GENETIC TOOLS, TRANSGENESIS, RNAi in different species

GENETIC EDITING / CRISPR

The TALEN approach works in C. briggsae Lo et al. 2013,Wood et al. 2011, Wei et al. 2013.

The CRISPR/Cas9 method is now implemented in C. briggsae and other species.

Using the same plasmids as in C. elegans is possible, at least in C. briggsae: see Culp et al. in biorxiv.

Using Cas9 protein and synthetic guide RNA may overcome problems of germ line silencing and of inadequate promoters or 3'UTR in other species. See Witte et al. 2015 in Pristionchus pacificus. This method has been successfully used in several Caenorhabditis species (Marie Delattre).

TRANSGENESIS

Microinjection and extra-chromosomal (Ex) array formation works seems to work in most Caenorhabditis species: Table 1 in Nuez & Félix 2012 . However, even in C. briggsae, the formation of Ex arrays is less efficient than in C. elegans and mosaic silencing can be observed in somatic tissues.

Bombardment requires a positive selection marker: unc-119 mutants are available in C. briggsae, Zhao et al. 2010; dual antibiotic selection was implemented in Cel CB4856, Cbr, Cre, Cbn: Semple et al. 2012.

CRISPR now provides another method for transgenesis.

RNAi

RNAi susceptibility is a fast-evolving trait. External administration of dsRNA (synthetic dsRNA, or ds-RNA producing bacterial feeding) does not work in all species: Winston et al. 2007, Nuez & Félix 2012. Efficiency also varies between tissues, including the germ line, even in C. elegans: Tijsterman et al. 2002; Pollard & Rockman 2013.

SEE ALSO the Discussion page.