Fig. 1

Expression atlas of AAAP-536 and APC-8904 genes in asexual A. pisum before symbiont invasion. Staged embryos hybridized with DIG-labeled antisense (a–l) and sense riboprobes (m, n) of AAAP-536 and APC-8904. Signals were revealed by NBT/BCIP brown precipitates. All embryos are displayed with anterior of the germaria to the left. Arrowheads mark AAAP-536- and APC-8904-positive signals. Dashed lines indicate the location of germ cells. a–f Germarium, oocyte, and embryos before Buchnera invasion; transcripts of AAAP-536 were detected in the posterior syncytium (ps) of late stage 6 embryo. g–l Germarium, oocyte, and embryos before Buchnera invasion; preferential expression of APC-8904 was detected in the posterior syncytium (ps) of late stage 6 embryo. m, n Oocytes and developing embryos hybridized with sense riboprobes. No signal was detected with AAAP-536 sense riboprobes, but ubiquitous background signals were detected with APC-8904 sense riboprobes. o Illustration displaying presented developmental stages. Germ cells and specific signals of AAAP-536 and APC-8904 detected in the posterior syncytium by in situ hybridization are indicated by the color key. Scale bars are all 20 μm. blc blastodermal cells, cs central syncytium, dn dividing nucleus, eflc enlarged follicle cells, fc follicle cells, gc germ cells, gl germarial lumen, gm germarium, nc nurse cells, on oocyte nucleus, ps posterior syncytium, sn syncytial nucleus, st stage