Fig. 7. (A) Autoradiography of an RNA slot-blot of different stages oocytes hybridized with the Pw70/3′ probe, and quantitation of hsp70 mRNA. Standard: synthetic sense Pw70/3′ RNA. Left to right, 5×107, 1×108, 2×108, 4×108, and 5×108 copies. Oocyte: total RNA of 5 oocytes per slot. Left to right, stages II,III, IV, V and VI. We determined by optical scanning of the autoradiogram that there are, respectively 1×107, 2.9×107, 4×107, 5×107, and 1×108 copies of the hsp70 mRNA per oocyte at stage II, III, IV, V and VI. (B) Western blot analysis of proteins from an equal number of different stage oocytes, incubated with the mAbH3F18 antibody, and then revealed with an 125I-labelled IgG. Left to right, stages II, III, IV, V and VI. The amount of HSP70 was quantified in protein extracted from oocytes at each vitellogenic stage of oogenesis, i.e. stages II to VI of oogenesis. The signal of each track was quantified by both linear scanning and γ radioactive counting of cut-out filter pieces (these two methods give identical results). Taking 100 at stage VI (end of oogenesis) as a base, we estimate at respectively 4.5, 10.6, 26, 74.5, and 100 arbitrary units, the amount of HSP70 protein per oocyte at stages II, III, IV, V and VI.