The visualisation of Quadruple-Helix DNA in Living Human Cells

The DNA molecule is often associated with its well-known double-stranded helical B conformation, first discovered using crystallographic evidence sought by English chemist and x-ray crystallographer Rosalind Franklin. While this is the most common structure, it can also be found in two other double helical conformations, the A and Z forms, and it has also been found to adopt a range of other structures such as cruciform and slipped structures, and triple helices.1 The diversity of known possible non-B conformations has increased  with the discovery of four-stranded ‘quadruple helix’ DNA molecules, also known as ‘G-quadruplexes’ or ‘G4s’, having been detected in guanine-rich regions of the genome. While this form of DNA has been previously theorized to exist and has been synthesized ‘in vitro’ by researchers, it was only found to exist in human cells in 2013. 2 It has been found to have an essential role in telomere function, replication, transcription, and translation. However, imaging the molecules remained a challenge and in January 2021, researchers identified a probe exhibiting fluorescence in the presence of G-quadruplexes which could be used in order to visualize quadruple-stranded DNA in live cells using fluorescent lifetime imaging microscopy (FLIM).

Motor neurone disease: Edinburgh scientists reveal breakthrough

A group of scientists led by Dr. Arpan Mehta in the Euan MacDonald centre have published a breakthrough paper for Motor Neurone Disease research. Motor Neurone Disease (MND) also known as Amyotrophic Lateral Sclerosis (ALS) is characterised as the loss of upper and lower motor neurons that are involved in voluntary muscle contraction. Sclerosis of motor neurons usually starts in the neuromuscular junctions (NMJ) which is the point of transmission of electric potential between the axon and the muscle. The selectivity of neuronal degeneration is still under active research, but is thought to be related to an interruption of the glutamate-mediated communication between neurons (Van den Bosch, 2006). Most current MND drugs approved by the FDA target glutamate regulation, as well as pain regulation drugs and treatment for respiratory failure associated with NMD. The recent research, published by Mehta et al. 2021 shows a new identifiable characteristic of MND neurons that is a possible target for treatment. The main medication used for treatment called Riluzole only increases survival of patients by around 2-3 months, this is why the findings are crucial as they may offer a more effective treatment solution. Mehta et al. used analysis of patient derived pluripotent stem cells as well as patient post mortem tissue analysis to identify key differences in axonal length and mitochondrial movement within the axons between control and affected cells. 

Can we predict the next pandemic virus?

Viruses are obligate microparasites (Lodish et al., 2000) which pose a great public health threat, as highlighted by the current COVID-19 pandemic (WHO, 2020a). Pandemics are the global spread of disease, with the ongoing HIV/AIDS (Eisinger and Fauci, 2018) and 2009 influenza A/H1N1 pandemics (WHO, 2020b), as viral examples. Virus emergence is increasing with rising human population density, changes in land use, and the arrival of international trade and travel (Morse et al., 2012). This highlights the need to identify and prevent pandemics through identification and targeted surveillance of candidate viruses (Neumann and Kawaoka, 2019). This essay aims to discuss whether the next pandemic virus can be predicted; focusing on identifying, characterising, and modelling viruses to assess their pandemic potential, and the associated challenges. 

One step closer to saving the northern white rhino

A new milestone has been accomplished in the mission to save the northern white rhino (Ceratotherium simum cottoni). There are only two known northern white rhinos left, both of whom are females. Without the ability to reproduce, this subspecies is functionally extinct. An international team are now one step closer to using assisted reproduction technology (ART) including in vitro fertilisation (IVF) to increase subspecies numbers and bring them back from the edge of extinction.