Methods for elucidating biopolymer interactions with known and/or unknown small molecules (e.g. candidate drug compounds) are disclosed. These methods utilize novel (usually motile) organisms transformed with one or more heterologous biopolymer sequences. Biopolymer expression is promoted in cells mediating movement in said organism, generally dually-promoted in paired sets of cells mediating oppositely-directed movement. Modulation of motility in the resultant organism due to the presence of small molecules demonstrates small molecule interaction with said natural and/or mutated biopolymer. Analyzed in a chemical gradient, one or more interacting small molecule species can be identified by oriented migration, even in the presence of one or more non-interacting small molecule species. A competing and/or interfering biopolymer can be introduced without obscuring the motility signal. Methods described herein have utility for the discovery of novel therapeutic compounds (drug discovery), for the improvement of existing therapeutic compounds (drug refinement), and for the precise identification of small molecule binding sites on biopolymers via mutagenesis (structural elucidation). A specific embodiment, a Nematode Olfaction-based Structural Elucidation (NOSE) assay, is described herein.

A system is provided comprising a plurality of C. elegans cultures, where each culture comprises a transgenic C. elegans strain that models a mammalian disease or condition. Methods of using a system, e.g., for characterizing microbial strains of a mammalian microbiome and determining whether such microbial strains affect a mammalian disease or disorder.

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.

Provided herein, are compositions and methods of treatment for neurodegenerative diseases, such as neurodegenerative diseases associated with aging and methods for increasing longevity by inhibiting the expression of the protein exportin-1 (XPO1, CRM-1 or karyopherin) or a fragment thereof.

Provided herein are screening methods that utilize transgenic nematodes exposed to heat shock conditions, such as agents that increase stability of F-actin. The transgenic nematodes used can be in a wild-type background, functionally deleted for OSG-1, or express human ARHGEF10 in an OSG-1 background. Such transgenic nematodes also express a fluorescent protein, such as GFP. Such methods are in some examples high throughput and automated. Also provided are recombinant nematodes and kits that can be used with such methods.

Systems and methods relate to transgenic organisms and their use as biosensors are described. In some embodiments, the systems and methods include a first population of transgenic organisms that includes a first constitutively expressed reporter gene, and a first transgene that includes a first inducible promoter from a response pathway gene, wherein the first inducible promoter is coupled to a first reporter gene. Other embodiments are described.

The present disclosure provides transgenic nematode systems for assessing function of heterologous genes, their variants and drug discovery. The transgenic nematodes contain a heterologous gene that is inserted via homologous recombination at the native locus replacing and removing the nematode ortholog, wherein expression of the heterologous gene rescues function of the removed nematode ortholog and a transgenic control animal is provided. The heterologous gene may be further modified to provide a variant, such as a human clinical variant, whereby a transgenic test animal is provided. Those transgenic test animals are used in methods to assess function of the heterologous variant and drug screens to find therapeutic candidates reversing deviant activity back to wildtype.

The present disclosure provides methods and systems for performing, observing, and/or recording defecation motor program (DMP) events using microfluidic devices. The methods may be performed wherein the nematodes ingest fluorescent or color material and are then loaded in a microfluidic chip and stimulated to feed and defecate. DMP events are observed with use of a fluorescent microscope. In other methods, a microfluidic device with two or more electrodes is used to record electrical events of the DMP.

The present disclosure provides a microfluidic device and system for measuring a composite electropharyngeogram (EPG) signal from a pool of multiple nematodes, wherein the composite EPG signal is measured from the pool of nematodes present in a single recording channel connected to two or more integrated electrodes. The microfluidic device includes an inlet port and outlet port directly connected to a single recording channel and two or more electrodes directly connected to the recording channel. The recording channel is configured to hold 10 to 10,000 nematodes.

Disclosed herein are microinjection chips, devices, and systems for injection of unicellular or multicellular organisms. The microinjection chip and device disclosed herein include the microfluidic features, inlet port, pre-injection reservoir, injection channel and post injection channel in fluid communication with each other. The inlet port is adapted to sequentially move individual organisms into the injection channel, which is adapted to immobilize the individual organism in fluid. The injection channel features a side wall adapted to receive a microinjection pipette without a microinjection port and to reseal when the microinjection pipette is removed.