P granules are non-membrane-bound organelles found in the germ-line cytoplasm throughout Caenorhabditiselegans development. Like their “germ granule” counterparts in...Full Text Available
Stem cells are expected to play a key role in the development and maintenance of organisms, and hold great therapeutic promises. However, a number of questions must be answered to achieve an...Full Text Available
The methylation of lysine 4 of Histone H3 (H3K4me) is an important component of epigenetic regulation. H3K4 methylation is a consequence of transcriptional activity, but also has been shown to contribute...Full Text Available
Summary of recent advancesA family of small molecules called ascarosides act as pheromones to control multiple behaviors in the nematode Caenorhabditiselegans....Full Text Available
The nuo-6 and isp-1 genes of C. elegans encode, respectively, subunits of complex I and III of the mitochondrial respiratory chain. Partial loss-of-function...Full Text Available
Transient receptor potential (TRP) ion channels have been implicated in detecting chemical, thermal and mechanical stimuli in organisms ranging from mammals to Caenorhabditiselegans....Full Text Available
A common property of aging in all animals is that chronologically and genetically identical individuals age at different rates. To unveil mechanisms that influence aging variability, we identified markers...Full Text Available
Genetic defects in the dystrophin-associated protein complex (DAPC) are responsible for a variety of pathological conditions including muscular dystrophy, cardiomyopathy, and vasospasm. Conserved DAPC...Full Text Available
Although acetylated α-tubulin is known to be a marker of stable microtubules in neurons, precise factors that regulate α-tubulin acetylation are, to date, largely unknown. Therefore,...Full Text Available
Disorders of mitochondrial fat metabolism lead to sudden death in infants and children. Although survival is possible, the underlying molecular mechanisms which enable this outcome have not yet been...Full Text Available
Activation of the innate immune system results in a rapid microbicidal response against microorganisms, which needs to be fine-tuned because uncontrolled immune responses can lead to infection and cancer,...Full Text Available
The insulin/IGF-1 signaling (IIS) pathway is a conserved regulator of longevity, development, and metabolism. In Caenorhabditiselegans IIS involves activation of DAF-2 (insulin/IGF-1...Full Text Available
Cross-resistance to cefoxitin (FOX), chloramphenicol (CMP), and quinolones (nalidixic acid [NAL]) related to a putative efflux system overexpression has recently been reported for Klebsiella...Full Text Available
The decline in immune function with aging, known as immunosenescence, has been implicated in evolutionarily diverse species, but the underlying molecular mechanisms are not understood. During aging...Full Text Available
X-linked sideroblastic anemia with ataxia (XLSA/A) is a rare inherited disorder characterized by mild anemia and ataxia. XLSA/A is caused by mutations in the ABCB7 gene, which encodes...Full Text Available
Gamete development requires a coordinated soma-germline interaction that ensures renewal and differentiation of germline and somatic stem cells. The physical contact between the germline and somatic...Full Text Available
A regional analysis of nucleotide substitution rates along human genes and their flanking regions allows us to quantify the effect of mutational mechanisms associated with transcription in germline...Full Text Available
We review the application of C. elegans as a model system to understand key aspects of stem cell biology. The only bona fide stem cells in C. elegans...Full Text Available
Germline-specific granules of unknown function are found in a wide variety of organisms, including C. elegans, where they are called P granules. P granules are cytoplasmic bodies...Full Text Available
Motivation: Automatic recognition of cell identities is critical for quantitative measurement, targeting and manipulation of cells of model animals at single-cell resolution. It has been...Full Text Available
BackgroundMutations that impair mitochondrial functioning are associated with a variety of metabolic and age-related disorders. A barrier to rigorous tests of the role of mitochondrial...Full Text Available
We consider a general, neutral, dynamical model of biodiversity. Individuals have i.i.d. lifetime durations, which are not necessarily exponentially distributed, and each individual gives birth independently at constant rate \\lambda. We assume that types are clonally inherited. We consider two classes of speciation models in this setting. In the immigration model, new individuals of an entirely new species singly enter the population at constant rate \\mu (e.g., from the mainland into the island). In the mutation model, each individual independently experiences point mutations in its germline, at constant rate \\theta. We are interested in the species abundance distribution, i.e., in the numbers, denoted I_n(k) in the immigration model and A_n(k) in the mutation model, of species represented by k individuals, k=1,2,...,n, when there are n individuals in the total population. In the immigration model, we prove that the numbers (I_t(k);k\\ge 1) ...
SummaryThe life span of C. elegans can be increased via reduced function of the mitochondria; however, the extent to which mitochondrial alteration in a single,...Full Text Available
A mild reduction in mitochondrial respiration extends the life span of many species, including C. elegans. We recently showed that hypoxia-inducible factor 1 (HIF-1) is required for...Full Text Available
Many lifespan-modulating genes are involved in either generation of oxidative substrates and end-products, or their detoxification and removal. Among such metabolites, only lipoperoxides have the ability...Full Text Available
BackgroundA strong association between stress resistance and longevity in multicellular organisms has been established as many mutations that extend lifespan also show increased...Full Text Available
DYF-13, originally identified in C. elegans within a collection of dye-filling chemosensory mutants, is one of several proteins that have been classified as putatively involved...Full Text Available
Ataxin-3, the protein involved in Machado-Joseph disease, is able to bind ubiquitylated substrates and act as a deubiquitylating enzyme in vitro, and it has been involved in the modulation of protein...Full Text Available
BackgroundProteins may evolve through the recruitment and modification of discrete domains, and in many cases, protein action can be dissected at the domain level. PDZ domains are...Full Text Available
Mutations or multiplications in a-synuclein gene cause familial forms of Parkinson disease or dementia with Lewy bodies (LB), and the deposition of wild-type a-synuclein as LB occurs as a hallmark lesion of these disorders, collectively referred to as synucleinopathies, implicating a-synuclein in the pathogenesis of synucleinopathy. To identify modifier genes of a-synuclein-induced neurotoxicity, we conducted an RNAi screen in transgenic C. elegans (Tg worms) that overexpress human a-synuclein in a pan-neuronal manner. To enhance the RNAi effect in neurons, we crossed a-synuclein Tg worms with an RNAi-enhanced mutant eri-1 strain. We tested RNAi of 1673 genes related to nervous system or synaptic functions, and identified 10 genes that, upon knockdown, caused severe growth/motor abnormalit...
Recent studies have shown Y chromosome microdeletions associated with male infertility. The factors responsible for Y chromosome microdeletions in spermatozoa remain unresolved. However, the environmental pollutants are known to damage DNA in differentiating and maturing germ cells in the male reproductive tract. Therefore, the aim of this study was to investigate the effects of seminal hexachlorocyclohexane (HCH) and its isomers, an environmental pollutant, in 50 fertile and 50 infertile males in relation to semen quality and the incidence of Y chromosome microdeletion in azoospermic factor (AZF) region. As compared to control, an increased HCH level and significantly decreased semen quality were observed in the infertile males. A positive significant association was found between sperm count with alpha-HCH and beta-HCH in the infertile males. A negative significant association was observed between sperm counts with gamma-HCH in asthenospermia patients and with beta-HCH and total HCH ...
Genomic instability can be produced by ionising radiation, so-called radiation-induced genomic instability, and chemical mutagens. Radiation-induced genomic instability occurs in both germinal and somatic cells and also in the offspring of irradiated individuals, and it is characterised by genetic changes including chromosomal rearrangements. The majority of studies of trans-generational, radiation-induced genomic instability have been described in the male germline, whereas the authors who have chosen the female as a model are scarce. The aim of this work is to find out the radiation-induced effects in the foetal offspring of X-ray-treated female rats and, at the same time, the possible impact of this radiation-induced genomic instability on the action of a chemical mutagen. In order to achieve both goals, the quantity and quality of chromosomal damage were analysed. In order to detect trans-generational genomic instability, a total of 4806 ...
We describe an efficient procedure for proving stabilization of biological systems modeled as qualitative networks or genetic regulatory networks. For scalability, our procedure uses modular proof techniques, where state-space exploration is applied only locally to small pieces of the system rather than the entire system as a whole. Our procedure exploits the observation that, in practice, the form of modular proofs can be restricted to a very limited set. For completeness, our technique falls back on a non-compositional counterexample search. Using our new procedure, we have solved a number of challenging published examples, including: a 3-D model of the mammalian epidermis; a model of metabolic networks operating in type-2 diabetes; a model of fate determination of vulval precursor cells in the C. elegans worm; and a model of pair-rule regulation during segmentation in the Drosophila embryo. Our results show many orders of magnitude speedup in cases where ...