SEQUENCE VARIATION IN THE CIRCUMSPOROZOITE PROTEIN GENE OF PLASMODIUM-VIVAX APPEARS TO BE REGIONALLY BIASED

We have sequenced the circumsporozoite protein gene from 16 isolates f rom China, the Philippines, Papua New Guinea and the Solomon Islands. We found very limited polymorphisms in the non-repetitive regions of t he circumsporozoite gene from these isolates. All samples from China c ontained a 36-base insert 3' to the repeats previously seen only in a North Korean isolate. Limited variation was found in the repeat region s, which allowed these and previously sequenced isolates to be classif ied into groups based on repeat structure. These groupings also correl ate with the geographical origin of the isolates.