The Function of Lipin in the Wing Development of Drosophila melanogaster

Abstract

Lipin is evolutionarily conserved from yeast to mammals. Although its roles in lipid metabolism in adipocyte tissue, skeletal muscle, and the liver, and as a transcriptional co-activator are known, its functions during development are still under investigation. In this study, we analyzed the role of Drosophila lipin (dLipin) in development. Specifically, we showed that the tissue-selective knockdown of dLipin in the wing pouch led to an atrophied wing. Elevated DNA damage was observed in the wing imaginal disc of dLipin-knockdown flies. dLipin dysfunction induced accumulation of cells in S phase and significantly reduced the number of mitotic cells, indicating DNA damage-induced activation of the G2/M checkpoint. Reduced expression of cyclin B, which is critical for the G2 to M transition, was observed in the margin of the wing imaginal disc of dLipin-knockdown flies. The knockdown of dLipin led to increased apoptotic cell death in the wing imaginal disc. Thus, our results suggest that dLipin is involved in DNA replication during normal cell cycle progression in wing development of Drosophila melanogaster.

Role of Serotonin Transporter in Eye Development of Drosophila melanogaster

“…A previous study showed that rux mutation caused defects in the cell cycle regulation that led to the premature entry into S phase (represented by substantial increases in 5-bromo-2'-deoxyuridine staining), resulting in a similar but more severe rough eye phenotype to that observed in the present study and in the absence of changes in mitosis [32]. Moreover, our recent study of the regulation of the developing wing suggested that the knockdown of dLipin by an sd-GAL4 driver induces the accumulation of cells in S-phase while also decreasing the number of mitotic cells [33]. These studies suggest that increases in S-and M-phase cells can be regulated differently due to cell cycle defects; however, the underlying mechanism needs to be investigated further.…”

“…Cells in the S-phase were detected using Click-iT EdU (5-ethynyl-2 -deoxyuridine) labeling Alexa Fluor 594 Imaging Kit (Invitrogen, Carlsbad, CA, USA) [33]. Third instar larvae were dissected in phosphate buffer saline (PBS), and the eye discs were fixed in 4% paraformaldehyde for 20 min at 25 • C. After washing with PBS containing 0.3% Triton X-100 (PBST), the samples were blocked with 0.1% PBST and 10% normal goat serum for 30 min at 25 • C, and incubated with diluted primary antibodies in 0.1% PBST and 10% normal goat serum for 16 h at 4 • C [52,53].…”

Dysfunction of lipid storage droplet-2 suppresses endoreplication and induces JNK pathway-mediated apoptotic cell death in Drosophila salivary glands

“…To reveal that salivary gland cells induce DNA damage by the depletion of LSD-2, we examined the expression of histone variant H2Av phosphorylated at Ser137 (γH2Av), a marker for an early signal of DNA damage induced by replication stress 33 , 34 . As shown in Fig.…”

“…The delay in cell entry into the S-phase in KD flies might be associated with DNA damage induced by replication stress 34 . Our results demonstrated that the salivary gland showed an extremely high level of γH2Av protein, a marker of DNA damage (Fig.…”

“…TAG content was measured using an Infinity Triglyceride Assay Kit (Thermo Fisher Scientific, MA, USA), as described previously 34 . Protein concentration was measured using the Bradford assay (Bio-Rad Protein Assay Kit II, Bio-Rad Laboratories, Inc., CA, USA) to adjust the sample amount.…”