A bacterial artificial chromosome library for the Chinese alligator (Alligator sinensis)

Chinese alligator (Alligator sinensis) is a rare and endangered species endemic to China. To better understand genetic details of the Chinese alligator genomic structure, a highly redundant bacterial artificial chromosome (BAC) library was constructed. This library consists of 216,238 clones with an average insert size of about 90 kb, indicating that the library contains 6.8-fold genome equivalents. Subsequently, we constructed a 516 kb contig map for the Chinese alligator olfactory receptor (OR) genes, which spans nine BAC clones, and subjected the BACs to full sequencing. The sequence analysis revealed that this contig contained 16 OR functional genes and meanwhile demonstrated that the nine BACs, which constituted the contig, overlapped correctly, proving the usability of this genome library. As a result, this BAC library could provide a useful platform for physical mapping, genome sequencing or complex analysis of targeted genomic regions for this rare species.

► We constructed a deep-coverage bacterial artificial chromosome (BAC) genomic library for the Chinese alligator.
► We constructed the largest BAC-based genomic contig among the reptiles studied.
► We identified 16 functional olfactory receptor (OR) genes of the crocodilians for the first time.
► The BAC library provides a useful platform for genomic studies of the alligator.