The 9-kDa calbindin gene of Rousettus aegyptiacus: its identification and isolation from a genomic library

A genomic library of the fruit bat (Rousettus aegyptiacus) was constructed in lambda phage gt11. The titre of the library was determined to be 2 × 10⁵ pfu/ml. The genomic library was amplified and the titre of the amplified library increased 300-fold to 7 × 10⁷ pfu/ml. The library was screened by in situ hybridization techniques using a fragment of the mouse 9-kDa calbindin cDNA as a probe. Screening of 10⁵ plaques yielded a positive clone. Three additional rounds of screening were performed to purify the positive. Lambda phage DNA was isolated from the positive clone and restriction digest analysis, followed by hybridization studies, was performed on these digests in order to determine the location of the bat 9-kDa calbindin gene in the insert of the lambda phage vector. Restriction maps so derived were interpreted from the published sequence for the rat 9-kDa calbindin gene and indicate the successful isolation of the 9-kDa calbindin gene of Rousettus aegyptiacus.