Demographic History and Genomic Response to Environmental Changes in a Rapid Radiation of Wild Rats

For organisms to survive and prosper in a harsh environment, particularly under rapid climate change, poses tremendous challenges. Recent studies have highlighted the continued loss of megafauna in terrestrial ecosystems and the subsequent surge of small mammals, such as rodents, bats, lagomorphs, and insectivores. However, the ecological partitioning of these animals will likely lead to large variation in their responses to environmental change. In the present study, we investigated the evolutionary history and genetic adaptations of white-bellied rats (Niviventer Marshall, 1976), which are widespread in the natural terrestrial ecosystems in Asia but also known as important zoonotic pathogen vectors and transmitters. The southeastern Qinghai-Tibet Plateau was inferred as the origin center of this genus, with parallel diversification in temperate and tropical niches. Demographic history analyses from mitochondrial and nuclear sequences of Niviventer demonstrated population size increases and range expansion for species in Southeast Asia, and habitat generalists elsewhere. Unexpectedly, population increases were seen in N. eha, which inhabits the highest elevation among Niviventer species. Genome scans of nuclear exons revealed that among the congeneric species, N. eha has the largest number of positively selected genes. Protein functions of these genes are mainly related to olfaction, taste, and tumor suppression. Extensive genetic modification presents a major strategy in response to global changes in these alpine species.     

Ten-a Affects the Fusion of Central Complex Primordia in Drosophila

The central complex of Drosophila melanogaster plays important functions in various behaviors, such as visual and olfactory memory, visual orientation, sleep, and movement control. However little is known about the genes regulating the development of the central complex. Here we report that a mutant gene affecting central complex morphology, cbd (central brain defect), was mapped to ten-a, a type II trans-membrane protein coding gene. Down-regulation of ten-a in pan-neural cells contributed to abnormal morphology of central complex. Over-expression of ten-a by C767-Gal4 was able to partially restore the abnormal central complex morphology in the cbd mutant. Tracking the development of FB primordia revealed that C767-Gal4 labeled interhemispheric junction that separated fan-shaped body precursors at larval stage withdrew to allow the fusion of the precursors. While the C767-Gal4 labeled structure did not withdraw properly and detached from FB primordia, the two fan-shaped body precursors failed to fuse in the cbd mutant. We propose that the withdrawal of C767-Gal4 labeled structure is related to the formation of the fan-shaped body. Our result revealed the function of ten-a in central brain development, and possible cellular mechanism underlying Drosophila fan-shaped body formation.     

Sesame Utilization in China: New Archaeobotanical Evidence from Xinjiang

Sesame Utilization in China: New Archaeobotanical Evidence from Xinjiang. A cache of sesame (Sesamum indicum L.) seeds, discovered in the Thousand Buddha Grottoes at Boziklik, Turpan, China, dating to ca. 700 years before present (BP), is hard evidence of their use in China since that time. Morphological and anatomical features suggest a white sesame cultivar. The sizeable quantity unearthed implies that sesame was a valued commodity that could provision the monks and enrich the diet of ancient inhabitants as an oil source.     

Decreased dengue cases attributable to the effect of COVID-19 in Guangzhou in 2020

The dengue fever epidemic in Guangzhou may have been affected by the Coronavirus Disease 2019 (COVID-19) pandemic. The number of dengue cases dropped drastically in 2020, and there have been only 2 local cases, suggesting that dengue has not become endemic in Guangzhou.

Guangzhou is located on the southeast coast of China and is the country’s third largest city. Since 1978, outbreaks of dengue fever have occurred intermittently in this city. In the past decade, the number of reported dengue cases reached more than 1,000 in 2013, 2014, 2018, and 2019, with 37,385 cases reported in 2014 alone. Therefore, dengue fever is a major public health concern in Guangzhou, and there is a continuing argument that it is endemic in Guangzhou [1–3].The numbers of dengue cases from 2017 to 2020 are shown in Table 1. In 2020, the total and local case numbers dropped dramatically compared to the previous years. With a high proportion of imported cases (n = 32, 94.12%), the proportion of local cases (n = 2, 5.88%) was considerably low in 2020. All the prevention and control strategies for dengue, including issuing public education messages, preventing further mosquito bites in patients, cleaning vector breeding sites, and using pesticides, were similar during these years. Additionally, dengue, as a mosquito-borne viral infectious disease, is closely related to mosquito density. The mosquito ovitrap index (MOI), which is the proportion of positive mosquito ovitraps, is usually used to indicate mosquito density. The MOI in 2017, 2018, and 2019 was 7.073 ± 1.016, 9.657 ± 1.307, and 8.464 ± 0.961, respectively. The average MOI was 8.398 ± 0.648 from 2017 to 2019 in Guangzhou. The MOI in 2020 was 7.135 ± 0.786, which remained at the median risk level. Therefore, the abnormal decline in dengue cases could not be attributed to the change in mosquito density in 2020.Table 1Numbers and percentages of dengue cases from 2017 to 2019.

Perfect Terahertz Absorption with Graphene Surface Plasmons in the Modified Otto Configuration

Perfect terahertz (THz) absorption in the modified Otto configuration with the insertion of monolayer graphene sheet has been numerically demonstrated. This perfect absorption originates from the enhancement of the electrical field owing to the excitation of the transverse magnetic (TM) polarized surface plasmons at the interface of two dielectrics with monolayer graphene. It is found that the absorption peak occurs at the specific incident angles, which can be employed for realizing the angular absorbers. We further demonstrate that the angle of the peak absorption and the corresponding wavelength can be manipulated by changing the Fermi energy of monolayer graphene sheet via electrostatic biasing. Moreover, the behaviors of the perfect absorption are strongly dependent on the dielectric constants and thicknesses of the surrounding dielectrics.     

Overexpression of microRNA-23a-5p induces myocardial infarction by promoting cardiomyocyte apoptosis through inhibited of PI3K/AKT signalling pathway

Myocardial infarction (MI) leads to cardiac remodelling and heart failure. Cardiomyocyte apoptosis is considered a critical pathological phenomenon accompanying MI, but the pathogenesis mechanism remains to be explored. MicroRNAs (miRs), with the identity of negative regulator of gene expression, exist as an important contributor to apoptosis. During the experiment of this study, MI mice models were successfully established and sequencing data showed that the expression of miR-23a-5p was significantly enhanced during MI progression. Further steps were taken and it showed that apoptosis of cardiac cells weakened as miR-23a-5p was downregulated and on the contrary that apoptosis strengthened with the overexpression of miR-23a-5p. To explore its working mechanisms, bioinformatics analysis was conducted by referring to multi-databases to predict the targets of miR-23a-5p. Further analysis suggested that those downstream genes enriched in several pathways, especially in the PI3K/Akt singling pathway. Furthermore, it demonstrated that miR-23a-5p was negatively related to the phosphorylation of PI3K/Akt, which plays a critical role in triggering cell apoptosis during MI. Recilisib-activated PI3K/Akt singling pathway could restrain apoptosis from inducing miR-23a-5p overexpression, and Miltefosine-blocked PI3K/Akt singling pathway could restrict apoptosis from inhibiting miR-23a-5p reduction. In conclusion, these findings revealed the pivotal role of miR-23a-5p-PI3K/Akt axis in regulating apoptosis during MI, introducing this novel axis as a potential indicator to detect ischemic heart disease and it could be used for therapeutic intervention.     

便携多路环境数据采集系统

便携多路环境数据采集系统姜仕仁，常杰，葛滢（杭州大学生物科学与技术系，３１００１２）ＡＰｏｒｔａｂｌｅＭｕｌｔｉ－ＰａｓｓａｇｅＥｎｖｉｒｏｎｍｅｎｔａｌＤａｔａＡｕｔｏ－ＳａｍｐｌｉｎｇＳｙｓｔｅｍ．￥ＪｉａｎｇＳｈｉｒｅｎ；ＣｈａｎｇＪｉｅ；Ｇｅ...