Recently, new serine integrases have been identified, increasing the possibility of scaling up genomic modulation tools. Here, we describe the use of unidirectional genetic switches to evaluate the functionality of six serine integrases in different eukaryotic systems: the HEK 293T cell lineage, bovine fibroblasts and plant protoplasts. Moreover, integrase activity was also tested in human cell types of therapeutic interest: peripheral blood mononuclear cells (PBMCs), neural stem cells (NSCs) and undifferentiated embryonic stem (ES) cells. The switches were composed of plasmids designed to flip two different genetic parts driven by serine integrases. Cell-based assays were evaluated by measurement of EGFP fluorescence and by molecular analysis of attL/attR sites formation after integrase functionality. Our results demonstrate that all the integrases were capable of inverting the targeted DNA sequences, exhibiting distinct performances based on the cell type or the switchable genetic sequence. These results should support the development of tunable genetic circuits to regulate eukaryotic gene expression.

Herbaceous flowering plants of the genus Cuphea (Lythraceae) are noted for synthesizing significant amounts of medium-chain caprylic, capric, lauric, and myristic fatty acids (FAs) in the seed oils, with each species typically emphasizing one of several FAs. The genus is a prospective temperate source of oilseeds for fatty acids used in the manufacture of products as diverse as soaps, food, and biofuels, and it has become a model research system for the study of enzyme-mediated fatty acid synthesis. Seed oil FA composition for 44 species is reported here, including first records for 25 species from South America, primarily from Brazil. Nineteen species are re-analyzed to verify earlier results and expand information on variability in oil composition. An appendix summarizes seed oil composition of 108