Biodiversity of Chironomidae (Diptera) and genome response to trace metals in the environment

The effects of pollution on the biodiversity and genome response of Chironomidae larvae (Diptera, Insect) were evaluated in the trace metal contaminated water environments. No change on the Chironomid species diversity was found. The higher concentrations of trace metals (Cd, Pb, Cr, and Zn) affect the genome of 5 cytogenetically studied Chironomid species: Chironomus bernensis, C. plumosus, C. sp.1. Kiefferulus tendipediformis (cytotype 2), Glyptotendipes cauliginellus (syn. Glyptotendipes gripekoveni). Genome instability of Chironomid larvae was manifested by two ways: 1. Fixed chromosome rearrangements; homozygous inversions and tandem fusions created new gene linkage groups and show an intensive microevolutionary process of species. 2. Somatic structural (inversions, deficiencies, deletions, breaks); and functional alterations (decreasing the activity of the key structures: Balbiani rings (BRs) and Nucleolar Organizer (NOR)) in salivary gland chromosomes of cytogenetically studied Chironomidae species. Detecting somatic rearrangements in salivary gland chromosomes of these widely distributed aquatic insects is potentially one of the best validated bioassay and can be used as a cost effective early warning signals of environmental damage in freshwater basins

The tropical African genus Morgenia (Orthoptera, Tettigoniidae, Phaneropterinae) with emphasis on the spur at the mid tibia.

The authors revised the genus Morgenia Karsch, 1890 which now consists of eight species, of which three are here newly described (Morgenia plurimaculata Massa & Moulin, sp. n., M. angustipinnata Massa, sp. n., and M. lehmannorum Heller & Massa, sp. n.). Six of the eight species occur in the Tri National Sangha (TNS) comprising Dzanga-Sangha Special Reserve and Dzanga Ndoki National Park (Central African Republic), whose high biodiversity has been recently highlighted. In particular the genus is characterised by the presence of a more or less long spur at the inner mid tibia, different in each species; in M. modulata, it moved lower down into a new position at about ¼ of tibia, which has a hollow underneath where the rest of the spur remains hidden. This is a unique known case in Phaneropterinae. Morphological characters distinguishing males of different species are presented. Bioacoustics of the new species M. lehmannorum are described. The patterns of the chromosome evolution in M. lehmannorum differ from other investigated African Phaneropterinae in terms of chromosome number and morphology, reduced ancestral chromosome number (2n = 25) implying a more derived condition

Autosomal rearrangement in Gryllus assimilis Fabricius, 1775 (Orthoptera, Gryllidae)

Gryllus assimilis L. has a karyotype of 2n = 29 (X0, male) and 30 (XX, female). The above karyotype was encountered along with another in which 2n = 28 (X0, male) and 2n = 29 (XX, female) in a population from the outskirts of Rio Claro city (São Paulo State, Brazil). Of eight specimens studied, five had the heterozygous karyotype involving a translocation and three had the basic karyotype. There were no individuals homozygous for the rearrangement. The heterozygous karyotype was the result of a chromosomal rearrangement between chromosome pairs 6 and 10, both of which were initially submetacentric. The members of the sixth pair normally have two constrictions in the small arm, with a satellite at the chromosome tip. The chromosome of the tenth pair involved in the translocation was generally submetacentric and probably underwent a pericentric inversion which transported the centromere to a subterminal position before being translocated. In this case, the long arm of the inverted chromosome of the tenth pair was translocated with the satellite of a member of the sixth pair.<br>A espécie Gryllus assimilis L. apresenta 2n = 29, X0 (macho) e 2n = 30, XX (fêmea), porém em alguns indivíduos coletados na cidade de Rio Claro, São Paulo, Brasil, foram encontrados dois cariótipos distintos: o cariótipo básico e outro rearranjado, com 2n = 28, X0 e 2n = 29, XX. O rearranjo foi interpretado como sendo autossômico e heterozigoto, caracterizado pela translocação envolvendo dois pares de homólogos submetacêntricos: o par 10, que possivelmente tem um dos elementos com uma inversão pericêntrica, e o par 6, que possui em seu braço curto duas constrições secundárias, diferenciando satélites em suas extremidades