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- Nakajima, Yoko, et al.
(författare)
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Altered Pre-mRNA Splicing Caused by a Novel Intronic Mutation c.1443+5G>A in the Dihydropyrimidinase (DPYS) Gene.
- 2016
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Dihydropyrimidinase (DHP) deficiency is an autosomal recessive disease caused by mutations in the DPYS gene. Patients present with highly elevated levels of dihydrouracil and dihydrothymine in their urine, blood and cerebrospinal fluid. The analysis of the effect of mutations in DPYS on pre-mRNA splicing is hampered by the fact that DHP is primarily expressed in liver and kidney cells. The minigene approach can detect mRNA splicing aberrations using cells that do not express the endogenous mRNA. We have used a minigene-based approach to analyze the effects of a presumptive pre-mRNA splicing mutation in two newly identified Chinese pediatric patients with DHP deficiency. Mutation analysis of DPYS showed that both patients were compound heterozygous for a novel intronic mutation c.1443+5G>A in intron 8 and a previously described missense mutation c.1001A>G (p.Q334R) in exon 6. Wild-type and the mutated minigene constructs, containing exons 7, 8 and 9 of DPYS, yielded different splicing products after expression in HEK293 cells. The c.1443+5G>A mutation resulted in altered pre-mRNA splicing of the DPYS minigene construct with full skipping of exon 8. Analysis of the DHP crystal structure showed that the deletion of exon 8 severely affects folding, stability and homooligomerization of the enzyme as well as disruption of the catalytic site. Thus, the analysis suggests that the c.1443+5G>A mutation results in aberrant splicing of the pre-mRNA encoding DHP, underlying the DHP deficiency in two unrelated Chinese patients.
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| 2. |
- Walck, Jeffery L., et al.
(författare)
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Seed germination and seedling development ecology in world-wide populations of a circumboreal Tertiary relict
- 2012
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Ingår i: AoB Plants. - : Oxford University Press. - 2041-2851. ; , s. pls007-
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims Temperate forests are disjunct in the Northern Hemisphere, having become fragmented from the earlier widespread (Tertiary) boreotropical forest. We asked ‘What are the contemporary patterns of population variation in ecological traits of a Tertiary relict in a macroecological context?’. This issue underpins our understanding of variation in populations occurring in the same biome but on different continents.Methodology We examined characters associated with root and shoot emergences among populations of Viburnum opulus in temperate forests of Asia, North America and Europe. This species has complex seedling emergence extending over several years and requiring various temperature cues.Principal results Populations varied in germination responses and clustered into groups that were only partly related to varietal status. Whereas roots (at warm temperatures) and shoots (following a cold period) simultaneously emerged from seeds of all populations when simulated dispersal occurred in winter, they were delayed in some populations when dispersal occurred in summer.Conclusions Viburnum opulus populations, some separated by 10 300 km, showed high similarity in seedling development and in germination phenology, and we suggest that stabilizing selection has played a key role in maintaining similar dormancy mechanisms. Nevertheless, there was some degree of variation in other germination characters, suggesting local adaptation.
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