**2. Brief history of CRISPER**

Ishino and his colleagues identified CRISPER for the first time in *E. coli* in 1987, with a 1664-nucleotide sequence [2]. From 1993 until 2005, it was extensively discovered. CRISPER function were established in 2007 following the discovery of genes proximal to the CRISPER locus in 2002 and foreign viral DNA sequences in CRISPER space in 2005. CRISPER was discovered by two laboratories at the same time in 2013 to become the most powerful gene editing technique known (**Figure 2**).

Arbo viral diseases such as dengue, chikungunya, Zika and malaria are a major public health problem across the world. To counteract the spread of mosquito-borne disease, researchers transformed CRISPER/Cas 9 into extremely effective "gene

#### **Figure 2.**

*Flow chart showing history and discovery of CRISPER/Cas technique.*

drive" systems capable of spreading disease resistance genes across whole populations. Researchers packaged disease resistance genes, CRISPER, gRNA, and Cas9 components into a single DNA construct to produce a gene drive [10]. After insertion, the gene drive replicates autonomously into both parental chromosomes and is inherited by around 99.5% of progeny. Advances in gene drive technology promises urgent alternatives for disease control. Two approaches for controlling arbo-viral diseases for controlling arbo-viral disease using gene-edited mosquitoes have recently gained significant attention. The first approach is "Population Replacement" where the wild mosquito population, which carry or transmits the pathogen, is replaced by the normal ones. The principle of gene drive underlies this strategy. Gene drive makes use of an inheritance quirk to pass on a trait to more than half of a mosquito's offspring allowing it to spread rapidly over a population. Another strategy is "Population Suppression" which involves the reduction of mosquito population, resulting in less mosquito genic condition and fever mosquito capable of transmitting pathogens.
