Combinations of Independent Dominant Loci Conferring Clubroot Resistance in All Four Turnip Accessions (Brassica rapa) From the European Clubroot Differential Set

Clubroot disease is devastating to Brassica crop production when susceptible cultivars are planted in infected fields. European turnips are the most resistant sources and their resistance genes have been introduced into other crops such oilseed rape (Brassica napus L.), Chinese cabbage and other Brassica vegetables. The European clubroot differential (ECD) set contains four turnip accessions (ECD1–4). These ECD turnips exhibited high levels of resistance to clubroot when they were tested under controlled environmental conditions with Canadian field isolates. Gene mapping of the clubroot resistance genes in ECD1–4 were performed and three independent dominant resistance loci were identified. Two resistance loci were mapped on chromosome A03 and the third on chromosome A08. Each ECD turnip accession contained two of these three resistance loci. Some resistance loci were homozygous in ECD accessions while others showed heterozygosity based on the segregation of clubroot resistance in 20 BC1 families derived from ECD1 to 4. Molecular markers were developed linked to each clubroot resistance loci for the resistance gene introgression in different germplasm

Conversion Discriminative Analysis on Mild Cognitive Impairment Using Multiple Cortical Features from MR Images

Neuroimaging measurements derived from magnetic resonance imaging provide important information required for detecting changes related to the progression of mild cognitive impairment (MCI). Cortical features and changes play a crucial role in revealing unique anatomical patterns of brain regions, and further differentiate MCI patients from normal states. Four cortical features, namely, gray matter volume, cortical thickness, surface area, and mean curvature, were explored for discriminative analysis among three groups including the stable MCI (sMCI), the converted MCI (cMCI), and the normal control (NC) groups. In this study, 158 subjects (72 NC, 46 sMCI, and 40 cMCI) were selected from the Alzheimer's Disease Neuroimaging Initiative. A sparse-constrained regression model based on the l2-1-norm was introduced to reduce the feature dimensionality and retrieve essential features for the discrimination of the three groups by using a support vector machine (SVM). An optimized strategy of feature addition based on the weight of each feature was adopted for the SVM classifier in order to achieve the best classification performance. The baseline cortical features combined with the longitudinal measurements for 2 years of follow-up data yielded prominent classification results. In particular, the cortical thickness produced a classification with 98.84% accuracy, 97.5% sensitivity, and 100% specificity for the sMCI–cMCI comparison; 92.37% accuracy, 84.78% sensitivity, and 97.22% specificity for the cMCI–NC comparison; and 93.75% accuracy, 92.5% sensitivity, and 94.44% specificity for the sMCI–NC comparison. The best performances obtained by the SVM classifier using the essential features were 5–40% more than those using all of the retained features. The feasibility of the cortical features for the recognition of anatomical patterns was certified; thus, the proposed method has the potential to improve the clinical diagnosis of sub-types of MCI and predict the risk of its conversion to Alzheimer's disease

Ovarian expression and localization of a low-density lipoprotein receptor related protein 13 (Lrp13) in orange-spotted grouper (Epinephelus coioides)

Low-density lipoprotein receptor (LDLR) superfamily is an ancient gene family composed of different genes encoding membrane receptors involved in ligand binding and endocytosis. These receptors typically consist of class A ligand-binding repeats (LBRs), epidermal growth factor precursor-like (EGF) domain, class b YWXD motifs, transmembrane (TM) domain, and cytoplasmic (CP) domain. Low-density lipoprotein receptor related protein 13 (Lrp13), a vitellogenin receptor with a unique domain structure, belonging to the LDLR superfamily, would play an important role in vitellogenesis in teleosts. In this study, the full-length cDNA of Ec-lrp13 was isolated from the ovary of orange-spotted grouper (Epinephelus coioides), an economically important aquaculture species in China. The open reading frame (ORF) of Ec-lrp13 is 3831 bp in length, encoding 1276 amino acids. The Ec-Lrp13 includes several typical domains of the LDLR superfamily and contains the specific structure of the Lrp13 protein. Ec-lrp13 is predominantly expressed in ovary. During ovarian development, Ec-lrp13 was highly expressed in stage II and III ovaries but its mRNA level was significantly decreased in stage IV ovary. In situ hybridization (ISH) analysis revealed that Ec-lrp13 mRNA signals were obviously observed in the ooplasm of PG and EPV oocytes, but decreased in the LPV oocytes, and weakly found in the VG oocytes. Immunohistochemistry (IHC) detection showed that Ec-Lrp13 protein signals were only observed in the LPV and VG oocytes. Our data provides preliminary evidence that Lrp13 may be involved in the Vtg uptake during ovarian development of orange-spotted grouper

Chromosome-Level Genome Assembly and Transcriptome Comparison Analysis of Cephalopholis sonnerati and Its Related Grouper Species

The tomato hind, Cephalopholis sonnerati, is a bottom-dwelling coral reef fish, which is widely distributed in the Indo-Pacific and Red Sea. C. sonnerati also features complex social structures and behaviour mechanisms. Here, we present a high-quality, chromosome-level genome assembly for C. sonnerati that was derived using PacBio sequencing and Hi-C technologies. A 1043.66 Mb genome with an N50 length of 2.49 Mb was assembled, produced containing 795 contigs assembled into 24 chromosomes. Overall, 97.2% of the complete BUSCOs were identified in the genome. A total of 26,130 protein-coding genes were predicted, of which 94.26% were functionally annotated. Evolutionary analysis revealed that C. sonnerati diverged from its common ancestor with E. lanceolatus and E. akaara approximately 41.7 million years ago. In addition, comparative genome analyses indicated that the expanded gene families were highly enriched in the sensory system. Finally, we found the tissue-specific expression of 8108 genes. We found that these tissue-specific genes were highly enriched in the brain. In brief, the high-quality, chromosome-level reference genome will provide a valuable genome resource for studies of the genetic conservation, resistance breeding, and evolution of C. sonnerati

Molecular cloning, identification, and expression analysis of Pyy and its effect on mechanisms regulating appetite in Spotted scat, Scatophagus argus

The peptide YY (Pyy) is a member of the Neuropeptide Y family of peptides known to play anorexigenic roles in the regulation of feed intake in several fishes. In this study, to examine the role of Pyy in the spotted scat (Scatophagus argus), the peptide was cloned from this fish for the first time. The peptide is made from a 294-bp open reading frame with a 97-amino-acid sequence that is highly conserved when compared to other organisms. The pyy gene is expressed widely throughout the spotted scat, with the highest levels in the intestine and muscle tissue. According to our pre-and post-prandial experiments, feeding has a minimal short-term effect on pyy mRNA levels. In comparison to fish that were refed on the 8th day after 7 days of starvation, pyy mRNA levels in the hypothalamus were considerably higher after 7 days of feeding. Results from this study also identified a local interaction between Pyy and some appetite-regulating peptides in spotted scat. We aimed to build a solid foundation for future research into feed intake regulation of the spotted scat, as this is one of the most cultured species

Microbiota Community Structure and Interaction Networks within <i>Dermacentor silvarum</i>, <i>Ixodes persulcatus</i>, and <i>Haemaphysalis concinna</i>

Ticks carry and transmit a variety of pathogens, which are very harmful to humans and animals. To characterize the microbial interactions in ticks, we analysed the microbiota of the hard ticks, Dermacentor silvarum, Ixodes persulcatus, and Haemaphysalis concinna, using 16S rRNA, showing that microbial interactions are underappreciated in terms of shaping arthropod microbiomes. The results show that the bacterial richness and microbiota structures of these three tick species had significant differences. Interestingly, the bacterial richness (Chao1 index) of all ticks decreased significantly after they became engorged. All the operational taxonomic units (OTUs) were assigned to 26 phyla, 67 classes, 159 orders, 279 families, and 627 genera. Microbial interactions in D. silvarum demonstrated more connections than in I. persulcatus and H. concinna. Bacteria with a high abundance were not important families in microbial interactions. Positive interactions of Bacteroidaceae and F_Solibacteraceae Subgroup 3 with other bacterial families were detected in all nine groups of ticks. This study provides an overview of the microbiota structure and interactions of three tick species and improves our understanding of the role of the microbiota in tick physiology and vector capacity, thus being conducive to providing basic data for the prevention of ticks and tick-borne diseases

Genetic variability within and among Haemonchus contortus isolates from goats and sheep in China

BACKGROUND: Haemonchus contortus (order Strongylida) is a common parasitic nematode infecting small ruminants and causing significant economic losses worldwide. Knowledge of genetic variation within and among H. contortus populations can provide a foundation for understanding transmission patterns, the spread of drug resistance alleles and might assist in the control of haemonchosis. METHODS: 152 H. contortus individual adult worms were collected from seven different geographical regions in China. The second internal transcribed spacer (ITS-2) of the nuclear ribosomal DNA and mitochondrial nicotinamide dehydrogenase subunit 4 gene (nad4) were amplified by polymerase chain reaction (PCR) and sequenced directly. The sequence variations and population genetic diversities were determined. RESULTS: Nucleotide sequence analyses revealed 18 genotypes (ITS-2) and 142 haplotypes (nad4) among the 152 worms, with nucleotide diversities of 2.6% and 0.027, respectively, consistent with previous reports from other countries, including Australia, Brazil, Germany, Italy, Malaysia, Sweden, the USA and Yemen. Population genetic analyses revealed that 92.4% of nucleotide variation was partitioned within populations; there was no genetic differentiation but a high gene flow among Chinese populations; some degree of genetic differentiation was inferred between some specimens from China and those from other countries. CONCLUSIONS: This is the first study of genetic variation within H. contortus in China. The results revealed high within-population variations, low genetic differentiation and high gene flow among different populations of H. contortus in China. The present results could have implications for studying the epidemiology and ecology of H. contortus in China

Controllable synthesis of monodispersed silver nanoparticles as standards for quantitative assessment of their cytotoxicity.

<p id="abspara0010"> Silver nanoparticles (Ag NPs) are appealing due to their excellent antibacterial/antivirus properties. At the meantime, the wide applications of Ag NPs as antibacterial/antivirus agents arise the concern of Ag NPs&rsquo; toxicity. However, quantitative understanding of the cytotoxicity of Ag NPs is minimum since that the Ag NPs in current studies have wide size distributions, in which the size effect of Ag NPs on cytotoxicity was unable to be accurately evaluated. In this work, unprecedentedly monodispersed Ag NPs with sizes of 25, 35, 45, 60 and 70&nbsp;nm were obtained, respectively, by using an optimized polyol method with poly(vinyl pyrrolidone) (PVP) as surfactant. It was found that the reaction temperature, reaction time, concentration of the surfactant and reactants are playing important roles in determining the size and size distribution of Ag NPs. With the monodispersed Ag NPs as standard samples, the size- and dose- dependent cytotoxicity of Ag NPs against Human lung fibroblast (HLF) cells was accurately accomplished in terms of cell viability, apoptosis and necrosis, reactive oxygen species, etc. We expect that the monodispersed Ag NPs will act as the standard samples for quantitatively characterizing the toxicity of Ag NPs <em>in&nbsp;vitro</em> and <em>in&nbsp;vivo</em>.</p

Additional file 1: Figure S1. of Population structure of Haemonchus contortus from seven geographical regions in China, determined on the basis of microsatellite markers

Locations of seven populations of Haemonchus contortus in China. (TIF 2529 kb