FIGURE 2.

Genetic engineering tools-induced genome editing in Microalgae. The double-stranded breaks (DSBs) introduced at the target site by CRISPR/Cas or TALEN or ZFN complexes stimulates the endogenous DNA repair machineries, non-homologous end joining (NHEJ) in the absence of the donor template or the homology-directed repair (HDR) in presence of the donor template. The NHEJ is generally associated with the introduction of insertions and/or deletions (indels) of varying lengths at the DSB site, often leading to the disruption of the reading frame of the target gene. The HDR pathway results in a precise insertion or deletion at the DSB site by homologous recombination. The preferred tool is the CRISPR/Cas9 which is highlighted in red as it is very accurate, easy, and fast.