Compositions and methods are provided for genetically modifying cells to guide in situ chemical synthesis of electroactive, conductive, or insulating polymers on plasma membranes, organelle membranes, or subcellular surfaces of cells. In particular, compositions and methods are provided for genetically modifying excitable cells such as neurons, muscle cells, and endocrine cells to guide in situ chemical synthesis of polymers on the extracellular side of the plasma membrane. The subject methods can be used in various applications, for example, to assemble polymers in vivo at targeted locations to modulate electrical conduction and create new electrical conduction pathways, allow cell-type-specific neuromodulation, provide a conductive structure on cells for connection to electrodes, sensors, or other external electronic and electrochemical devices, and create a durable structure to replace damaged tissue for use in regenerative medicine.

A quantum dot (QD)-rhodopsin bioconjugate system uses Förster resonance energy transfer (FRET)-mediated induction of cellular membrane depolarization via optical activation of ion channel proteins channelrhodopsin (ChR).

A quantum dot (QD)-rhodopsin bioconjugate system uses Förster resonance energy transfer (FRET)-mediated induction of cellular membrane depolarization via optical activation of ion channel proteins channelrhodopsin (ChR).

The invention involves mutant or recombinant Chlorophyte algal organisms that have a genetic modification in a gene encoding a chloroplastic signal recognition particle 43 (cpSRP43). In one embodiment the Chlorophyte organisms are Trebouxiophyte algae that are diploid or polyploid for a gene encoding a chloroplastic signal recognition particle 43 (cpSRP43). The mutant organisms can have a genetic modification in one allele of the gene but not in another allele of the gene. The mutant or algal organisms have higher biomass and lipid productivity. Additional mutant or algal organisms are disclosed that also have a genetic modification to one or more genes encoding a light harvesting chlorophyll a/b (binding) protein.

The invention involves mutant or recombinant Chlorophyte algal organisms that have a genetic modification in a gene encoding a chloroplastic signal recognition particle 43 (cpSRP43). In one embodiment the Chlorophyte organisms are Trebouxiophyte algae that are diploid or polyploid for a gene encoding a chloroplastic signal recognition particle 43 (cpSRP43). The mutant organisms can have a genetic modification in one allele of the gene but not in another allele of the gene. The mutant or algal organisms have higher biomass and lipid productivity. Additional mutant or algal organisms are disclosed that also have a genetic modification to one or more genes encoding a light harvesting chlorophyll a/b (binding) protein.

A transgenic plant which exhibits a growth capacity which is enhanced compared to that of a host plant, and has a chimeric protein of a peptide containing an amino acid sequence derived from a motor domain of myosin XI of a donor plant 1, which is a plant species other than the host plant, and a peptide containing an amino acid sequence derived from a domain other than the motor domain of myosin XI of a donor plant 2, which is the host plant or a plant species other than the host plant, the transgenic plant being characterized in that the motor domain loop 2 region has EEPKQGGKGGGKSSFSSIG or EEPKQGGGKGGSKSSFSSIG, and in addition to these sequences, has an amino acid sequence in which one to six amino acids have been deleted, replaced or added.

Phototropin is a blue light receptor, which mediates a variety of blue-light elicited physiological processes in plants and algae. In higher plants these processes include phototropism, chloroplast movement and stomatal opening. In the green alga Chlamydomonas reinhardtii, phototropin plays a vital role in progression of the sexual life cycle and in the control of the eye spot size and light sensitivity Phototropin is also involved in blue-light mediated changes in the synthesis of chlorophylls, carotenoids, chlorophyll binding proteins. We compared the transcriptome of phototropin knock out (PHOT KO) mutant and wild-type parent to analyze differences in gene expression in high light grown cultures (500 .Math.mol photons m.sup.-2s.sup.-1). Our results indicate the up-regulation of genes involved in photosynthetic electron transport chain, carbon fixation pathway, starch, lipid, and cell cycle control genes. With respect to photosynthetic electron transport genes, genes encoding proteins of the cytochrome b6f and ATP synthase complex were up regulated potentially facilitating proton-coupled electron transfer. In addition genes involved in limiting steps in the Calvin cycle Ribulose-1 ,5-bisphosphate carboxylase/oxygenase (RuBisCO), Sidoheptulose 1,7 bisphosphatase (SBPase), Glyceraldehyde-3-phosphate dehydrogenase (3PGDH) and that mediate cell-cycle control (CDK) were also up regulated along with starch synthase and fatty acid biosynthesis genes involved in starch and lipid synthesis. In addition, transmission electron micrographs show increased accumulation of starch granules in PHOT mutant compared to wild type, which is consistent with the higher expression of starch synthase genes. Collectively, the altered patterns of gene expression in the PHOT mutants were associated with a two-fold increase in growth and biomass accumulation compared to wild type when grown in environmental photobioreactors (Phenometrics) that simulate a pond environment. In conclusion, our studies suggest that phototropin may be a master gene regulator that suppresses rapid cell growth and promotes gametogenesis and sexual recombination in wild type strains.

Phototropin is a blue light receptor, which mediates a variety of blue-light elicited physiological processes in plants and algae. In higher plants these processes include phototropism, chloroplast movement and stomatal opening. In the green alga Chlamydomonas reinhardtii, phototropin plays a vital role in progression of the sexual life cycle and in the control of the eye spot size and light sensitivity Phototropin is also involved in blue-light mediated changes in the synthesis of chlorophylls, carotenoids, chlorophyll binding proteins. We compared the transcriptome of phototropin knock out (PHOT KO) mutant and wild-type parent to analyze differences in gene expression in high light grown cultures (500 .Math.mol photons m.sup.-2s.sup.-1). Our results indicate the up-regulation of genes involved in photosynthetic electron transport chain, carbon fixation pathway, starch, lipid, and cell cycle control genes. With respect to photosynthetic electron transport genes, genes encoding proteins of the cytochrome b6f and ATP synthase complex were up regulated potentially facilitating proton-coupled electron transfer. In addition genes involved in limiting steps in the Calvin cycle Ribulose-1 ,5-bisphosphate carboxylase/oxygenase (RuBisCO), Sidoheptulose 1,7 bisphosphatase (SBPase), Glyceraldehyde-3-phosphate dehydrogenase (3PGDH) and that mediate cell-cycle control (CDK) were also up regulated along with starch synthase and fatty acid biosynthesis genes involved in starch and lipid synthesis. In addition, transmission electron micrographs show increased accumulation of starch granules in PHOT mutant compared to wild type, which is consistent with the higher expression of starch synthase genes. Collectively, the altered patterns of gene expression in the PHOT mutants were associated with a two-fold increase in growth and biomass accumulation compared to wild type when grown in environmental photobioreactors (Phenometrics) that simulate a pond environment. In conclusion, our studies suggest that phototropin may be a master gene regulator that suppresses rapid cell growth and promotes gametogenesis and sexual recombination in wild type strains.

A recombinantly expressed nucleotide triphosphate transporter efficiently imports the triphosphates of unnatural nucleotides into cells, and the endogenous cellular machinery incorporates those nucleotides into cellular nucleic acids. UBPs can therefore form within the cell's nucleic acids. Moreover, neither the presence of the unnatural triphosphates nor the replication of the UBP represents a significant growth burden. The UBP is not efficiently excised by nucleic acid repair pathways, and therefore can be retained as long as the unnatural triphosphates are available in the growth medium. Thus, the resulting cell is the first organism to stably propagate an expanded genetic alphabet.

A recombinantly expressed nucleotide triphosphate transporter efficiently imports the triphosphates of unnatural nucleotides into cells, and the endogenous cellular machinery incorporates those nucleotides into cellular nucleic acids. UBPs can therefore form within the cell's nucleic acids. Moreover, neither the presence of the unnatural triphosphates nor the replication of the UBP represents a significant growth burden. The UBP is not efficiently excised by nucleic acid repair pathways, and therefore can be retained as long as the unnatural triphosphates are available in the growth medium. Thus, the resulting cell is the first organism to stably propagate an expanded genetic alphabet.