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Mammary gland myoepithelial cells were isolated from cattle and cell lines were established. Cells were plated onto tissue culture dishes with or without collagen. Cells were transfected with bovine growth hormone rDNA containing one of the following eucaryotic transcriptional regulatory sequences: human cytomegalovirus immediate early promoter, simian virus 40 early promoter, mouse metallothionein I promoter and the Rous sarcoma virus long terminal repeat. These sequences were evaluated for their ability to direct recombinant bovine growth hormone DNA expression in myoepithelial cells. The most effective transcriptional regulatory sequences were the cytomegalovirus immediate early and simian virus 40 early promoters.

Differential amyloid precursor protein (APP) gene expression was investigated in primary cultures of astrocytes, neurons and microglia from neonatal rat cerebral cortex as well as in meninges, and young and adult cerebral cortex tissues in order to define the possible contribution of individual CNS cell types in βAP deposition. Meninges and neurons contained higher levels of total APP mRNA than glial cells and APP 695mRNA was abundant in neurons while glial cells and meninges contained higher levels of KPI-containing mRNAs. These results demonstrate cell-specific transcriptional and post-transcriptional regulation of APP gene expression in CNS cell types. In addition, the steady-state level of APPs in each cell type did not reflect mRNA levels indicating translational or post-translational regulation.

The presence of the zinc-finger motif in nuclear protein structure often confers specific DNA-binding capabilities and, consequently, may implicate such proteins as being involved in gene regulation. We measured the zinc-binding capacity of nuclear proteins by using a zinc (Zn 2+) blotting technique. This assay revealed that some non-histone proteins are selectively associated with this metal ion. Of particular interest, a nuclear protein, B 2( Mr68000; pI 7.3), associated with actively transcribed nucleosomes and possibly involved with premessenger splicing, exhibits Zn 2+-binding activity. Moreover, this activity can be achieved with as little as 2 μg of nuclear protein and the zinc-binding capacity is, on average, 2 ions per molecule of the protein B 2.