While the genome is "only" 100 Mb in size, there are two known problems which are making the project more difficult:

• the high AT content of the genome (>75%) means that large pieces of genomic DNA may not clone succesfully or stably in bacterial vectors. This may be a particular problem for the cosmid library.
• the 50% AT endosymbiont genome may clone much more efficiently than the nuclear genome

We are currently following several routes to mapping

genome survey sequencing

verification of the cosmid library (insert size 35 kb, completed)

verification of a 4600 clone BAC library (insert size ~70 kb)

hybridisation of selected ESTs to the BAC library

generation of end probes and hybridisation to the BAC library

mapping of the endosymbiont genome

construction and verification of a YAC library (insert size >100 kb)

identification of operons in Brugia

methods for genome mapping