The present disclosure provides a method for screening a probiotic strain in promoting reproductive health by using a reproductive disorder model of Caenorhabditis elegans. Cyclophosphamide (CTX) drug intervention is applied to the C. elegans to destroy a normal reproductive system of the C. elegans, thereby obtaining the reproductive disorder model of the C. elegans. Strains capable of significantly improving a reproductive capacity of individuals with reproductive disorders are selected from 3,985 kinds of gene-knockout strains in a Keio gene-knockout library of Escherichia coli; and homologous gene knockout is conducted on a probiotic strain E. coli Nissle 1917 by gene editing, and a probiotic strain with a potential to promote the reproductive health is selected.

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).

Protein indicators useful for calcium imaging, in particular, red genetically-encoded calcium indicators (GECIs) disclosed herein rival best-of-class green GECIs in terms of sensitivity for detecting neural activity, and can be monitored in vivo. The presently-disclosed subject matter further includes a method of monitoring cell activity comprising stimulating a cell comprising a red GECI polypeptide; and detecting fluorescence emitted by the cell.

Provided are transgenic Caenorhabditis elegans (C. elegans) overexpressing DNA methyltransferase 3a (Dnmt3a) and a method of producing the same. According to the method, a specific mechanism and related factors for DNA methylation mediated by Dnmt3a may be found, and a critical gene for regulating the life span of C. elegans may be identified, and therefore C. elegans may be used as an animal model for screening a drug for a DNA methylation-related disease.

Protein indicators useful for calcium imaging, in particular, red genetically-encoded calcium indicators (GECIs) disclosed herein rival best-of-class green GECIs in terms of sensitivity for detecting neural activity, and can be monitored in vivo. The presently-disclosed subject matter further includes a method of monitoring cell activity comprising stimulating a cell comprising a red GECI polypeptide; and detecting fluorescence emitted by the cell.

In a method for counting embryos developing in a uterus of Caenorhabditis elegans, a complete set of experimental procedures are designed to count embryos in the uterus of Caenorhabditis elegans by using Caenorhabditis elegans as a model organism. The method is applicable to Caenorhabditis elegans exposed from an L1 stage to a final stage of pregnancy, and can provide an easy-to-observe, fast, simple, accurate and reliable experimental method to apply Caenorhabditis elegans to research of reproductive ability, detection results of which are highly accurate and reliable, and the experimental method is suitable for promotion.

The present invention relates to a nucleic acid for vaccine that has undergone codon optimization for expression in Bombyx mori, a vector comprising the nucleic acid, Bombyx mori comprising the vector, and a method for producing a vaccine in which they are used.

Provided are transgenic Caenorhabditis elegans (C. elegans) overexpressing DNA methyltransferase 3a (Dnmt3a) and a method of producing the same. According to the method, a specific mechanism and related factors for DNA methylation mediated by Dnmt3a may be found, and a critical gene for regulating the life span of C. elegans may be identified, and therefore C. elegans may be used as an animal model for screening a drug for a DNA methylation-related disease.

Described are Caenorhabditis elegans (C. elegans) strains exhibiting an RNA toxicity phenotype. The C. elegans strains comprise a detectable reporter gene expressed in one or more cell types, with the expressed reporter gene RNA having in instance of at least fifty oligonucleotide repeats (e.g., trinucleotide repeats). Exemplary C. elegans reporter strains are generated that exhibit phenotypes characteristic of the human disorder Myotonic Dystrophy 1. The C. elegans strains are amenable for high-throughput screening applications, for both gene target as well as small molecule identification.

Entomopathogenic nematode Heterorhabditis bacteriophora having an enhanced longevity, comprising a first locus comprising a single nucleotide polymorphism at position 75 of the nucleotide sequence SC00004647 as depicted in SEQ ID NO: 5, in which C is substituted by T; and/or a second locus comprising a single nucleotide polymorphism at position 54 of the nucleotide sequence SC00006203 as depicted in SEQ ID NO: 7, in which C is substituted by T.