| 1. |
- Lind, Martin I., Dr, et al.
(författare)
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Experimentally reduced insulin/IGF‐1 signaling in adulthood extends lifespan of parents and improves Darwinian fitness of their offspring
- 2019
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Ingår i: Evolution Letters. - : Oxford University Press (OUP). - 2056-3744. ; 3:2, s. 207-216
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Tidskriftsartikel (refereegranskat)abstract
- Classical theory maintains that ageing evolves via energy trade-offs between reproduction and survival leading to accumulation of unrepaired cellular damage with age. In contrast, the emerging new theory postulates that ageing evolves because of deleterious late-life hyper-function of reproduction-promoting genes leading to excessive biosynthesis in late-life. The hyper-function theory uniquely predicts that optimizing nutrient-sensing molecular signaling in adulthood can simultaneously postpone ageing and increase Darwinian fitness. Here, we show that reducing evolutionarily conserved insulin/IGF-1 nutrient-sensing signaling via daf-2 RNA interference (RNAi) fulfils this prediction in Caenorhabditis elegans nematodes. Long-lived daf-2 RNAi parents showed normal fecundity as self-fertilizing hermaphrodites and improved late-life reproduction when mated to males. Remarkably, the offspring of daf-2 RNAi parents had higher Darwinian fitness across three different genotypes. Thus, reduced nutrient-sensing signaling in adulthood improves both parental longevity and offspring fitness supporting the emerging view that suboptimal gene expression in late-life lies at the heart of ageing.
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| 2. |
- Lind, Martin I., et al.
(författare)
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The alignment between phenotypic plasticity, the major axis of genetic variation and the response to selection
- 2015
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 282:1816
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Tidskriftsartikel (refereegranskat)abstract
- Phenotypic plasticity is the ability of a genotype to produce more than one phenotype in order to match the environment. Recent theory proposes that the major axis of genetic variation in a phenotypically plastic population can align with the direction of selection. Therefore, theory predicts that plasticity directly aids adaptation by increasing genetic variation in the direction favoured by selection and reflected in plasticity. We evaluated this theory in the freshwater crustacean Daphnia pulex, facing predation risk from two contrasting size-selective predators. We estimated plasticity in several life-history traits, the G matrix of these traits, the selection gradients on reproduction and survival, and the predicted responses to selection. Using these data, we tested whether the genetic lines of least resistance and the predicted response to selection aligned with plasticity. We found predator environment-specific G matrices, but shared genetic architecture across environments resulted in more constraint in the G matrix than in the plasticity of the traits, sometimes preventing alignment of the two. However, as the importance of survival selection increased, the difference between environments in their predicted response to selection increased and resulted in closer alignment between the plasticity and the predicted selection response. Therefore, plasticity may indeed aid adaptation to new environments.
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| 3. |
- Buza-Vidas, Natalija, et al.
(författare)
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Cytokines regulate postnatal hematopoietic stem cell expansion : Opposing roles of thrombopoietin and LNK
- 2006
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Ingår i: Genes & Development. - Woodbury, NY, USA : Cold Spring Harbor Laboratory Press (CSHL). - 0890-9369 .- 1549-5477. ; 20:15, s. 2018-2023
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Tidskriftsartikel (refereegranskat)abstract
- The role of cytokines as regulators of hematopoietic stem cell (HSC) expansion remains elusive. Herein, we identify thrombopoietin (THPO) and the cytokine signaling inhibitor LNK, as opposing physiological regulators of HSC expansion. Lnk(-/-) HSCs continue to expand postnatally, up to 24-fold above normal by 6 mo of age. Within the stem cell compartment, this expansion is highly selective for self-renewing long-term HSCs (LT-HSCs), which show enhanced THPO responsiveness. Lnk(-/-) HSC expansion is dependent on THPO, and 12-wk-old Lnk(-/-)Thpo(-/-) mice have 65-fold fewer LT-HSCs than Lnk(-/-) mice. Expansions of multiple myeloid, but not lymphoid, progenitors in Lnk(-/-) mice also proved THPO-dependent.
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| 4. |
- Figueroa-Martinez, Francisco, et al.
(författare)
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Reconstructing the mitochondrial protein import machinery of Chlamydomonas reinhardtii
- 2008
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Ingår i: Genetics. - Austin, Tex. : The Genetics Society. - 0016-6731 .- 1943-2631. ; 179:1, s. 149-155
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Tidskriftsartikel (refereegranskat)abstract
- In Chlamydomonas reinhardtii several nucleus-encoded proteins that participate in the mitochondrial oxidative phosphorylation are targeted to the organelle by unusually long mitochondrial targeting sequences. Here, we explored the components of the mitochondrial import machinery of the green alga. We mined the algal genome, searching for yeast and plant homologs, and reconstructed the mitochondrial import machinery. All the main translocation components were identified in Chlamydomonas as well as in Arabidopsis thaliana and in the recently sequenced moss Physcomitrella patens. Some of these components appear to be duplicated, as is the case of Tim22. In contrast, several yeast components that have relatively large hydrophilic regions exposed to the cytosol or to the intermembrane space seem to be absent in land plants and green algae. If present at all, these components of plants and algae may differ significantly from their yeast counterparts. We propose that long mitochondrial targeting sequences in some Chlamydomonas mitochondrial protein precursors are involved in preventing the aggregation of the hydrophobic proteins they carry.
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| 5. |
- Gaskell, George, et al.
(författare)
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Europeans and biotechnology in 2002 - Eurobarometer 58.0 : A report to the EC Directorate General for Research from the project "Life Sciences in European Society"
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This is the fifth in a series of Eurobarometer surveys on biotechnology and the life sciences. The surveys have been conducted in 1991, 1993, 1996, 1999 and in 2002. The survey is based on a representative sample of 16 500 respondents, approximately 1 000 in each EU member state (see report for exceptions). Survey design and analysis was conducted by an international research group ‘Life Sciences in European Society’ supported by DG Research. In a year when many European countries are involved in public discussions on aspects of biotechnology, this survey stands as a contribution to the informed debate.
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| 6. |
- Hviid Nielsen, Torben, et al.
(författare)
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Traditional blue and modern green resistance
- 2002. - 1
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Ingår i: Biotechnology. - Cambridge : Cambridge University Press. - 052177439X - 0521773172 ; , s. 179-202
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Johannesson, Martina, et al.
(författare)
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Identification of epistasis through a partial advanced intercross reveals three arthritis loci within the Cia5 QTL in mice
- 2005
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Ingår i: Genes and Immunity. - : Springer Science and Business Media LLC. - 1466-4879 .- 1476-5470. ; 6:3, s. 175-185
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Tidskriftsartikel (refereegranskat)abstract
- Identification of genes controlling complex diseases has proven to be difficult; however, animal models may pave the way to determine how low penetrant genes interact to promote disease development. We have dissected the Cia5/Eae3 susceptibility locus on mouse chromosome 3 previously identified to control disease in experimental models of multiple sclerosis and rheumatoid arthritis. Congenic strains showed significant but small effects on severity of both diseases. To improve the penetrance, we have now used a new strategy that defines the genetic interactions. The QTL interacted with another locus on chromosome 15 and a partial advanced intercross breeding of the two congenic strains for eight generations accumulated enough statistical power to identify interactions with several loci on chromosome 15. Thereby, three separate loci within the original QTL could be identified; Cia5 affected the onset of arthritis by an additive interaction with Cia31 on chromosome 15, whereas the Cia21 and Cia22 affected severity during the chronic phase of the disease through an epistatic interaction with Cia32 on chromosome 15. The definition of genetic interactions was a prerequisite to dissect the Cia5 QTL and we suggest the partial advanced intercross strategy to be helpful also for dissecting other QTL controlling complex phenotypes.
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| 8. |
- Kohli, Manpreet K, et al.
(författare)
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Extremely low genetic diversity in a circumpolar dragonfly species, Somatochlora sahlbergi (Insecta: Odonata: Anisoptera)
- 2018
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Ingår i: Scientific Reports. - London : Nature Publishing Group. - 2045-2322. ; 8, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- We present the first empirical treatment of the northernmost breeding dragonfly, Somatochlora sahlbergi. We sequenced populations from United States, Canada, Finland, Sweden and Norway for cytochrome oxidase I (COI) and D2 region of 28s. We found that, despite geographic barriers across its vast arctic range, S. sahlbergi is a single species. Not only does it appear to interbreed across its entire range, there also seems to be almost no variation among European and North American populations in their COI gene fragment (the barcode gene), which is usually extremely variable. We further found that characters thought to be diagnostic for the larvae of S. sahlbergi were absent in our European samples. We review and re-describe the habitat of this species based on new findings from recent field observations. Finally, we report for the first time the likely presence of this species in Japan. We hope our findings will encourage further study of this species and other under-studied insect taxa that inhabit the remote Arctic.
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| 9. |
- Lemcke, S., et al.
(författare)
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Nerve conduction velocity is regulated by the inositol polyphosphate-4-phosphatase II gene
- 2014
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Ingår i: American Journal of Pathology. - : Elsevier BV. - 0002-9440 .- 1525-2191. ; 184:9, s. 2420-2429
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Tidskriftsartikel (refereegranskat)abstract
- Impairment of nerve conduction is common in neurodegenerative and neuroinflammatory diseases such as multiple sclerosis (MS), and measurement of evoked potentials (visual, motor, or sensory) has been widely used for diagnosis and recently also as a prognostic marker for MS. We used a classical genetic approach to identify novel genes controlling nerve conduction. First, we used quantitative trait mapping in F2 progeny of B10/SJL mice to identify EAE31, a locus controlling latency of motor evoked potentials (MEPs) and clinical onset of experimental autoimmune encephalomyelitis. Then, by combining congenic mapping, in silico haplotype analyses, and comparative genomics we identified inositol polyphosphate-4-phosphatase, type II (Inpp4b) as the quantitative trait gene for EAE31. Sequence variants of Inpp4b (C/A, exon 13; A/C, exon 14) were identified as differing among multiple mouse strains and correlated with individual cortical MEP latency differences. To evaluate the functional relevance of the amino acid exchanges at positions S474R and H548P, we generated transgenic mice carrying the longer-latency allele (Inpp4b(474R/548P)) in the C57BL/6J background. Inpp4b(474R/548P) mice exhibited significantly longer cortical MEP latencies (4.5 +/- 0.22 ms versus 3.7 +/- 0.13 ms; P = 1.04 x 10(-9)), indicating that INPP4B regulates nerve conduction velocity. An association of an INPP4B polymorphism (rs13102150) with MS was observed in German and Spanish MS cohorts (3676 controls and 911 cases) (P = 8.8 x 10(-3)).
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| 10. |
- Wagner, Wolfgang, et al.
(författare)
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Pandora's genes — images of genes and nature
- 2002. - 1
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Ingår i: Biotechnology. - Cambridge : Cambridge University Press. - 052177439X ; , s. 244-278
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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