LOCATION IN THE SOURCE CHROMOSOME OF THE 180-KB MINICHROMOSOME OF LEISHMANIA-MAJOR AND CHARACTERIZATION OF THE NOVEL JUNCTION

The 180-kb LD1 minichromosome of Leishmania major (M180) is a large in verted duplication which arises spontaneously from a megabasic chromos ome. In this work this locus has been located in the source chromosome at a telomeric position. Both the novel junction created in the middl e of the minichromosome, as well as its counterpart region in the sour ce chromosome were cloned and sequenced. Two inverted repeats, which c ould give rise to two imperfect stem-loops, and an Af T-rich DNA seque nce were the only particular features observed in this region. A putat ive model for the formation of the minichromosome is proposed.