The CRISPR-Cas9 genome editing system can be used to edit genes and correct mutations associated with inherited diseases. However, this technology also has the potential to edit genes in germline cells in order to irreversibly modify the human species and the natural evolution of life
Explanation:
The CRISPR-Cas9 (Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9) system is a natural prokaryotic defense system used by bacteria to defend against invading DNA. In the laboratory, the CRISPR-Cas9 system has been repurposed to create a versatile genome-editing tool that allows us to modify the genome of mammalian cells in a targeted fashion. The CRISPR-Cas9 is a simple gene-editing tool that consists of a single guide RNA (sgRNA) that guides the Cas9 enzyme to the exact genomic location where Cas9 needs to make a cut, which is then repaired by different DNA repair mechanisms. During DNA repair, nucleotides can be replaced and/or deleted, thereby producing desired genomic modifications. The CRISPR-Cas9 has an enormous potential to repair mutations in genes associated with inherited genetic disorders and cancer (i.e., oncogenes might be reversed in vivo by using this technology). However, the CRISPR-Cas9 genome editing system is also a subject of concern due to its dual use. For example, this technology can be used to modify the genome of germline cells by inducing mutations that can be passed across generations, thereby irreversibly modifying human DNA and altering the normal course of evolution.
Osmoregulation is an example of a negative feedback, homeostatic control system. This system detects changes in the salinity of the water Chinook salmon live in, working to keep the body water concentration constant.
