Bacterial Artificial Chromosome (BAC) Use in the Study of Nervous System

Bacterial Artificial Chromosome (BAC)

BAC is a high-throughput low-copy plasmid vector constructed based on the F plasmid of E. coli. Each circular DNA molecule carries an antibiotic resistance marker, a strictly controlled replicon derived from E. coli F factor (fertility factor), an ATP-driven helicase (RepE) that facilitates DNA replication, and three loci (italic, parB, and parCemphasis) that ensure accurate distribution of low-copy plasmids to progeny cells. The use of BAC vectors in transgenic mice is one of the strategies to achieve effective and reproducible cell-specific expression of proteins of interest in vivo.

The Application of BAC System in Neuroscience

Due to the diversification of nerve cell types and the complexity of their interconnections, it is extremely difficult to provide a comprehensive central nervous system (CNS) gene expression analysis. The development of transgenic mice methods for reporter gene analysis using precisely modified BAC provide a new method for neuroscience and related disease research.

Fig.1 One-step BAC modify used to introduce reporter genes into BAC clones. (Heintz, 2020)

GENSAT BAC Transgenic Project

The ability to use reporter genes to detect cell-resolved gene expression in transgenic mice has been demonstrated for the first time by a modified BAC carrying approximately 150k bases of genomic DNA around the mouse Ziprol gene. Subsequent research established a large-scale project using BAC transgenic mice to provide detailed CNS expression gene information, to identify BAC vector libraries used to manipulate specific CNS cell types, and to provide a set of mouse lines of enhanced green fluorescent protein (EGFP) reporter gene carried in a variety of CNS cell types. The usefulness of GENSAT data, vectors, and animals to the field of neuroscience depends in part on the accuracy of the obtained expression data and the ability to reproducibly target gene expression using the BAC vectors described in the GENSAT project.

BAC-Cre Constructs

Using the BAC structure to efficiently produce Cre drivers, targeting specific cell populations in the brain, including neuron and glial cell types, has universal applicability. BAC-Cre constructs for 10 genes (Chat, Th, Slc6a4, Slc6a2, Etv1, Ntsr1, Drd2, Drd1, Pcp2, and Cmtm5) produced 14 lines with Cre expression in specific neuronal and glial populations in the brain. The EGFP-Cre substitution adds functional utility to neurobiological research, allowing gene functions to be changed in specific neuron or glial cell populations, thereby supporting various research.

Fig.2 Cre expression in forebrain circuits. (Gong, 2007)

The Human Genome Project has had a profound impact on the development of biological sciences and medicine. Functional genomics in the post-sequencing era has changed the trajectory of medical practice in the diagnosis, treatment, and prevention of diseases. The BAC system is widely used by researchers from various countries in sequencing work, as well as research on genomics and functional genomics to further reveal the mysteries of the human neurological field.

Creative Biolabs has advanced technology and services in neurobiology research. We have decades of exploration and practice in neuroscience problems, and we have established a wide range of mouse models in the use of different vectors to target genes of interest, and we will provide you with the most suitable solutions and detection methods. Please feel free to contact us if you are interested or have any questions.

References

1. Heintz, N.; Gong, S. One-step bacterial artificial chromosome (BAC) modification: Preparation of plasmids. Cold Spring Harbor Protocols. 2020, 2020(7): pdb. prot098095.
2. Gong, S.; et al. Targeting Cre recombinase to specific neuron populations with bacterial artificial chromosome constructs. Journal of Neuroscience. 2007, 27(37): 9817-9823.