Individual expression: We describe a method that allows the observation of real-time gene expression in a large number of individual giant liposomes encapsulating identical genetic material. We followed the gene expression profiles from DNA and mRNA templates coding for different proteins. Although the average profiles of individual liposomes were similar to those measured in bulk solution, strong variability between individual liposomes was observed at both transcription and translation.

The effects of vasoactive intestinal polypeptide (VIP), TRH, dopamine, and rat median eminence extract on GH release from GH-secreting pituitary adenomas were studied in vitro using a sensitive superfusion method. Dispersed pituitary tumor cells obtained from three patients with acromegaly were placed in a superfusion column, and the amounts of GH in the superfusate were determined. The addition of VIP (10(-6) M) to the perfusion system resulted in a marked increase in GH release in all three cases, and a dose-response relationship in VIP (10(-8) 10(-6) M) induced GH secretion was observed in one case studied. TRH (10(-7) M) and median eminence extract (1 equivalent/ml) also caused an abrupt and marked increase in GH release in all of the experiments. The infusion of either dopamine (10(-7) M) or bromocriptine (10(-7) M) inhibited GH secretion. These results suggest that VIP as well as TRH stimulate GH secretion by a direct action on GH-secreting pituitary tumor cells in at least some acromegalic patients.

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To study regulation of delta-crystallin expression during ontogeny, we transferred the gene from chicken into developing mouse embryos by first transforming an embryonic stem (ES) cell line of mouse and then producing chimaeric embryos by combining them with normal mouse embryos. Using this technique, genes were transferred into a variety of developing mouse tissues with high efficiency. Two delta-crystallin gene constructs were used: the wild-type gene with 2200 bp of the 5′ flanking sequence, shown to be lens-specific in an assay using cultured mouse cells, and a mutant gene with 51 bp of the 5′ flanking sequence, lacking the sequence required for expression in lens cells. Five independent lines carrying the former and two lines carrying the latter were employed in producing chimaeras. In the chimaeric embryos having the wild-type gene, delta-crystallin was expressed in the lens and in specific regions of the primitive central nervous system (CNS) as is seen in embryonic expression in the chicken. In adult mouse chimaeras also, expression was restricted to the lens and the CNS, in the pyramidal neurones of the piriform cortex and the hippocampus. delta-crystallin expression in these tissues is due to proper transcriptional regulation, since no expression was observed when chimaeras were produced with the ES lines carrying the mutant gene. The experimental results reported here demonstrate the advantage of ES-cell-mediated gene transfer in the study of embryonic gene regulation, because a number of gene constructs and chromosomal sites can be analysed shortly after embryo manipulation without requiring gene transmission to the next generation.

biologist often takes the following procedures to analyze The emerging field of synthetic biology seems to have a great biological data; (1) isolating each component (e.g. genes or potential to the development of new biotechnologies and the proteins) from cellular systems, (2) analysing the connection understanding of self-organizing principle in life. Currently, and networks between components, (3) describing a model several synthetic biologists aim to understand the evolution of of molecular networks. In contrast, synthetic biologists naturally occurring biological systems through a "bottom-up initially aim to design and "evolve" molecular parts or approach" in contrast to the conventional reductive approach. devices, and then construct or rewire genetic networks, Several lines of pioneering works have been demonstrated in wish to then "artior ce gen e nethe that behaviors of programmed synthetic networks are finally wish to synthesize "artificial cells". (please see the predicted in vitro. However, it is crucial to create new other review [4]). molecular "parts" for (re)constructing synthetic genetic networks in artificial cell-like compartments, such as giant M O RBiOIOD w it Lifd? liposomes. We focus on RNA and RNP (ribonucleoprotein) that hold promise as new "parts" for synthetic biology. They are constructed with molecular design and an experimental * solatirng each comnponent Synthesizing artificial cells. evolution technique. So far, designed self-folding RNAs, RNA (molecular pats/devices). Constructing new systems. (RNP) enzymes, and nanoscale RNA architectures have been Analyzing the conrnection Rewiring cellular networks. successfully constructed by utilizing Watson-Crick base-pairs batween parts.

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