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Few Genes (few + gene)
Selected AbstractsThe Candida Genome Database: Facilitating research on Candida albicans molecular biologyFEMS YEAST RESEARCH, Issue 5 2006Maria C. Costanzo Abstract The Candida Genome Database (CGD; http://www.candidagenome.org) is a resource for information about the Candida albicans genomic sequence and the molecular biology of its encoded gene products. CGD collects and organizes data from the biological literature concerning C. albicans, and provides tools for viewing, searching, analysing, and downloading these data. CGD also serves as an organizing centre for the C. albicans research community, providing a gene-name registry, contact information, and research community news. This article describes the information contained in CGD and how to access it, either from the perspective of a bench scientist interested in the function of one or a few genes, or from the perspective of a biologist or bioinformatician interpreting large-scale functional genomic datasets. [source] Neoplastic development in plasma cellsIMMUNOLOGICAL REVIEWS, Issue 1 2003Michael Potter Summary:, An increasing number of model systems of plasma cell tumor (PCT) formation have been and are being developed. Discussed here are six models in mice and multiple myeloma (MM) in humans. Each model illustrates a unique set of biological factors. There are two general types of model systems: those that depend upon naturally arising mutagenic changes (pristane-induced PCTs, 5TMM, and MM) and those that are associated with oncogenes (Eµ-v-abl), growth factors [interleukin-6 (IL-6)], and anti-apoptotic factors (Bcl-xL/Bcl-2). PCTs develop in several special tissue microenvironments that provide essential cytokines (IL-6) and cell,cell interactions. In mice, the activation and deregulation of c-myc by chromosomal translocations is a major feature in many of the models. This mechanism is much less a factor in MM and the 5T model in mice. Genetically determined susceptibility is involved in many of the mouse models, but only a few genes have been implicated thus far. [source] Porcine ESTs detected by differential display representing possible candidates for the trait ,eye muscle area'JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 1 2000By S. Ponsuksili In order to identify ESTs which represent possible candidates for carcass traits in pigs, the differential display approach was used. F2 animals of a resource population and pure-bred German Landrace (DL) pigs were selected for the trait ,eye muscle area' in order to build up groups of three high and three low performing individuals within each population. To increase the probability that differentially expressed DNA fragments were not found due to the genetic background but due to differences in a few genes affecting the trait of interest, siblings were included in the high and in the low performing groups. RNA was isolated from M. longissimus dorsi and four ,intra-litter constrasting pools' were prepared: high performing F2, low performing F2, high performing DL and low performing DL. Differential display banding patterns were produced using (d)T11VA (V:A,C,G) and 20 arbitrary primers. Comparing the banding patterns of the four RNA pools revealed 27 nonshared bands. Here we report on the analysis of seven of these bands, including sequencing, search for homology and mapping using a somatic cell hybrid panel. Two clones showed high homology to known genes, two were homologous to an EST and a SINE sequence. Three clones did not show any homology. Differential expression was tested by semiquantitative reverse transcription,polymerase chain reaction (RT,PCR) and could be confirmed for six clones. [source] Insights from comparative analyses of aging in birds and mammalsAGING CELL, Issue 2 2010Robert E. Ricklefs Summary Many laboratory models used in aging research are inappropriate for understanding senescence in mammals, including humans, because of fundamental differences in life history, maintenance in artificial environments, and selection for early aging and high reproductive rate. Comparative studies of senescence in birds and mammals reveal a broad range in rates of aging among a variety of taxa with similar physiology and patterns of development. These comparisons suggest that senescence is a shared property of all vertebrates with determinate growth, that the rate of senescence has been modified by evolution in response to the potential life span allowed by extrinsic mortality factors, and that most variation among species in the rate of senescence is independent of commonly ascribed causes of aging, such as oxidative damage. Individuals of potentially long-lived species, particularly birds, appear to maintain high condition to near the end of life. Because most individuals in natural populations of such species die of aging-related causes, these populations likely harbor little genetic variation for mechanisms that could extend life further, or these mechanisms are very costly. This, and the apparent evolutionary conservatism in the rate of increase in mortality with age, suggests that variation in the rate of senescence reflects fundamental changes in organism structure, likely associated with the rate of development, rather than physiological or biochemical processes influenced by a few genes. Understanding these evolved differences between long-lived and short-lived organisms would seem to be an essential foundation for designing therapeutic interventions with respect to human aging and longevity. [source] Putative heterotopic ossification progenitor cells derived from traumatized muscle,JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 12 2009Wesley M. Jackson Abstract Heterotopic ossification (HO) is a frequent complication following combat-related trauma, but the pathogenesis of traumatic HO is poorly understood. Building on our recent identification of mesenchymal progenitor cells (MPCs) in traumatically injured muscle, the goal of this study was to evaluate the osteogenic potential of the MPCs in order to assess the role of these cells in HO formation. Compared to bone marrow-derived mesenchymal stem cells (MSCs), a well-characterized population of osteoprogenitor cells, the MPCs exhibited several significant differences during osteogenic differentiation and in the expression of genes related to osteogenesis. Upon osteogenic induction, MPCs showed increased alkaline phosphatase activity, production of a mineralized matrix, and up-regulated expression of the osteoblast-associated genes CBFA1 and alkaline phosphatase. However, MPCs did not appear to reach terminal differentiation as the expression of osteocalcin was not substantially up-regulated. With the exception of a few genes, the osteogenic gene expression profile of traumatized muscle-derived MPCs was comparable to that of the MSCs after osteogenic induction. These findings indicate that traumatized muscle-derived MPCs have the potential to function as osteoprogenitor cells when exposed to the appropriate biochemical environment and are the putative osteoprogenitor cells that initiate ectopic bone formation in HO. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1645,1651, 2009 [source] A developing paradigm for the development of bird beaksBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2006PETER R. GRANT Some adaptive radiations are notable for extreme interspecific diversification in one or a few adult traits. How and why have trait differences evolved? Natural and sexual selection often provide answers to the question of why. An answer to the question of how is to be found in the genetic control of the phenotypic traits, especially in the early stages of development, when interspecific differences first become expressed. Recent studies of the molecular genetic control of beak development in Darwin's finches have shown that a signalling molecule (BMP4) plays a key role in the development of large and deep beaks. Expression of this molecule occurs earlier (heterochrony) and at higher levels in species with deep beaks compared with species with more pointed beaks. The implication of this finding is that variation in the regulation of one or a few genes that are expressed early could be the source of evolutionarily significant variation that is subject to natural selection in speciation and adaptive radiation. This view is reinforced by parallel findings with the same signalling molecule in the development of jaw morphology in cichlid fish of the Great Lakes of Africa. Further research into regulatory mechanisms is to be expected, as well as extension to other examples of radiation such as honeycreepers in Hawaii and Anolis lizards in the Caribbean. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 88, 17,22. [source] Limits to gene flow in marine animals with planktonic larvae: models of Littorina species around Point Conception, CaliforniaBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2004PAUL A. HOHENLOHE Simulation models examined the process of gene flow in marine animals with planktonic larvae, and three factors that may influence it: ocean currents, planktonic period and spawning season. To focus on a realistic example, the models were based on measured ocean currents around Point Conception in southern California and the life histories of two intertidal gastropods, Littorina scutulata and L. plena. Results suggested that: (1) convergent ocean currents can create an effective barrier to gene flow that can be relaxed by temporal variation; (2) longer scales of temporal variation have a greater effect than shorter scales; (3) planktonic period has little effect above a minimum duration; and (4) an extended spawning season can eliminate gene flow barriers when currents vary seasonally. Failure of past studies to detect a phylogeographical boundary at Point Conception may be explained by extended spawning seasons and temporal variation at seasonal to millennial scales. These results fit a conceptual model of marine speciation in which short-lived, leaky barriers restrict gene flow, and divergence in a few genes may quickly produce reproductive isolation, resulting in cryptic sibling species. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 82, 169,187. [source] Genetic and environmental factors in the etiology of esophageal atresia and/or tracheoesophageal fistula: An overview of the current conceptsBIRTH DEFECTS RESEARCH, Issue 9 2009Janine F. Felix Abstract Esophageal atresia and/or tracheoesophageal fistula (EA/TEF) are severe congenital anomalies. Although recent years have brought significant improvement in clinical treatment, our understanding of the etiology of these defects is lagging. Many genes and genetic pathways have been implicated in the development of EA/TEF, but only a few genes have been shown to be involved in humans, in animals, or in both. Extrapolating data from animal models to humans is not always straightforward. Environmental factors may also carry a risk, but the mechanisms are yet to be elucidated. This review gives an overview of the current state of knowledge about both genetic and environmental risk factors in the etiology of EA/TEF. Birth Defects Research (Part A) 2009. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||