Analysis of amelogenin mRNA during bovine tooth development.
The amelogenins are highly conserved enamel-matrix proteins that are essential for proper mineral formation. Transcriptionally active genes encoding the bovine amelogenin proteins reside on both the X and Y chromosomes. Comparison of relative levels of amelogenin mRNAs at various stages of development indicated that the X-chromosomal amelogenin message is at least six fold more abundant than the Y. Alternative splicing generates at least seven messages, five from the X primary transcript, and two from the Y. The two most abundant X-chromosomal amelogenin messages are approx. 850 and 450 nucleotides long, and nearly 10-fold more 850-nucleotide mRNA can be measured than 450 nucleotide, which has lost most of exon 6 by splicing. The predominant small message encodes leucine-rich amelogenin protein (LRAP), and amounts of LRAP message are relatively constant during development. However, the amelogenin message from which exon 3 has been spliced declines approximately 2.3-fold, when compared to total X chromosomal amelogenin transcripts, suggesting differential regulation of alternative splicing. In addition, a new exon was identified within genomic DNA, which was shown to be expressed by the use of reverse transcriptase-polymerase chain reaction, and the exons were renamed accordingly. This new exon-4 sequence is unusual in that it is not highly conserved between species.
Yuan
Z A
ZA
Department of Anatomy, University of Pennsylvania School of Dental Medicine, Philadelphia, PA 19104, USA.
Collier
P M
PM
Rosenbloom
J
J
Gibson
C W
CW
D017398:Alternative Splicing; D053523:Amelogenin; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002417:Cattle; D017931:DNA Primers; D003746:Dental Enamel Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D005314:Embryonic and Fetal Development; D004658:Enamel Organ / Q000378:metabolism*; D018628:Gene Dosage; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D009805:Odontogenesis; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000032:analysis; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D014070:Tooth / Q000196:embryology; D014158:Transcription, Genetic; D014960:X Chromosome; D014998:Y Chromosome
D053523:Amelogenin; D017931:DNA Primers; D003746:Dental Enamel Proteins; D012333:RNA, Messenger; C067432:leucine-rich amelogenin peptide