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1.
Virginia Edgcomb William Orsi John Bunge Sunok Jeon Richard Christen Chesley Leslin Mark Holder Gordon T Taylor Paula Suarez Ramon Varela Slava Epstein 《The ISME journal》2011,5(8):1344-1356
Microbial diversity and distribution are topics of intensive research. In two companion papers in this issue, we describe the results of the Cariaco Microbial Observatory (Caribbean Sea, Venezuela). The Basin contains the largest body of marine anoxic water, and presents an opportunity to study protistan communities across biogeochemical gradients. In the first paper, we survey 18S ribosomal RNA (rRNA) gene sequence diversity using both Sanger- and pyrosequencing-based approaches, employing multiple PCR primers, and state-of-the-art statistical analyses to estimate microbial richness missed by the survey. Sampling the Basin at three stations, in two seasons, and at four depths with distinct biogeochemical regimes, we obtained the largest, and arguably the least biased collection of over 6000 nearly full-length protistan rRNA gene sequences from a given oceanographic regime to date, and over 80 000 pyrosequencing tags. These represent all major and many minor protistan taxa, at frequencies globally similar between the two sequence collections. This large data set provided, via the recently developed parametric modeling, the first statistically sound prediction of the total size of protistan richness in a large and varied environment, such as the Cariaco Basin: over 36 000 species, defined as almost full-length 18S rRNA gene sequence clusters sharing over 99% sequence homology. This richness is a small fraction of the grand total of known protists (over 100 000–500 000 species), suggesting a degree of protistan endemism. 相似文献
2.
Dongliang Liu Jun Liu Weilan Wang Lijie Xia Jianhua Yang Surong Sun Fuchun Zhang 《Food biophysics》2016,11(4):319-331
Cecropin XJ, as a heat stable antimicrobial peptide (AMP), displayed broad bacteriostatic activities, effectively inhibited proliferation of cancer cells and induced cell apoptosis in vitro. However, it exhibited little hemolytic activity and very low cytotoxicity to erythrocytes and normal cells. Although exerts multiple remarkable bioactivities, the refined molecular conformation of native Cecropin XJ remains unsolved. The aim of the present study is to comprehensively investigate the physicochemical characteristics and structure-function relationship of this antimicrobial peptide by using a series of bioinformatics and experimental approaches. In this study, we revealed that the mature Cecropin XJ consists of 41 amino acids, containing two α-helical structures from Lys7 to Lys25 and from Ala29 to Ile39. The phylogenetic tree indicated that Cecropin XJ belongs to the Class I AMPs of cecropin family. Hydrophobic analysis showed Cecropin XJ is a typical amphiphilic molecule. The surface of Cecropin XJ was found to have a much wide range of electrostatic potential from ?83.243 to +83.243. The amphipathicity and surface potential of Cecropin XJ partially supported the AMP pore-forming hypothesis. Scanning electron microscopy experimentally confirmed the damages of Cecropin XJ to microbial membrane. Four predicted docking sites respectively for magnesium ion (Mg2+), adenosine diphosphate (ADP), bacteriopheophytin (BPH), and guanosine triphosphate (GTP) were found on the surface of Cecropin XJ. Thereinto, Mg2+ was experimentally proved to suppress the antibacterial activity of Cecropin XJ; both GTP and ADP enhanced the bactericidal activities to varying degrees. The present study provides a foundation for further investigation of molecular evolution, structural modification, and functional mechanisms of Cecropin XJ. 相似文献
3.
Effect of fertilizers on Cd accumulation and subcellular distribution of two cosmos species (Cosmos sulphureus and Cosmos bipinnata) 总被引:1,自引:0,他引:1
Addition of fertilizer amendments is regarded as an ideal approach to enhancing phytoextraction. However, there is little information available on the influence of common fertilizers on Cd accumulation of two newly reported Cd accumulators, Cosmos sulphureus and Cosmos bipinnata (C. sulphureus and C. bipinnata). The effects of N (CO(NH2)2), NP (CO(NH2)2 + Ca(H2PO4)2), and NPK (CO(NH2)2 + Ca(H2PO4)2 + KCl) fertilizers on Cd accumulation and subcellular distribution of C. sulphureus and C. bipinnata were studied in a 70-d pot experiment. The results showed that Cd uptake of C. sulphureus and C. bipinnata with NPK fertilizer was significantly higher than control, N, and NP fertilizers, especially 3.8- and 4.7-fold higher than control (p < 0.05). Compared with C. bipinnata, C. sulphureus achieved higher biomass and Cd uptake in aboveground parts under fertilizer treatments, especially NPK fertilizer. The Cd subcellular distribution revealed that segregation of Cd to Cd-rich granules (MRG) might play an important role in Cd detoxification in both species. C. sulphureus is more likely than C. bipinnata to separate the Cd in MRG and reduce the partition in the heat-denatured protein fraction, especially with NPK fertilizer. Therefore, C. sulphureus combined with NPK fertilizers could be an effective method to remediate Cd-polluted farmland soils in China. 相似文献
4.
1. Larval success was compared when one, two, or three egg clutches were laid in kumquat fruits (≈ 10 ml in volume) either successively on the same day or at the rate of one clutch per day. 2. Increased clutch density was associated with a significant decrease in larval survival rate and non‐significant decreases in larval growth rate and pupal mass. 3. Larval and pupal parameters showed significantly larger variance when clutches were laid on successive days than on the same day, suggesting a competitive advantage for older larvae over younger larvae. 4. The results suggest that, in small fruit, reduced fitness due to larval competition may act against possible fitness benefits due to social facilitation among adult females, hence reducing the likelihood of non‐linear population dynamics caused by processes such as the Allee effect. 相似文献
5.
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
6.
Jun‐juan Wang Qi‐min Zhang Wei‐wei Ni Xin Zhang Ying Li Ai‐li Li Peng Du Chun Li Su‐su Yu 《Microbiology and immunology》2019,63(8):303-315
We investigated the correlation between the beneficial effect of Lactobacillus acidophilus on gut microbiota composition, metabolic activities, and reducing cow's milk protein allergy. Mice sensitized with β‐lactoglobulin (β‐Lg) were treated with different doses of L. acidophilus KLDS 1.0738 for 4 weeks, starting 1 week before allergen induction. The results showed that intake of L. acidophilus significantly suppressed the hypersensitivity responses, together with increased fecal microbiota diversity and short‐chain fatty acids (SCFAs) concentration (including propionate, butyrate, isobutyrate, and isovalerate) when compared with the allergic group. Moreover, treatment with L. acidophilus induced the expression of SCFAs receptors, G‐protein–coupled receptors 41 (GPR41) and 43 (GPR43), in the spleen and colon of the allergic mice. Further analysis revealed that the GPR41 and GPR43 messenger RNA expression both positively correlated with the serum concentrations of transforming growth factor‐β and IFN‐γ (p < .05), but negatively with the serum concentrations of IL‐17, IL‐4, and IL‐6 in the L. acidophilus–treated group compared with the allergic group (p < .05). These results suggested that L. acidophilus protected against the development of allergic inflammation by improving the intestinal flora, as well as upregulating SCFAs and their receptors GPR41/43. 相似文献
7.
Barakaeli Abdieli Ndosi Hansol Park Dongmin Lee Seongjun Choe Yeseul Kang Tilak Chandra Nath Mohammed Mebarek Bia Chatanun Eamudomkarn Hyeong-Kyu Jeon Keeseon S. Eom 《The Korean journal of parasitology》2020,58(6):653
Spirometra tapeworms (Cestoda: Diphyllobothriidae) collected from carnivorous mammals in Tanzania were identified by the DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit 1 (cox1) and internal transcribed spacer 1 (ITS1), and by morphological characteristics. A total of 15 adult worms were collected from stool samples and carcasses of Panthera leo, Panthera pardus, and Crocuta crocuta in the Serengeti and Selous ecosystems of Tanzania. Three Spirometra species: S. theileri, S. ranarum and S. erinaceieuropaei were identified based on morphological features. Partial cox1 sequences (400 bp) of 10 specimens were revealed. Eight specimens showed 99.5% similarity with Spirometra theileri (), 1 specimen showed 99.5% similarity with the Korean S. erinaceieuropaei and 1 specimen had 99.5% similarity with Myanmar S. ranarum. Sequence homology estimates for the ITS1 region of S. theileri were 89.8% with S. erinaceieuropaei, 82.5% with S. decipiens, and 78.3% with S. ranarum; and 94.4% homology was observed between S. decipiens and S. ranarum. Phylogenetic analyses were performed with 4 species of Spirometra and 2 species of Dibothriocephalus (=Diphyllobothrium). By both ML and BI methods, cox1 and ITS1 gave well supported, congruent trees topology of S. erinaceieuropaei and S. theileri with S. decipiens and S. ranarum forming a clade. The Dibothriocephalus species were sisters of each other and collectively forming successive outgroups. Our findings confirmed that 3 Spirometra species (S. theileri, S. ranarum, and S. erinaceieuropaei) are distributed in the Serengeti and Selous ecosystems of Tanzania. MK955901相似文献
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