A low-copy-number vector utilizing beta-galactosidase for the analysis of gene control elements

Area of Science:

• Molecular Biology
• Genetics
• Biotechnology

Background:

• Analyzing gene regulatory elements requires precise tools for in vivo studies.
• Existing high-copy-number vectors can be influenced by copy number, affecting regulatory element analysis.

Purpose of the Study:

• To construct and validate a low-copy-number vector, pFZY1, for accurate in vivo analysis of regulatory elements.
• To compare the performance of pFZY1 with a high-copy-number vector (pKO-vector series) in analyzing promoter activity.

Main Methods:

• Construction of the pFZY1 low-copy-number vector containing a promoterless beta-galactosidase (lacZ) gene and an oriF replication origin.
• Insertion and analysis of tetracycline resistance (TcR) and lac promoter fragments within pFZY1 and pKO-vector series.
• Measurement of beta-galactosidase (beta Gal) activity to quantify transcriptional activity and promoter regulation.

Main Results:

• The pFZY1 vector consistently yielded reliable beta Gal activity values for inserted promoters.
• Transcriptional activity of TcR promoter fragments in pFZY1 showed variations within a six-fold range.
• Regulation of lac promoters in pFZY1 mirrored chromosomal regulation, while high copy numbers in pKO-1mp18 significantly altered regulation.

Conclusions:

• The pFZY1 low-copy-number vector offers a robust and accurate system for in vivo analysis of gene regulatory elements.
• pFZY1 minimizes the artifacts associated with high-copy-number vectors, enabling more reliable assessment of promoter function and regulation.