Figure 7.

Distributions of telomeric repeats and rDNA clusters on chromosomes of pinnipeds. G-banding (left) followed by FISH (right) of a telomeric probe (TTAGGG)_n (red) and an 18S, 5.8S, and 28S rDNA probe (green) on DAPI-stained chromosomes. (a) The walrus and true seals, (b) the bearded seal, (c) ringed seal, (d) spotted seal, (e) Baikal seal, and (f) harbor seal. The telomeric probe highlighted the termini of all chromosomes in the investigated species. Note differences in the size and signal intensity on telomeres (some were very faint) in species, with the walrus’s telomeric blocks being larger than those in the other species. No interstitial telomeric sites marking fusions of ancestral elements were detectable in pinnipeds here [33]. The chromosome numbers are indicated for NOR bearing chromosomes. NOR sizes vary between homologs among several species. The eared seals: (g) the New Zealand fur seal, (h) northern fur seal, (i) New Zealand sea lion, and (j) northern sea lion.