We report the first global study of dynamic correlation energies (DCEs) associated with rotational motion and quadrupole shape vibrational motion in a covariant energy density functional (CEDF) for 575 even-even nuclei with proton numbers ranging from Z = 8 to Z = 108 by solving a fivedimensional collective Hamiltonian, the collective parameters of which are determined from triaxial relativistic mean-field plus BCS calculation using the PC-PK1 force. After taking into account these beyond mean-field DCEs, the root-mean-square (rms) deviation with respect to nuclear masses is reduced significantly down to 1.14 MeV, which is smaller than those of other successful CEDFs: NL3* (2.96 MeV), DD-ME2 (2.39 MeV), DD-MEδ (2.29 MeV) and DD-PC1 (2.01 MeV). Moreover, the rms deviation for two-nucleon separation energies is reduced by ∼ 34% in comparison with cranking prescription. Nuclear energy density functional theory is nowadays one of the most important microscopic approaches for large-scale nuclear structure calculations in medium and heavy nuclei based on a universal energy density functional (EDF) with a few parameters constrained by the properties of finite nuclei and nuclear matter or neutron stars. It stands out as a unique microscopic model that can describe not only the masses of all existing nuclei, but also other key quantities for simulating nucleonthesis process, including beta decay rate and fission rate in a unified way [1]. However, it is still a challenge for the current implementation of EDF to achieve satisfied accuracy. Therefore, great efforts have been devoted in many aspects to improving the accuracy of the EDF for atomic nuclei and subsequently deepening our understanding on the origin of elements in universe. Nuclear binding energy or mass is one of the most fundamental properties of atomic nuclei. The root-meansquare (rms) deviation with respect to the measured nuclear masses in the EDF is typically around several MeV. Only after taking into account the beyond mean-field dynamic correlation energies (DCEs) in global fitting of the EDF to nuclear masses can one achieve the rms deviation of a few hundred keV [2,3] by keeping a good description of nuclear matter properties. In these studies [2,3], the DCEs related to rotational and vibrational motions have been included phenomenologically with the cranking prescription. A better treatment of these DCEs is to carry out calculation with exact quantum number projec- * zpliphy@swu.edu.cn † mengj@pku.edu.cn tion and generator coordinate method (GCM), which has been done based on a Skyrme SLy4 force [4,5] with the assumption of topological Gaussian overlap approximation (GOA) or based on Gogny D1M and D1S forces [6] without using the GOA. In both the beyond mean-field (BMF) calculations, only axially deformed configurations are included and the obtained quadrupole DCEs are on average 3 − 4 MeV. Although the BMF approaches with exact projections and GCM for triaxially deformed nuclei have already been developed in recent years [7][8][9], they cannot be ado...
The silkworm Bombyx mori is an important economic insect for producing silk, the “queen of fabrics”. The currently available genomes limit the understanding of its genetic diversity and the discovery of valuable alleles for breeding. Here, we deeply re-sequence 1,078 silkworms and assemble long-read genomes for 545 representatives. We construct a high-resolution pan-genome dataset representing almost the entire genomic content in the silkworm. We find that the silkworm population harbors a high density of genomic variants and identify 7308 new genes, 4260 (22%) core genes, and 3,432,266 non-redundant structure variations (SVs). We reveal hundreds of genes and SVs that may contribute to the artificial selection (domestication and breeding) of silkworm. Further, we focus on four genes responsible, respectively, for two economic (silk yield and silk fineness) and two ecologically adaptive traits (egg diapause and aposematic coloration). Taken together, our population-scale genomic resources will promote functional genomics studies and breeding improvement for silkworm.
The insect cuticle is a critical protective shell that is composed predominantly of chitin and various cuticular proteins and pigments. Indeed, insects often change their surface pigment patterns in response to selective pressures, such as threats from predators, sexual selection and environmental changes. However, the molecular mechanisms underlying the construction of the epidermis and its pigmentation patterns are not fully understood. Among Lepidoptera, the silkworm is a favorable model for color pattern research. The black dilute (bd) mutant of silkworm is the result of a spontaneous mutation; the larval body color is notably melanized. We performed integument transcriptome sequencing of the wild-type strain Dazao and the mutant strains +/bd and bd/bd. In these experiments, during an early stage of the fourth molt, a stage at which approximately 51% of genes were expressed genome wide (RPKM ≥1) in each strain. A total of 254 novel transcripts were characterized using Cuffcompare and BLAST analyses. Comparison of the transcriptome data revealed 28 differentially expressed genes (DEGs) that may contribute to bd larval melanism, including 15 cuticular protein genes that were remarkably highly expressed in the bd/bd mutant. We suggest that these significantly up-regulated cuticular proteins may promote melanism in silkworm larvae.
Cytosine arabinoside (Ara-c) is a pyrimidine anti-metabolite that is capable of interfering with cellular proliferation by inhibiting DNA synthesis. Each inhibitor of cyclin-dependent kinase 4 (INK4) family member has the ability to bind to cyclin-dependent kinase 4 (CDK4) and inhibit the formation of the cell cycle-dependent CDK4/cyclin D1 complex, subsequently leading to cell cycle arrest in the G1/S phase. In this study, the expression of INK4 family genes in kidney cancer and the impact of these genes on patient prognosis were examined. Additionally, the effects of INK4 family genes and Ara-c on cell proliferation and tumor formation and development were examined. Finally, a potential association between Ara-c-induced cell cycle arrest and INK4-associated gene expression was evaluated. An upregulation of INK4 family genes was found to be positively correlated with the prognosis of patients with kidney cancer. Both the INK4 family genes and Arac were shown to induce cell cycle arrest and inhibit tumor formation and development. Moreover, Ara-c-induced cell cycle arrest was found to be associated with an Ara-c-induced upregulation of INK4 family gene expression, which ultimately inhibited the formation of the CDK4/cyclin D1 complex. These findings suggested that an upregulation of INK4 family genes has a positive effect on kidney cancer prognosis and can inhibit the formation and development of tumors. Moreover, Ara-c was shown to promote the upregulation of INK4 family genes, at the same time, Ara-c could directly regulate the cell cycle-dependent genes CDK4 and cyclin D1 (CCND1), independent of the INK4 family genes.
Holometabolous insects have distinct larval, pupal, and adult stages. The pupal stage is typically immobile and can be subject to predation, but cocoon offers pupal protection for many insect species. The cocoon provides a space in which the pupa to adult metamorphosis occurs. It also protects the pupa from weather, predators and parasitoids. Silk protein is a precursor of the silk used in cocoon construction. We used the silkworm as a model species to identify genes affecting silk protein synthesis and cocoon construction. We used quantitative genetic analysis to demonstrate that β-1 , 4-N-acetylglucosaminidase 1 ( BmGlcNase1 ) is associated with synthesis of sericin, the main composite of cocoon. BmGlcNase1 has an expression pattern coupled with silk gland development and cocoon shell weight (CSW) variation, and CSW is an index of the ability to synthesize silk protein. Up-regulated expression of BmGlcNase1 increased sericin content by 13.9% and 22.5% while down-regulation reduced sericin content by 41.2% and 27.3% in the cocoons of females and males, respectively. Genomic sequencing revealed that sequence variation upstream of the BmGlcNase1 transcriptional start site (TSS) is associated with the expression of BmGlcNase1 and CSW. Selective pressure analysis showed that GlcNase1 was differentially selected in insects with and without cocoons ( ω 1 = 0.044 vs. ω 2 = 0.154). This indicates that this gene has a conserved function in the cocooning process of insects. BmGlcNase1 appears to be involved in sericin synthesis and silkworm cocooning.
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