Many animals exhibit different behaviors in different seasons. The photoperiod can have effects on migration, breeding, fur growth, and other processes. The cyclic growth of the fur and feathers of some species of mammals and birds, respectively, is stimulated by the photoperiod as a result of hormone-dependent regulation of the nervous system. To further examine this phenomenon, we evaluated the Arbas Cashmere goat (Capra hircus), a species that is often used in this type of research. The goats were exposed to an experimentally controlled short photoperiod to study the regulation of cyclic cashmere growth. Exposure to a short photoperiod extended the anagen phase of the Cashmere goat hair follicle to increase cashmere production. Assessments of tissue sections indicated that the short photoperiod significantly induced cashmere growth. This conclusion was supported by a comparison of the differences in gene expression between the short photoperiod and natural conditions using gene chip technology. Using the gene chip data, we identified genes that showed altered expression under the short photoperiod compared to natural conditions, and these genes were found to be involved in the biological processes of hair follicle growth, structural composition of the hair follicle, and the morphogenesis of the surrounding skin appendages. Knowledge about differences in the expression of these genes as well as their functions and periodic regulation patterns increases our understanding of Cashmere goat hair follicle growth. This study also provides preliminary data that may be useful for the development of an artificial method to improve cashmere production by controlling the light cycle, which has practical significance for livestock breeding. 相似文献
Bacteria closely related to Bacillus pumilus cannot be distinguished from such other species as B. safensis, B. stratosphericus, B. altitudinis and B. aerophilus simply by 16S rRNA gene sequence. In this report, 76 marine strains were subjected to phylogenetic analysis based on 7 housekeeping genes to understand the phylogeny and biogeography in comparison with other origins. A phylogenetic tree based on the 7 housekeeping genes concatenated in the order of gyrB-rpoB-pycA-pyrE-mutL-aroE-trpB was constructed and compared with trees based on the single genes. All these trees exhibited a similar topology structure with small variations. Our 79 strains were divided into 6 groups from A to F; Group A was the largest and contained 49 strains close to B. altitudinis. Additional two large groups were presented by B. safensis and B. pumilus respectively. Among the housekeeping genes, gyrB and pyrE showed comparatively better resolution power and may serve as molecular markers to distinguish these closely related strains. Furthermore, a recombinant phylogenetic tree based on the gyrB gene and containing 73 terrestrial and our isolates was constructed to detect the relationship between marine and other sources. The tree clearly showed that the bacteria of marine origin were clustered together in all the large groups. In contrast, the cluster belonging to B. safensis was mainly composed of bacteria of terrestrial origin. Interestingly, nearly all the marine isolates were at the top of the tree, indicating the possibility of the recent divergence of this bacterial group in marine environments. We conclude that B. altitudinis bacteria are the most widely spread of the B. pumilus group in marine environments. In summary, this report provides the first evidence regarding the systematic evolution of this bacterial group, and knowledge of their phylogenetic diversity will help in the understanding of their ecological role and distribution in marine environments. 相似文献
Classical major histocompatibility complex (MHC) class I, first identified in the immune system, is also expressed in the developing and adult central nervous system (CNS). Although the MHC class I molecules have been found to be expressed in the CNS of different species, a necessary step to elucidate the temporal and spatial expression patterns of MHC class I molecules in the brain development has never been taken. Frozen sections were made from the brains of embryonic and postnatal C57BL/6 J mice, and the expression of H-2Db mRNA was examined by in situ hybridization. Immunofluorescence was also performed to define the cell types that express H2-Db in P15 mice. At E10.5, the earliest stage we examined, H2-Db was expressed in neuroepithelium of the brain vesicles. From E12.5 to P0, H2-Db expression was mainly located at cerebral cortex, neuroepithelium of the lateral ventricle, neuroepithelium of aquaeductus and developing cerebellum. From P4 to adult, H2-Db mRNA was detected at olfactory bulb, hippocampus, cerebellum and some nerve nuclei. The major cell types expressing H-2Db in P15 hippocampus, cerebral cortex and olfactory bulb were neuron. H2-Kb signal paralleled that of H2-Db and the expression levels of the two molecules were comparable throughout the brain. The investigation of the expression pattern of H-2Db at both embryonic and postnatal stages is important for further understanding the physiological and pathological roles of H2-Db in the developing CNS. 相似文献
This study reveals the microbial community succession and diversity during the whole solid-fermentation processes of naturally fermented Liangzhou fumigated vinegar (LZFV). Dynamics and diversity of microbial community succession in “Daqu” starter and other fermentation stages (starch saccharification, alcoholic fermentation, and acetic acid fermentation) were monitored using a metagenomic approach involving high-throughput sequencing. Meanwhile, dynamic changes of characteristic flavor compounds of vinegar were determined by gas chromatograph (GC) analysis. The result showed that the microbiota composition exhibited rich diversity. Twenty-five bacterial and 18 fungal genera were found in the whole fermentation process where Lactobacillus, Acetobacter, Aspergillus, Saccharomyces, and Alternaria were the predominant microorganisms. Alpha diversity metrics showed that bacterial diversity in Daqu was greater than that in AF and AAF. By contrast, fungal diversity increased from Daqu to AF and decreased in the initial stage (5–8 days) of AAF then remained relatively steady. Hence, these results could help understand dynamics of microbial community succession in continuous fermentation of traditional Chinese vinegars. The LZFV fermentation is a continuous process with spontaneous growth that affects the dynamics of microbial communities. Continuous changes of micro-environment conditions in substrate affect the diversity and structure of microbiota. Microbial growth and metabolism were closely related to the changes in the physicochemical characteristics of the cultures. The microbial flora composition showed rich diversity, and with the increase in brewing time and the change in micro-ecological environmental conditions; the microbial community showed a complex dynamic changes.
Anthropogenic environments such as those created by intensive farming of livestock, have been proposed to provide ideal selection pressure for the emergence of antimicrobial-resistant Escherichia coli bacteria and antimicrobial resistance genes (ARGs) and spread to humans. Here, we performed a longitudinal study in a large-scale commercial poultry farm in China, collecting E. coli isolates from both farm and slaughterhouse; targeting animals, carcasses, workers and their households and environment. By using whole-genome phylogenetic analysis and network analysis based on single nucleotide polymorphisms (SNPs), we found highly interrelated non-pathogenic and pathogenic E. coli strains with phylogenetic intermixing, and a high prevalence of shared multidrug resistance profiles amongst livestock, human and environment. Through an original data processing pipeline which combines omics, machine learning, gene sharing network and mobile genetic elements analysis, we investigated the resistance to 26 different antimicrobials and identified 361 genes associated to antimicrobial resistance (AMR) phenotypes; 58 of these were known AMR-associated genes and 35 were associated to multidrug resistance. We uncovered an extensive network of genes, correlated to AMR phenotypes, shared among livestock, humans, farm and slaughterhouse environments. We also found several human, livestock and environmental isolates sharing closely related mobile genetic elements carrying ARGs across host species and environments. In a scenario where no consensus exists on how antibiotic use in the livestock may affect antibiotic resistance in the human population, our findings provide novel insights into the broader epidemiology of antimicrobial resistance in livestock farming. Moreover, our original data analysis method has the potential to uncover AMR transmission pathways when applied to the study of other pathogens active in other anthropogenic environments characterised by complex interconnections between host species. 相似文献
More than 170 million individuals worldwide are infected with hepatitis C virus (HCV), and up to an estimated 30% of chronically infected individuals will go on to develop progressive liver disease. Despite the recent advances in antiviral treatment of HCV infection, it remains a major public health problem. Thus, development of an effective vaccine is urgently required. In this study, we constructed novel adeno-associated virus (AAV) vectors expressing the full-length NS3 or NS3/4 protein of HCV genotype 1b. The expression of the NS3 or NS3/4 protein in HepG2 cells was confirmed by western blotting. C57BL/6 mice were intramuscularly immunised with a single injection of AAV vectors, and the resultant immune response was investigated. The AAV2/rh32.33.NS3/4 vaccine induced stronger humoral and cellular responses than did the AAV2/rh32.33.NS3 vaccine. Our results demonstrate that AAV-based vaccines exhibit considerable potential for the development of an effective anti-HCV vaccine. 相似文献
A taxonomic study was carried out on strain 22II-S11-z10T, which was isolated from the surface seawater of the Atlantic Ocean. The bacterium was found to be Gram-stain negative, oxidase and catalase positive, oval- to rod-shaped and non-motile. Growth was observed at salinities of 0.5–9 % and at temperatures of 10–41 °C. The isolate can reduce nitrate to nitrite, degrade gelatin and aesculin, but can not degrade Tween 80. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 22II-S11-z10T belongs to the genus Actibacterium, with the highest sequence similarity to the type strain Actibacterium mucosum CECT 7668T (97.3 %). The DNA–DNA hybridization estimate value between strain 22II-S11-z10T and A. mucosum CECT 7668T was 19.30 ± 2.29 %. The principal fatty acids were identified as Summed Feature 8 (C18:1ω7c/ω6c as defined by the MIDI system, 75.2 %) and Summed Feature 3 (C16:1ω7c/ω6c, 6.9 %). The G+C content of the chromosomal DNA was determined to be 59.0 mol%. The respiratory quinone was determined to be Q-10 (100 %). Phosphatidylglycerol, phosphatidylcholine, two phospholipids, two aminolipids and two lipids were identified in the polar lipids. The combined genotypic and phenotypic data show that strain 22II-S11-z10T represents a novel species within the genus Actibacterium, for which the name Actibacterium atlanticum sp. nov. is proposed, with the type strain 22II-S11-z10T (=MCCC 1A09298T = LMG 27158T). 相似文献
The anti-yeast activities of a food-grade dilution-stable microemulsion against Candida albicans and Saccharomyces cerevisiae have been studied. The weight ratio of the formulated microemulsion is glycerol monolaurate (GML)/propionic acid/Tween 80/sodium
benzoate (SB)/water = 3:9:14:14:24. Results of anti-yeast activity on solid medium by agar diffusion method showed that the
anti-yeast activity of the microemulsion at 4.8 mg/ml was comparable to that of natamycin at 0.1 mg/ml as positive control.
Results of anti-yeast activity in liquid medium by broth dilution method showed that the growth of both C. albicans and S. cerevisiae was completely inhibited when the liquid medium containing 106 cfu/ml was treated with 1.2 mg/ml microemulsion, which was determined as minimum fungicidal concentration. The kinetics of
killing results showed that the microemulsion killed over 90% yeast cells rapidly within 15 min and caused a complete loss
of viability in 120 min. Among the components, SB and GML had a similar anti-yeast activity, followed by propionic acid, while
Tween 80 exhibited no activity and could not enhance the anti-yeast activities of these components, and it was revealed that
the anti-yeast activity of the microemulsion was attributed to a combination of propionic acid, GML, and SB. The anti-yeast
activity of the microemulsion was in good agreement with the leakage of 260-nm absorbing materials and the observation of
transmission electron microscopy, indicating that the microemulsion induced the disruption and dysfunction of the cell membrane. 相似文献