Dynamic Mutations

Author(s):  
R. Richards
Keyword(s):  
Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 628
Author(s):  
Agrita Puzuka ◽  
Baiba Alksere ◽  
Linda Gailite ◽  
Juris Erenpreiss

Genome instability may play a role in severe cases of male infertility, with disrupted spermatogenesis being just one manifestation of decreased general health and increased morbidity. Here, we review the data on the association of male infertility with genetic, epigenetic, and environmental alterations, the causes and consequences, and the methods for assessment of genome instability. Male infertility research has provided evidence that spermatogenic defects are often not limited to testicular dysfunction. An increased incidence of urogenital disorders and several types of cancer, as well as overall reduced health (manifested by decreased life expectancy and increased morbidity) have been reported in infertile men. The pathophysiological link between decreased life expectancy and male infertility supports the notion of male infertility being a systemic rather than an isolated condition. It is driven by the accumulation of DNA strand breaks and premature cellular senescence. We have presented extensive data supporting the notion that genome instability can lead to severe male infertility termed “idiopathic oligo-astheno-teratozoospermia.” We have detailed that genome instability in men with oligo-astheno-teratozoospermia (OAT) might depend on several genetic and epigenetic factors such as chromosomal heterogeneity, aneuploidy, micronucleation, dynamic mutations, RT, PIWI/piRNA regulatory pathway, pathogenic allelic variants in repair system genes, DNA methylation, environmental aspects, and lifestyle factors.


2000 ◽  
Vol 176 (1) ◽  
pp. 12-19 ◽  
Author(s):  
Walter J. Muir

BackgroundMedicine is rapidly becoming molecular medicine, and little escapes the grasp of modern genetics. Most disorders associated with learning disability have at least a genetic component influencing their expression; in many disorders, disturbances of genetic mechanisms play a pivotal role.AimsDynamic mutations, imprinting mechanisms and gene-dosage effects are explained with reference to genetic disorders that lead to learning disability.MethodA review of recent important studies in the genetics of learning disability.ResultsA host of new genetic connections to conditions associated with learning disability have been made.ConclusionsA basic understanding of these genetic connections is important for all learning disability psychiatrists if they are to follow the rapid changes – already beginning to influence our practice – that hold immense promise for the future.


1996 ◽  
Vol 6 ◽  
pp. S4-58-S4-59
Author(s):  
D. Souery ◽  
O. Lipp ◽  
B. Mahieu ◽  
C. Van Broeckhoven ◽  
J. Mendlewicz
Keyword(s):  

2005 ◽  
Vol 6 (10) ◽  
pp. 729-742 ◽  
Author(s):  
Christopher E. Pearson ◽  
Kerrie Nichol Edamura ◽  
John D. Cleary

2020 ◽  
Author(s):  
Vinicius Vilperte ◽  
Robert Boehm ◽  
Thomas Debener

Abstract Background: Mutation breeding is an extraordinary tool in plant breeding to increase the genetic variability, where mutations in anthocyanin biosynthesis are targets to generate distinctive phenotypes in ornamental species. In poinsettia, ionizing radiation is routinely applied in breeding programs to obtaining a range of colours, with nearly all pink and white varieties being obtained after γ- or X-ray mutagenesis of red varieties. In the present study we performed a thorough characterization of a potential mutagenesis target gene as the main responsible for the ‘white paradox’ in poinsettiaResults: We identified a GST gene in poinsettia (Bract1) as an essential factor for the expression of anthocyanin-based red colouration of bracts, which presents a high phylogenetic similarity to known anthocyanin-related GSTs. Red poinsettia varieties and white mutants generated from these varieties by X-ray were analysed for polymorphisms related to the ‘white paradox’ in the species. A 4 bp mutation in a short repeat within the coding region of Bract1 is most likely responsible for the appearance of white phenotypes upon irradiation treatment. The polymorphism between wild-type and mutant alleles co-segregates with the phenotype in progeny from heterozygous red and white parents. Moreover, overexpression of Bract1 wild-type allele in Arabidopsis tt19 mutants restored the anthocyanin phenotype, while the Bract1 mutated allele showed to be non-functional. Conclusions: The identified repeat seems to be highly unstable, since mutated plants can be easily detected among fewer than 200 shoots derived from 10 mutated plants. Our data indicate that particular short repeat sequences, similar to microsatellite sequences or so-called dynamic mutations, might be hot spots for genetic variability. Moreover, the identification of the Bract1 mutation fills a gap on the understanding on the molecular mechanism of colour formation in poinsettia


1996 ◽  
Vol 42 (10) ◽  
pp. 1582-1588 ◽  
Author(s):  
R C McGlennen

Abstract Routine clinical molecular testing of diseases associated with unstable or dynamic trinucleotide repeat syndromes poses unique technical, medical, and ethical challenges to the laboratory. Although the pathophysiology of these disorders is to date still largely undefined, the uniformity of their genetics has led to the development of highly informative diagnostic tests. In general, amplification techniques, such as the polymerase chain reaction (PCR), are used to determine the size of alleles within the genes linked to these disorders. Technically, these assays require empirical optimization so that the PCR reactions are both robust and reproducible, and occasionally other methods must be used to confirm diagnoses. Beyond execution of the test, however, the molecular diagnostics laboratory needs also to be fundamentally involved in the process of interpreting these tests in the correct clinical context and in setting policy as to how these data are presented to patients.


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