Ay Papi Capitulo 17
Even though the nucleus is very large in this clade, we used the term "chromosome" for being associated to the bionomical data. It turns out that it looks as if the diploid complement of P. papi consists of four chromosomes, but the B genome is large (about 250 Mb) [ 18 ].
ay papi capitulo 17
The most interesting aspect of these findings is that P. papi does not only cause pathology in its primary host, but is a vector in two different regions of the world. And there is still the fact that many New World firebugs do not carry this parasite, despite the fact that they are able to host it.
The whole ensemble of these three findings suggests that the P. papi life cycle might be easily transferred to a new tick species. In fact, firebugs are geographically restricted to the western hemipheres, where some vectors are widely spread, including the black-legged Ixodes ricinus [ 25, 26 ] and Ixodes cookei [ 27 ], the establishment of which in Europe is facilitated by the widespread host ticks I. ricinus and I. hexagonus, respectively. This scenario is particularly interesting because P. papi could jump to firebugs, and be transmitted to a new vector. This is interesting because it might be a mechanism to promote the expansion of this parasite. In fact, H. papi is probably not the only organism with this potential. This scenario might be observed in some other parasites of ticks, and not only I. ricinus (or I. hexagonus) but also *Trypanosoma cruzi*, the agent of Chagas disease. This is due to the fact that these two tick-borne species have high levels of genetic similarity, both at the nucleotide and at the haplotypic level [ 28 ].