| 1. |
- Aydin, Ebru, et al.
(författare)
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A hypomorphic Cbx3 allele causes prenatal growth restriction and perinatal energy homeostasis defects
- 2015
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Ingår i: Journal of Biosciences. - : Springer Science and Business Media LLC. - 0250-5991 .- 0973-7138. ; 40:2, s. 325-338
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Tidskriftsartikel (refereegranskat)abstract
- Mammals have three HP1 protein isotypes HP1 beta (CBX1), HPl gamma (CBX3) and HP1 alpha (CBX5) that are encoded by the corresponding genes Cbx1, Cbx3 and Cbx5. Recent work has shown that reduction of CBX3 protein in homozygotes for a hypomorphic allele (Cbx3(hypo)) causes a severe postnatal mortality with around 99% of the homozygotes dying before weaning. It is not known what the causes of the postnatal mortality are. Here we show that Cbx3(hypo/hypo) conceptuses are significantly reduced in size and the placentas exhibit a haplo-insufficiency. Late gestation Cbx3(hypo/hypo) placentas have reduced mRNA transcripts for genes involved in growth regulation, amino acid and glucose transport. Blood vessels within the Cbx3(hypo/hypo) placental labyrinth are narrower than wild-type. Newborn Cbx3(hypo/hypo) pups are hypoglycemic, the livers are depleted of glycogen reserves and there is almost complete loss of stored lipid in brown adipose tissue (BAT). There is a 10-fold reduction in expression of the BAT-specific Ucp1 gene, whose product is responsible for non-shivering themogenesis. We suggest that it is the small size of the ChX3(hypo/hypo) neonates, a likely consequence of placental growth and transport defects, combined with a possible inability to thermoregulate that causes the severe postnatal mortality.
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| 2. |
- Martin, Francis, et al.
(författare)
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The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis
- 2008
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 452:7183, s. 7-88
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Tidskriftsartikel (refereegranskat)abstract
- Mycorrhizal symbioses -- the union of roots and soil fungi -- are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants1,2. Boreal, temperate, and montane forests all depend upon ectomycorrhizae1. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of 2 ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here, we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-million-base genome assembly contains ~ 20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features most notably a battery of effector-type small secreted proteins (SSP) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific proteins likely play a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell walls, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus which enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem in order to perform vital functions in the carbon and nitrogen cycles that are fundamental to sustainable plant productivity.
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| 3. |
- Spada, Cristiano, et al.
(författare)
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Second-generation colon capsule endoscopy compared with colonoscopy
- 2011
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Ingår i: Gastrointestinal Endoscopy. - : Elsevier BV. - 1097-6779 .- 0016-5107. ; 74:3, s. 581-589
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Tidskriftsartikel (refereegranskat)abstract
- Background: Colon capsule endoscopy (CCE) represents a noninvasive technology that allows visualization of the colon without requiring sedation and air insufflation. A second-generation colon capsule endoscopy system (PillCam Colon 2) (CCE-2) was developed to increase sensitivity for colorectal polyp detection compared with the first-generation system. Objective: To assess the feasibility, accuracy, and safety of CCE-2 in a head-to-head comparison with colonoscopy. Design and Setting: Prospective, multicenter trial including 8 European sites. Patients: This study involved 117 patients (mean age 60 years). Data from 109 patients were analyzed. Intervention: CCE-2 was prospectively compared with conventional colonoscopy as the criterion standard for the detection of colorectal polyps that are >= 6 mm or masses in a cohort of patients at average or increased risk of colorectal neoplasia. Colonoscopy was independently performed within 10 hours after capsule ingestion or on the next day. Main Outcome Measurements: CCE-2 sensitivity and specificity for detecting patients with polyps >= 6 mm and >= 10 mm were assessed. Capsule-positive but colonoscopy-negative cases were counted as false positive. Capsule excretion rate, level of bowel preparation, and rate of adverse events also were assessed. Results: Per-patient CCE-2 sensitivity for polyps >= 6 mm and >= 10 mm was 84% and 88%, with specificities of 64% and 95%, respectively. All 3 invasive carcinomas were detected by CCE-2. The capsule excretion rate was 88% within 10 hours. Overall colon cleanliness for CCE-2 was adequate in 81% of patients. Limitations: Not unblinding the CCE-2 results at colonoscopy; heterogenous patient population; nonconsecutive patients. Conclusion: In this European, multicenter study, CCE-2 appeared to have a high sensitivity for the detection of clinically relevant polypoicl lesions, and it might be considered an adequate tool for colorectal imaging. (Gastrointest Enclose 201174:581-9.)
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