scispace - formally typeset
Search or ask a question
Topic

Mutant

About: Mutant is a research topic. Over the lifetime, 74520 publications have been published within this topic receiving 3477079 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: It is suggested that Hd1 functions in the promotion of heading under short- day conditions and in inhibition under long-day conditions and is a homolog of CONSTANS in Arabidopsis.
Abstract: A major quantitative trait locus (QTL) controlling response to photoperiod, Hd1, was identified by means of a map-based cloning strategy. High-resolution mapping using 1505 segregants enabled us to define a genomic region of ∼12 kb as a candidate for Hd1. Further analysis revealed that the Hd1 QTL corresponds to a gene that is a homolog of CONSTANS in Arabidopsis. Sequencing analysis revealed a 43-bp deletion in the first exon of the photoperiod sensitivity 1 (se1) mutant HS66 and a 433-bp insertion in the intron in mutant HS110. Se1 is allelic to the Hd1 QTL, as determined by analysis of two se1 mutants, HS66 and HS110. Genetic complementation analysis proved the function of the candidate gene. The amount of Hd1 mRNA was not greatly affected by a change in length of the photoperiod. We suggest that Hd1 functions in the promotion of heading under short-day conditions and in inhibition under long-day conditions.

1,404 citations

Journal ArticleDOI
27 Jun 2003-Cell
TL;DR: It is found that in an uninduced state, NPR1 is present as an oligomer formed through intermolecular disulfide bonds, which provides a missing link between accumulation of SA and activation of NPR1 in the SAR signaling pathway.

1,402 citations

Journal ArticleDOI
03 Jan 2002-Nature
TL;DR: It is suggested that p53 has a role in regulating organismal ageing by generating mice with a deletion mutation in the first six exons of the p53 gene that express a truncated RNA capable of encoding a carboxy-terminal p53 fragment.
Abstract: The p53 tumour suppressor is activated by numerous stressors to induce apoptosis, cell cycle arrest, or senescence. To study the biological effects of altered p53 function, we generated mice with a deletion mutation in the first six exons of the p53 gene that express a truncated RNA capable of encoding a carboxy-terminal p53 fragment. This mutation confers phenotypes consistent with activated p53 rather than inactivated p53. Mutant (p53+/m) mice exhibit enhanced resistance to spontaneous tumours compared with wild-type (p53+/+) littermates. As p53+/m mice age, they display an early onset of phenotypes associated with ageing. These include reduced longevity, osteoporosis, generalized organ atrophy and a diminished stress tolerance. A second line of transgenic mice containing a temperature-sensitive mutant allele of p53 also exhibits early ageing phenotypes. These data suggest that p53 has a role in regulating organismal ageing.

1,387 citations

Journal ArticleDOI
TL;DR: The data demonstrate that the preseniiin mutations cause a dominant gain of function and may induce AD by enhancing Aβ42 production, thus promoting cerebral β-amyloidosis.
Abstract: The mechanism by which mutations in the presenilin (PS) genes cause the most aggressive form of early-onset Alzheimer's disease (AD) is unknown, but fibroblasts from mutation carriers secrete increased levels of the amyloidogenic A beta 42 peptide, the main component of AD plaques. We established transfected cell and transgenic mouse models that coexpress human PS and amyloid beta-protein precursor (APP) genes and analyzed quantitatively the effects of PS expression on APP processing. In both models, expression of wild-type PS genes did not alter APP levels, alpha- and beta-secretase activity and A beta production. In the transfected cells, PS1 and PS2 mutations caused a highly significant increase in A beta 42 secretion in all mutant clones. Likewise, mutant but not wildtype PS1 transgenic mice showed significant overproduction of A beta 42 in the brain, and this effect was detectable as early as 2-4 months of age. Different PS mutations had differential effects on A beta generation. The extent of A beta 42 increase did not correlate with presenilin expression levels. Our data demonstrate that the presenilin mutations cause a dominant gain of function and may induce AD by enhancing A beta 42 production, thus promoting cerebral beta-amyloidosis.

1,361 citations

Journal ArticleDOI
01 Sep 1988-Nature
TL;DR: Observations provide the first example of a germ-line mutation in a mammalian proto-oncogene and implicate the c-kit gene as a candidate for the W locus and provide a molecular entry into this important region of the mouse genome.
Abstract: Mice carrying mutations at the W locus located on chromosome 5 are characterized by severe macrocytic anaemia, lack of hair pigmentation and sterility1. Mutations at this locus appear to affect the proliferation and/or migration of cells during early embryogenesis and result in an intrinsic defect in the haematopoietic stem cell hierarchy1,2. An understanding of the molecular basis of the complex and pleiotropic phenotype in W mutant mice would thus provide insights into the important developmental processes of gametogenesis, melanogenesis and haematopoiesis. Here we show that the mouse mutant W19H has a deletion of the c-kit proto-oncogene. Interspecific backcross analysis demonstrates that the W locus is very tightly linked to c-kit and that the two loci cannot be segregated at this level of analysis, c-kit is the cellular homologue of the oncogene v-kit of the HZ4 feline sarcoma virus3 and encodes a transmembrane protein tyrosine kinase receptor that is structurally similar to the receptors for colony-stimulating factor-1 (CSF-1) and platelet derived growth factor4,5. The co-localization of c-kit with W provides a molecular entry into this important region of the mouse genome. In addition, these observations provide the first example of a germ-line mutation in a mammalian proto-oncogene and implicate the c-kit gene as a candidate for the W locus.

1,349 citations


Network Information
Related Topics (5)
Gene
211.7K papers, 10.3M citations
94% related
Regulation of gene expression
85.4K papers, 5.8M citations
93% related
Peptide sequence
84.1K papers, 4.3M citations
93% related
Transcription factor
82.8K papers, 5.4M citations
93% related
Gene expression
113.3K papers, 5.5M citations
92% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
20237,150
20226,747
20211,630
20201,916
20191,849