Individual chromosome identification in Clarias magur using BAC-FISH and comparative genes analyses

BAC library has always been an important genomic source for preserving the genetic material of an organism for sequencing, developing physical map as well as addressing the novel evolutionary biology questions. Here, the end sequences of BAC clones were generated using a set of primers and mapped on the genome scaffolds of C. magur using bioinformatics tool. Numbers of genes present on the clones were identified using scaffolds’ annotation information. Further, the clone insert DNA was labeled through nick translation using tetra methyl rhodamine-5-dUTP (Pool A contained 6 clones possessing 36 genes mapped on scaffold A) and fluorescein 12-dUTP (Pool B contained 4 clones possessing 15 genes mapped on scaffold B) fluorophores for probe construction and was subsequently hybridized on metaphase chromosomes using FISH. The BAC-FISH revealed the mapping of red color probe on 19th sub-telocentric chromosome and green color on 14th sub-metacentric chromosome. These findings will be useful in understanding the chromosomes organization and evolution of genomic structure as well as function of the species in comparison to its closely related and well studies species, such as channel catfish and zebrafish.