Search results for "polymorph"
showing 10 items of 2115 documents
Identification of Colletotrichum species responsible for anthracnose of strawberry based on the internal transcribed spacers of the ribosomal region.
2000
In recent years, different molecular techniques have led to an important progress in the characterisation of Colletotrichum species, but there are no available methods which permit the easy identification of Colletotrichum strains and their assignation to classical species. In the present work, the restriction patterns generated from the region spanning the internal transcribed spacers (ITS1 and ITS2) and the 5.8S rRNA gene, were used to identify a total of 80 strains of Colletotrichum, the majority of them isolated from strawberry. One of the most interesting results derived from this study was the easy and reliable distinction, using the endonuclease MvnI, between Colletotrichum fragariae…
PCR ITS-RFLP: A useful method for identifying filamentous fungi isolates on grapes.
2010
Restriction digestion analysis of the ITS products was tested as an easy method to identify isolates of filamentous fungi on grapes. Endonucleases SduI, HinfI, MseI, HaeIII were used. Endonucleases BfmI, Cfr9I, Hpy188I, MaeII or PspGI were used as necessary to complete discrimination. The 43 species studied generated 42 different composite profiles. Only the species P. thomii and P. glabrum gave the same composite profile. 96.3% strains tested could be differentiated to the species level with only four enzymes. Hundred ninety nine strains of filamentous fungi were isolated from various vineyards in Burgundy and identified by this method. Penicillium (58.5%) was the genus the most frequently…
A Critical Period for Prefrontal Network Configurations Underlying Psychiatric Disorders and Addiction
2020
The medial prefrontal cortex (mPFC) has been classically defined as the brain region responsible for higher cognitive functions, including the decision-making process. Ample information has been gathered during the last 40 years in an attempt to understand how it works. We now know extensively about the connectivity of this region and its relationship with neuromodulatory ascending projection areas, such as the dorsal raphe nucleus (DRN) or the ventral tegmental area (VTA). Both areas are well-known regulators of the reward-based decision-making process and hence likely to be involved in processes like evidence integration, impulsivity or addiction biology, but also in helping us to predict…
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…
Sequence polymorphism of mitochondrial DNA control region in Japanese.
1998
Sequence polymorphisms of the mitochondrial DNA (mtDNA) control region, hypervariable regions I and II, from 100 unrelated Japanese were determined by PCR amplification and direct sequencing. Sequences of 404 nucleotides for hypervariable region I and 379 nucleotides for region II were obtained. Variable sites (85 and 45) were revealed in region I and region II, respectively, as compared to the reference sequence, and a total of 96 different genetic patterns from both regions I and II were determined. A point mutation heteroplasmy was observed at the ratio of approximately 50:50 from one individual at the sequence position 151 showing a nucleotide transition from C to T. The probability of …
Mitochondrial genome of Suberites domuncula: palindromes and inverted repeats are abundant in non-coding regions.
2007
The 26,300-nucleotide sequence of the mitochondrial DNA (mtDNA) molecule of the demosponge Suberites domuncula (Olivi, 1792), the largest in size yet found in Porifera, has been determined. We describe the second hadromerid sponge mitochondrial genome that contains the same set of 41 genes as the hadromerid sponge Tethya actinia, including trnMe(cau), trnI2(cau), trnR2(ucu), and atp9, all of which are transcribed in the same direction. Furthermore, rRNA genes for the small and large ribosomal subunit are very long, rns is indeed the longest among Metazoa (1833 bp). Intergenic regions (IGR) comprise about 25% of S. domuncula mtDNA and include numerous direct and inverted repeats, as well as …
Phylogenetic analysis of Sicilian goats reveals a new mtDNA lineage.
2006
The mitochondrial hypervariable region 1 (HVR1) sequence of 67 goats belonging to the Girgentana, Maltese and Derivata di Siria breeds was partially sequenced in order to present the first phylogenetic characterization of Sicilian goat breeds. These sequences were compared with published sequences of Indian and Pakistani domestic goats and wild goats. Mitochondrial lineage A was observed in most of the Sicilian goats. However, three Girgentana haplotypes were highly divergent from the Capra hircus clade, indicating that a new mtDNA lineage in domestic goats was found.
Characterization of the length polymorphism in the A + T-rich region of the Drosophila obscura group species
1993
In the twelve Drosophila obscura group species studied, belonging to the affinis, obscura, and pseudoobscura subgroups, the mitochondrial DNA length ranges from 15.8 to 17.2 kb. This length polymorphism is mainly due to insertions/deletions in the variable region of the A + T-rich region. In addition, one species (D. tristis) possess a tandem duplication of a 470-bp fragment that contains the replication origin. The same duplication has occurred at least twice in the Drosophila evolutionary history due to the fact that the repetition is analogous to repetitions found in the four species of the D. melanogaster complex. By comparing the nucleotide sequence of the conserved region in D. ambigu…
Diagnosis of sibling species of Drosophila involved in the colonization of North America by D. subobscura
1997
To determine the effects of the recent colonization of the west coast of North America by the Palaearctic species Drosophila subobscura on the dynamics of the Drosophila populations, the sibling species D. athabasca and D. azteca must be classified unambiguously. We have characterized these two species using three molecular techniques: allozymes, mtDNA and RAPDs. All three techniques allow the classification of any individual as belonging to either species. The study of five localities in northern California and southern Oregon show that the area of overlap is larger than previously described.
Molecular characterization and cytonuclear disequilibria of two Drosophila subobscura mitochondrial haplotypes.
1993
According to restriction site analyses of mitochondrial DNA, Drosophila subobscura shows a polymorphism that consists of two frequent haplotypes that are evenly distributed all over the Old World and several rare haplotypes never present in more than one locality. To ascertain the causes responsible for such distribution, three different mtDNA fragments from haplotypes I and II sampled in a population from Zürich have been partially sequenced. Only three silent nucleotide changes have been detected in the ND5 gene. One of them implies the loss of the HaeIII restriction site, which differentiates haplotype I from haplotype II. On the basis of these results as well as on others involving the…