Rhinolophus formosae

Two males and one female from Taiwan were studied cytogenetically. All specimens showed a karyotype with 2 n = 52 and a FNa = 60 (Fig. 6). There were five bi-armed and 19 acrocentric autosomal pairs. In addition, the smallest, dot-like pair no. 25 is likely also bi-armed. Due to the minuteness of this element, the metacentric condition was visible only in a small percentage of metaphase spreads. Therefore, this chromosome was counted as one arm only for the FNa. The medium-sized X chromosome

is submetacentric and the dot-like Y chromosome is probably bi-armed. Concerning the amount of centromeric heterochromatin, the acrocentric pairs differed from the bi-armed ones. In contrast to the faint staining of centromeric regions of bi-armed pairs 1 to 5 and 25, the acrocentric chromosomes showed dark stained pericentromeric regions after CBG-banding, which were also GTG-, QFQ- and DAPI-positive (Fig. 7 A–B). The amount of centromeric heterochromatin of the X chromosome was similar to that of other Rhinolophus species and not enlarged as in R. cf. luctoides and R. lanosus . The Y chromosome of R. formosae was hardly distinguishable from the autosomal pair 25 after CBG-banding and showed no clear centromeric heterochromatin (Fig. 7A). The secondary constriction of chromosomal pair 18 (homologous to MMY21) was shown to bear active NORs by silver-staining (Fig. 7C). Analysis of 20 metaphase spreads of one male specimen revealed a frequency of 2.0 NORs per cell.

The complete set of AST painting probes and some selected MMY probes (MMY8, 14, 23) were applied on R. formosae . The results are given on the G-banded karyogram (Fig. 6) and examples of FISH experiments are shown in Fig. 3C and 3F. Of the chromosomal pairs 1 to 5, only two, i.e., 4 and 5, show the same combination of chromosomal arms as found in R. luctoides, R. lanosus and R. morio . Pairs 1 to 3 show a unique combination hitherto found in no other rhinolophid species.