%0 Journal Article
%T Karyotype and male pre-reductional meiosis of the sharpshooter Tapajosa rubromarginata (Hemiptera: Cicadellidae)
%A Graciela R de Bigliardo
%A Eduardo Gabriel Virla
%A Sara Caro
%A Santiago Murillo Dasso
%J Revista de Biolog¨ªa Tropical
%D 2011
%I Universidad de Costa Rica
%X Cicadellidae in one of the best represented families in the Neotropical Region, and the tribe Proconiini comprises most of the xylem-feeding insects, including the majority of the known vectors of xylem-born phytopathogenic organisms. The cytogenetics of the Proconiini remains largely unexplored. We studied males of Tapajosa rubromarginata (Signoret) collected at El Manantial (Tucum¨¢n, Argentina) on native spontaneous vegetation where Sorghum halepense predominates. Conventional cytogenetic techniques were used in order to describe the karyotype and male meiosis of this sharpshooter. T. rubromarginata has a male karyological formula of 2n=21 and a sex chromosome system XO:XX (¡á:¡â). The chromosomes do not have a primary constriction, being holokinetic and the meiosis is pre-reductional, showing similar behavior both for autosomes and sex chromosomes during anaphase I. For this stage, chromosomes are parallel to the acromatic spindle with kinetic activities in the telomeres. They segregate reductionally in the anaphase I, and towards the equator during the second division of the meiosis. This is the first contribution to cytogenetic aspects on proconines sharpshooters, particularly on this economic relevant Auchenorrhyncha species. Rev. Biol. Trop. 59 (1): 309-314. Epub 2011 March 01. Los Cicadellidae son una de las familias mejor representadas en la regi¨®n neotropical. La tribu Proconiini incluye a muchos de los insectos que se alimentan de xilema y la mayor¨ªa de los vectores de organismos fitopat¨®genos asociados con dicho tejido de conducci¨®n. La citogen¨¦tica de los Proconiini es pr¨¢cticamente inexplorada. Por lo tanto, se utilizaron t¨¦cnicas citogen¨¦ticas convencionales para describir el cariotipo y la meiosis en los machos de Tapajosa rubromarginata Signoret. Este cicad¨¦lido presenta el complemento cromos¨®mico diploide de 2n=20A+X0 en los machos. Los cromosomas no presentan constricci¨®n primaria, son holocin¨¦ticos, y la meiosis es pre-reduccional, muestra un comportamiento similar tanto en los cromosomas sexuales como en los autos¨®micos durante la anafase I. En ese estado, los cromosomas se orientan de manera paralela a las fibras del huso acrom¨¢tico con actividad cin¨¦tica en los tel¨®meros y segregan de manera reduccional en la fase I y ecuacional en la fase II de la meiosis.
%K Insecta
%K citogen¨¦tica
%K Proconiini
%K cariotipo
%K cromosomas holocin¨¦ticos
%K cromosomas sexuales
%K Insecta
%K Cicadellidae
%K Proconiini
%K karyotype
%K holokinetic chromosomes
%K sex chromosomes
%U http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442011000100027