Neo-sex Chromosomes in the Maculipennis Species Group (Dichroplus: Acrididae, Melanoplinae): The Cases of D. maculipennis and D. vittigerum.
South American melanopline grasshoppers display a disproportionate number of derived karyotypes, including many cases of neo-sex chromosome systems. This is especially true of the genus Dichroplus and its Maculipennis species group. We analyzed the karyotype and neo-sex chromosomes in mitosis and meiosis of Dichroplus maculipennis and D. vittigerum from Argentina using conventional and fluorescent cytogenetic protocols in order to elucidate the behavior and origin of these neo-XY systems in relation to the current phylogeny of this group. Our results showed that D. maculipennis (2n = 22♂/22♀; neoXY/neoXX) and D. vittigerum, whose karyotype is described here for the first time (2n = 18♂/18♀; neoXY/neoXX), show highly evolved neo-XY systems, although with significant differences between them. Furthermore, both species differ for two autosomal fixed Robertsonian fusions present in D. vittigerum. Analysis of karyotypic character state optimization strongly suggests the independent origin and evolution of neo-sex systems within this species group.
1 Laboratorio de Genética Evolutiva. Instituto de Biología Subtropical (IBS) CONICET- Universidad Nacional de Misiones. Félix de Azara 1552, Piso 6°. CP3300. Posadas, Misiones Argentina.|2 Comité Ejecutivo de Desarrollo e Innovación Tecnológica (CEDIT) Félix de Azara 1890, Piso 5°, Posadas, Misiones 3300, Argentina.
Elio R D
ER
Castillo
1 Laboratorio de Genética Evolutiva. Instituto de Biología Subtropical (IBS) CONICET- Universidad Nacional de Misiones. Félix de Azara 1552, Piso 6°. CP3300. Posadas, Misiones Argentina.|2 Comité Ejecutivo de Desarrollo e Innovación Tecnológica (CEDIT) Félix de Azara 1890, Piso 5°, Posadas, Misiones 3300, Argentina.
Alberto
A
Taffarel
3 Centro de Estudios Parasitológicos y de Vectores (CEPAVE), CCT La Plata CONICET, Bulevar 120 e/60 y 64 S/N. 1900, La Plata, Argentina.
Yanina
Y
Mariottini
4 CONICET- INTA EEA Bariloche, Bote Modesta Victoria, 4450 (8400),Bariloche, Río Negro, Argentina.
Valeria
V
Fernández-Arhex
1 Laboratorio de Genética Evolutiva. Instituto de Biología Subtropical (IBS) CONICET- Universidad Nacional de Misiones. Félix de Azara 1552, Piso 6°. CP3300. Posadas, Misiones Argentina.
Dardo A
DA
Martí
5 Paraná y los Claveles, 3304, Garupá, Misiones, Argentina.
Claudio J
CJ
Bidau
D000818:Animals; D001118:Argentina; D019143:Evolution, Molecular; D005260:Female; D006110:Grasshoppers / Q000145:classification / Q000235:genetics*; D059785:Karyotype; D008297:Male; D008540:Meiosis / Q000235:genetics; D010802:Phylogeny; D012730:Sex Chromosomes / Q000235:genetics*
Dichroplus maculipennis; Dichroplus vittigerum; Melanoplinae; grasshopper; karyotype character state optimization; sex chromosomes