02507nas a2200253   4500008004100000022001400041245011200055210006900167300001400236490000700250520161800257653001301875653005101888653002201939653001501961653001001976653002001986653001602006100001902022700001602041700003102057700002302088856014202111       2009                        eng d  a0015-549700aThe distribution and population sex ratio of Cacopsylla myrtilli (W. Wagner, 1947) (Hemiptera: Psylloidea)*0 adistribution and population sex ratio of Cacopsylla myrtilli W W  a219–2260 v573 aGenetic and morphological divergence and phylogenetic relationships of Scorpaeniformes fish including two genera and six species,Helicolenus dactylopterus, Scorpaenamaderensis, Scorpaena porcus, Scorpaena elongata, Scorpaena scrofa, Scorpaena notata, living in the Mediterranean Sea, were investigated with morphological and mitochondrial 16S rDNA sequence data. The mean nucleotide diversity was found to be 0.0792. Average sequence divergence between species of Sebastidae and Scorpaenidae was 8.4%, and 6.4%. between species of the genus Scorpaena. For congeneric comparisions, the lowest genetic divergence (0.7%) was observed between S. porcus and S. notata, and the highest divergence (10.8%) was detected between S. maderensis and S. notata. High levels of nucleotide divergence were detected between species of two families, and the maximum value was found to be 14.5% between H. dactylopterus and S. elongata. The two phylogenetic methods (NJ and MP) identified twomajor lineages. In theNJ tree S. elongatawas the sister group to S. scrofa. S. maderensis was more divergent from these groups. Another lineage contained S. porcus and S. notata. The topology of the MP tree is similar to that of the NJ tree. The pattern and degree of morphological differentiation was not congruent with the genetic differentiation. The Euclidiean distances of morphological data revealed very high morphological divergence between the two families. The highest morphological divergence was observed betweenH. dactylopterus and S. porcus, and the lowestwas detected between S. elongata and S. notata. The present genetic a10aBulgaria10ahelicolenus dactylopterus scorpaena maderensis10amediterranean sea10amorphology10amtdna10ascorpaeniformes10aSystematics1 aLabina, E., S.1 aNokkala, S.1 aMaryañska-Nadachowska, A.1 aKuznetsova, V., G.  uhttps://psylloidea-bg.myspecies.info/content/distribution-and-population-sex-ratio-cacopsylla-myrtilli-w-wagner-1947-hemiptera-psylloidea01218nas a2200145   4500008004100000022001300041245005700054210005400111300001400165490000800179520074500187653001300932100003100945856009600976       2004                        eng d  a1424858100aB chromosomes in Sternorrhyncha (Hemiptera, Insecta)0 aB chromosomes in Sternorrhyncha Hemiptera Insecta  a210–2140 v1063 aIn the hemipteroid insects of the suborder Sternorrhyncha, B chromosomes are relatively common in comparison with other suborders of Hemiptera. However, the occurrence of supernumerary chromosomes is restricted, in most cases, to several genera or closely related species. At least in some species of Psylloidea with the XY sex determination system, a mitotically stable B chromosome integrated into an achiasmatic segregation system with the X, and became fixed as a Y chromosome. In some Aphidoidea with a multiple X system of sex determination, B chromosomes appear to be in fact non-functional X chromosomes. Supernumerary chromosomes thus probably play an important role in the evolution of sex determination systems in Sternorrhyncha.10aBulgaria1 aMaryañska-Nadachowska, A.  uhttps://psylloidea-bg.myspecies.info/content/b-chromosomes-sternorrhyncha-hemiptera-insecta01931nas a2200253   4500008004100000020001400041022001300055245011500068210006900183300001400252490000800266520107300274653002801347653001701375653001301392653001401405653001501419653001701434100001601451700001601467700002301483700003101506856014001537       2003                        eng d  a0016-6707  a0016670700aThe origin of the achiasmatic XY sex chromosome system in Cacopsylla peregrina (Frst.) (Psylloidea, Homoptera)0 aorigin of the achiasmatic XY sex chromosome system in Cacopsylla  a327–3320 v1193 aThe status of an extra univalent, if it is a B chromosome or an achiasmatic Y chromosome, associating with the X chromosome in male meiosis of Cacopsylla peregrina (Frst.) (Homoptera, Psylloidea) was analysed. One extra univalent was present in all males collected from three geographically well separated populations, it was mitotically stable, and showed precise segregation from the X chromosome. These findings led us to propose that the univalent represents in fact a Y chromosome. The behaviour of the X and Y chromosomes during meiotic prophase suggested that their regular segregation was based on an achiasmatic segregation mechanism characterised by a 'touch and go' pairing of segregating chromosomes at metaphase I. To explain the formation of the achiasmatic Y within an insect group with X0 sex chromosome system, it was suggested that the Y chromosome has evolved from a mitotically stable B chromosome that was first integrated into an achiasmatic segregation system with the X chromosome, and has later become fixed in the karyotype as a Y chromosome.10aAchiasmatic segregation10aB chromosome10aBulgaria10ahomoptera10aPsylloidea10aY chromosome1 aNokkala, S.1 aGrozeva, S.1 aKuznetsova, V., G.1 aMaryañska-Nadachowska, A.  uhttps://psylloidea-bg.myspecies.info/content/origin-achiasmatic-xy-sex-chromosome-system-cacopsylla-peregrina-frst-psylloidea-homoptera