Molecular cloning of the Matrix Gla Protein gene from Xenopus laevis. Functional analysis of the promoter identifies a calcium sensitive region required for basal activity.

To analyze the regulation of Matrix Gla Protein (MGP) gene expression in Xenopus laevis, we cloned the xMGP gene and its 5' region, determined their molecular organization, and characterized the transcriptional properties of the core promoter. The Xenopus MGP (xMGP) gene is organized into five exons, one more as its mammalian counterparts. The first two exons in the Xenopus gene encode the DNA sequence that corresponds to the first exon in mammals whereas the last three exons show homologous organization in the Xenopus MGP gene and in the mammalian orthologs.

Persistent expression of a newly characterized Hyposoter didymator polydnavirus gene in long-term infected lepidopteran cell lines.

An Hyposoter didymator ichnovirus (HdIV) gene was stably maintained and efficiently transcribed in lepidopteran cell lines more than 3 years after HdIV infection. This K-gene had two introns and the fully spliced cDNA, named K19, comprised a short open reading frame and a long 3'-untranslated region with 13 imperfectly repeated sequences (44 to 102 nt). Transcripts related to the K-gene were detected in several long-term infected cell lines (Sf9, Spodoptera littoralis haemocytes, Trichoplusia ni).