title: Buffalo alpha S1-casein gene 5'-flanking region and its interspecies comparison.
abstract: The expression of milk protein genes is tightly regulated in a spatio-temporal manner through the combinatorial interaction of lactogenic hormones and a set of transcription factors mediating developmental and tissue-specific gene expression. The recruitment of a unique set of transcription factors is determined by the cis-regulatory motifs present in the gene promoter region. Here, we report the isolation, sequencing, structural analysis and interspecies comparison of the 5'cis-regulatory region of the buffalo alpha S1 (αS1)-casein gene. The proximal promoter region of the buffalo αS1-casein gene harbored the insertion of a 72-bp fragment of long interspersed nuclear element of the L1_BT retrotransposon family. Among the core and vertebrate-specific promoter elements, the motifs for the binding of Brn POU domain factors (BRNF), Lim homeodomain factors (LHXF), NK6 homeobox transcription factors (NKX6), nuclear factor kappa B/c-rel (NFKB), AT-rich interactive domain factor (ARID), Brn POU domain factor 5 (BRN5), pancreatic and intestinal homeodomain transcription factor (PDX1), Distal-less homeodomain transcription factors (DLXF), T-cell factor/lymphoid enhancer-binding factor-1 (LEFF) and GHF-1 pituitary-specific POU domain transcription factor (PIT1) were over-represented in the αS1-casein gene regulatory region (Z score >4.0). The Multiple EM for Motif elicitation predicted three motifs which consisted of the sequences known to bind mammary gland factor/signal transducer and activator of transcription 5 (MGF/STAT5), estrogen receptor-related alpha (ERα), steroidogenic factor 1 (SF1) and glucocorticoid receptor (GR), indicating their potential role in the mammary gland-specific gene expression. The interspecies comparison of the proximal promoter region revealed conserved sequences for TATA boxes and MGF/STAT5 in all species, whereas activator protein 1 (AP1), pregnancy-specific mammary nuclear factor (PMF), CCAAT/enhancer binding protein (C/EBP), double-stranded and single-stranded DNA-binding protein 1 (DS1 and SS), ying and yang factor 1 (YY1), and GR half-sites were among ruminants. The functional significance of the L1_BT retrotransposon insertion on the buffalo αS1-casein gene expression needs to be experimentally validated.
authors.affiliation: Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, India.
authors.forename: Amrutlal K
authors.initials: AK
authors.lastname: Patel
authors.forename: Mahavir
authors.initials: M
authors.lastname: Singh
authors.forename: V V S
authors.initials: VV
authors.lastname: Suryanarayana
mesh_terms: D024506:5' Flanking Region / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002020:Buffaloes / Q000235:genetics*; D002364:Caseins / Q000235:genetics*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D059372:Nucleotide Motifs; D009928:Organ Specificity; D011401:Promoter Regions, Genetic / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D018626:Retroelements; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D002364:Caseins; D018626:Retroelements