Wednesday, December 13, 2017

DRSC screen contributes to research report on signaling and lifespan

Sung EJ, Ryuda M, Matsumoto H, Uryu O, Ochiai M, Cook ME, Yi NY, Wang H, Putney JW, Bird GS, Shears SB, Hayakawa Y. Cytokine signaling through Drosophila Mthl10 ties lifespan to environmental stress. Proc Natl Acad Sci U S A. 2017 Dec 11. PMID: 29229844.

From the abstract: "A systems-level understanding of cytokine-mediated, intertissue signaling is one of the keys to developing fundamental insight into the links between aging and inflammation. Here, we employed Drosophila, a routine model for analysis of cytokine signaling pathways in higher animals, to identify a receptor for the growth-blocking peptide (GBP) cytokine. Having previously established that the phospholipase C/Ca2+ signaling pathway mediates innate immune responses to GBP, we conducted a dsRNA library screen for genes that modulate Ca2+ mobilization in Drosophila S3 cells. A hitherto orphan G protein coupled receptor, Methuselah-like receptor-10 (Mthl10), was a significant hit. Secondary screening confirmed specific binding of fluorophore-tagged GBP to both S3 cells and recombinant Mthl10-ectodomain. We discovered that the metabolic, immunological, and stress-protecting roles of GBP all interconnect through Mthl10. This we established by Mthl10 knockdown in three fly model systems: in hemocyte-like Drosophila S2 cells, Mthl10 knockdown decreases GBP-mediated innate immune responses; in larvae, Mthl10 knockdown decreases expression of antimicrobial peptides in response to low temperature; in adult flies, Mthl10 knockdown increases mortality rate following infection with Micrococcus luteus and reduces GBP-mediated secretion of insulin-like peptides. ... We describe how our data offer opportunities for further molecular interrogation of yin and yang between homeostasis and longevity."

Monday, December 11, 2017

RNAi and the sterile insect technique

Darrington M, Dalmay T, Morrison NI, Chapman T. Implementing the sterile insect technique with RNA interference - a review. Entomol Exp Appl. 2017 Sep;164(3):155-175. PMID: 29200471; PMCID: PMC5697603.

From the abstract: "We review RNA interference (RNAi) of insect pests and its potential for implementing sterile insect technique (SIT)-related control. The molecular mechanisms that support RNAi in pest species are reviewed in detail, drawing on literature from a range of species including Drosophila melanogaster Meigen and Homo sapiens L. ... RNAi represents a plausible, non-GM system for targeting populations of insects for control purposes, if RNAi effector molecules can be delivered environmentally (eRNAi). We consider studies of eRNAi from across several insect orders and review to what extent taxonomy, genetics, and differing methods of double-stranded (ds) RNA synthesis and delivery can influence the efficiency of gene knockdown. ..."

Monday, December 4, 2017

New report on qPCR design for RNAi knockdown effectiveness testing

Mainland RL, Lyons TA, Ruth MM, Kramer JM. Optimal RNA isolation method and primer design to detect gene knockdown by qPCR when validating Drosophila transgenic RNAi lines. BMC Res Notes. 2017 Nov 29;10(1):647. PMID: 29187229.

From the abstract: "... the strongest gene knockdown was detected when qPCR was performed using 5' primer sets in combination with mRNA-derived cDNA. Our results indicate that detection of undegraded mRNA cleavage fragments can result in underestimation of true knockdown efficiency for a RNAi construct. ..."