Ann Arbor-based Velcura Therapeutics Inc. Thursday announced that it had worked with Santa Clara, Calif.-based Affymetrix Inc. (Nasdaq: AFFX) to develop a new "gene chip" array that should speed up research into bone disease. The device enables researchers to follow changes in gene expression during human bone formation. Approximately 1,500 genes are included on the chip -- about 1,250 bone-related genes discovered by Velcura scientists, as well as 250 more reported in scientific literature as bone-related.