We use transposon-based clonal analysis to identify the lineage classes that make the adult zebrafish caudal fin. We identify nine distinct lineage classes, including epidermis, ...melanocyte/xanthophore, iridophore, intraray glia, lateral line, osteoblast, dermal fibroblast, vascular endothelium, and resident blood. These lineage classes argue for distinct progenitors, or organ founding stem cells (FSCs), for each lineage, which retain fate restriction throughout growth of the fin. Thus, distinct FSCs exist for the four neuroectoderm lineages, and dermal fibroblasts are not progenitors for fin ray osteoblasts; however, artery and vein cells derive from a shared lineage in the fin. Transdifferentiation of cells or lineages in the regeneration blastema is often postulated. However, our studies of single progenitors or FSCs reveal no transfating or transdifferentiation between these lineages in the regenerating fin. This result shows that, the same as in growth, lineages retain fate restriction when passed through the regeneration blastema.
► Transposon-based clonal analysis identifies nine lineages in the adult zebrafish fin ► Lineage clones remain fate restricted throughout growth of the zebrafish fin ► Lineage clones do not transfate or transdifferentiate during regeneration ► Osteoblast lineage is excluded from the distal-most blastema
Definition Focused group discussions were held with the local people to identify reasons for harvest and consumption of WEPs. Data on the identified reasons for harvest, consumption, and conserving ...WEPs were determined using a questionnaire survey with ranking scales for a set of 76 randomly selected households. Representative field-observations and questionnaire surveys were carried out in villages close to forests. Parts of the plant used, how these were consumed, harvest season, and plant (life form) were recorded. The data was subjected to a Kruskal-Wallis rank sum test and weighted averages calculated. A total of 120 WEPs belonging to 63 families (including Agaricaceae) were reported. Most of the WEPs recorded were trees (45.0%) then herbs (25.8%), vines (13.3%) and shrubs (10.8%). The commonly consumed plant parts were the fruit (43.3%), shoots (28.3%) and leaves (20.8%).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The scaling relationship between the size of an appendage or organ and that of the body as a whole is tightly regulated during animal development. If a structure grows at a different rate than the ...rest of the body, this process is termed allometric growth. The zebrafish another longfin (alf) mutant shows allometric growth resulting in proportionally enlarged fins and barbels. We took advantage of this mutant to study the regulation of size in vertebrates. Here, we show that alf mutants carry gain-of-function mutations in kcnk5b, a gene encoding a two-pore domain potassium (K(+)) channel. Electrophysiological analysis in Xenopus oocytes reveals that these mutations cause an increase in K(+) conductance of the channel and lead to hyperpolarization of the cell. Further, somatic transgenesis experiments indicate that kcnk5b acts locally within the mesenchyme of fins and barbels to specify appendage size. Finally, we show that the channel requires the ability to conduct K(+) ions to increase the size of these structures. Our results provide evidence for a role of bioelectric signaling through K(+) channels in the regulation of allometric scaling and coordination of growth in the zebrafish.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In order to facilitate understanding of pigment cell biology, we developed a method to concomitantly purify melanocytes, iridophores, and retinal pigmented epithelium from zebrafish, and analyzed ...their transcriptomes. Comparing expression data from these cell types and whole embryos allowed us to reveal gene expression co-enrichment in melanocytes and retinal pigmented epithelium, as well as in melanocytes and iridophores. We found 214 genes co-enriched in melanocytes and retinal pigmented epithelium, indicating the shared functions of melanin-producing cells. We found 62 genes significantly co-enriched in melanocytes and iridophores, illustrative of their shared developmental origins from the neural crest. This is also the first analysis of the iridophore transcriptome. Gene expression analysis for iridophores revealed extensive enrichment of specific enzymes to coordinate production of their guanine-based reflective pigment. We speculate the coordinated upregulation of specific enzymes from several metabolic pathways recycles the rate-limiting substrate for purine synthesis, phosphoribosyl pyrophosphate, thus constituting a guanine cycle. The purification procedure and expression analysis described here, along with the accompanying transcriptome-wide expression data, provide the first mRNA sequencing data for multiple purified zebrafish pigment cell types, and will be a useful resource for further studies of pigment cell biology.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To summarize literature describing approaches aimed at automatically identifying patients with a common phenotype.
We performed a review of studies describing systems or reporting techniques ...developed for identifying cohorts of patients with specific phenotypes. Every full text article published in (1) Journal of American Medical Informatics Association, (2) Journal of Biomedical Informatics, (3) Proceedings of the Annual American Medical Informatics Association Symposium, and (4) Proceedings of Clinical Research Informatics Conference within the past 3 years was assessed for inclusion in the review. Only articles using automated techniques were included.
Ninety-seven articles met our inclusion criteria. Forty-six used natural language processing (NLP)-based techniques, 24 described rule-based systems, 41 used statistical analyses, data mining, or machine learning techniques, while 22 described hybrid systems. Nine articles described the architecture of large-scale systems developed for determining cohort eligibility of patients.
We observe that there is a rise in the number of studies associated with cohort identification using electronic medical records. Statistical analyses or machine learning, followed by NLP techniques, are gaining popularity over the years in comparison with rule-based systems.
There are a variety of approaches for classifying patients into a particular phenotype. Different techniques and data sources are used, and good performance is reported on datasets at respective institutions. However, no system makes comprehensive use of electronic medical records addressing all of their known weaknesses.
A general feeling of disillusionment with QSAR has settled across the modeling community in recent years. Most practitioners seem to agree that QSAR has not fulfilled the expectations set for its ...ability to predict biological activity. Among the possible reasons that have been proposed recently for this disappointment are chance correlation, rough response surfaces, incorrect functional forms, and overtraining. Undoubtedly, each of these plays an important role in the lack of predictivity seen in most QSAR models. Likely to be just as important is the role of the fallacy cum hoc ergo propter hoc in the poor prediction seen with many QSAR models. By embracing fallacy along with an over reliance on statistical inference, it may well be that the manner in which QSAR is practiced is more responsible for its lack of success than any other innate cause.
Since 2017, CARICOM member states have been divided in the positions they take on Organization of American States (OAS) resolutions addressing political instability in Venezuela. This article uses a ...neorealism framework to determine whether or not the provision of energy investments by Venezuela and the United States to CARICOM member countries is an attempt on their part to skew the OAS voting mechanism in their national interests. The article also examines the extent to which CARICOM member states’ response to Venezuela’s and United States’ interest in the OAS demonstrates a pattern of rationality. The findings suggest that though the OAS provides a medium for states to negotiate mutually beneficial solutions, states are rational actors and even where they do corporate, dominant states may try to manifest their self-interest.
Cellular proliferation requires the formation of new membranes. It is often assumed that the lipids needed for these membranes are synthesized mostly de novo. Here, we show that proliferating ...fibroblasts prefer to take up palmitate from the extracellular environment over synthesizing it de novo. Relative to quiescent fibroblasts, proliferating fibroblasts increase their uptake of palmitate, decrease fatty acid degradation, and instead direct more palmitate to membrane lipids. When exogenous palmitate is provided in the culture media at physiological concentrations, de novo synthesis accounts for only a minor fraction of intracellular palmitate in proliferating fibroblasts as well as proliferating HeLa and H460 cells. Blocking fatty acid uptake decreased the proliferation rate of fibroblasts, HeLa, and H460 cells, while supplementing media with exogenous palmitate resulted in decreased glucose uptake and rendered cells less sensitive to glycolytic inhibition. Our results suggest that cells scavenging exogenous lipids may be less susceptible to drugs targeting glycolysis and de novo lipid synthesis.
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•Exogenous palmitate is preferred over de novo synthesis for three cell lines•Proliferating fibroblasts decrease β-oxidation to support complex-lipid synthesis•Glutamine does not contribute more carbon to lipids in proliferating fibroblasts•An inhibitor of fatty acid uptake decreases cellular proliferation in three cell lines
Non-lipid nutrients have been the most studied source of lipids in proliferating cells. Yao et al. show that proliferating fibroblasts, HeLa, and H460 cells prefer to take up lipids from the extracellular environment directly rather than synthesize them de novo.
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