Evidence for the additions of clustered interacting nodes during the evolution of protein interaction networks from network motifs

<p>Abstract</p> <p>Background</p> <p>High-throughput screens have revealed large-scale protein interaction networks defining most cellular functions. How the proteins were added to the protein interaction network during its growth is a basic and important issue. Network motifs represent the simplest building blocks of cellular machines and are of biological significance.</p> <p>Results</p> <p>Here we study the evolution of protein interaction networks from the perspective of network motifs. We find that in current protein interaction networks, proteins of the same age class tend to form motifs and such co-origins of motif constituents are affected by their topologies and biological functions. Further, we find that the proteins within motifs whose constituents are of the same age class tend to be densely interconnected, co-evolve and share the same biological functions, and these motifs tend to be within protein complexes.</p> <p>Conclusions</p> <p>Our findings provide novel evidence for the hypothesis of the additions of clustered interacting nodes and point out network motifs, especially the motifs with the dense topology and specific function may play important roles during this process. Our results suggest functional constraints may be the underlying driving force for such additions of clustered interacting nodes.</p

A Liquid Metal Temperature Detection System Based on Multi-Node Sapphire Fiber Sensor

In order to accurately detect the temperature of molten aluminum and overcome the adverse influence of high temperature and corrosiveness on the sensing results, a temperature detection system based on a multi-node sapphire fiber sensor was proposed and developed. Through the structural parameter design of the fiber sensor, the scheme of utilizing the 0.7 mm diameter fiber and 0.5 mm groove was formulated. Simulation and analysis were carried out to determine the ultrasonic response distribution of the signal passing through the whole fiber sensor. The results indicate that the system is capable of distinguishing test signals from various positions and temperatures. Following the completion of the static calibration, the temperature of the molten aluminum was observed in real-time, and the data of the temperature measurements conducted at the two groove locations were compared. According to the obtained results, the test accuracy was greater than 1 degree Celsius and the temperature test stability was good, laying a solid foundation for the potential development of temperature measurement devices

Comparative transcriptome analyses reveal the genetic basis underlying the immune function of three amphibians’ skin

<div><p>Skin as the first barrier against external invasions plays an essential role for the survival of amphibians on land. Understanding the genetic basis of skin function is significant in revealing the mechanisms underlying immunity of amphibians. In this study, we <i>de novo</i> sequenced and comparatively analyzed skin transcriptomes from three different amphibian species, <i>Andrias davidianus</i>, <i>Bufo gargarizans</i>, and <i>Rana nigromaculata</i> Hallowell. Functional classification of unigenes in each amphibian showed high accordance, with the most represented GO terms and KEGG pathways related to basic biological processes, such as binding and metabolism and immune system. As for the unigenes, GO and KEGG distributions of conserved orthologs in each species were similar, with the predominantly enriched pathways including RNA polymerase, nucleotide metabolism, and defense. The positively selected orthologs in each amphibian were also similar, which were primarily involved in stimulus response, cell metabolic, membrane, and catalytic activity. Furthermore, a total of 50 antimicrobial peptides from 26 different categories were identified in the three amphibians, and one of these showed high efficiency in inhibiting the growth of different bacteria. Our understanding of innate immune function of amphibian skin has increased basis on the immune-related unigenes, pathways, and antimicrobial peptides in amphibians.</p></div

Statistical summary of the transcriptome data and assembled unigenes of each amphibian skin library.

<p>Statistical summary of the transcriptome data and assembled unigenes of each amphibian skin library.</p

Significantly enriched KEGG pathways for conserved orthologs in each amphibian.

<p>Significantly enriched KEGG pathways for conserved orthologs in each amphibian.</p

Histogram of KEGG pathway annotation of the unigenes in each amphibian.

<p>The <i>x-axis</i> represents hierarchy two pathways; the left <i>y-axis</i> represents unigene numbers in each pathway. Bars with different colors represent different species.</p