Biology

How did pollsters get the Australian election result so wrong?

Genetics - Mon, 2019-05-20 16:22
Polling companies will be doing some major self-reflection in the aftermath of the Australian Coalition’s surprise victory last weekend
Categories: Biology

Sabre-toothed cats bit rivals in the head and punctured their skulls

Genetics - Mon, 2019-05-20 15:41
Two sabre-toothed cat skulls have holes in them that precisely match the cats’ famously long canine teeth, suggesting rival cats bit through the bone
Categories: Biology

Blacklisting Huawei from Android upgrades will end up hurting Google

Genetics - Mon, 2019-05-20 15:25
Huawei may end up making its own operating system, after Donald Trump put the company on a blacklist forcing Google to revoke its Android licence
Categories: Biology

The kilogram has been transformed today as new definition takes hold

Genetics - Mon, 2019-05-20 13:28
This picture shows the Kibble balance – the new way to measure the kilogram, as it joins other units in the SI measurement system which are pegged to physical constants
Categories: Biology

Some baby dinosaurs crawled before learning to walk on two legs

Genetics - Mon, 2019-05-20 13:00
A dinosaur that walked on its two hind legs, may have started out crawling around on all fours whilst its body was still developing
Categories: Biology

Mini universes could be constantly exploding at every point in space

Genetics - Mon, 2019-05-20 12:48
If every point in space acts like a tiny universe, growing and then shrinking, it could explain our universe’s expansion and solve one of physics’ biggest problems
Categories: Biology

I went hunting for willow seeds in the home of Winnie-the-Pooh

Genetics - Sun, 2019-05-19 10:00
Willow trees in the UK are potentially at risk from rising disease outbreaks, so efforts are underway to bank their seeds
Categories: Biology

Funding crisis threatens crucial UK ocean monitoring project

Genetics - Sat, 2019-05-18 10:00
The array of moorings monitoring a weakening in the Atlantic conveyor belt risk being left in the lurch when funding expires in 2020, leaving key questions about the climate unanswered
Categories: Biology

Scientists have finally worked out what screaming sounds like

Genetics - Sat, 2019-05-18 10:00
Can you tell the difference between a scream and a whistle? Most people consider rough, high-pitched noises a scream – and 70 per cent were tricked by a whistle
Categories: Biology

Reversible association with motor proteins (RAMP): A streptavidin-based method to manipulate organelle positioning

PLOS Biology (new articles) - Fri, 2019-05-17 23:00

by Carlos M. Guardia, Raffaella De Pace, Aritra Sen, Amra Saric, Michal Jarnik, David A. Kolin, Ambarish Kunwar, Juan S. Bonifacino

We report the development and characterization of a method, named reversible association with motor proteins (RAMP), for manipulation of organelle positioning within the cytoplasm. RAMP consists of coexpressing in cultured cells (i) an organellar protein fused to the streptavidin-binding peptide (SBP) and (ii) motor, neck, and coiled-coil domains from a plus-end–directed or minus-end–directed kinesin fused to streptavidin. The SBP–streptavidin interaction drives accumulation of organelles at the plus or minus end of microtubules, respectively. Importantly, competition of the streptavidin–SBP interaction by the addition of biotin to the culture medium rapidly dissociates the motor construct from the organelle, allowing restoration of normal patterns of organelle transport and distribution. A distinctive feature of this method is that organelles initially accumulate at either end of the microtubule network in the initial state and are subsequently released from this accumulation, allowing analyses of the movement of a synchronized population of organelles by endogenous motors.
Categories: Biology, Journals

mRNA association by aminoacyl tRNA synthetase occurs at a putative anticodon mimic and autoregulates translation in response to tRNA levels

PLOS Biology (new articles) - Fri, 2019-05-17 23:00

by Ofri Levi, Yoav Arava

Aminoacyl-tRNA synthetases (aaRSs) are well studied for their role in binding and charging tRNAs with cognate amino acids. Recent RNA interactome studies had suggested that these enzymes can also bind polyadenylated RNAs. Here, we explored the mRNA repertoire bound by several yeast aaRSs. RNA immunoprecipitation (RIP) followed by deep sequencing revealed unique sets of mRNAs bound by each aaRS. Interestingly, for every tested aaRSs, a preferential association with its own mRNA was observed, suggesting an autoregulatory process. Self-association of histidyl-tRNA synthetase (HisRS) was found to be mediated primarily through binding to a region predicted to fold into a tRNAHis anticodon-like structure. Introducing point mutations that are expected to disassemble this putative anticodon mimic alleviated self-association, concomitant with increased synthesis of the protein. Finally, we found that increased cellular levels of uncharged tRNAHis lead to reduced self-association and increased HisRS translation, in a manner that depends on the anticodon-like element. Together, these results reveal a novel post-transcriptional autoregulatory mechanism that exploits binding mimicry to control mRNA translation according to tRNA demands.
Categories: Biology, Journals

Dysfunctional peripheral T follicular helper cells dominate in people with impaired influenza vaccine responses: Results from the FLORAH study

PLOS Biology (new articles) - Fri, 2019-05-17 23:00

by Suresh Pallikkuth, Lesley R. de Armas, Stefano Rinaldi, Varghese K. George, Li Pan, Kristopher L. Arheart, Rajendra Pahwa, Savita Pahwa

Antigen-primed cluster of differentiation (CD) 4+ T follicular helper (Tfh) cells interact with B cells in the germinal centers (GCs) of lymph nodes to generate vaccine-induced antibody (Ab) responses. In the circulation, peripheral Tfh (pTfh) cells, a subset of memory CD4 T cells, serve as surrogates for GC Tfh because of several functional and phenotypic similarities between them. We investigated features of H1N1 influenza antigen-specific pTfh (Ag.pTfh) in virologically controlled HIV+ volunteers on antiretroviral therapy (ART) and healthy control (HC) participants selected from a seasonal influenza vaccine responsiveness study. Selection of the participants was made based on age, defined as young (18–40 y) and old (>60 y) and on their classification as a vaccine responder (VR) or vaccine nonresponder (VNR). VRs demonstrated expansion of CD40L+ and CD69+ Ag.pTfh, with induction of intracellular interleukin 21 (IL-21) and inducible costimulator (ICOS) post vaccination; these responses were strongest in young HC VRs and were less prominent in HIV+ individuals of all ages. Ag.pTfh in VNRs exhibited dramatically different characteristics from VRs, displaying an altered phenotype and a cytokine profile dominated by cytokines IL-2, tumor necrosis factor alpha (TNF-α), or IL-17 but lacking in IL-21. In coculture experiments, sorted pTfh did not support the B cell IgG production in VNRs and were predominantly an inflammatory T helper 1 (Th1)/T helper 17 (Th17) phenotype with lower ICOS and higher programmed cell death protein 1 (PD1) expression. IL-21 and ICOS on Ag.pTfh cells are negatively affected by both aging and HIV infection. Our findings demonstrate that dysfunctional Ag.pTfh cells with an altered IL-21/IL-2 axis contribute to inadequate vaccine responses. Approaches for targeting inflammation or expanding functional Tfh may improve vaccine responses in aging and those aging with HIV infection.
Categories: Biology, Journals

No, koalas are not 'functionally extinct', but they are in trouble

Genetics - Fri, 2019-05-17 16:29
A conservation group has claimed that koalas are "functionally extinct". That isn't true, but many populations are falling sharply due to habitat loss and global warming
Categories: Biology

Cannabis plant evolved super high (on the Tibetan Plateau)

Genetics - Fri, 2019-05-17 14:47
An analysis of pollen suggests cannabis evolved on the Tibetan Plateau, not far from a cave that was frequented by our ancient Denisovan cousins
Categories: Biology

Digital camera sees around corners by guessing what's lurking behind

Genetics - Fri, 2019-05-17 14:00
An algorithm allows digital cameras to photograph objects hidden around a wall by interpreting subtle patterns of light that reflect on the floor or walls
Categories: Biology

Sea otters are bouncing back - and into the jaws of great white sharks

Genetics - Fri, 2019-05-17 13:23
Decades of conservation work have boosted sea otter populations in many parts of the North Pacific, but the animals are now being killed by great white sharks
Categories: Biology

Compulsory vaccines are needed to keep measles under control in the UK

Genetics - Fri, 2019-05-17 03:00
The UK should make measles vaccinations compulsory before children start school, according to an analysis of international measles data
Categories: Biology

Cellular labeling of endogenous retrovirus replication (CLEVR) reveals de novo insertions of the gypsy retrotransposable element in cell culture and in both neurons and glial cells of aging fruit flies

PLOS Biology (new articles) - Thu, 2019-05-16 23:00

by Yung-Heng Chang, Richard M. Keegan, Lisa Prazak, Josh Dubnau

Evidence is rapidly mounting that transposable element (TE) expression and replication may impact biology more widely than previously thought. This includes potential effects on normal physiology of somatic tissues and dysfunctional impacts in diseases associated with aging, such as cancer and neurodegeneration. Investigation of the biological impact of mobile elements in somatic cells will be greatly facilitated by the use of donor elements that are engineered to report de novo events in vivo. In multicellular organisms, reporter constructs demonstrating engineered long interspersed nuclear element (LINE-1; L1) mobilization have been in use for quite some time, and strategies similar to L1 retrotransposition reporter assays have been developed to report replication of Ty1 elements in yeast and mouse intracisternal A particle (IAP) long terminal repeat (LTR) retrotransposons in cultivated cells. We describe a novel approach termed cellular labeling of endogenous retrovirus replication (CLEVR), which reports replication of the gypsy element within specific cells in vivo in Drosophila. The gypsy-CLEVR reporter reveals gypsy replication both in cell culture and in individual neurons and glial cells of the aging adult fly. We also demonstrate that the gypsy-CLEVR replication rate is increased when the short interfering RNA (siRNA) silencing system is genetically disrupted. This CLEVR strategy makes use of universally conserved features of retroviruses and should be widely applicable to other LTR retrotransposons, endogenous retroviruses (ERVs), and exogenous retroviruses.
Categories: Biology, Journals

Resistance diagnostics as a public health tool to combat antibiotic resistance: A model-based evaluation

PLOS Biology (new articles) - Thu, 2019-05-16 23:00

by David McAdams, Kristofer Wollein Waldetoft, Christine Tedijanto, Marc Lipsitch, Sam P. Brown

Rapid point-of-care resistance diagnostics (POC-RD) are a key tool in the fight against antibiotic resistance. By tailoring drug choice to infection genotype, doctors can improve treatment efficacy while limiting costs of inappropriate antibiotic prescription. Here, we combine epidemiological theory and data to assess the potential of resistance diagnostics (RD) innovations in a public health context, as a means to limit or even reverse selection for antibiotic resistance. POC-RD can be used to impose a nonbiological fitness cost on resistant strains by enabling diagnostic-informed treatment and targeted interventions that reduce resistant strains’ opportunities for transmission. We assess this diagnostic-imposed fitness cost in the context of a spectrum of bacterial population biologies and find that POC-RD have a greater potential against obligate pathogens than opportunistic pathogens already subject to selection under “bystander” antibiotic exposure during asymptomatic carriage (e.g., the pneumococcus). We close by generalizing the notion of RD-informed strategies to incorporate carriage surveillance information and illustrate that coupling transmission-control interventions to the discovery of resistant strains in carriage can potentially select against resistance in a broad range of opportunistic pathogens.
Categories: Biology, Journals

Squished faces aren’t the only cause of bulldog breathing difficulties

Genetics - Thu, 2019-05-16 21:00
A gene mutation present in English and French bulldogs may be partly responsible for their breathing problems
Categories: Biology