Cytogenetic features of N. furzeri. (a) Karyotype of DAPI-stained chromosomes of a female N. furzeri of the GRZ strain. Note the absence of bright staining at the centromeric regions. Four pairs of chromosomes (1, 6, 9, 17) are metacentric, three pairs (16, 18, 19) are acrocentric and the remaining 12 pairs are subtelo-/submetacentric. (b) C-banded karyotype of a female N. furzeri GRZ reveals centromeric heterochromatin in most chromosomes. (c) Mithramycin staining results in bright fluorescence of centromeres, which is due to G+C enriched heterochromatin.