA and protein expression in intestinal tissues as well as in porcine intestinal epithelial cells (IPEC-J2). This IL-17C production is largely dependent on TLR5 signaling in IPEC-J2 cells. Both F4+ ETEC infection and exogenous IL-17C increased the expression of antimicrobial peptides and tight junction proteins, such as porcine beta-defensin (pBD)-2, claudin-1, claudin-2 and occludin in IPEC-J2 cells. Taken together, our data demonstrate that TLR5-mediated IL-17C expression in intestinal epithelial cells enhances mucosal host defense responses in a unique autocrine/paracrine manner in the intestinal epithelium against ETEC infection

Research Progress on the Application of Spectroscopy in Meat Spoilage Detection

The growth and metabolism of microorganisms is the main cause of meat spoilage. The rapid and nondestructive techniques for detecting microorganisms in meat have attracted more and more attentions. Spectroscopic techniques such as Raman spectroscopy, infrared spectroscopy and spectral imaging show great advantages in rapid and non-destructive detection, but their application in meat spoilage detection has not been timely summarized. Based on an overview of the dominant spoilage organisms and microbial metabolism in meat under different storage conditions, this paper briefly describes the material basis for spectroscopic prediction of meat spoilage. Then, the application of Raman spectroscopy, infrared spectroscopy and spectral imaging technology in predicting the shelf life of meat is summarized. The efficiency of predictive modeling of meat shelf life based on total bacterial count or total volatile basic nitrogen (TVB-N) content and problems existing in this field are highlighted. We anticipate that this review will provide new ideas and theoretical guidance for the development and application of rapid and nondestructive techniques for meat spoilage identification

Difference between Pb and Cd Accumulation in 19 Elite Maize Inbred Lines and Application Prospects

In the last two decades, the accumulation of heavy metal in crop grains has become the study hotspot. In this study, 19 representative elite maize inbred lines and 3 hybrid varieties were investigated at the seedling stage, which can accumulate Pb and Cd in the stems and leaves, respectively. The results demonstrated that significant differences are among inbred lines for accumulation of heavy metals, implying that the Cd accumulation is significant correlation between the male parents and their hybrids and some inbred lines have been selected for cross-breeding with low Pb or Cd accumulation, such as S37, 9782, and ES40; Moreover, some inbred lines could be suitable for phytoremediation species for soil bioremediation with high levels of Pb and Cd accumulation, including 178, R08, 48-2, and Mo17ht

Heterosis in Early Maize Ear Inflorescence Development: A Genome-Wide Transcription Analysis for Two Maize Inbred Lines and Their Hybrid

Heterosis, or hybrid vigor, contributes to superior agronomic performance of hybrids compared to their inbred parents. Despite its importance, little is known about the genetic and molecular basis of heterosis. Early maize ear inflorescences formation affects grain yield, and are thus an excellent model for molecular mechanisms involved in heterosis. To determine the parental contributions and their regulation during maize ear-development-genesis, we analyzed genome-wide digital gene expression profiles in two maize elite inbred lines (B73 and Mo17) and their F1hybrid using deep sequencing technology. Our analysis revealed 17,128 genes expressed in these three genotypes and 22,789 genes expressed collectively in the present study. Approximately 38% of the genes were differentially expressed in early maize ear inflorescences from heterotic cross, including many transcription factor genes and some presence/absence variations (PAVs) genes, and exhibited multiple modes of gene action. These different genes showing differential expression patterns were mainly enriched in five cellular component categories (organelle, cell, cell part, organelle part and macromolecular complex), five molecular function categories (structural molecule activity, binding, transporter activity, nucleic acid binding transcription factor activity and catalytic activity), and eight biological process categories (cellular process, metabolic process, biological regulation, regulation of biological process, establishment of localization, cellular component organization or biogenesis, response to stimulus and localization). Additionally, a significant number of genes were expressed in only one inbred line or absent in both inbred lines. Comparison of the differences of modes of gene action between previous studies and the present study revealed only a small number of different genes had the same modes of gene action in both maize seedlings and ear inflorescences. This might be an indication that in different tissues or developmental stages, different global expression patterns prevail, which might nevertheless be related to heterosis. Our results support the hypotheses that multiple molecular mechanisms (dominance and overdominance modes) contribute to heterosis

Molecular phylogenetic characterization and analysis of the WRKY transcription factor family responsive to Rhizoctonia solani in maize

In this study we have identified, based on the maize genome, 85 WRKY genes that were phylogenetically clustered into three families formed by 8 distinct subfamilies. The exon/intron structures and motif compositions of these WRKY genes were highly conserved in each subfamily suggesting their functional conservation. Moreover, based on qTelller analyses, the majority of these WRKY genes showed a specific temporal and spatial expression pattern. These WRKY genes, within the same group, manifested a distinct expression, indicating a similar function in their expression during the evolutionary process; this is reflected by their sub-functionalizations in their expression pattern concerning leaf developmental gradient, while mature bundle sheath, and mesophyll cells had a similar cellular localization and modality of expression. This study has also provided evidence of the presence of a subset of WRKY genes exhibiting a putative functional role in leaf sheath when infected with Rhizoctonia solani. This finding appears helpful for future functional investigations to unravel the roles of WRKY genes in plant pathogen resistance. Interestingly, in this study we have identified three WRKY genes that are predicted to be potential targets of miR160 and miR171b families. Therefore, this finding appears relevant in elucidating the biological functions of these transcription factors to clarify the molecular mechanisms affecting leaf sheath growth and development during fungal infection and plant resistance

Whole-genome sequencing of cultivated and wild peppers provides insights into Capsicum domestication and specialization

As an economic crop, pepper satisfies people's spicy taste and has medicinal uses worldwide. To gain a better understanding of Capsicum evolution, domestication, and specialization, we present here the genome sequence of the cultivated pepper Zunla-1 (C. annuum L.) and its wild progenitor Chiltepin (C. annuum var. glabriusculum). We estimate that the pepper genome expanded similar to 0.3 Mya (with respect to the genome of other Solanaceae) by a rapid amplification of retrotransposons elements, resulting in a genome comprised of similar to 81% repetitive sequences. Approximately 79% of 3.48-Gb scaffolds containing 34,476 protein-coding genes were anchored to chromosomes by a high-density genetic map. Comparison of cultivated and wild pepper genomes with 20 resequencing accessions revealed molecular footprints of artificial selection, providing us with a list of candidate domestication genes. We also found that dosage compensation effect of tandem duplication genes probably contributed to the pungent diversification in pepper. The Capsicum reference genome provides crucial information for the study of not only the evolution of the pepper genome but also, the Solanaceae family, and it will facilitate the establishment of more effective pepper breeding programs

Structural variation and introgression from wild populations in East Asian cattle genomes confer adaptation to local environment

BACKGROUND: Structural variations (SVs) in individual genomes are major determinants of complex traits, including adaptability to environmental variables. The Mongolian and Hainan cattle breeds in East Asia are of taurine and indicine origins that have evolved to adapt to cold and hot environments, respectively. However, few studies have investigated SVs in East Asian cattle genomes and their roles in environmental adaptation, and little is known about adaptively introgressed SVs in East Asian cattle. RESULTS: In this study, we examine the roles of SVs in the climate adaptation of these two cattle lineages by generating highly contiguous chromosome-scale genome assemblies. Comparison of the two assemblies along with 18 Mongolian and Hainan cattle genomes obtained by long-read sequencing data provides a catalog of 123,898 nonredundant SVs. Several SVs detected from long reads are in exons of genes associated with epidermal differentiation, skin barrier, and bovine tuberculosis resistance. Functional investigations show that a 108-bp exonic insertion in SPN may affect the uptake of Mycobacterium tuberculosis by macrophages, which might contribute to the low susceptibility of Hainan cattle to bovine tuberculosis. Genotyping of 373 whole genomes from 39 breeds identifies 2610 SVs that are differentiated along a "north-south" gradient in China and overlap with 862 related genes that are enriched in pathways related to environmental adaptation. We identify 1457 Chinese indicine-stratified SVs that possibly originate from banteng and are frequent in Chinese indicine cattle. CONCLUSIONS: Our findings highlight the unique contribution of SVs in East Asian cattle to environmental adaptation and disease resistance

G1CSF DISPLAYS RESTRICTED ABILITY TO PROMOTE ADULT RESIDENT SCA-1+ CARDIAC STEM CELL PROLIFERATION IN VITRO

N/DAims: Myocardial homing of mobilized bone marrow-derived cells is thought to play a critical role in observed granulocyte colony-stimulating factor (G-CSF)-induced cardiac repair after myocardial infarction; how to harness the potential of cardiac stem cells (CSCs) residing in the heart holds a significant challenge. This study aims to investigate whether G-CSF receptor (G-CSFR) is expressed in adult resident Sca-1+ CSCs, the CSC proliferative and phenotypic changes after G-CSF treatment. Methods and results: The cells were isolated from 12-week-old mouse hearts. Magnetic activated cell sorting (MACS) was employed to acquire highly purified Sca-1+ CSCs. Immunofluorescence staining and Western blotting were performed to examine G-CSFR expression. Cell phenotypic profiles were observed by flow cytometry. Cell proliferation with G-CSF treatment was assessed by carboxyl fluorescein succinimidyl ester (CFSE) proliferation assay and cell cycle analysis. Immunofluorescence staining and Western blotting indicated that G-CSFR was expressed in Sca-1+ CSCs. Exposure of Sca-1+ CSCs to G-CSF existing culture medium for 72 hours induced a cell cycle acceleration with only limited increase in CFSE level and a reduction of CD44 expression that is required for cell-matrix adhesion and cell motility. Conclusions: The results show that G-CSFR is expressed in adult resident Sca-1+ CSCs. G-CSF stimulates CSC proliferation with a restricted ability, which may imply a suggestion to reappraise the clinical settings of G-CSF administration especially for cardiac cell therapy. By means of a combination of G-CSF-pharmacological and CSC-phenotypic investigations, we presume that adult resident Sca-1+ CSCs may play a role during G-CSF-induced cardiac repair