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N Dabhade

Publications and source records attributed to N Dabhade.

4 recordsLinked to original sources

Gene expression during cardiac development.

The vertebrate heart forms as two concentric epithelial cylinders of myocardium and endocardium separated by an extended basement membrane matrix commonly referred to as cardiac jelly. Subsequent maturation involves a complex series of events including asymmetric changes in cell shape and division which contribute to bending and the formation of the bulboventricular loop, the formation of specialised tissues including endocardial cushion tissue of the atrioventricular (AV) and outflow tract regions, the development of conductive tissue and myocyte maturation leading to the overall pattern of expression characteristic of mature heart muscle. These processes depend on a precise spatial and temporal control of gene expression both of genes encoding regulatory molecules and those encoding structural components of the heart. In this chapter we address three aspects of cardiac development, namely, the determination of cell fate during formation of endocardial cushion tissue in the embryonic heart, transitions in troponin gene expression during fetal myocyte maturation, and the use of cloning techniques based on the polymerase chain reaction for identifying transcription factors present in the heart.

Animals

Determination of the 5' exon structure of the human cardiac alpha-myosin heavy chain gene.

We have deduced the exon structure of the 5' untranslated region of the human cardiac alpha-myosin heavy chain gene by cloning a cDNA for this region using the polymerase chain reaction. Comparison of the cDNA and genomic DNA sequences demonstrates that the 5' non-coding region of the alpha-myosin heavy chain gene is interrupted by two introns of 645 and 337 nucleotides. Secondly we have identified the transcriptional start-site by primer extension, corroborating the previous putative assignment for the alpha-myosin heavy chain promoter based on comparisons between the rat and human genes.

Amino Acid Sequence

Molecular cloning of human cardiac troponin I using polymerase chain reaction.

We have used the polymerase chain reaction (PCR) to synthesise a cDNA encoding part of human cardiac troponin I. Amplification was achieved using fully degenerate sets of oligonucleotides corresponding to conserved regions of amino acid sequence identified in other troponin I isoforms. The cloned PCR fragment was subsequently used to isolate full-length cDNAs from a cardiac cDNA library. We describe the approach, as a general cloning strategy starting from limited amino-acid sequence data and report the cloning, and complete amino acid sequence of human cardiac troponin I. Analysis of human development using these clones demonstrates early expression of this gene in the heart.

Amino Acid Sequence