Gene editing technology can be used to change the genes of plants and animals to affect their color or morphology to a certain extent. The following are general steps and related technologies: ### Choose the right gene editing technology. The commonly used gene editing technologies are: - **CRISPR/Cas9 technology**: This is the most widely used gene editing tool. It can accurately cut and edit specific genes. By designing a guide RNA (gRNA) complementary to the target gene, the Cas9 protein is guided to a specific DNA site, and then the gene is knocked out, inserted or replaced. - **TALEN technology**: Transcription activator-like effector nuclease is also a technology that can specifically recognize and cut specific DNA sequences. ### Determine the target gene. Which genes need to be studied to affect the color or morphological expression of plants and animals. For example, in plants, genes that may be related to pigment synthesis, changing these genes may change the color of flowers; in animals, such as genes that control hair color or body shape development. ### Design a gene editing plan According to the selected gene editing technology and target gene, design a specific experimental plan. This includes: - Design a suitable gRNA or TALEN target sequence to ensure that the target gene can be accurately targeted. - Construct a vector containing gene editing elements, and introduce the Cas9 protein or TALEN protein encoding gene and the corresponding gRNA expression frame and other elements into the vector. ### Introduction of gene editing elements Introduce the constructed vector into animal and plant cells by appropriate methods. - **Plant**: Common methods include Agrobacterium-mediated transformation and gene gun method. For example, Agrobacterium-mediated transformation is to co-culture Agrobacterium containing the target gene vector with plant cells, so that Agrobacterium transfers the gene editing elements on the vector into the plant cell genome. - **Animal**: Gene editing elements can be directly injected into fertilized eggs by microinjection; or the vector can be introduced into animal cells by viral vector-mediated method. ### Screening and identification of successfully edited individuals- After the gene editing elements are introduced, it is necessary to use specific screening methods to find those animal and plant individuals with successful gene editing. - **Plant**: Antibiotic resistance markers or reporter genes can be used to screen successfully transformed cells, and then regenerate complete plants through tissue culture technology. Then, molecular biological methods such as PCR amplification and sequencing are used to identify whether the target gene has been successfully edited. - **Animals**: Determine whether the expected gene editing has occurred by testing the genomic DNA of the offspring individuals. For example, DNA from animal cells or tissues can be extracted, sequenced after PCR amplification, and the sequence changes of the target gene can be analyzed. For individuals that have been successfully edited, further observe whether their phenotypic changes such as color and morphology are in line with expectations. ### Subsequent cultivation and optimization- For animals and plants that have been successfully edited, subsequent cultivation and reproduction are carried out to obtain a stable genetic individual population. - Optimize and adjust the editing effect according to actual conditions. If the ideal color or morphological changes are not achieved, the reasons can be further analyzed. It may be necessary to adjust the gene editing target or optimize the cultivation conditions. It should be noted that gene editing of animals and plants involves many ethical, safety and regulatory issues. Before any relevant operations are carried out, it is necessary to ensure strict compliance with national and international laws and regulations and relevant ethical standards to prevent potential risks to the ecological environment and human health. In addition, in many countries and regions, there are strict controls on the use of gene-edited animals and plants for non-scientific research purposes.