935 resultados para SOMATIC MOSAICISM
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BACKGROUND: PCR detects clonal rearrangements of the Ig gene in lymphoproliferative disorders. False negativity occurs in germinal centre/post-germinal centre lymphomas (GC/PGCLs) as they display a high rate of somatic hypermutation (SHM), which causes primer mismatching when detecting Ig rearrangements by PCR. AIMS: To investigate the degree of SHM in a group of GC/PGCLs and assess the rate of false negativity when using BIOMED-2 PCR when compared with previously published strategies. METHODS: DNA was isolated from snap-frozen tissue from 49 patients with GC/PGCL (23 diffuse large B cell lymphomas (DLBCLs), 26 follicular lymphomas (FLs)) and PCR-amplified for complete (VDJH), incomplete (DJH) and Ig kappa/lambda rearrangements using the BIOMED-2 protocols, and compared with previously published methods using consensus primers. Germinal centre phenotype was defined by immunohistochemistry based on CD10, Bcl-6 and MUM-1. RESULTS: Clonality detection by amplifying Ig rearrangements using BIOMED-2 family-specific primers was considerably higher than that found using consensus primers (74% DLBCL and 96% FL vs 69% DLBCL and 73% FL). Addition of BIOMED-2 DJH rearrangements increased detection of clonality by 22% in DLBCL. SHM was present in VDJH rearrangements from all patients with DLBCL (median (range) 5.7% (2.5-13.5)) and FL (median (range) 5.3% (2.3-11.9)) with a clonal rearrangement. CONCLUSIONS: Use of BIOMED-2 primers has significantly reduced the false negative rate associated with GC/PGCL when compared with consensus primers, and the inclusion of DJH rearrangements represents a potential complementary target for clonality assessment, as SHM is thought not to occur in these types of rearrangements.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Avocado genetic resources are currently maintained in the form of field repositories at great cost and risk of natural disasters, pest and diseases. Cryopreservation offers a necessary, complimentary method that is safe, cost-effective and long-term. However, long-term maintenance and regeneration of plantlets from avocado somatic embryos has been a major barrier in the development of new avocado cultivars. In this study, two protocols for vitrification-based cryopreservation of avocado somatic embryos were investigated. Globular somatic embryos of two avocado cultivars were tested, revealing cultivar-dependent differences in desiccation tolerance and subsequent freezing resistance, possibly attributed to their size and culture age. A two-step regeneration system, involving an intermediate liquid phase step between subcultures in solid medium, significantly enhanced shoot development from somatic embryo tissue. This work will add considerable value towards cryopreservation of avocado somatic embryos for germplasm conservation and the generation of new and improved avocado cultivars.
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Somatic embryogenesis has been shown to be an efficient in vitro plant regeneration system for many crops such as the important ornamental plant Cyclamen persicum, for which this regeneration pathway of somatic embryogenesis is of interest for the vegetative propagation of parental lines as well as elite plants. However, somatic embryogenesis is not commercially used in many crops due to several unsolved problems, such as malformations, asynchronous development, deficiencies in maturation and germination of somatic embryos. In contrast, zygotic embryos in seeds develop and germinate without abnormalities in most cases. Instead of time-consuming and labor-intensive experiments involving tests of different in vitro culture conditions and plant growth regulator supplements, we follow a more directed approach. Zygotic embryos served as a reference and were compared to somatic embryos in metabolomic analyses allowing the future optimization of the in vitro system. The aims of this study were to detect differences in the metabolite profiles of torpedo stage somatic and zygotic embryos of C. persicum. Moreover, major metabolites in endosperm and testa were identified and quantified. Two sets of extracts of two to four biological replicates each were analyzed. In total 52 metabolites were identified and quantified in the different tissues. One of the most significant differences between somatic and zygotic embryos was that the proline concentration in the zygotic embryos was about 40 times higher than that found in somatic embryos. Epicatechin, a scavenger for reactive oxygen species, was found in highest abundance in the testa. Sucrose, the most abundant metabolite was detected in significantly higher concentrations in zygotic embryos. Also, a yet unknown trisaccharide, was significantly enriched in zygotic embryos.
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This article presents a dataset proving the simultaneous presence of a 5′UTR-truncated PDHA1 mRNA and a full-length PDHA2 mRNA in the somatic cells of a PDC-deficient female patient and all members of her immediate family (parents and brother). We have designed a large set of primer pairs in order to perform detailed RT-PCR assays allowing the clear identification of both PDHA1 and PDHA2 mRNA species in somatic cells. In addition, two different experimental approaches were used to elucidate the copy number of PDHA1 gene in the patient and her mother. The interpretation and discussion of these data, along with further extensive experiments concerning the origin of this altered gene expression and its potential therapeutic consequences, can be found in “Complex genetic findings in a female patient with pyruvate dehydrogenase complex deficiency: null mutations in the PDHX gene associated with unusual expression of the testis-specific PDHA2 gene in her somatic cells” (A. Pinheiro, M.J. Silva, C. Florindo, et al., 2016).
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Presently avocado germplasm is conserved ex situ in the form of field repositories across the globe including Australia. The maintenance of germplasm in the field is costly, labour and land intensive, exposed to natural disasters and always at the risk of abiotic and biotic stresses. The aim of this study was to overcome these problems using cryopreservation to store avocado (Persea americana Mill.) somatic embryos (SE). Two vitrification-based methods of cryopreservation were optimised (cryovial and droplet-vitrification) using four avocado cultivars (‘A10′, ‘Reed’, ‘Velvick’ and ‘Duke-7′). SE of the four cultivars were stored for short-term (one hour) in liquid nitrogen using the cryovial-vitrification method and showed a viability of 91%, 73%, 86% and 80% respectively. While when using the droplet vitrification method viabilities of 100%, 85% and 93% were recorded for ‘A10′, ‘Reed’ and ‘Velvick’. For long-term storage, SE of cultivars ‘A10′, ‘Reed’ and ‘Velvick’ were successfully recovered with viability of 65–100% after 3 months of LN storage. For cultivar ‘Reed’ and ‘Velvick’ SE were recovered after 12 months of LN storage with viability of 67% and 59%, respectively. The outcome of this work contributes towards the establishment of a cryopreservation protocol that is applicable across multiple avocado cultivars.
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This study investigated cow characteristics, farm facilities, and herd management strategies during the dry period to examine their joint influence on somatic cell counts (SCC) in early lactation. Data from 52 commercial dairy farms throughout England and Wales were collected over a 2-yr period. For the purpose of analysis, cows were separated into those housed for the dry period (6,419 cow-dry periods) and those at pasture (7,425 cow-dry periods). Bayesian multilevel models were specified with 2 response variables: ln SCC (continuous) and SCC >199,000 cells/mL (binary), both within 30 d of calving. Cow factors associated with an increased SCC after calving were parity, an SCC >199,000 cells/mL in the 60 d before drying off, increasing milk yield 0 to 30 d before drying off, and reduced DIM after calving at the time of SCC estimation. Herd management factors associated with an increased SCC after calving included procedures at drying off, aspects of bedding management, stocking density, and method of pasture grazing. Posterior predictions were used for model assessment, and these indicated that model fit was generally good. The research demonstrated that specific dry-period management strategies have an important influence on SCC in early lactation.
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Objetivou-se com o presente trabalho, estimar a correlação genética entre idades de seleção (juvenil-adulta) e eficiência da seleção precoce para as características altura, diâmetro e volume de indivíduos de famílias de Pinus taeda propagados via embriogênese somática. O estudo foi realizado por meio de análise genético-estatística pelo procedimento de estimação de componentes de variância (Reml) e de predição de valores genéticos (Blup), usando-se o software Selegen-Reml/Blup. As correlações genéticas entre idades juvenis e idade de rotação foram realizadas aplicando o modelo linear desenvolvido por Lambeth (1980). Segundo os resultados do modelo estabelecido, a seleção precoce pode ser realizada em clones de Pinus taeda com alta eficiência de seleção. As idades de 4 a 6 anos são suficientes para selecionar clones de Pinus taeda propagados via embriogênese somática para colheita aos 8 e 12 anos e, as idades de 6 a 10 anos são suficientes para selecionar para colheita aos 20 anos. De acordo com as estimativas de correlação genotípicaa partir dos ambientes, a seleção de clones de Pinus taeda propagados via embriogênese somática deve ser praticada de forma específica para cada ambiente. Pode-se realizar a seleção de clones considerando o diâmetro, visto a alta correlação observada entre volume e diâmetro.
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Here we propose a protocol for embryogenic cultures induction, proliferation and maturation for the Brazilian conifer Podocarpus lambertii, and investigated the effect of abscisic acid (ABA) and glutathione (GSH) supplementation on the maturation phase. ABA, zeatin (Z) and salicylic acid (SA) endogenous levels were quantified. Number of somatic embryos obtained in ABA-supplemented treatment was signifi- cant higher than in ABA-free treatment, showing the relevance of ABA supplementation during somatic embryos maturation. Histological analysis showed the stereotyped sequence of developmental stages in conifer somatic embryos, reaching the late torpedo-staged embryo. GSH supplementation in maturation culture medium improved the somatic embryos number and morphological features. GSH 0 mM and GSH 0.1 mM treatments correlated with a decreased ABA endogenous level during maturation, while GSH 0.5 mM treatment showed constantlevels. Alltreatments resulted in decreased Z endogenous levels, supporting the concept that cytokinins are important during the initial cell division but not for the later stages of embryo development. The lowest SA levels found in GSH 0.5 mM treatment were coincident with early embryonic development, and this treatment resulted in the highest development of somatic embryos. Thus, a correlation between lower SA levels and improved somatic embryo formation can be hypothesized
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2016
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The aim was to analyse the physical growth and body composition of rhythmic gymnastics athletes relative to their level of somatic maturation. This was a cross-sectional study of 136 athletes on 23 teams from Brazil. Mass, standing height and sitting height were measured. Fat-free and fat masses, body fat percentages and ages of the predicted peak height velocity (PHV) were calculated. The z scores for mass were negative during all ages according to both WHO and Brazilian references, and that for standing height were also negative for all ages according to WHO reference but only until 12 years old according to Brazilian reference. The mean age of the predicted PHV was 12.1 years. The mean mass, standing and sitting heights, body fat percentage, fat-free mass and fat mass increased significantly until 4 to 5 years after the age of the PHV. Menarche was reached in only 26% of these athletes and mean age was 13.2 years. The mass was below the national reference standards, and the standing height was below only for the international reference, but they also had late recovery of mass and standing height during puberty. In conclusion, these athletes had a potential to gain mass and standing height several years after PHV, indicating late maturation.
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Metastasizing pleomorphic adenoma (MPA) is a rare tumour, and its mechanism of metastasis still is unknown. To date, there has been no study on MPA genomics. We analysed primary and secondary MPAs with array comparative genomic hybridization to identify somatic copy number alterations and affected genes. Tumour DNA samples from primary (parotid salivary gland) and secondary (scalp skin) MPAs were subjected to array comparative genomic hybridization investigation, and the data were analysed with NEXUS COPY NUMBER DISCOVERY. The primary MPA showed copy number losses affecting 3p22.2p14.3 and 19p13.3p123, and a complex pattern of four different deletions at chromosome 6. The 3p deletion encompassed several genes: CTNNB1, SETD2, BAP1, and PBRM1, among others. The secondary MPA showed a genomic profile similar to that of the primary MPA, with acquisition of additional copy number changes affecting 9p24.3p13.1 (loss), 19q11q13.43 (gain), and 22q11.1q13.33 (gain). Our findings indicated a clonal origin of the secondary MPA, as both tumours shared a common profile of genomic copy number alterations. Furthermore, we were able to detect in the primary tumour a specific pattern of copy number alterations that could explain the metastasizing characteristic, whereas the secondary MPA showed a more unbalanced genome.
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A cytotaxonomic analysis of species of Acosmium Schott e Leptolobium Vogel was carried out, by determining their chromosome numbers. The three species of Acosmium and five species of Leptolobium (representing 50% of the genus) were studied from seeds obtained from different regions of Brazil. Chromosome counts were new for all Acosmium species and for four Leptolobium species. For Acosmium cardenasii, 2n = 18 was constantly observed, while occurring at the same meristem were found 2n = 18, 24 e 32 in A. diffusissimum and 2n = 18 e 32 in A. lentiscifolium. For Leptolobium, all studied species had 2n = 18, confirming a previous count for L. dasycarpum. The results showed that chromosome numbers of Acosmium and Leptolobium species are homogeneous, confirming the basic number x = 9 for both genera. Therefore, chromosome numbers do not provide a useful taxonomic character distinguishing Acosmium from Leptolobium.
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Universidade Estadual de Campinas . Faculdade de Educação Física