The present invention relates to a Drosophila in vitro system which was used to demonstrate that dsRNA is processed to RNA segments 21-23 nucleotides (nt) in length. Furthermore, when these 21-23 nt fragments are purified and added back to Drosophila extracts, they mediate RNA interference in the absence of long dsRNA. Thus, these 21-23 nt fragments are the sequence-specific mediators of RNA degradation. A molecular signal, which may be their specific length, must be present in these 21-23 nt fragments to recruit cellular factors involved in RNAi. This present invention encompasses these 21-23 nt fragments and their use for specifically inactivating gene function. The use of these fragments (or chemically synthesized oligonucleotides of the same or similar nature) enables the targeting of specific mRNAs for degradation in mammalian cells, where the use of long dsRNAs to elicit RNAi is usually not practical, presumably because of the deleterious effects of the interferon response. This specific targeting of a particular gene function is useful in functional genomic and therapeutic applications.

The present invention provides compositions and methods for light-activated cation channel proteins and their uses within cell membranes and subcellular regions. The invention provides for proteins, nucleic acids, vectors and methods for genetically targeted expression of light-activated cation channels to specific cells or defined cell populations. In particular the invention provides millisecond-timescale temporal control of cation channels using moderate light intensities in cells, cell lines, transgenic animals, and humans. The invention provides for optically generating electrical spikes in nerve cells and other excitable cells useful for driving neuronal networks, drug screening, and therapy.

Stimulation of target cells using light, e.g., in vivo or in vitro, is implemented using a variety of methods and devices. One example involves a vector for delivering a light-activated NpHR-based molecule comprising a nucleic acid sequence that codes for light-activated NpHR-based molecule and a promoter. Either a high expression of the molecule manifests a toxicity level that is less than about 75%, or the light-activated NpHR-based proteins are expressed using at least two NpHR-based molecular variants. Each of the variants characterized in being useful for expressing a light-activated NpHR-based molecule that responds to light by producing an inhibitory current to dissuade depolarization of the neuron. Other aspects and embodiments are directed to systems, methods, kits, compositions of matter and molecules for ion pumps or for controlling inhibitory currents in a cell (e.g., in in vivo and in vitro environments).

A process is provided of introducing an RNA into a living cell to inhibit gene expression of a target gene in that cell. The process may be practiced ex vivo or in vivo. The RNA has a region with double-stranded structure. Inhibition is sequence-specific in that the nucleotide sequences of the duplex region of the RNA and of a portion of the target gene are identical. The present invention is distinguished from prior art interference in gene expression by antisense or triple-strand methods.

The present invention relates to: a transgenic Caenorhabditis elegans in which a glutamine tRNA 5 terminus-derived fragment (Gln 5-tsRNA) is overexpressed; a preparation method therefor; and a method for screening for aging-associated factors by using the transgenic Caenorhabditis elegans. A transgenic Caenorhabditis elegans model provided in the present invention is an animal model in which Gln 5-tsRNA is overexpressed such that aging is inhibited. When the model of the present invention is used, anti-aging mechanisms can be easily investigated, thereby significantly contributing to various research fields such as that of developing new anti-aging drugs and screening for age-inducing materials.

Disclosed are methods, compositions, and systems for transforming silkworms to produce spider silk and analogs of spider silk. In certain embodiments, the method may include inserting a DNA sequence coding for at least a portion of a spider silk fibroin polypeptide, or an analog of a spider silk fibroin polypeptide, positioned between at least a portion of the 5 and 3 ends of a silkworm fibroin gene to generate a fusion gene construct having a sequence that encodes for a polypeptide comprising both spider silk fibroin and silkworm silk fibroin sequences. In certain embodiments, the fused gene is able to replace a native gene present in the silkworm such that the transformed silkworm expresses a polypeptide comprising a spider silk fibroin polypeptide, or an analog thereof, and expresses significantly less of the native silkworm silk.

Provided herein are devices, systems and methods for separating age and size matched nematodes from a mixed size population of nematodes and/or debris. The device and system use a filter membrane with a defined pore size located between an upper housing with a first chamber adapted to receive a liquid sample comprising the mixed size population nematodes and a lower housing with a second chamber. Use of the system, along with a sample vessel, provide the user a method for efficiently and effectively isolating an age and size synchronized population of nematodes.

The present invention provides compositions and methods for light-activated cation channel proteins and their uses within cell membranes and subcellular regions. The invention provides for proteins, nucleic acids, vectors and methods for genetically targeted expression of light-activated cation channels to specific cells or defined cell populations. In particular the invention provides millisecond-timescale temporal control of cation channels using moderate light intensities in cells, cell lines, transgenic animals, and humans. The invention provides for optically generating electrical spikes in nerve cells and other excitable cells useful for driving neuronal networks, drug screening, and therapy.

It is intended to develop and provide a technique of conveniently allowing a transgenic silkworm by itself and at an individual level to produce a recombinant protein having a mammalian-type sugar chain sialic acid attached thereto, without the need of a baculovirus expression system or oral and transdermal administration of sialic acid. An expression vector was developed which can induce the expression of a mammalian-type glycosylation-related gene group only in a silk gland such that the recombinant protein modified with the mammalian-type sugar chain has no adverse effect on the silkworm itself. A transgenic silkworm harboring the expression vector was prepared.

Provided is a non-invasive method of modulating the activity of a cell, comprising the steps of delivering a MAR gene into said cell and applying a magnetic stimulation to said cell. The medical use of magnetogenetics in treating diseases is also provided.