C-bands and NORs on chromosomes in four species of the genus Trechus Clairv. (Coleoptera, Carabidae)

SUMMARY

C-banding pattern and Ag-NORs on chromosomes of Trechus latus, T. pilisensis, T. pulchellus, and T. quadristriatus are presented. T. pulchellus has a paracentromeric C-band similar in size on all chromosomes. T. latus has euchromatic the X chromosome but all autosomes have a paracentromeric C-positive band. In the karyotype of T. quadristriatus the 1st pair of autosomes is euchromatic while the autosomes have a paracentromeric C-band. T. pilisensis has a constitutive heterochromatic segment in a paracentromeric position on all chromosomes and in addition the terminal C-band on the 1st pair of autosomes. Males of the examined species have the same pattern of silver precipitation during spermatogenesis. In the mitotic stages, from the prophase to the prometaphase stage one silver dot on the end of two autosomes is visible. In prophase I (to diakinesis) one active NOR is observed.

Key words:

• chromosomes
• Giemsa C-banding
• NORs