Search results for "Microsatellite"
showing 10 items of 425 documents
A new system for animal products traceability and authentication: Use of DNA analysis of natural tracers and example of application to dry cured hams
2010
A few DNA based approaches have been developed to trace animal products from the farm to the consumer “fork”. These approaches make use of the animal DNA that can be recovered during all steps of t...
Conservation of genetic diversity in artificially regenerated holm oak (Quercus ilex L.) populations
2004
Reforestation with autochtonous species should take into account the preservation of the variability and the geographical structure of genetic diversity in forest species. In order to provide empirical data, genetic composition of an artificial population of holm oak (Quercus ilex L.) and its natural seed-origin population in Andalusia were analysed with six microsatellite loci. The genetic diversity indices applied show a reduction in the artificial stand if compared with the natural one, probably due to an inappropriate forester seed collection strategy limited to a few trees.
The marbled crayfish as a paradigm for saltational speciation by autopolyploidy and parthenogenesis in animals
2015
ABSTRACT The parthenogenetic all-female marbled crayfish is a novel research model and potent invader of freshwater ecosystems. It is a triploid descendant of the sexually reproducing slough crayfish, Procambarus fallax, but its taxonomic status has remained unsettled. By cross-breeding experiments and parentage analysis we show here that marbled crayfish and P. fallax are reproductively separated. Both crayfish copulate readily, suggesting that the reproductive barrier is set at the cytogenetic rather than the behavioural level. Analysis of complete mitochondrial genomes of marbled crayfish from laboratory lineages and wild populations demonstrates genetic identity and indicates a single o…
Genetic relationships between sympatric and allopatric Coregonus ciscoes in North and Central Europe
2021
Abstract Background Sympatric speciation along ecological gradients has been studied repeatedly, in particular in freshwater fishes. Rapid post-glacial ecological divergence has resulted in numerous endemic species or ecologically distinct populations in lakes of the temperate zones. Here, we focus on the Baltic cisco (Coregonus albula) complex, to study the genetic similarity among two pairs of sympatric autumn- and spring-spawning populations from post-glacial German Lakes Stechlin and Breiter Luzin. For comparison, we included a similar pair of sympatric populations from the Swedish Lake Fegen. We wanted to explore potential genetic similarities between the three sympatric cisco populati…
New polymorphic microsatellite markers and development of mitotyping primers for West Mediterranean green toad species (Bufo viridis subgroup).
2009
We report new polymorphic microsatellites for three species of Palearctic green toads (Bufo viridis subgroup): 10 in B. balearicus and seven each in B. siculus and B. boulengeri. Diversity at these loci, measured for 27 B. balearicus, 23 B. siculus and 11 B. boulengeri, ranged from low to high (two to 10 alleles). Mitotyping primers, specific to the control region, which allow fast screening of parapatric Sicilian endemic B. siculus and Italian mainland-origin B. balearicus, were developed.
Genetic and pharmacological modulation of DNA mismatch repair heterogeneous tumors promotes immune surveillance.
2023
Patients affected by colorectal cancer (CRC) with DNA mismatch repair deficiency (MMRd), often respond to immune checkpoint blockade therapies, while those with mismatch repair-proficient (MMRp) tumors generally do not. Interestingly, a subset of MMRp CRCs contains variable fractions of MMRd cells, but it is unknown how their presence impacts immune surveillance. We asked whether modulation of the MMRd fraction in MMR heterogeneous tumors acts as an endogenous cancer vaccine by promoting immune surveillance. To test this hypothesis, we use isogenic MMRp (Mlh1+/+) and MMRd (Mlh1-/-) mouse CRC cells. MMRp/MMRd cells mixed at different ratios are injected in immunocompetent mice and tumor reje…
The “unnatural” history of colorectal cancer in Lynch syndrome : lessons from colonoscopy surveillance
2021
Individuals with Lynch syndrome (LS), one of the most common inherited cancer syndromes, are at increased risk of developing malignancies, in particular colorectal cancer (CRC). Regular colonoscopy with polypectomy is recommended to reduce CRC risk in LS individuals. However, recent independent studies demonstrated that a substantial proportion of LS individuals develop CRC despite regular colonoscopy. The reasons for this surprising observation confirmed by large prospective studies are a matter of debate. In this review, we collect existing evidence from clinical, epidemiological and molecular studies and interpret them with regard to the origins and progression of LS-associated CRC. Alon…
Epidemiological, clinical and molecular characterization of Lynch‐like syndrome: A population‐based study
2019
Colorectal carcinomas that are mismatch repair (MMR)‐deficient in the absence of MLH1 promoter methylation or germline mutations represent Lynch‐like syndrome (LLS). Double somatic events inactivating MMR genes are involved in the etiology of LLS tumors. Our purpose was to define the clinical and broader molecular hallmarks of LLS tumors and the population incidence of LLS, which remain poorly characterized. We investigated 762 consecutive colorectal carcinomas operated in Central Finland in 2000–2010. LLS cases were identified by a stepwise protocol based on MMR protein expression, MLH1 methylation and MMR gene mutation status. LLS tumors were profiled for CpG Island Methylator Phenotype (…
Low frequency of HLA haplotype loss associated with loss of heterozygocity in chromosome region 6p21 in clear renal cell carcinomas.
2004
HLA class I loss or downregulation is a widespread mechanism used by tumor cells to avoid tumor recognition by cytotoxic T lymphocytes favoring tumor immune escape. Multiple molecular mechanisms are responsible for these altered HLA class I tumor phenotypes. It has been described in different epithelial tumors that loss of heterozygosity (LOH) at chromosome region 6p21.3 is a frequent mechanism that leads to HLA haplotype loss, ranging between 40 and 50%, depending on the tumor entity analyzed. Here we have tested the frequency of LOH at 6p21 chromosome region in Renal Cell Carcinomas (RCC) of the clear cell and chromophobe subtype. A low frequency of HLA haplotype loss (6.6%) was found in …
No evidence of EMAST in whole genome sequencing data from 248 colorectal cancers.
2021
Microsatellite instability (MSI) is caused by defective DNA mismatch repair (MMR), and manifests as accumulation of small insertions and deletions (indels) in short tandem repeats of the genome. Another form of repeat instability, elevated microsatellite alterations at selected tetranucleotide repeats (EMAST), has been suggested to occur in 50% to 60% of colorectal cancer (CRC), of which approximately one quarter are accounted for by MSI. Unlike for MSI, the criteria for defining EMAST is not consensual. EMAST CRCs have been suggested to form a distinct subset of CRCs that has been linked to a higher tumor stage, chronic inflammation, and poor prognosis. EMAST CRCs not exhibiting MSI have b…