Bioinformatic analyses of RNA-seq data.

<p>(A) Pearson correlation between samples. (B) FPKM density distribution of two groups. (C) FPKM distribution of two groups. ZOT: 0°C treatment; ZRT: 25°C treatment.</p

Results of qRT-PCR and RNA-seq on genes encoding cold-resistance proteins.

<p>Results of qRT-PCR and RNA-seq on genes encoding cold-resistance proteins.</p

Bioinformatic analyses of DEGs (differentially expressed genes).

<p>(A) DEGs distribution of the two treatment groups (ZOT: 0°C, ZRT: 25°C). (B) Venn diagrams showing the number of genes expressed in the two groups. (C) Cluster analysis of DEGs.</p

Transcriptomic analysis to uncover genes affecting cold resistance in the Chinese honey bee (<i>Apis cerana cerana</i>)

<div><p>The biological activity and geographical distribution of honey bees is strongly temperature-dependent, due to their ectothermic physiology. In China, the endemic <i>Apis cerana cerana</i> exhibits stronger cold hardiness than Western honey bees, making the former species important pollinators of winter-flowering plants. Although studies have examined behavioral and physiological mechanisms underlying cold resistance in bees, data are scarce regarding the exact molecular mechanisms. Here, we investigated gene expression in <i>A</i>. <i>c</i>. <i>cerana</i> under two temperature treatments, using transcriptomic analysis to identify differentially expressed genes (DEGs) and relevant biological processes, respectively. Across the temperature treatments, 501 DEGs were identified. A gene ontology analysis showed that DEGs were enriched in pathways related to sugar and amino acid biosynthesis and metabolism, as well as calcium ion channel activity. Additionally, heat shock proteins, zinc finger proteins, and serine/threonine-protein kinases were differentially expressed between the two treatments. The results of this study provide a general digital expression profile of thermoregulation genes responding to cold hardiness in <i>A</i>. <i>c</i>. <i>cerana</i>. Our data should prove valuable for future research on cold tolerance mechanisms in insects, and may be beneficial in breeding efforts to improve bee hardiness.</p></div

Bar graph showing gene ontology (GO) of DEGs between ZOT (0°C) and ZRT (25°C).

<p>(A) The most enriched GO terms for upregulated DEGs between the two treatment groups. (B) The most enriched GO terms for downregulated DEGs between the two treatment groups.</p

Statistics for filtering and mapping reads.

<p>Statistics for filtering and mapping reads.</p

Data_Sheet_1_Acute and chronic viruses mediated by an ectoparasite targeting different developmental stages of honeybee (Apis mellifera and Apis cerana) brood.pdf

The health of the western honeybee, Apis mellifera, the most crucial pollinator, has been challenged globally over the past decades. An ectoparasitic mite, Varroa destructor, together with the viruses it vectored, is generally regarded as the vital pathogenic agent. Although the poor health status of A. mellifera compared to its eastern counterpart, Apis cerana, has been broadly identified, the underlying mechanism remains poorly understood and comparison between susceptible and resistant hosts will potentially ameliorate this predicament. Here, we investigated the impacts of two widespread viruses—deformed wing virus type A (DWV-A) and Israeli acute paralysis virus (IAPV), mediated by V. destructor mite, on the capped developing honeybee brood, in the absence of adult workers, of A. mellifera and A. cerana, with positive and negative controls. Our results demonstrated that the endogenous viruses imposed limited damage on the hosts even if the brood was wounded. In contrast, the exogenous viruses introduced by ectoparasites triggered variable mortality of the infested brood between host species. Intriguingly, death causes of both honeybee species presented a similar trend: the acute IAPV generally causes morbidity and mortality of late larvae, while the chronic DWV-A typically leads to brood mortality during and after pupation. Notably, the susceptible immature A. cerana individuals, supported by higher observed mortality and a lower virus tolerance, serve the interests of the colony and foster the overall survival of a resistant honeybee superorganism. These results improve our understanding of the interactions between viruses carried by ectoparasites and their developing hosts, and the novel insight of weak individuals fostering strong colonies may promote breeding efforts to mitigate the indefensible colony losses globally.</p

Allylsamarium Bromide-Mediated Cascade Cyclization of Homoallylic Esters. Synthesis of 2‑(2-Hydroxyalkyl)cyclopropanols and 2‑(2-Hydroxyethyl)bicyclo[2.1.1]hexan-1-ols

In continuation of our previous study on the intramolecular reductive coupling of simple homoallylic esters promoted by allylSmBr/HMPA/H₂O, which afforded a facile synthesis of 2-(2-hydroxyalkyl)­cyclopropanols, here we report the reductive cascade cyclization of but-3-enyl but-3-enoates mediated by allylSmBr/HMPA/CuCl₂·2H₂O, in which the two CC bonds were successively coupled to allow the construction of the structurally interesting bridged bicyclic tertiary alcohols. Thus, the 2-(2-hydroxyethyl)­bicyclo[2.1.1]­hexan-1-ols were prepared in moderate to good yields with excellent diastereoselectivity

Table1_CircRNA-regulated immune responses of asian honey bee workers to microsporidian infection.XLSX

Nosema ceranae is a widespread fungal parasite for honey bees, causing bee nosemosis. Based on deep sequencing and bioinformatics, identification of circular RNAs (circRNAs) in Apis cerana workers’ midguts and circRNA-regulated immune response of host to N. ceranae invasion were conducted in this current work, followed by molecular verification of back-splicing sites and expression trends of circRNAs. Here, 10185 and 7405 circRNAs were identified in the midguts of workers at 7 days (AcT1) and 10 days (AcT2) post inoculation days post-inoculation with N. ceranae. PCR amplification result verified the back-splicing sites within three specific circRNAs (novel_circ_005123, novel_circ_007177, and novel_circ_015140) expressed in N. ceranae-inoculated midgut. In combination with transcriptome data from corresponding un-inoculated midguts (AcCK1 and AcCK2), 2266 circRNAs were found to be shared by the aforementioned four groups, whereas the numbers of specific ones were 2618, 1917, 5691, and 3723 respectively. Further, 83 52) differentially expressed circRNAs (DEcircRNAs) were identified in AcCK1 vs. AcT1 (AcCK2 vs. AcT2) comparison group. Source genes of DEcircRNAs in workers’ midgut at seven dpi were involved in two cellular immune-related pathways such as endocytosis and ubiquitin mediated proteolysis. Additionally, competing endogenous RNA (ceRNA) network analysis showed that 23 13) DEcircRNAs in AcCK1 vs. AcT1 (AcCK2 vs. AcT2) comparison group could target 18 14) miRNAs and further link to 1111 (1093) mRNAs. These target mRNAs were annotated to six cellular immunity pathways including endocytosis, lysosome, phagosome, ubiquitin mediated proteolysis, metabolism of xenobiotics by cytochrome P450, and insect hormone biosynthesis. Moreover, 284 164) internal ribosome entry site and 54 26) ORFs were identified from DEcircRNAs in AcCK1 vs. AcT1 (AcCK2 vs. AcT2) comparison group; additionally, ORFs in DEcircRNAs in midgut at seven dpi with N. ceranae were associated with several cellular immune pathways including endocytosis and ubiquitin-mediated proteolysis. Ultimately, RT-qPCR results showed that the expression trends of six DEcircRNAs were consistent with those in transcriptome data. These results demonstrated that N. ceranae altered the expression pattern of circRNAs in A. c. cerana workers’ midguts, and DEcircRNAs were likely to regulate host cellular and humoral immune response to microsporidian infection. Our findings lay a foundation for clarifying the mechanism underlying host immune response to N. ceranae infection and provide a new insight into interaction between Asian honey bee and microsporidian.</p