Tuesday, February 9, 2016

Analysis of steroid hormone signaling in 41 Drosophila fly cell lines

Stoiber M, Celniker S, Cherbas L, Brown B, Cherbas P. Diverse Hormone Response Networks in 41 Independent Drosophila Cell Lines. G3 (Bethesda). 2016 Jan 15. pii: g3.115.023366. PMID: 26772746.

From the abstract: "Steroid hormones induce cascades of gene activation and repression with transformative effects on cell fate. Steroid transduction plays a major role in the development and physiology of nearly all metazoan species, and in the progression of the most common forms of cancer. Despite the paramount importance of steroids in developmental and translational biology, a complete map of transcriptional response has not been developed for any hormone. In the case of 20-hydroxyecdysone (ecdysone) in Drosophila melanogaster, these trajectories range from apoptosis to immortalization. We mapped the ecdysone transduction network in a cohort of 41 cell lines, the largest such atlas yet assembled. ... This atlas of steroid response reveals organizing principles of gene regulation by a model type II nuclear receptor and lays the foundation for comprehensive and predictive understanding of the ecdysone transduction network in the fruit fly."

Monday, February 8, 2016

in vivo RNAi screen related to chromatin remodeling and assembly factor (CHD1)

Kim S, Bugga L, Hong ES, Zabinsky R, Edwards RG, Deodhar PA, Armstrong JA. An RNAi-Based Candidate Screen for Modifiers of the CHD1 Chromatin Remodeler and Assembly Factor in Drosophila melanogaster. G3 (Bethesda). 2015 Nov 23;6(2):245-54. PMID: 26596648.

From the abstract: "The conserved chromatin remodeling and assembly factor CHD1 (chromodomains, helicase, DNA-binding domain) is present at active genes where it participates in histone turnover and recycling during transcription. In order to gain a more complete understanding of the mechanism of action of CHD1 during development, we created a novel genetic assay in Drosophila melanogaster to evaluate potential functional interactions between CHD1 and other chromatin factors. We found that overexpression of CHD1 results in defects in wing development and utilized this fully penetrant and reliable phenotype to conduct a small-scale RNAi-based candidate screen ..."

Saturday, January 23, 2016

Tuesday, January 19, 2016

Intriguing new potential Alzheimer's biomarker test based on response by engineered Drosophila cells

Lau HC, Lee IK, Ko PW, Lee HW, Huh JS, Cho WJ, Lim JO. Non-invasive screening for Alzheimer's disease by sensing salivary sugar using Drosophila cells expressing gustatory receptor (Gr5a) immobilized on an extended gate ion-sensitive field-effect transistor (EG-ISFET) biosensor. PLoS One. 2015 Feb 25;10(2):e0117810. PMID: 25714733; PMCID: PMC4340960.

From the abstract:  "Body fluids are often used as specimens for medical diagnosis. With the advent of advanced analytical techniques in biotechnology, the diagnostic potential of saliva has been the focus of many studies. We recently reported the presence of excess salivary sugars, in patients with Alzheimer's disease (AD). In the present study, we developed a highly sensitive, cell-based biosensor to detect trehalose levels in patient saliva. The developed biosensor relies on the overexpression of sugar sensitive gustatory receptors (Gr5a) in Drosophila cells to detect the salivary trehalose. ... "

Thursday, January 14, 2016

Another paper reporting concern about an RNAi fly library

Any of us using the relevant RNAi stocks should be aware.

Vissers JH, Manning SA, Kulkarni A, Harvey KF. A Drosophila RNAi library modulates Hippo pathway-dependent tissue growth. Nat Commun. 2016 Jan 13;7:10368. PMID: 26758424.
From the abstract: "... Here we investigate an important technical limitation with the widely used VDRC KK RNAi collection. We find that approximately 25% of VDRC KK RNAi lines cause false-positive enhancement of the Hippo pathway, owing to ectopic expression of the Tiptop transcription factor. Of relevance to the broader Drosophila community, ectopic tiptop (tio) expression can also cause organ malformations and mask phenotypes such as organ overgrowth. To enhance the use of the VDRC KK RNAi library, we have generated a D. melanogaster strain that will allow researchers to test, in a single cross, whether their genetic screen of interest will be affected by ectopic tio expression."

Tuesday, January 12, 2016