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In vivo expansion of functionally integrated GABAergic interneurons by targeted increase in neural progenitors 下载免费PDF全文
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Alvarado-Vázquez MA R Foroughbakhch MA Guzmán- Lucio A Rocha-Estrada JL Hernández-Piñero ML Cárdenas-Ávila BM Soto-García 《Phyton》2015,84(1):70-79
Candelilla (Euphorbia antisiphylitica Zucc.) is a very important plant resource in the arid lands of Northern Mexico. This is because the wax content coating the stem has unique properties which have been useful for multiple applications in the food industry, electronics, cosmetics, etc. However, the intensive exploitation of this resource has caused a great decrease in the populations of this species making necessary to consider strategies for their conservation and sustainable use. One of the primary needs with regeneration purposes is to know their reproductive processes, particularly the biotic and/or abiotic factors that determine the viability and germination of seeds. The present study evaluated the (1) germination and seed viability in relation to the ripeness degree of the fruit at the time of collection, (2) weight of the seed (low, medium and high), and (3) storage time (1, 3, and 5 months). Fruits from four locations, two in the State of Coahuila (Las Coloradas and Candela) and two in the State of Nuevo Leon (Icamole 1 and Icamole 2), were collected. Three germination assays were carried out corresponding to each month of storage. Seed viability was determined by the tetrazolium test. The average weight of the candelilla seeds was 0.0029 ± 0.0010 g, with extreme average values of 0.0018 ± 0.0006 g at Las Coloradas and 0.0036 ± 0.0010 g in Icamole 2. Those seeds with heavier weight obtained from red fruits and with 1 month of storage showed the highest average percentage of viability (66.87 ± 24.19%). At the same time, seeds with around average weight, obtained from red fruits and five months of storage, showed the highest average germination percentage (50.00 ± 9.42%). 相似文献
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Embryo biotechnologies contribute significantly to the genetic enhancement of livestock, although their efficiency remains limited in sheep, mainly owing to variable ovarian responses to gonadotropins. At present, anti-Müllerian hormone (AMH), which is produced by the granulosa cells of the small antral follicles, is a reliable endocrine marker of the ovarian follicle reserve in many species. The expression of AMH in granulosa cells was shown to be stimulated by bone morphogenetic proteins (BMPs) in vitro, so a mutation affecting the BMP15 gene might modulate AMH production in vivo. The present study aimed to assess plasma AMH concentrations before puberty in two groups of Rasa Aragonesa ewes that were carrying (R+) or not carrying (++) the prolific FecXR allele and to relate them with their AMH concentrations at adulthood. Additionally, we sought to establish in both genotypes whether AMH measurements during a laparoscopic ovum pick-up (LOPU) program could be predictive of the number of ovarian follicles (≥3 mm) and recovered cumulus-oocyte complexes (COCs). No differences in AMH were found between the R+ and ++ ewes before puberty or during the adult age. Before puberty, the AMH concentration tended to increase from 3 to 4.5 months and to decline at 6 months to levels similar to those observed later in adults (333.8 ± 73.3, 483.2 ± 135.5, and 184.1 ± 38.2 pg/mL, respectively; P < 0.1), showing a large variability between individuals and between ages. A relationship between the AMH concentrations before puberty and during adulthood was not found, likely reflecting different follicular growth dynamics. In adults, the AMH concentration at the beginning of the FSH treatment was strongly correlated with the number of punctured follicles at LOPU in R+ and ++ ewes (r = 0.75 and 0.78, respectively; P < 0.001), and it was possible to accurate determine AMH cutoff values for both genotypes to identify high-responding ewes. On average, 5.1 extra follicles and 2.7 extra COCs were expected per each 100 pg/mL increase in AMH (P < 0.0001 and P < 0.01, respectively). The repeatability of AMH concentration from session to session was 0.70 (P < 0.0001). Our results demonstrated that, regardless of age, the presence of the FecXR allele did not affect plasma AMH levels. During adulthood, AMH proved to be a good predictor of the ovarian response to FSH stimulation. Such an indicator could therefore be used to improve the performance of embryo biotechnologies in sheep. 相似文献
116.
Combining protein evolution and secondary structure 总被引:10,自引:9,他引:10
An evolutionary model that combines protein secondary structure and amino
acid replacement is introduced. It allows likelihood analysis of aligned
protein sequences and does not require the underlying secondary (or
tertiary) structures of these sequences to be known. One component of the
model describes the organization of secondary structure along a protein
sequence and another specifies the evolutionary process for each category
of secondary structure. A database of proteins with known secondary
structures is used to estimate model parameters representing these two
components. Phylogeny, the third component of the model, can be estimated
from the data set of interest. As an example, we employ our model to
analyze a set of sucrose synthase sequences. For the evolution of sucrose
synthase, a parametric bootstrap approach indicates that our model is
statistically preferable to one that ignores secondary structure.
相似文献
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Marija Cvijović Daniel Dalevi Elizabeth Bilsland Graham JL Kemp Per Sunnerhagen 《BMC bioinformatics》2007,8(1):295
Background
The translational efficiency of an mRNA can be modulated by upstream open reading frames (uORFs) present in certain genes. A uORF can attenuate translation of the main ORF by interfering with translational reinitiation at the main start codon. uORFs also occur by chance in the genome, in which case they do not have a regulatory role. Since the sequence determinants for functional uORFs are not understood, it is difficult to discriminate functional from spurious uORFs by sequence analysis. 相似文献119.
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