Cytogenetic homogeneity of the family Issidae (Hemiptera, Auchenorrhyncha) revealed by conventional chromosome staining techniques and fish with telomeric (TTAGG)n and 18S RDNA probes
We report on fluorescence in situ hybridization (FISH) using (TTAGG)n telomeric sequences and a probe for the 18S rRNA gene in 11 species from eight genera of the tribes Issini, Parahiraciini and Hemispheriini in the planthopper family Issidae. Furthermore, for part of these species data on standard karyotypes (ten species, eight genera) and on the number of testicular follicles (eight species, seven genera) are provided for the first time. All the species present a 2n = 27, X(0) chromosome complement known to be ancestral for the family. The karyotype is conserved in structure and consists of a pair of very large autosomes; the remaining chromosomes more or less gradually decrease in size. For selected species, analyses based on C-, AgNOR- and CMA3- banding techniques were also carried out. The (TTAGG)n probe identified telomeres in all species, and the major rDNA site was universally detected on the largest pair of autosomes. Basically, rDNA loci were found in an interstitial position while in two species they were located in the telomeric regions suggesting that chromosomal rearrangements involving the rDNA segments occurred in the evolution of the family Issidae.
This study was supported by the grant (no 14-14-00541) from the Russian Science Foundation.