Genomic Imprinting
Mostrando 13-24 de 124 artigos, teses e dissertações.
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13. Population Genetic Models of Genomic Imprinting
The phenomenon of genomic imprinting has recently excited much interest among experimental biologists. The population genetic consequences of imprinting, however, have remained largely unexplored. Several population genetic models are presented and the following conclusions drawn: (i) systems with genomic imprinting need not behave similarly to otherwise ide
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14. The Evolution of Genomic Imprinting
In some mammalian genes, the paternally and maternally derived alleles are expressed differently: this phenomenon is called genomic imprinting. Here we study the evolution of imprinting using multivariate quantitative genetic models to examine the feasibility of the genetic conflict hypothesis. This hypothesis explains the observed imprinting patterns as an
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15. A Rheostat Model for a Rapid and Reversible Form of Imprinting-Dependent Evolution
The evolutionary advantages of genomic imprinting are puzzling. We propose that genomic imprinting evolved as a mechanism that maximizes the interindividual variability in the rates of gene expression for dosage-sensitive loci that, with minimal unrelated deleterious effects, can alter the phenotype over a wide continuum. We hypothesize (1) that genomic impr
The American Society of Human Genetics.
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16. Mutation-Selection Balance under Genomic Imprinting at an Autosomal Locus
I model the effect of genomic imprinting on the equilibrium allele frequencies at an autosomal diallelic locus subject to viability selection and mutation. The population size is assumed to be very large; male and female mutation rates may be unequal. Different models examine cases of the inactivation of one gene (with both complete and partial penetrance) a
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17. Phylogenetic Footprint Analysis of IGF2 in Extant Mammals
Genomic imprinting results in monoallelic gene transcription that is directed by cis-acting regulatory elements epigenetically marked in a parent-of-origin-dependent manner. We performed phylogenetic sequence and epigenetic comparisons of IGF2 between the nonimprinted platypus (Ornithorhynchus anatinus) and imprinted opossum (Didelphis virginiana), mouse (Mu
Cold Spring Harbor Laboratory Press.
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18. Defining Contributions of Paternally Methylated Imprinted Genes at the Igf2-H19 and Dlk1-Gtl2 Domains to Mouse Placentation by Transcriptomic Analysis*♦
Parental genome functions in ontogeny are determined by interactions among transcripts from the maternal and paternal genomes, which contain many genes whose expression is strictly dependent on their parental origin as a result of genomic imprinting. Comprehensive recognition of the interactions between parental genomes is important for understanding genomic
American Society for Biochemistry and Molecular Biology.
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19. Genomic imprinting of XX spermatogonia and XX oocytes recovered from XX↔XY chimeric testes
We produced XX↔XY chimeras by using embryos whose X chromosomes were tagged with EGFP (X*), making the fluorescent green female (XX*) germ cells easily distinguishable from their nonfluorescent male (XY) counterparts. Taking advantage of tagging with EGFP, the XX* “prospermatogonia” were isolated from the testes, and the status of their genomic imprint
National Academy of Sciences.
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20. Genomic imprinting proposed as a surveillance mechanism for chromosome loss.
One consequence of genomic imprinting is that loss of the transcriptionally active chromosomal homologue causes a change in gene expression that might permit surveillance of chromosome-loss events. Possible selective advantages of such surveillance include protection against cancer and early elimination of monosomic and trisomic fetuses. Potential mechanisms
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21. Genomic Imprinting Controls Matrix Attachment Regions in the Igf2 Gene
Genomic imprinting at the Igf2/H19 locus originates from allele-specific DNA methylation, which modifies the affinity of some proteins for their target sequences. Here, we show that AT-rich DNA sequences located in the vicinity of previously characterized differentially methylated regions (DMRs) of the imprinted Igf2 gene are conserved between mouse and huma
American Society for Microbiology.
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22. Escape from Genomic Imprinting at the Mouse T-Associated Maternal Effect (Tme) Locus
Genomic imprinting occurs at the paternally inherited allele of the mouse T-associated maternal effect (Tme) locus. As a consequence, maternal transmission of a functional Tme gene is normally required for viability and individuals that receive a Tme-deleted chromosome (T(hp) or t(lub2)) from their mother die late in gestation or shortly thereafter. Here we
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23. Genomic imprinting of two antagonistic loci.
We present a model that considers the coevolution of genomic imprinting at a growth factor locus and an antagonistic growth suppressor locus. With respect to the two loci considered independently, our model makes the familiar predictions that an imprinted growth factor locus will only be expressed from the paternally derived allele and an imprinted growth su
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24. Linkage analysis with chromosome 15q11-13 markers shows genomic imprinting in familial Angelman syndrome.
Angelman syndrome (AS) and Prader-Willi syndrome (PWS) have become the classical examples of genomic imprinting in man, as completely different phenotypes are generated by the absence of maternal (AS) or paternal (PWS) contributions to the q11-13 region of chromosome 15 as a result of deletion or uniparental disomy. Apparently, most patients are sporadic cas