Stage Specific Expression of ATP-Binding Cassette and Solute Carrier Superfamily of Transporter Genes in Mammary Gland of Riverine Buffalo (Bubalus bubalis)

Abstract

In the present study, expression level of various ATP-binding cassette (ABC) viz., ABCA1, ABCA7, ABCG1, ABCG2, and ABCG5; associated transcription factors viz., SREBF1, LXRα (NR1H3), PPARA, and Solute Carriers (SLC); or Glucose transporters (GLUT) viz., SLC2A1(GLUT1), SLC2A4 (GLUT4), SLC2A8 (GLUT8), and SLC2A12 (GLUT12) superfamily of transporters were compared across physiological stages of buffalo mammary gland. The relative expression of ABCA1, and ABCG1 was significantly (p < 0.05) higher in mammary gland of heifer followed by involution and lactation stages. Similarly, ABCA7 gene expression was highest in heifer mammary gland followed by lactation and involution stages. ABCG2 gene expression was significantly (p < 0.05) high in lactating mammary gland in comparison to involution and heifer stages. On the other hand, ABCG5 gene expression was highest in involuting mammary gland followed by lactation and involution stages. Additionally, the expression of LXRα SREBF1, and PPARA which are known to regulate some of the ABC tranporters were also analyzed. The expression of LXRα gene was high in involuting as compared to lactating mammary gland. In contrast, SREBF1 and PPARA expression was significantly (p < 0.05) high in lactating mammary gland. Among the several SLC transporters studied, SLC2A1, SLC2A4, and SLC2A8 showed significant (p < 0.05) higher expression during lactation stage, whereas SLC2A12 expression was greater during heifer stage suggesting SLC2A1, SLC2A4, and SLC2A8 to be the major transporters associated with glucose uptake in buffalo mammary gland. The expression profile of (lactoferrin) LTF, known to be expressed at high level in mammary gland during involution was also studied. As expected, its expression was significantly (p < 0.05) higher during involution in comparison to lactating mammary gland.in buffaloes as well. The inclusion of LTF as a control gene further provided the confidence in the buffalo mammary gland expression data generated in the present study. This study thus helped to provide information about the distinct expression pattern of various transporters and their regulators in buffalo mammary gland during different physiological states.