CHARACTERIZATION OF 2 NOVEL CASEIN TRANSCRIPTS IN RABBIT MAMMARY-GLAND

Two clones were isolated from a cDNA library corresponding to mRNAs wh ich accumulate in mid-lactating (14 day) rabbit mammary gland and char acterized by DNA sequencing. The two clones sequenced corresponded to two novel casein transcripts (pBRM5 and pBRM42). Relative mRNA abundan ces for the two clones were assessed by dot-blot analysis. Phylogeneti c analysis and comparison of both pBRM5 and pBRM42 with other members of the casein family revealed that the rabbit may be unique among mamm als in expressing two alpha(s2)-casein genes. The presence of two alph a(s2)-casein genes in the rabbit may be the result of a relatively rec ent intergenic duplication event.