def read_transcripts(transcript_file):
    """Return a dict containing transcript data with UCSC ID as key"""
    transcripts = dict()
    f_in = open(transcript_file)
    for line in f_in:
        data = line.rstrip('\n').split()
        transcript_data = { 'chrom': data[2],
                            'start': int(data[4]),
                            'end': int(data[5]) }
        transcripts[data[1]] = transcript_data
    return transcripts