Figure 4
FISH mapping of S. cynthia orthologues of B. mori autosomal genes on female pachytene chromosome complements of S. cynthia subspecies. Red signals (arrowheads) are Cy3-labelled orthologous probes of the B. mori genes RpL4 (a), eEF-2 (b) and hemolin (c). GISH with Green-labelled female genomic probe (green signals) identified the original W-heterochromatin compartment of the neo-W chromosome and also highlighted a heterochromatin block on the NOR bivalent (asterisk) in S. cynthia subsp. indet. (a, b) and S. c. walkeri (c). Chromosomes were counterstained with DAPI (light blue). In S. cynthia subsp. indet., the RpL4 orthologue mapped to the NOR bivalent (a), whereas the eEF-2 orthologue mapped to an autosome bivalent (b). The hemolin orthologue mapped to the NOR bivalent in S. c. walkeri (c); note a conspicuous nucleolus (N) associated with the NOR bivalent. Bar represents 10 μm.
