def getPossibleGenesD(rHitsL):
    """return dict containing an entry for each gene in species 0 that has
    a best reciprocal hit in all other species.  format of an entry is
    gene:(tuple of recip hit genes in other species). We do this to
    quickly eliminate things we aren't interested in.
    """
    possibleGenesD = {}
    firstRow = rHitsL[0]
    firstDict = firstRow[1]
    for gene in firstDict:
        isPossible = True
        hitsL = [firstDict[gene]]
        for colInd in range(2, len(firstRow)):
            compareDict = firstRow[colInd]
            hit = compareDict.get(gene)
            if hit == None:
                isPossible = False
                break
            else:
                hitsL.append(hit)
        if isPossible:
            possibleGenesD[gene] = tuple(hitsL)
    return possibleGenesD
