Integrated and sequence-ordered BAC- and YAC-based physical maps for the rat genome.

Area of Science:

• Genomics
• Comparative Genomics
• Bioinformatics

Background:

• The sequencing of the Rattus norvegicus (rat) genome requires robust physical mapping resources.
• Bacterial artificial chromosome (BAC) libraries are essential tools for constructing genome-wide physical maps.
• Integration of physical maps with sequence assemblies is critical for accurate genome annotation.

Purpose of the Study:

• To construct a high-resolution physical map of the Rattus norvegicus genome.
• To integrate this physical map with the existing rat genome sequence assembly (version 3.1).
• To provide a foundational resource for future genomic studies and gene mapping in rats.

Main Methods:

• Construction of a physical map using fingerprinted bacterial artificial chromosome (BAC) clones from the CHORI-230 library.
• Assembly of BAC clones into fingerprint contigs, providing approximately 13-fold genome coverage.
• Alignment and integration of the BAC map with a yeast artificial chromosome (YAC) map using shared markers and in silico mapping methods, including BAC-end sequences.

Main Results:

• A physical map comprising 376 fingerprint contigs was assembled.
• 95% of the fingerprint map clones were annotated with coordinates on the rat genome sequence assembly.
• 358 of 376 contigs were anchored to the sequence assembly, with 324 localized to specific chromosomes.

Conclusions:

• The developed fingerprint map is a high-resolution, integrative resource for the Rattus norvegicus genome.
• It establishes genome-ordered associations between BAC, YAC, and PAC clones and the assembled rat genome sequence.
• This map significantly aids in the accurate placement and annotation of genomic features within the rat genome.