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Each approach has distinct implications. Nuclear
transformation is well-established and allows for tissue-
specific expression and complex regulatory control—but
the expression levels can vary, and the inserted gene can
sometimes be silenced over time. In contrast, chloroplast
transformation offers significant advantages for biologic
production. Each plant cell contains hundreds of
chloroplasts, each with dozens of genome copies—creating
a natural system for gene amplification. As a result,
chloroplast expression can yield extraordinarily high levels
of the therapeutic protein.

There’s also a biosafety benefit: chloroplast DNA is
typically maternally inherited in most plant species,
meaning it doesn’t travel through pollen. This dramatically
reduces the risk of gene flow to surrounding crops or wild
plants—a major advantage when growing pharmaceutical
products in open or semi-contained environments.

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