BmILF and I-motif Structure Are Involved in Transcriptional Regulation of \u3cem\u3eBmPOUM2\u3c/em\u3e in \u3cem\u3eBombyx mori\u3c/em\u3e

Guanine-rich and cytosine-rich DNA can form four-stranded DNA secondary structures called G-quadruplex (G4) and i-motif, respectively. These structures widely exist in genomes and play important roles in transcription, replication, translation and protection of telomeres. In this study, G4 and i-motif structures were identified in the promoter of the transcription factor gene BmPOUM2, which regulates the expression of the wing disc cuticle protein gene (BmWCP4) during metamorphosis. Disruption of the i-motif structure by base mutation, anti-sense oligonucleotides (ASOs) or inhibitory ligands resulted in significant decrease in the activity of the BmPOUM2 promoter. A novel i-motif binding protein (BmILF) was identified by pull-down experiment. BmILF specifically bound to the i-motif and activated the transcription of BmPOUM2. The promoter activity of BmPOUM2 was enhanced when BmILF was over-expressed and decreased when BmILF was knocked-down by RNA interference. This study for the first time demonstrated that BmILF and the i-motif structure participated in the regulation of gene transcription in insect metamorphosis and provides new insights into the molecular mechanism of the secondary structures in epigenetic regulation of gene transcription

Identification, Expression and Target Gene Analyses of MicroRNAs in Spodoptera litura

MicroRNAs (miRNAs) are small RNAs widely present in animals and plants and involved in post-transcriptional regulation of gene transcripts. In this study we identified and validated 58 miRNAs from an EST dataset of Spodoptera litura based on the computational and experimental analysis of sequence conservation and secondary structure of miRNA by comparing the miRNA sequences in the miRbase. RT-PCR was conducted to examine the expression of these miRNAs and stem-loop RT-PCR assay was performed to examine expression of 11 mature miRNAs (out of the 58 putative miRNA) that showed significant changes in different tissues and stages of the insect development. One hundred twenty eight possible target genes against the 11 miRNAs were predicted by using computational methods. Binding of one miRNA (sli-miR-928b) with the three possible target mRNAs was confirmed by Southern blotting, implying its possible function in regulation of the target genes

A family of memristive multibutterfly chaotic systems with multidirectional initial-based offset boosting

© 2023 Elsevier Ltd. All rights reserved. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1016/j.chaos.2023.113518Memristors are commonly used to construct memristive chaotic systems with complex dynamics because of their strong nonlinearity and unique memory effects. In this paper, a simplified multi-piecewise memristor is applied for designing a family of memristive multibutterfly chaotic systems (MMBCSs). By coupling different numbers of the simplified multi-piecewise memristors into a modified Sprott C system, three MMBCSs are constructed. Theoretical analysis and numerical simulations show that the three MMBCSs can not only generate connected 1D(direction)-, 2D(plane)-, and 3D(space)-multibutterfly chaotic attractors (MBCAs), respectively, but also can respectively produce unconnected 1D-, 2D-, and 3D-MBCAs. Also, the number and position of butterfly attractors can be easily controlled by switching the memristor’s integer parameters and initial states, respectively. More importantly, the constructed three MMBCSs exhibit different initial-based offset boosting including 1D-, 2D-, and 3D-boosting behaviors, respectively. Especially, the 3D-initial-offset behavior is found in chaotic systems at the first time. Furthermore, we further implement the physical circuit of the three MMBCSs, and various typical dynamical behaviors are demonstrated by hardware experiments and Multisim simulations. Finally, a medical image encryption solution for online medical treatment is designed based on the proposed MMBCSs.Peer reviewe

Protein profiles of the midgut of Spodoptera litura larvae at the sixth instar feeding stage by shotgun ESI-MS approach

By using shotgun HPLC-ESI-MS proteomics approach, 2043 peptides were identified from the midgut of Spodoptera litura larvae at the sixth instar feeding stage, out of which 1489 (72.9%) were found to have their homologues in the public protein databases and 842 had identities of molecular functions. Seven-hundred forty-one peptides were annotated according to Gene Ontology Annotation in terms of molecular function, biological process, and cellular localization, with 336 and 251 peptides being related to catalytic activity and binding activity, respectively. Most of the catalytic proteins had activity of hydrolases, oxidoreductases and transferases and most of the binding proteins were involved in protein-binding activity. Among the annotated peptides, 487 were classified into different cellular processes and 490 were classified to locate in the cytoplasm. Nonredundant enzymes associated with the metabolisms of carbohydrates, lipids and fatty acids, amino acids and proteins, translation, transport, and stress resistance were identified. Presence and expression at high levels of numerous enzymes of glycolysis pathway, synthesis of proteins, and absorption and transport of fatty acids and lipids indicate that active metabolism processes of carbohydrates, proteins, and lipids occurred in the midgut of sixth instar feeding larvae of S. litura. The protein profile provides a basis for further study of the physiological events in the midgut of S. litura

Algorithms and statistical analysis for linear structured weighted total least squares problem

Weighted total least squares (WTLS) have been regarded as the standard tool for the errors-in-variables (EIV) model in which all the elements in the observation vector and the coefficient matrix are contaminated with random errors. However, in many geodetic applications, some elements are error-free and some random observations appear repeatedly in different positions in the augmented coefficient matrix. It is called the linear structured EIV (LSEIV) model. Two kinds of methods are proposed for the LSEIV model from functional and stochastic modifications. On the one hand, the functional part of the LSEIV model is modified into the errors-in-observations (EIO) model. On the other hand, the stochastic model is modified by applying the Moore-Penrose inverse of the cofactor matrix. The algorithms are derived through the Lagrange multipliers method and linear approximation. The estimation principles and iterative formula of the parameters are proven to be consistent. The first-order approximate variance-covariance matrix (VCM) of the parameters is also derived. A numerical example is given to compare the performances of our proposed three algorithms with the STLS approach. Afterwards, the least squares (LS), total least squares (TLS) and linear structured weighted total least squares (LSWTLS) solutions are compared and the accuracy evaluation formula is proven to be feasible and effective. Finally, the LSWTLS is applied to the field of deformation analysis, which yields a better result than the traditional LS and TLS estimations

Thermodynamics of Hydrophobic Amino Acids in Solution: A Combined Experimental–Computational Study

We present a joint experimental–computational study to quantitatively describe the thermodynamics of hydrophobic leucine amino acids in aqueous solution. X-ray scattering data were acquired at a series of solute and salt concentrations to effectively measure interleucine interactions, indicating that a major scattering peak is observed consistently at <i>q</i> = 0.83 Å^–1. Atomistic molecular dynamics simulations were then performed and compared with the scattering data, achieving high consistency at both small and wider scattering angles (<i>q</i> = 0–1.5 Å^–1). This experimental–computational consistence enables a first glimpse of the leucine–leucine interacting landscape, where two leucine molecules are aligned mostly in a parallel fashion, as opposed to antiparallel, but also allows us to derive effective leucine–leucine interactions in solution. Collectively, this combined approach of employing experimental scattering and molecular simulation enables quantitative characterization of effective intermolecular interactions of hydrophobic amino acids, critical for protein function and dynamics such as protein folding