The reporter gene that is constructed is injected into the rat ortholog of ISL 1 (ultra-conserved element) into the fertilized mouse oocytes. The expression of the reporter gene of the rat is expressed along the spinal cord. And head of the transgene mouse embryo as we expect for the location of future motor neurons.
Most significantly, the expression pattern corresponds to part of expression pattern of the native mouse ISL1 gene. The pattern of expression strongly suggests that the conserved element is regulatory region, for the ISL1 gene.
In addition, a transcriptional cis-acting regulatory element is identified in an ultra-conserved element of the rat genome. Thousands of non-coding regulatory elements will likely identify on the basis of the sequence conservation and the activity of those elements in reporter assays.