You have identified a recessive mutation that alters bristle patterning in Drosophila and have used recombinant DNA technology to identify a genomic clone that you believe harbors the gene. How would you demonstrate that your gene is on the genomic clone?

Verified step by step guidance

1. Step 1: Perform a rescue experiment. Introduce the genomic clone containing the suspected gene into mutant Drosophila using a transgenic approach. Observe whether the bristle patterning phenotype is restored to wild-type, which would indicate that the gene on the clone is responsible for the phenotype.
2. Step 2: Conduct a loss-of-function experiment. Use RNA interference (RNAi) or CRISPR-Cas9 to specifically knock down or delete the gene on the genomic clone in wild-type Drosophila. Observe whether the bristle patterning phenotype mimics the mutant phenotype, confirming the gene's involvement.
3. Step 3: Analyze gene expression. Use techniques such as RT-PCR or in situ hybridization to determine whether the gene on the genomic clone is expressed in tissues or developmental stages relevant to bristle patterning. Correlation of expression with the phenotype supports the gene's role.
4. Step 4: Sequence the gene. Compare the sequence of the gene on the genomic clone from wild-type and mutant Drosophila. Look for mutations in the gene that are consistent with the recessive bristle patterning phenotype.
5. Step 5: Perform functional assays. Introduce the wild-type version of the gene from the genomic clone into mutant Drosophila and observe whether it rescues the phenotype. Additionally, introduce the mutant version of the gene into wild-type Drosophila to see if it recapitulates the mutant phenotype.

Key Concepts

Recessive Mutation

A recessive mutation is a genetic alteration that only manifests phenotypically when an individual has two copies of the mutated allele. In the context of Drosophila, this means that the altered bristle patterning will only be observed in flies that inherit the recessive allele from both parents. Understanding this concept is crucial for determining how the mutation affects the phenotype and for designing experiments to identify the responsible gene.

Recombinant DNA Technology

Recombinant DNA technology involves combining DNA from different sources to create new genetic combinations. This technique is essential for isolating and characterizing genes, as it allows researchers to clone specific DNA fragments, such as the genomic clone suspected to contain the gene of interest. Mastery of this technology is vital for demonstrating the presence of the gene on the genomic clone through methods like gene mapping or functional assays.

Genomic Cloning

Genomic cloning is the process of isolating and amplifying a specific segment of DNA from an organism's genome. This technique is used to create a genomic library, which can be screened to find clones that contain genes of interest. To demonstrate that the gene responsible for the bristle patterning mutation is on the genomic clone, one could use techniques such as PCR amplification, sequencing, or complementation tests to confirm the presence and functionality of the gene within the clone.