Cis-acting elements stimulating kinetoplastid guide RNA-directed editing

The coding sequence of several mitochondrial mRNAs of the kinetoplastid protozoa is created through the insertion and deletion of specific uridylates. The editing reactions are required to be highly specific in order to ensure that functional open reading frames are created in edited mRNAs and that potentially deleterious modification of normally nonedited sequence does not occur. Selection-amplification and mutagenesis were previously used to identify the optimal sequence requirements for in vitro editing. There is, however, a minority of natural editing sites with suboptimal sequence. Several cis-acting elements, obtained from an in vitro selection, are described here that are able to compensate for a suboptimal editing site. An A + U sequence element within the 5'-untranslated region of cytochrome b mRNA from Leishmania tarentolae is also demonstrated to function as a cis-acting guide RNA and is postulated to compensate for a suboptimal editing site in vivo. Two proteins within an enriched editing extract are UV-cross-linked to two different in vitro selected editing substrates more efficiently than poorly edited RNAs. The results suggest that these proteins contribute to the specificity of the editing reaction.     

The de novo engineering of pyrrolysyl-tRNA synthetase for genetic incorporation of L-phenylalanine and its derivatives

Using evolved pyrrolysyl-tRNA synthetase-tRNA(CUA)(Pyl) pairs, L-phenylalanine, p-iodo-L-phenylalanine and p-bromo-L-phenylalanine have been genetically incorporated into proteins at amber mutation sites in E. coli.     

Deficiency of Macf1 in osterix expressing cells decreases bone formation by Bmp2/Smad/Runx2 pathway

Microtubule actin cross‐linking factor 1 (Macf1) is a spectraplakin family member known to regulate cytoskeletal dynamics, cell migration, neuronal growth and cell signal transduction. We previously demonstrated that knockdown of Macf1 inhibited the differentiation of MC3T3‐E1 cell line. However, whether Macf1 could regulate bone formation in vivo is unclear. To study the function and mechanism of Macf1 in bone formation and osteogenic differentiation, we established osteoblast‐specific Osterix (Osx) promoter‐driven Macf1 conditional knockout mice (Macf1^f/fOsx‐Cre). The Macf1^f/fOsx‐Cre mice displayed delayed ossification and decreased bone mass. Morphological and mechanical studies showed deteriorated trabecular microarchitecture and impaired biomechanical strength of femur in Macf1^f/fOsx‐Cre mice. In addition, the differentiation of primary osteoblasts isolated from calvaria was inhibited in Macf1^f/fOsx‐Cre mice. Deficiency of Macf1 in primary osteoblasts inhibited the expression of osteogenic marker genes (Col1, Runx2 and Alp) and the number of mineralized nodules. Furthermore, deficiency of Macf1 attenuated Bmp2/Smad/Runx2 signalling in primary osteoblasts of Macf1^f/fOsx‐Cre mice. Together, these results indicated that Macf1 plays a significant role in bone formation and osteoblast differentiation by regulating Bmp2/Smad/Runx2 pathway, suggesting that Macf1 might be a therapeutic target for bone disease.     

Ionic Organic Thermoelectrics with Impressively High Thermopower for Sensitive Heat Harvesting Scenarios

As the worldwide energy crisis is worsened, thermoelectric materials that can harvest low-grade waste heat and directly convert it into electricity provide promising alternative energy sources. Emerging ionic thermoelectrics (iTEs) have recently attracted widespread attention thanks to their impressively high thermopower that can reach hundreds of times more than conventional electronic thermoelectrics (eTEs). Based on the Soret effect, the performances of iTEs depend on the thermo-diffusion of mobile ions in electrolytes, resulting in electrical characteristics distinct from eTE materials and opening up additional potential applications of thermoelectrics. Among these materials, organics-based iTEs (i-OTEs) provide unique advantages such as low-cost, light-weight, and eco-friendliness, thereby offering more promising application scenarios that can utilize dissipated heat, for example, from human bodies or mobile devices. This concise review begins with the comparison of iTE and eTE, and then discusses their different mechanisms and applied devices in detail. Next, the recent advances of i-OTEs will be in-depth highlighted, including the merits and weaknesses of representative types of materials, effects of additives, and effective strategies for performance optimization. Finally, the state-of-the-art achievements of i-OTEs are summarized, and an overview is provided of the existing challenges and an outlook of prospective development and applications in future efforts.     

Long-term study of female multiple mating indicates direct benefits in Tribolium castaneum

Polyandry or female mating with several different partners in a single fertile period is a widespread phenomenon possibly involving both costs and benefits. This study tested whether remating after weeks of initial copulation (periodic multiple mating) has fitness consequences for females of red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), a cosmopolitan storage pest. We hypothesize that females benefit from higher mating frequency and more mates through sperm replenishment and/or compatible sperm. Thus, offspring production and survivorship were examined of females that were mated to multiple males or the same male repeatedly at variable intervals (every 2 weeks, 1, 3, and 5 months). Our results suggest that remating, after months of initial copulation, confers direct benefits to females, likely by providing additional sperm or through an alternative mechanism such as better ability of fresh sperm to fertilize eggs, stimulation of oviposition from copulation itself, and/or hydration benefit of the ejaculate. We did not detect any additional benefit of female multiple mating.     

Photonics of human saliva: potential optical methods for the screening of abnormal health conditions and infections

Human saliva can be treated as a pool of biological markers able to reflect on the state of personal health. Recent years have witnessed an increase in the use of optical devices for the analysis of body fluids. Several groups have carried out studies investigating the potential of saliva as a non-invasive and reliable clinical specimen for use in medical diagnostics. This brief review aims to highlight the optical technologies, mainly surface plasmon resonance (SPR), Raman, and Fourier transform infrared (FTIR) spectroscopy, which are being used for the probing of saliva for diverse biomedical applications. Advances in bio photonics offer the promise of unambiguous, objective and fast detection of abnormal health conditions and viral infections (such as COVID-19) from the analysis of saliva.