Developmental Origin and Evolution of Bacteriocytes in the Aphid–Buchnera Symbiosis (original) (raw)
Figure 2
The Second Wave of Bacteriocyte Determination
In (A)–(D), the embryos, which are normally folded in upon themselves in a pretzel shape within the ovariole (Miura et al. 2003), have been dissected flat, stained with anti-Dll antibody (red) and phalloidin (green), and examined with a confocal microscope.
(A) Dll expression (red) in a stage 14 embryo is detected in the labrum (La) and all developing limbs on the ventral surface except the mandibular segment (Mn). (Other abbreviations: An, antenna; Mx, maxilla; Lb, labium; T1, T2, T3, first, second, and third thoracic leg, respectively.) The dorsal surface of the abdomen of the same embryo is shown illustrating Dll expression in the original bacteriocytes (white arrow) and in a more posterior population of nuclei or cells (blue arrow). Germ cells (gc) are labeled.
(B) Dll expression is first observed in the new bacteriocyte nuclei at stage 13.
(C) By stage 15, many of the new bacteriocytes have migrated to and begun intercalating between the original bacteriocytes.
(D) By stage 16, all of the new bacteriocytes have intercalated between the original bacteriocytes.
(E) The migration of the new bacteriocytes is seen in a confocal section of an undissected stage 14 embryo.
Embryos in (A)–(D) are oriented with the anterior of the germband towards the left.