The CRISPR-Cas9 system has been widely used for inducing targeted mutations
in a variety of species. In Arabidopsis, CRISPR relies on the edited cells
where the Cas9 protein does its activity to obtain heritable and stable
mutated lines. Fudan University researchers designed an improved CRISPR-Cas9
system, named MSC (meiocyte-specific CRISPR-Cas9) system. In this system,
the Cas9 expression is driven by an experimentally approved
meiocyte-specific promoter.

To test the system, the team, led by Penghui Xu, targeted two endogenous
genes, the vegetative gene AtDET2, and reproductive gene AtDMC1. In the T1
generation, heterozygous plants for the targeted genes were obtained in high
efficiency. Meanwhile, homozygous plants were abundant in the T2 generation.



The team also made a suicide-MSC system, which can edit the targeted
endogenous gene and the exogenous Cas9 gene simultaneously, maintaining the
stable mutated alleles for functional studies.

These two new systems provide new approaches to generate mutations for gene
functional studies.

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