Figure 3.

Developmental Northern blot analysis of total RNA isolated from the methoprene-susceptible Oregon-RC strain at various times in development and probed with a [³²P]UTP-labeled 331-bp riboprobe for Met. Each lane was loaded with 40 μg of total RNA, and the blot was probed with the Met gene riboprobe followed by a DNA probe for the Rp49 gene as described for Fig. 2. The decreased levels of Rp49 in pupae reflect decreased expression during this stage of development (22). Embryos were collected from overnight cultures and either frozen in liquid nitrogen or maintained at 25°C until the desired age. Larvae were staged from timed embryo collections; the indicated times are ±8 hr. Pupae were staged from the white prepupal stage, which lasts for about 1 hr. Adult males consistently show only the 5.5-kb transcript; females show both and, when fully gravid, show more of the 3.3-kb transcript than appears on this blot.