The B chromosomes of the grasshopper Eyprepocnemis plorans and the intragenomic conflict.
The grasshopper Eyprepocnemis plorans harbours an extremely widespread polymorphism for supernumerary (B) chromosomes, which is found in almost all circum-Mediterranean and Caucasian populations hitherto analysed. B chromosomes in this species have been shown to evolve through several stages of parasitic and near-neutral nature, presumably because of an arms race between the standard (A) and B chromosomes. This intragenomic conflict can either be solved with the extinction of the neutralised B chromosome or, more interestingly, with the replacement of the neutralised B by a mutant version being parasitic again and thus prolonging B chromosome life. This species thus provides a complete view of the long-term life-cycle of parasitic B chromosomes.
Camacho
J P M
JP
Departamento de Genética, Universidad de Granada, 18071 Granada, Spain. jpmcamac@ugr.es
Cabrero
J
J
López-León
M D
MD
Bakkali
M
M
Perfectti
F
F
D000818:Animals; D002875:Chromosomes / Q000235:genetics*; D019143:Evolution, Molecular; D005787:Gene Frequency; D006110:Grasshoppers / Q000235:genetics*; D008957:Models, Genetic; D011110:Polymorphism, Genetic / Q000235:genetics*; D020080:Tandem Repeat Sequences