Fig. 3

Dr-SLC38A9 mRNA expression in asexual and sexual worms. a-d Asexual (a, b) and sexual worms (c, d) were hybridized with an antisense probe to Dr-SLC38A9 mRNA. Dr-SLC38A9 transcripts are stained blue. Ventral views (a, c) and dorsal views (b, d) are shown with the anterior part of the worm at the top. White arrowheads indicate signals in the ovarian primordia (a) and mature ovaries (c). Orange arrowheads indicate signals in the parenchyma of the dorsal midline (b). Magenta arrows indicate signals in the yolk glands (c). White arrows indicate signals in the mature testes (d). Scale bars, a-d 1 mm. e Schematic of a sagittal section of a sexual planarian: e, eye; ov, ovary; ph, pharynx; te, testis; yg, yolk gland. f-n In situ hybridization of adjacent sections using an antisense probe to Dr-SLC38A9 (f, j, n) or Dr-nanos (h, l) mRNA. g, i, k, m Nuclei in blue. The anterior part of the worm is to the left, and the dorsal part is at the top. f Dr-SLC38A9 transcripts were detected at the periphery of the main ovary (magenta circle) and in satellite cells (magenta dotted circles) next to the main ovary. h Dr-nanos transcripts were detected at high levels in satellite cells (magenta dotted circle) next to the main ovary (magenta circle) and at low levels in the main ovary. j, l Dr-SLC38A9 and Dr-nanos transcripts were detected in spermatogonia at the periphery of the testes (blue circle). (N) Dr-SLC38A9 transcripts were widely detected throughout the yolk glands (orange circles). White arrowheads indicate signals of Dr-SLC38A9 (f) and Dr-nanos (h) in mature ovaries. Black arrows indicate signals of Dr-SLC38A9 (j) and Dr-nanos (l) in the mature testes. Magenta arrows indicate signals in the yolk glands (n). h, l We also detected nonspecific Dr-nanos signals in the epidermis. Scale bars, f-n 20 μm