Search results for "Phenotype"
showing 10 items of 1875 documents
Studies on the population genetics of the ceruloplasmin polymorphism
1969
Phenotype and gene frequencies of the ceruloplasmin polymorphism are reported. In all populations considered here (Germans, Icelanders, Iranians, Pakistani, and Koreans) high frequencies of the allele CpB (0.978–0.996) could be observed, whilst the frequencies of the alleles CpA (0.003–0.013) and CpC (0.000–0.013) are very low.
Basic issues in forensic DNA typing
1997
DNA analysis has become the standard method in forensic stain typing (termed DNA profiling). In contrast to conventional serological methods, any human tissue or body fluid can be analysed by DNA profiling as long as it contains nucleated cells. The majority of genetic systems studied at the DNA level are derived from "non-coding" portions from the human genome, and are located either in the vicinity of expressed (coding) genes or in stretches of DNA sequences interspersing with the genes. The typing results are usually recorded as DNA fragment lengths or "alleles" indicating the number of core repeat elements for short tandem repeat systems. These typing results do not contain any useful i…
Roles of adenine methylation and genetic mutations in adaptation to different temperatures in Serratia marcescens
2019
AbstractEpigenetic modifications can contribute to adaptation, but the relative contributions of genetic and epigenetic variation are unknown. Previous studies on the role of epigenetic changes in adaptation in eukaryotes have nearly exclusively focused on cytosine methylation (m5C), while prokaryotes exhibit a richer system of methyltransferases targetting adenines (m6A) or cytosines (m4C, m5C). DNA methylation in prokaryotes has many roles, but its potential role in adaptation still needs further investigation. We collected phenotypic, genetic, and epigenetic data using single molecule real-time sequencing of clones of the bacterium Serratia marcescens that had undergone experimental evol…
Analysis of 100 HSP Exomes and Characterization of Mutations in Known Autosomal Dominant Genes (P05.166)
2012
Objective: Comprehensive screening of all known autosomal dominant HSP genes in a large cohort of patients. Background Hereditary spastic paraplegias comprise a group of clinically and genetically heterogeneous neurodegenerative disorders that share the common clinical feature of lower limb spastic paraplegia. Ten genes causing autosomal dominant HSP are known to date, together explaining about 60% of cases. Knowledge about frequency of HSP subtypes and genotype-phenotype correlation is limited by the fact that most screenings so far are biased due to phenotypic pre-selection of the study cohort or inhomogeneous a priori genetic diagnostic testing. Design/Methods: We have screened a large c…
Molecular Analysis of the Supramolecular Usher Protein Complex in the Retina
2007
Human Usher syndrome (USH) is the most common form of deaf-blindness and also the most frequent case of recessive retinitis pigmentosa. According to the degree of the clinical symptoms, three different types of the Usher syndrome are distinguished: USH1, USH2 and USH3 (Davenport and Omenn, 1977). USH is genetically heterogeneous with eleven chromosomal loci, which can be assigned to the three USH types (USH1A-G, USH2A-C, USH3A) (Petit, 2001). Out of these, USH1 is the most severe form, characterized by profound congenital deafness, constant vestibular dysfunction and prepubertal-onset retinitis pigmentosa. USH2 patients show a milder congenital deafness, a slightly later onset of retinitis …
A genome-wide association study identifies Arabidopsis thaliana genes that contribute to differences in the outcome of infection with two Turnip mosa…
2021
Viruses lie in a continuum between generalism and specialism depending on their ability to infect more or less hosts. While generalists are able to successfully infect a wide variety of hosts, specialists are limited to one or a few. Even though generalists seem to gain an advantage due to their wide host range, they usually pay a pleiotropic fitness cost within each host. On the contrary, a specialist has maximal fitness within its own host. A relevant yet poorly explored question is whether viruses differ in the way they interact with their hosts’ gene expression depending on their degree of specialization. Using a genome-wide association study approach, we have identified host genes whos…
Some notes on the geographical distribution of the human red cell acid phosphatase phenotypes
1972
Basing on the data of 65 populations the geographical variability of the human red cell acid phosphatase phenotypes resp. alleles was studied. We found a marked distribution gradient: The frequency of pB-alleles increases with the increase of the mean annual temperature of the various biotops, whereas the pA-allele frequencies show a clear decrease. For this allele we calculated a significant negative correlation between its frequency and the mean annual temperature: r=-0.71; P<0.001. We suppose that the pB-allele is in some way adaptive under the climatic conditions of tropical biotops. The possible reasons are discussed.
Overexpression of Septin 4, the Drosophila homologue of human CDCrel-1, is toxic for dopaminergic neurons
2007
parkin loss-of-function mutations are linked to autosomal recessive juvenile parkinsonism. Parkin is an E3 ubiquitin ligase that promotes degradation of specific target proteins by the proteasome. It has been proposed that loss of Parkin activity will result in accumulation of its substrates, thus leading to dopaminergic (DA) neuron death. In Drosophila, parkin mutations cause degeneration of a subset of DA neurons in the brain but no Parkin substrates have yet been described. Here we characterized the septin 4 gene, which encodes the Drosophila orthologue of human CDCrel-1, a Parkin substrate. We showed that Septin 4 overexpression causes age-dependent disruption of DA neuron integrity in …
Classification of prokaryotic genetic replicators: between selfishness and altruism
2015
Prokaryotes harbor a variety of genetic replicators, including plasmids, viruses, and chromosomes, each having different effects on the phenotype of the hosting cell. Here, we propose a classification for replicators of bacteria and archaea on the basis of their horizontal-transfer potential and the type of relationships (mutualistic, symbiotic, commensal, or parasitic) that they have with the host cell vehicle. Horizontal movement of replicators can be either active or passive, reflecting whether or not the replicator encodes the means to mediate its own transfer from one cell to another. Some replicators also have an infectious extracellular state, thus separating viruses from other mobil…
Point Mutation Rate of Bacteriophage ΦX174
2009
Abstract The point mutation rate of phage ΦX174 was determined using the fluctuation test. After identifying the genetic changes associated with the selected phenotype, we obtained an estimate of 1.0 × 10−6 substitutions per base per round of copying, which is consistent with Drake's rule (0.003 mutations per genome per round of copying in DNA-based microorganisms).