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排序方式: 共有288条查询结果,搜索用时 31 毫秒
271.
Cossette P Liu L Brisebois K Dong H Lortie A Vanasse M Saint-Hilaire JM Carmant L Verner A Lu WY Wang YT Rouleau GA 《Nature genetics》2002,31(2):184-189
Although many genes that predispose for epilepsy in humans have been determined, those that underlie the classical syndromes of idiopathic generalized epilepsy (IGE) have yet to be identified. We report that an Ala322Asp mutation in GABRA1, encoding the alpha1 subunit of the gamma-aminobutyric acid receptor subtype A (GABA(A)), is found in affected individuals of a large French Canadian family with juvenile myoclonic epilepsy. Compared with wildtype receptors, GABA(A) receptors that contain the mutant subunit show a lesser amplitude of GABA-activated currents in vitro, indicating that seizures may result from loss of function of this inhibitory ligand-gated channel. Our results confirm that mutation of GABRA1 predisposes towards a common idiopathic generalized epilepsy syndrome in humans. 相似文献
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273.
Grimwood J Gordon LA Olsen A Terry A Schmutz J Lamerdin J Hellsten U Goodstein D Couronne O Tran-Gyamfi M Aerts A Altherr M Ashworth L Bajorek E Black S Branscomb E Caenepeel S Carrano A Caoile C Chan YM Christensen M Cleland CA Copeland A Dalin E Dehal P Denys M Detter JC Escobar J Flowers D Fotopulos D Garcia C Georgescu AM Glavina T Gomez M Gonzales E Groza M Hammon N Hawkins T Haydu L Ho I Huang W Israni S Jett J Kadner K Kimball H Kobayashi A Larionov V Leem SH Lopez F Lou Y Lowry S 《Nature》2004,428(6982):529-535
Chromosome 19 has the highest gene density of all human chromosomes, more than double the genome-wide average. The large clustered gene families, corresponding high G + C content, CpG islands and density of repetitive DNA indicate a chromosome rich in biological and evolutionary significance. Here we describe 55.8 million base pairs of highly accurate finished sequence representing 99.9% of the euchromatin portion of the chromosome. Manual curation of gene loci reveals 1,461 protein-coding genes and 321 pseudogenes. Among these are genes directly implicated in mendelian disorders, including familial hypercholesterolaemia and insulin-resistant diabetes. Nearly one-quarter of these genes belong to tandemly arranged families, encompassing more than 25% of the chromosome. Comparative analyses show a fascinating picture of conservation and divergence, revealing large blocks of gene orthology with rodents, scattered regions with more recent gene family expansions and deletions, and segments of coding and non-coding conservation with the distant fish species Takifugu. 相似文献
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275.
The histone H3.3 chaperone HIRA is essential for chromatin assembly in the male pronucleus 总被引:1,自引:0,他引:1
In sexually reproducing animals, a crucial step in zygote formation is the decondensation of the fertilizing sperm nucleus into a DNA replication-competent male pronucleus. Genome-wide nucleosome assembly on paternal DNA implies the replacement of sperm chromosomal proteins, such as protamines, by maternally provided histones. This fundamental process is specifically impaired in sésame (ssm), a unique Drosophila maternal effect mutant that prevents male pronucleus formation. Here we show that ssm is a point mutation in the Hira gene, thus demonstrating that the histone chaperone protein HIRA is required for nucleosome assembly during sperm nucleus decondensation. In vertebrates, HIRA has recently been shown to be critical for a nucleosome assembly pathway independent of DNA synthesis that specifically involves the H3.3 histone variant. We also show that nucleosomes containing H3.3, and not H3, are specifically assembled in paternal Drosophila chromatin before the first round of DNA replication. The exclusive marking of paternal chromosomes with H3.3 represents a primary epigenetic distinction between parental genomes in the zygote, and underlines an important consequence of the critical and highly specialized function of HIRA at fertilization. 相似文献
276.
Amnionless,essential for mouse gastrulation,is mutated in recessive hereditary megaloblastic anemia 总被引:7,自引:0,他引:7
Tanner SM Aminoff M Wright FA Liyanarachchi S Kuronen M Saarinen A Massika O Mandel H Broch H de la Chapelle A 《Nature genetics》2003,33(3):426-429
The amnionless gene, Amn, on mouse chromosome 12 encodes a type I transmembrane protein that is expressed in the extraembryonic visceral layer during gastrulation. Mice homozygous with respect to the amn mutation generated by a transgene insertion have no amnion. The embryos are severely compromised, surviving to the tenth day of gestation but seem to lack the mesodermal layers that normally produce the trunk. The Amn protein has one transmembrane domain separating a larger, N-terminal extracellular region and a smaller, C-terminal cytoplasmic region. The extracellular region harbors a cysteine-rich domain resembling those occurring in Chordin, found in Xenopus laevis embryos, and Sog, found in Drosophila melanogaster. As these cysteine-rich domains bind bone morphogenetic proteins (Bmps), it has been speculated that the cysteine-rich domain in Amn also binds Bmps. We show that homozygous mutations affecting exons 1-4 of human AMN lead to selective malabsorption of vitamin B12 (a phenotype associated with megaloblastic anemia 1, MGA1; OMIM 261100; refs. 5,6) in otherwise normal individuals, suggesting that the 5' end of AMN is dispensable for embryonic development but necessary for absorption of vitamin B12. When the 5' end of AMN is truncated by mutations, translation is initiated from alternative downstream start codons. 相似文献
277.
Dodé C Levilliers J Dupont JM De Paepe A Le Dû N Soussi-Yanicostas N Coimbra RS Delmaghani S Compain-Nouaille S Baverel F Pêcheux C Le Tessier D Cruaud C Delpech M Speleman F Vermeulen S Amalfitano A Bachelot Y Bouchard P Cabrol S Carel JC Delemarre-van de Waal H Goulet-Salmon B Kottler ML Richard O Sanchez-Franco F Saura R Young J Petit C Hardelin JP 《Nature genetics》2003,33(4):463-465
We took advantage of overlapping interstitial deletions at chromosome 8p11-p12 in two individuals with contiguous gene syndromes and defined an interval of roughly 540 kb associated with a dominant form of Kallmann syndrome, KAL2. We establish here that loss-of-function mutations in FGFR1 underlie KAL2 whereas a gain-of-function mutation in FGFR1 has been shown to cause a form of craniosynostosis. Moreover, we suggest that the KAL1 gene product, the extracellular matrix protein anosmin-1, is involved in FGF signaling and propose that the gender difference in anosmin-1 dosage (because KAL1 partially escapes X inactivation) explains the higher prevalence of the disease in males. 相似文献
278.
279.
Anne Dain G. A. Kerkut R. C. Smith K. A. Munday T. H. Wilmshurst 《Cellular and molecular life sciences : CMLS》1964,20(2):76-78
Résumé L'addition de mélanine au blanc d'uf frais diminue la concentration des radicaux libres due à la lumière de 366 mµ. Cela permet de supposer que la mélanine agit comme un capteur d'électrons. 相似文献
280.