| 1. |
- Chen, Wenbo, et al.
(författare)
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The draft genome of whitefly Bemisia tabaci MEAM1, a global crop pest, provides novel insights into virus transmission, host adaptation, and insecticide resistance
- 2016
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Ingår i: BMC Biology. - : Springer Science and Business Media LLC. - 1741-7007. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is among the 100 worst invasive species in the world. As one of the most important crop pests and virus vectors, B. tabaci causes substantial crop losses and poses a serious threat to global food security. Results: We report the 615-Mb high-quality genome sequence of B. tabaci Middle East-Asia Minor 1 (MEAM1), the first genome sequence in the Aleyrodidae family, which contains 15,664 protein-coding genes. The B. tabaci genome is highly divergent from other sequenced hemipteran genomes, sharing no detectable synteny. A number of known detoxification gene families, including cytochrome P450s and UDP-glucuronosyltransferases, are significantly expanded in B. tabaci. Other expanded gene families, including cathepsins, large clusters of tandemly duplicated B. tabaci-specific genes, and phosphatidylethanolamine-binding proteins (PEBPs), were found to be associated with virus acquisition and transmission and/or insecticide resistance, likely contributing to the global invasiveness and efficient virus transmission capacity of B. tabaci. The presence of 142 horizontally transferred genes from bacteria or fungi in the B. tabaci genome, including genes encoding hopanoid/sterol synthesis and xenobiotic detoxification enzymes that are not present in other insects, offers novel insights into the unique biological adaptations of this insect such as polyphagy and insecticide resistance. Interestingly, two adjacent bacterial pantothenate biosynthesis genes, panB and panC, have been co-transferred into B. tabaci and fused into a single gene that has acquired introns during its evolution. Conclusions: The B. tabaci genome contains numerous genetic novelties, including expansions in gene families associated with insecticide resistance, detoxification and virus transmission, as well as numerous horizontally transferred genes from bacteria and fungi. We believe these novelties likely have shaped B. tabaci as a highly invasive polyphagous crop pest and efficient vector of plant viruses. The genome serves as a reference for resolving the B. tabaci cryptic species complex, understanding fundamental biological novelties, and providing valuable genetic information to assist the development of novel strategies for controlling whiteflies and the viruses they transmit.
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| 2. |
- Song, Kai, 1988-, et al.
(författare)
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Demographic history and divergence of sibling grouse species inferred from whole genome sequencing reveal past effects of climate change
- 2021
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Ingår i: BMC Ecology and Evolution. - : BioMed Central (BMC). - 2730-7182. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Background The boreal forest is one of the largest biomes on earth, supporting thousands of species. The global climate fluctuations in the Quaternary, especially the ice ages, had a significant influence on the distribution of boreal forest, as well as the divergence and evolution of species inhabiting this biome. To understand the possible effects of on-going and future climate change it would be useful to reconstruct past population size changes and relate such to climatic events in the past. We sequenced the genomes of 32 individuals from two forest inhabiting bird species, Hazel Grouse (Tetrastes bonasia) and Chinese Grouse (T. sewerzowi) and three representatives of two outgroup species from Europe and China. Results We estimated the divergence time of Chinese Grouse and Hazel Grouse to 1.76 (0.46-3.37) MYA. The demographic history of different populations in these two sibling species was reconstructed, and showed that peaks and bottlenecks of effective population size occurred at different times for the two species. The northern Qilian population of Chinese Grouse became separated from the rest of the species residing in the south approximately 250,000 years ago and have since then showed consistently lower effective population size than the southern population. The Chinese Hazel Grouse population had a higher effective population size at the peak of the Last Glacial Period (approx. 300,000 years ago) than the European population. Both species have decreased recently and now have low effective population sizes. Conclusions Combined with the uplift history and reconstructed climate change during the Quaternary, our results support that cold-adapted grouse species diverged in response to changes in the distribution of palaeo-boreal forest and the formation of the Loess Plateau. The combined effects of climate change and an increased human pressure impose major threats to the survival and conservation of both species.
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| 3. |
- Song, Kai, 1988-, et al.
(författare)
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Genetic differentiation in Sichuan jay (Perisoreus internigrans) and itssibling species Siberian jay (P. infaustus)
- 2020
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Ingår i: Conservation Genetics. - : Springer Nature. - 1566-0621 .- 1572-9737. ; 21:2, s. 319-327
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Tidskriftsartikel (refereegranskat)abstract
- The Pleistocene ice age and recent forest fragmentation have both played a significant role in shaping the population geneticvariation of boreal coniferous species in the Qinghai-Tibet Plateau (QTP) and Eurasian coniferous forests. The Sichuan jay isone of the least know endemic bird species in QTP coniferous forests in western China while its sibling species, the SiberianJay, is widespread within the coniferous forests in northern Eurasia. Here we used 11 microsatellite markers to assay geneticdiversity across 58 Sichuan jay samples from China and 205 Siberian jay samples from Sweden and Russia. Results showedthree distinct genetic clusters from the Sichuan jay sampling. Furthermore, the pair-wise FST values indicated high geneticdifferentiation not only among the two species but also between Swedish and Russian Siberian jay populations. What ismore, a pattern of isolation by distance was found among the analyzed populations. Our study suggests that targeted
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| 4. |
- Sun, Chengtao, et al.
(författare)
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Novel Insight into Utilization of Flavonoid Glycosides and Biological Properties of Saffron (Crocus sativus L.) Flower Byproducts
- 2020
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Ingår i: Journal of Agricultural and Food Chemistry. - : AMER CHEMICAL SOC. - 0021-8561 .- 1520-5118. ; 68:39, s. 10685-10696
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Tidskriftsartikel (refereegranskat)abstract
- Saffron (Crocus sativus L.) byproducts are considered as a cheap source of bioactive polyphenolics endowed with potential antioxidant effects. The saffron biowaste is utilized for extraction of flavonoid glycosides and their potential biological properties. The total amount of polyphenolics and polysaccharides was found to be higher in the tepal than in the stamen. The bioactive compounds quercetin-3-O-sophoroside (Q-3-sop) and kaempferol-3-O-sophoroside (K-3-sop) were analyzed using high-performance liquid chromatography equipped with a photodiode array detector (HPLC-PDA) and identified by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR). The antioxidant effects were studied using 2,2 diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), ferric ion reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC); Q-3-sop showed stronger antioxidant effects compared to K-3-sop, crocin-I, and crocin-II. Furthermore, Q-3-sop also inhibited cell apoptosis caused by H2O2 by reducing the levels of cellular reactive oxygen species (ROS). In terms of cytogenetic effects, Q-3-sop revealed no cytogenic effects on onion root meristem cells but chromosomal aberration was observed at the highest dose (200 ppm). Thus, saffron byproducts and its flavonoids could be utilized as natural antioxidant agents with no cytogenetic effects.
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