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Since the publication of the human reference genome, the identities of specific genes associated with human diseases are being discovered at a rapid rate. A central problem is that the [...]

BACKGROUND: [C.sub.60] is a highly insoluble nanoparticle that can form colloidal suspended aggregates in water, which may lead to environmental exposure in aquatic organisms. Previous research has indicated toxicity from [...]

Every once in a while a superstar comes onto the scientific stage and revolutionizes our understanding of the world. Readers might be imagining the likes of Newton, Darwin or even [...]

The zebrafish has become a favorite organism for genetic analysis of vertebrate development, but methods for generating mutants by reverse genetic approaches have been lacking. We report a method to obtain stable mutants of a gene based on knowledge of the gene sequence only. Parental fish were mutagenized with N-ethyl-N-nitrosourea; in 2679 [F.sub.1] fish, the rag1 gene was analyzed for heterozygous mutations by resequencing. In total, we found 15 mutations: 9 resulted in amino acid substitutions and 1 resulted in a premature stop codon. This truncation mutant was found to be homozygous viable and defective in V(D)J joining. Although presumably immune deficient, these homozygous rag1 mutant fish are able to reach adulthood and are fertile. As sperm samples from all 2679 [F.sub.1] fish were collected and cryopreserved, we have in principle generated a mutant library from which mutants of most zebrafish genes can be isolated., Forward genetic screens in the zebrafish have identified thousands of mutants defective in many kinds of biological processes (1, 2). Cloning of the affected genes is accelerated by both an [...]

To facilitate molecular genetic analysis of vertebrate development, haploid genetics was used to construct a recombination map for the zebrafish Danio (Brachydanio) rerio. The map consists of 401 random amplified [...]

Circadian clocks are time-keeping systems found in most organisms. In zebrafish, expression of the clock gene Period3 (Per3) oscillates throughout embryogenesis in the central nervous system and the retina. Per3 rhythmic expression was free-running and was reset by light but not by the developmental delays caused by low temperature. The time of fertilization had no effect on Per3 expression. Per3 messenger RNA accumulates rhythmically in oocytes and persists in embryos. Our results establish that the circadian dock functions during early embryogenesis in zebrafish. Inheritance of maternal dock gene products suggests a mechanism of phase inheritance through ovogenesis., Circadian rhythms in physiology and behavior allow living organisms to anticipate daily environmental changes (1). These rhythms are driven by endogenous circadian clocks synchronized to external time cues. All known [...]