Normal table of embryonic development in the Anji salamander Hynobius amjiensis (Hynobiidae).

We established a normal embryonic development table for the Anji salamander Hynobius amjiensis, a critically endangered tailed amphibian of the family Hynobiidae with a very limited distribution in East China, following the standards set by the early developmental table of vertebrates. Put together 32 embryonic stages for the Anji salamander was defined. The total embryonic period from oviposition to hatching is approximately 30 days at 9 °C. Stages 1-16 represent early development from cleavage to neurulation. Stages 17-32 represent organogenesis documenting later developmental events such as tail, gill, and limb formation, and hatching (Stage 32). We provided a detailed description of the external morphology and color changes of the head, trunk, limbs, tail, external gills, and balancers at various stages from egg-laying to hatching. We also described several cases of abnormal embryonic development. The establishment of the embryonic development table in H. amjiensis contributes to better understanding of the ontogeny in tailed amphibians, distinguishing closely related species, and identifying abnormal embryonic amphibians.

LINC00116-encoded microprotein mitoregulin regulates fatty acid metabolism at the mitochondrial outer membrane.

LINC00116 encodes a microprotein first identified as Mitoregulin (MTLN), where it was reported to localize to the inner membrane of mitochondria to regulate fatty acid oxidation and oxidative phosphorylation. These initial discoveries were followed by reports with differing findings about its molecular functions and submitochondrial localization. To clarify the apparent discrepancies, we constructed multiple orthogonal methods of determining the localization of MTLN, including split GFP-based reporters that enable efficient and reliable topology analyses for microproteins. These methods unequivocally demonstrate MTLN primarily localizes to the outer membrane of mitochondria, where it interacts with enzymes of fatty acid metabolism including CPT1B and CYB5B. Loss of MTLN causes the accumulation of very long-chain fatty acids (VLCFAs), especially docosahexaenoic acid (DHA). Intriguingly, loss of MTLN protects mice against western diet/fructose-induced insulin-resistance, suggests a protective effect of VLCFAs in this context. MTLN thus serves as an attractive target to control the catabolism of VLCFAs.

Genetic structure and characteristics of Tibetan chickens.

Tibetan chicken is one of the most common and widely distributed highland breeds, and is often used as a model organism for understanding genetic adaptation to extreme environments in Tibet. Despite its apparent geographical diversity and large variations in plumage patterns, the genetic differences within breed were not accounted for in most studies and have not been systematically investigated. In order to reveal and genetically differentiate the current existing TBC sub-populations that might have major implications for genomic research in TBCs, we systematically evaluated the population structure and demography of current TBC populations. Based on 344 whole-genome sequenced birds including 115 Tibetan chickens that were mostly sampled from family-farms across Tibet, we revealed a clear separation of Tibetan chickens into 4 sub-populations that broadly aligns with their geographical distribution. Moreover, population structure, population size dynamics, and the extent of admixture jointly suggest complex demographic histories of these sub-populations, including possible multiple origins, inbreeding, and introgressions. While most of the candidate selected regions found between the TBC sub-populations and Red Jungle fowls were nonoverlapping, 2 genes RYR2 and CAMK2D were revealed as strong selection candidates in all 4 sub-populations. These 2 previously identified high altitude associated genes indicated that the sub-populations responded to similar selection pressures in an independent but functionally similar fashion. Our results demonstrate robust population structure in Tibetan chickens that will help inform future genetic analyses on chickens and other domestic animals alike in Tibet, recommending thoughtful experimental design.

The behavior of microplastics and nanoplastics release from UV-aged masks in the water.

In this study, three types of disposable masks were exposed to ultraviolet (UV) irradiation to determine the effect of UV irradiation on the release of microplastics (MPs) and nanoplastic (NPs) from the masks. A kinetic model was used to investigate the mechanisms of M/NP release from the masks under UV irradiation. Results showed that UV irradiation exacerbated the damage to the structure of the mask over time. As the irradiation time increased, the middle layer of the mask was damaged first (15 d) and subsequently all layers of the mask were damaged (30 d). There was no significant difference in the quantity of M/NPs released from the treatment groups at different irradiance during a 5-d irradiation period. When the UV time reached 15 and 30 d, the highest quantity of M/NPs was released at 8.5 W/m2 followed by 4.9 W/m2, 15.4 W/m2, and 17.1 W/m2. Exponential equations fitted the release curve of M/NPs. The release quantity of M/NPs increases exponentially with increasing UV irradiation time, and the longer the irradiation time, the faster the rate of increase. Estimated release of 1.78 × 1017-3.66 × 1019 particles/piece of MPs and 8.23 × 1019-2.18 × 1022 particles/piece of NPs into the water when the masks are exposed to the real environment for 1-3 years.

Rice Root Hair Phenotypes Imaged by Cryo-SEM.

Cryo-scanning electron microscopy (cryo-SEM) was first introduced for scientific use in the 1980s. Since then, cryo-SEM has become a routine technique for studying the surfaces and internal structures of biological samples with a high water content. In contrast to traditional SEM, cryo-SEM requires no sample pretreatment processes; thus, we can obtain the most authentic images of the sample shape and structure. Cryo-SEM has two main steps: cryoprocessing of samples and scanning electron microscopy (SEM) observation. The cryoprocessing step includes preparation of the cooled slushing station, cooling of the preparation chamber, sample preparation, and sputtering. The sample is then transferred to an SEM cold stage for observation. We used cryo-SEM to study rice root hair tissues, but the methods and protocols can be applied to other root systems. This protocol optimizes the two key operation steps of reducing the humidity in the growth chamber and previewing the samples before sputtering and can more quickly obtain high-quality images.

An integrated platform for fibrinogen quantification on a microfluidic paper-based analytical device.

Fibrinogen (FIB) plays a key role in blood coagulation and thrombosis and its concentration in blood can directly reflect health conditions, thus efficient detection of FIB would benefit the treatments of certain diseases such as liver and heart diseases. However, there is a lack of sensitive, simple, rapid and cheap FIB detection device currently, in lieu of expensive and sophisticated approaches in laboratories. Here, we propose a novel plasma separation and FIB detection platform based on a microfluidic paper-based analytical device (µPAD). It is the first time that dielectrophoretic (DEP) force is combined with capillary force on paper for plasma separation, and the separation efficiency of plasma reaches about 95%, ensuring reliable downstream FIB detection, for which we also propose a new method called the resistance-fibrinogen detection (RFD) method. It not only avoids the use of large-scale instruments for detection, but also possesses high precision and simplicity. The method is found to be reliable in FIB detection for various concentrations ranging from 127.0 to 508.0 mg dL-1. Moreover, the results obtained from the proposed µPAD show an excellent agreement (R2 = 0.9985) with those obtained from an automatic coagulation analyzer with natural human blood samples. Overall, the proposed platform provides a low-cost and reliable approach for FIB detection, especially for clinical use in resource-limited areas.