Grey Fox Lung Cells with mEmerald-MAP4 and mApple-H2B
The grey fox is a mammal belonging to the order Carnivora, which ranges throughout the majority of the lower half of North America to northern Venezuela and Colombia. The grey fox and the Island Fox are the last living members of the genus Urocyon, which is regarded as one of the most primitive of living canids. Though at one point it was the most populous fox in the east, human advancement permitted the red fox to become dominant.
This collection of digital video sequences demonstrates the proximity of the nucleus to the intracellular microtubule network in fox lung (FoLu line) fibroblasts. The nucleus was visualized with mApple fused to H2B, one of the highly conserved classes of proteins known as histones. Closely associated with DNA molecules, histones are found in eukaryotic cell nuclei where they are involved with the regulation of chromatin, genes, and nucleosomes. The fluorescent protein shown fused to H2B, mApple, is a red member of the mFruit series selected for enhanced photostability.
Microtubules in the featured fox lung cells were tagged with mEmerald fused to MAP4, a microtubule-associated protein. mEmerald is a variant of EGFP, an enhanced Aequorea derivative. The presence of four additional point mutations its parent protein does not have renders mEmerald brighter and more photostable than EGFP. Excitation and emission maxima of mEmerald occur at 487 and 509 nanometers, respectively.