C-banding pattern in metaphase chromosomes of Phyllotis xanthopygus. a Female from Malargüe, the presence a large block of heterochromatin in acrocentric chromosome (arrow) b Small pericentromeric C-band in an acrocentric autosome (arrow), and the entirely heterochromatic Y chromosome, Jujuy, male c Small C-band in one acrocentric and a prominent pericentromeric C-heterochromatin in the second acrocentric, Jujuy, female (arrows) d C-banded karyotype, with small telomeric C-bands in one autosome pair (in box) and the heteromorphic metacentric/acrocentric pair No.7. Bar = 10 µm.