Ricerche cariologiche ed elettroforetiche su Parascaris univalens e Parascaris equorum
The karyotypes of the two sibling species Parascaris equorum and P. univalens are illustrated, as well as their chromosome morphology. The chromosomes are characterized by heteropycnotic extremities and the absence of a well-defined centromerical zone. Furthermore in P. equorum one chromosome pair appears distinctly longer than the other, which would exclude the evolution of this species by a simple process of tetraploidization; this is also ruled out by the electrophoretic data. The electrophoretic...