26 research outputs found

    The genomes of two key bumblebee species with primitive eusocial organization

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    Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

    Restoration of mesenchymal retinal pigmented epithelial cells by TGFβ pathway inhibitors: implications for age-related macular degeneration

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    Notch signaling promotes intestinal crypt fission in the infant rat

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    BACKGROUND Growth of the small intestine in the infant rat is promoted by crypt fission and later by increased crypt cell proliferation. Notch signaling could promote crypt fission. Hes-1 is a Notch target gene. AIM We assessed the effect of Notch signaling on intestinal crypt fission and on growth of the intestine in the infant rat. METHODS Hes-1 expression was determined in the small intestine of litters of Hooded Wistar rats aged between 3 and 72 days. Hes-1 RNA expression was measured by quantitative RT-PCR. Four groups of rats (n = 8 or 9) were injected daily, ip, either with vehicle or with the Notch inhibitor DAPT at doses of 3, 10, and 30 mg/kg, from days 9 to 13 of life, and killed on day 14. A microdissection technique was used to measure crypt fission, mitotic count, and apoptotic count. Data were analyzed by ANOVA and by use of Dunnett’s F test. RESULTS Hes-1 expression and crypt fission peaked on day 14. DAPT reduced Hes-1 immunostaining in proportion to dose. DAPT reduced villous area to 72 % (p < 0.01), 53 % (p < 0.001), and 38 % (p < 0.001) of control values for 3, 10 and 30 mg/kg doses, respectively, and reduced crypt fission to 53 % (p < 0.001) and 38 % (p < 0.001) of control values, respectively, for 10 and 30 mg/kg doses. Crypt mitotic count was not affected by any DAPT dose. DAPT at 10 and 30 mg/kg significantly increased apoptosis in crypts, by 6.5 and 4.8-fold, respectively. CONCLUSIONS We conclude that Notch signaling promotes crypt fission and growth of the intestine by maintaining low apoptosis of crypt cells.Adrian G. Cummins, Joshua A. Woenig, Rino P. Donato, Simon J. Proctor, Gordon S. Howarth, Phulwinder K. Grove

    Chemical composition and health benefits of coconut oil: an overview

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    Coconut oil is an integral part of Sri Lankan and many South Asian diets. Initially, coconut oil was classified along with saturated fatty acid food items and criticized for its negative impact on health. However, research studies have shown that coconut oil is a rich source of medium-chain fatty acids. Thus, this has opened new prospects for its use in many fields. Beyond its usage in cooking, coconut oil has attracted attention due to its hypocholesterolemic, anticancer, antihepatosteatotic, antidiabetic, antioxidant, anti-inflammatory, antimicrobial and skin moisturizing properties. Despite all the health benefits, consumption of coconut oil is still underrated due to a lack of supportive scientific evidence. Even though studies done in Asian countries claim a favorable impact on cardiac health and serum lipid profile, the limitations in the number of studies conducted among Western countries impede the endorsement of the real value of coconut oil. Hence, long-term extensive studies with proper methodologies are suggested to clear all the controversies and misconceptions of coconut oil consumption. This review discusses the composition and functional properties of coconut oils extracted using various processing methods
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