Bacterial artificial chromosomes (BACs)

Definition

Bacterial artificial chromosomes (BACs) are large plasmid vectors used to clone DNA fragments in bacterial cells. They can accommodate DNA inserts of up to 300 kilobases, making them essential tools in genomic mapping and sequencing projects, particularly in the Human Genome Project. BACs help researchers to efficiently study large genes or genomic regions that are difficult to analyze using smaller vectors.

5 Must Know Facts For Your Next Test

1. BACs can carry much larger fragments of DNA compared to conventional plasmids, which typically hold around 10-15 kilobases.
2. The use of BACs was pivotal in the sequencing of the human genome, allowing for the cloning and analysis of large genomic regions.
3. BACs are derived from the F plasmid of E. coli and are engineered to replicate and maintain stability within bacterial cells.
4. These vectors facilitate the manipulation of eukaryotic genes in prokaryotic systems, which is crucial for functional studies.
5. One of the key advantages of using BACs is their ability to reduce chimerism, where unrelated DNA fragments are combined during cloning, thus providing more accurate genomic representations.

Review Questions

• How do bacterial artificial chromosomes (BACs) compare to traditional plasmid vectors in terms of capacity and application?
  • BACs have a significantly larger capacity than traditional plasmid vectors, allowing them to carry DNA inserts up to 300 kilobases compared to the 10-15 kilobases typical for plasmids. This larger capacity makes BACs particularly useful for cloning large genes or genomic regions that are important in various studies, including genomic mapping and sequencing projects like the Human Genome Project. Their ability to hold more extensive DNA sequences allows for a more comprehensive analysis of complex genomic structures.
• Discuss the role of BACs in the development of genomic libraries and their importance in genetic research.
  • BACs play a crucial role in the construction of genomic libraries by allowing researchers to clone large fragments of DNA representing an organism's entire genome. This is significant for genetic research as it enables scientists to access a complete range of genetic material for study, facilitating advancements in areas such as gene function analysis, evolutionary biology, and disease research. By maintaining stable inserts, BACs ensure that libraries contain accurate representations of genomic information necessary for further investigation.
• Evaluate the impact of bacterial artificial chromosomes on the Human Genome Project and subsequent advancements in genomics.
  • Bacterial artificial chromosomes were instrumental in the success of the Human Genome Project by enabling the cloning and analysis of large segments of human DNA. Their ability to maintain larger inserts allowed researchers to work with extensive genomic sequences more efficiently, which was essential for mapping out complex regions of the human genome. The innovations brought by BAC technology have had lasting impacts on genomics, paving the way for enhanced sequencing techniques and facilitating ongoing research into gene function and regulation, ultimately advancing personalized medicine and biotechnology.

Related terms

Plasmid: A small, circular piece of DNA that can replicate independently of chromosomal DNA in bacteria, often used as a vector in genetic engineering.

Genomic Library: A collection of DNA fragments that represent the genetic material of an organism, stored in vectors such as BACs for further study and analysis.

Restriction Enzymes: Proteins that cut DNA at specific sequences, allowing for the insertion of DNA fragments into vectors like BACs for cloning purposes.