Construction and evaluation of directionally cloned cDNA libraries from lactating and non-lactating mammary gland of river buffalo (Bubalus bubalis): A resource for gene identification in bubaline genome

Directionally cloned cDNA libraries from lactating (Lac-MG) and non-lactating (NLac-MG) buffalo mammary gland were constructed and characterized. The total number of independent primary clones were: 8.0 x 10⁴ and 1.1 x 10⁵ for Lac-MG and Nlac-MG cDNA libraries, respectively, with >90% of the clones having cDNA inserts. The occurrence of large cDNA insert length (average 0.90 Kb: range 0.45–2.5 Kb in Lac-MG and average 0.57 Kb: range 0.32–1.8 Kb in NLac-MG cDNA libraries) was indicative of the good quality status of both the libraries. The single-pass sequencing of randomly selected cDNA clones found several full-length cDNA sequences with complete 5’ and 3’ UTR. The initial sequence analysis showed several clones harboring milk protein, ribosomal and regulatory gene transcripts like ubiquitin, mammary derived growth inhibitor, lipoprotein lipase etc. The two cDNA libraries can be utilized as gene resources for cataloguing and annotation of mammary gland transcripts/ESTs in river buffaloes.