Building on the mapping results of Kobayashi et al. (2000) (see Mapping section above), Hirano et al. (2000) did some further fine mapping, and then constructed a cosmid library of the fine-mapped region of BTA1, and then used the best cosmid clone as a probe of kidney cDNA from normal and affected animals, identifying a single cDNA, which, when sequenced, turned out to be the bovine paracellin-1 gene, which they called Claudin-16, and which lacked exons 1-4 in affected animals. Independently, and building on the mapping results of Ohba et al. (2000; Mammalian Genome 11:316-319), Ohba et al. (2000; Genomics 68:229-236) did some further fine mapping and physical mapping of the region, and then identified and sequenced their comparative positional candidate gene, paracellin-1, revealing "a region of 37 kb including exons 1 to 4 of the bovine paracellin-1 gene was deleted in the affected animals". Thus both groups arrived at the same result at around the same time: the former paper was published in May 2000, and the latter in September 2000.
