Transgenesis, gene trapping, enhancer trapping, and the Gal4FF-UAS system were created in zebrafish utilising the Tol2 transposable element. Gene trap constructions include a splice acceptor as well as the GFP or Gal4FF (a modified form of the yeast Gal4 transcription activator) gene, whereas enhancer trap constructs include the zebrafish hsp70l promoter as well as the GFP or Gal4FF gene. They have created transgenic zebrafish by running genetic screenings with these constructs and expressing GFP and Gal4FF in particular cells, tissues, and organs. The expression of Gal4FF is observed by generating twin transgenic fish with a Gal4FF transgene and a GFP reporter gene inserted downstream of the Gal4-recognition region (UAS). Furthermore, by mating with UAS effector fish, the Gal4FF-expressing cells may be controlled. When fish expressing Gal4FF in particular neurons are crossed with UAS:TeTxLC fish carrying the tetanus neurotoxic gene downstream of UAS, the neuronal activity in the double transgenic fish are suppressed.
Green fluorescence protein (GFP) transgenic zebrafish lines that are controlled by the LCR(RH2)-RH2-1 or LCR(RH2)-RH2-2 green opsin regulatory elements. the Tg(LCR(RH2)-RH2-1:GFP)(pt112) and Tg(LCR(RH2)-RH2-2:GFP)(pt115) transgenic zebrafish lines express GFP in the pineal gland and specific kinds of photoreceptors using confocal immunomicroscopy, stereo-fluorescence microscopy, and Western blotting. Furthermore, GFP is expressed in the hatching gland, optic tectum, and olfactory bulb in several of these lines. Patterns differ considerably from previously reported comparable transgenic fish lines, making them excellent instruments for investigating tissue and organ development. Furthermore, the differences in GFP expression across various lines support the idea that transgenic expression is frequently sensitive to location effect, highlighting the importance of rigorous verification of expression patterns when transgenic animal models are used for study.
To meet the demand for genomic alteration in zebrafish, several genome editing methods such as zinc-finger nucleases (ZFNs), TAL effector nucleases (TALENs), and the clustered regularly interspersed short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system have developed .These genome editing approaches rely on tailored endonucleases to induce targeted DNA double-strand breaks (DSBs) at specified locations. When DSBs form in DNA, the cleaved DNA is repaired via nonhomologous end joining (NHEJ) or homology-directed repair (HDR). Because of the great DNA cutting effectiveness and versatility of CRISPR/Cas9 compared to other reverse genetic methods, the CRISPR/Cas9 strategy is more extensively employed to alter endogenous genes in a variety of cell lines and live animals. Toxicological and pharmacological researchers have seized on zebrafish’s several advantages, such as their short generation time, well-characterized development, and early maturation as transparent embryos. Standard husbandry techniques in zebrafish are meant to sustain population variety, which distinguishes them from many other model species. While this variety is appealing for translational applications in human and environmental health, it raises crucial issues about how interindividual genetic variation may lead to variations in chemical exposure or disease susceptibility. Findings from pooled zebrafish populations support this hypothesis of variety, although they cannot directly quantify allele frequencies for reference vs alternative alleles. A whole genome sequencing was performed on a large group (n = 276) of individual zebrafish embryos using the Tanguay lab Tropical 5D zebrafish line (T5D). On an Illumina 3000HT, paired-end reads were obtained and matched to the most current zebrafish reference genome (GRCz10). These data were utilised to examine observed population genetic variation across species (humans, mice, and zebrafish), and then across zebrafish lines. They have discovered more single nucleotide polymorphisms (SNPs) in T5D than in any of the WIK, TU, TL, or AB lines previously reported in SNP databases that some of the new SNPs are shared with other zebrafish lines but have not been found in earlier research due to the limitations of pooled sequencing techniques in capturing population diversity. T5D is established as a model that is indicative of variety levels among laboratory zebrafish lines, it is seen that experimental design and analysis may have a significant impact on assessing genetic diversity in diverse