Figure 1
Test results of multiple tissues in silkworms.
The 5th instar larvae 48 h after molting were injected with 0.56 nM (10 μl 56 μΜ) of CdTe QDs via the oral cavity. Exposure levels of QDs530 and QDs720, represented by Cd2+, were 60 μg and 65.3 μg per larva, respectively. The control organisms were injected with deionized water (water). (a) Basic transfer route of QDs among tissues in vivo. The QDs are injected orally and taken by the digestive track firstly. Subsequently, they pass through the digestive tract membrane barrier and arrive into the hemolymph (He)/blood cells. Finally, they are transported concomitantly to the floating tissues in hemolymph such as silk gland (SG), fat body (FB) and Malpighian tubule (MT). The arrow of number ① shows QDs from the digestive tract to hemolymph, the arrows of number ②,③ and ④ show QDs from hemolymph to the fat body, silk gland and Malpighian tubule concomitantly. (b) After 24 h or 48 h of exposure, the characteristic fluorescence of QDs was observed in multiple tissues at emission wavelengths of 530 nm and 720 nm. The green fluorescence indicated tissues with an accumulation of QDs530 and the red fluorescence indicated tissues with an accumulation of QDs720. The fluorescent images and the views of tissues were detected using CRI MaestroTM (Photometric, USA) and canon EOS70D camera (Cannon, Japan), respectively. The clean tissue removed peritrophic membrane from midgut (MG), which the longest part and main function part of the digestive tract (DT), was used to avoid the impact of food. (c) Atomic absorption spectrometry was used to determine the cadmium content in multiple tissues, (d) transport efficiency in silk glands 48 h after exposure and in exocrine silk proteins 120 h after exposure. *P < 0.05 and **P < 0.01 indicate significant differences, every tissue sample was collected from 5 larvae and tested three times. Bars are 1 cm.
