Search results for "Nuclear gene"
showing 10 items of 42 documents
Evidence for the Existence of a Pseudogene for the Large Subunit of Rubisco within the Chloroplast DNA of Norway Spruce (Picea Abies)
1998
Many hundreds of genes are involved in the synthesis, maintenance and degradation of chloroplasts. Although quite a number of these genes are located in the chloroplast genome, by far the greater proportion is present in the nuclear genome. The sizes of chloroplast DNAs (cpDNA) were estimated from restriction enzyme mapping studies and the complete sequences of different cpDNAs from diverse plant lineages have been determined to date (Marchantia polymorpha [1], Nicotiana tabacum [2], Oryza saliva [3], Epifagus virginiana [4], Euglena gracilis [5], Pinus thunbergii [6], Porphyra purpurea [7], Odontella sinensis [8], Zea mays [9], Chlorella vulgaris [10]).
Intergenomic interactions affect female reproduction: evidence from introgression and inbreeding depression in a haplodiploid mite
2004
Nuclear and cytoplasmic genomes can coevolve antagonistically or harmoniously to affect fitness. One commonly used test for nuclear-cytoplasmic coadaptation relies on the breakup of coadapted gene complexes by introgression, potentially resulting in an increased frequency of nuclear alleles in deleterious interaction with an alien cytoplasm. We investigated the phenotypic effect of such genes on female reproduction in outbred and inbred introgressed lines of the haplodiploid mite Tetranychus urticae. Introgression changed female lifetime fecundity and increased male production, in ways suggesting a control of fecundity by nuclear genes. Conversely introgression reduced the fertilization rat…
The molecular characterization of new types of Saccharomyces cerevisiae × S. kudriavzevii hybrid yeasts unveils a high genetic diversity
2012
New double- and triple-hybrid Saccharomyces yeasts were characterized using PCR-restriction fragment length polymorphism of 35 nuclear genes, located on different chromosome arms, and the sequencing of one nuclear and one mitochondrial gene. Most of these new hybrids were originally isolated from fermentations; however, two of them correspond to clinical and dietary supplement isolates. This is the first time that the presence of double-hybrid S. cerevisiae×S. kudriavzevii in non-fermentative substrates has been reported and investigated. Phylogenetic analysis of the MET6 nuclear gene confirmed the double or triple parental origin of the new hybrids. Restriction analysis of gene regions in …
Characterisation of four species of the genus Kluyveromyces by mitochondrial DNA restriction analysis
1997
Summary In the present work, we determine the relationships at the within-species level among strains of Kluyveromyces dobzhanskii, K. lactis, K. marxianus, and K. thermotolerans, through the restriction analysis of their mtDNAs. The three first species showed a high level of intraspecific mtDNA divergence, this polymorphism is correlated to the varieties or species defined according to the original taxonomy of the genus, which is in concordance with that shown by other phenotypic or genotypic markers codified for by the nuclear genome. In these species, the analysis of the relationships among strains based on mtDNA restriction data agrees with previous classifications based on morphologica…
Retroposon insertions provide insights into deep lagomorph evolution.
2010
The homogenous mammalian order Lagomorpha comprises about 80 species in two families, Ochotonidae (pikas) and Leporidae (rabbits and hares). However, the phylogenetic relationships among leporids are controversial. Molecular data, particularly from mitochondrial sequences, give highly homoplasious signals. To resolve the controversy between mitochondrial and nuclear data, we analyzed genomic orthologous retroposon insertion sites, a virtually homoplasy-free marker system. From a differential screen of rabbit genomic data for intronic retroposon insertions of CSINE elements, we polymerase chain reaction-amplified and sequenced 11 retroposons in eight representative lagomorphs. We found three…
Natural hybrids of S. cerevisiae×S. kudriavzevii share alleles with European wild populations of Saccharomyces kudriavzevii
2010
Saccharomyces kudriavzevii, a yeast species described from a pair of strains isolated from decayed leaves in Japan, has recently been isolated from oak barks in Portugal. Some data suggest that these European S. kudriavzevii populations could be closely related to the S. kudriavzevii genetic background present in natural hybrids isolated from wines and beers in different regions of Europe. However, a more exhaustive study of European S. kudriavzevii natural populations is necessary to confirm this observation. In this study, new S. kudriavzevii isolates were recovered from oak trees in different areas in Spain, and identified and characterized according to their molecular and physiological …
Genomic instability in an interspecific hybrid of the genus Saccharomyces: a matter of adaptability
2020
Ancient events of polyploidy have been linked to huge evolutionary leaps in the tree of life, while increasing evidence shows that newly established polyploids have adaptive advantages in certain stress conditions compared to their relatives with a lower ploidy. The genus Saccharomyces is a good model for studying such events, as it contains an ancient whole-genome duplication event and many sequenced Saccharomyces cerevisiae are, evolutionary speaking, newly formed polyploids. Many polyploids have unstable genomes and go through large genome erosions; however, it is still unknown what mechanisms govern this reduction. Here, we sequenced and studied the natural S. cerevisiae × Saccharomyces…
Intraspecific and within-isolate sequence variation in the ITS rRNA gene region of Pythium mercuriale sp. nov. (Pythiaceae)
2008
Belbahri, Lassaad et al.
Molecular and ecological signs of mitochondrial adaptation: consequences for introgression?
2013
The evolution of the mitochondrial genome and its potential adaptive impact still generates vital debates. Even if mitochondria have a crucial functional role, as they are the main cellular energy suppliers, mitochondrial DNA (mtDNA) introgression is common in nature, introducing variation in populations upon which selection may act. Here we evaluated whether the evolution of mtDNA in a rodent species affected by mtDNA introgression is explained by neutral expectations alone. Variation in one mitochondrial and six nuclear markers in Myodes glareolus voles was examined, including populations that show mtDNA introgression from its close relative, Myodes rutilus. In addition, we modelled prote…
Genes, Ageing and Longevity in Humans: Problems, Advantages and Perspectives.
2006
Many epidemiological data indicate the presence of a strong familial component of longevity that is largely determined by genetics, and a number of possible associations between longevity and allelic variants of genes have been described. A breakthrough strategy to get insight into the genetics of longevity is the study of centenarians, the best example of successful ageing. We review the main results regarding nuclear genes as well as the mitochondrial genome, focusing on the investigations performed on Italian centenarians, compared to those from other countries. These studies produced interesting results on many putative "longevity genes". Nevertheless, many discrepancies are reported, l…