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

Friday, January 8, 2016

Searched "Drosophila" at DSHB antibody hybridoma bank? Try again!

Rumor has it DSHB has updated search rules such that a search with the term "Drosophila" that used to bring back about 100 results now retrieves more than 200. Happy antibody hunting!

Tuesday, January 5, 2016

Fly cell RNAi screen identifies "first in vivo mediator of hypercapnic immune suppression" in study relevant to COPD and other lung disorders

Congrats to Taneli and the rest of the team on this report of a screen performed at the DRSC!

Helenius IT, Haake RJ, Kwon YJ, Hu JA, Krupinski T, Casalino-Matsuda SM, Sporn PH, Sznajder JI, Beitel GJ. Identification of Drosophila Zfh2 as a Mediator of Hypercapnic Immune Regulation by a Genome-Wide RNA Interference Screen. J Immunol. 2015 Dec 7. pii: 1501708. PMID: 26643480.

From the abstract: "Hypercapnia, elevated partial pressure of CO2 in blood and tissue, develops in many patients with chronic severe obstructive pulmonary disease and other advanced lung disorders. Patients with advanced disease frequently develop bacterial lung infections ... We previously demonstrated that hypercapnia suppresses induction of NF-κB-regulated innate immune response genes ... However, the molecular mediators of hypercapnic immune suppression are undefined. In this study, we report a genome-wide RNA interference screen in Drosophila S2* cells stimulated with bacterial peptidoglycan. The screen identified 16 genes with human orthologs whose knockdown reduced hypercapnic suppression of the gene encoding the antimicrobial peptide Diptericin (Dipt), but did not increase Dipt mRNA levels in air. In vivo tests of one of the strongest screen hits, zinc finger homeodomain 2 (Zfh2; mammalian orthologs ZFHX3/ATBF1 and ZFHX4), demonstrate that reducing zfh2 function using a mutation or RNA interference improves survival of flies exposed to elevated CO2 and infected with Staphylococcus aureus. Tissue-specific knockdown of zfh2 in the fat body, the major immune and metabolic organ of the fly, mitigates hypercapnia-induced reductions ... and improves resistance of CO2-exposed flies to infection. Zfh2 mutations also partially rescue hypercapnia-induced delays in egg hatching ... Taken together, to our knowledge, these results identify Zfh2 as the first in vivo mediator of hypercapnic immune suppression."