Genome-Wide Analysis of Gene Families of Pattern Recognition Receptors in Fig Wasps (Hymenoptera, Chalcidoidea).

Pattern recognition receptors (PRRs) play important roles in detecting pathogens and initiating the innate immune response. Different evolutionary histories of pollinators and non-pollinators may result in different immune recognition systems. A previous study had reported that there were significant differences in peptidoglycan recognition proteins (PGRPs) between pollinators and non-pollinators in gene number and lineage of specific genes. In this study, based on the genomic data of 12 fig wasp species, with seven pollinators and five non-pollinators, we investigated the evolution patterns of PRRs, such as Gram-negative bacteria-binding proteins (GNBPs), C-type lectins (CTLs), scavenger receptors class B (SCRBs), fibrinogen-related proteins (FREPs), galectins, and thioester-containing proteins (TEPs). Our results showed that pollinators had no GNBP, but non-pollinators all had two gene members, which were clustered into two different clades in the phylogenetic tree, with each clade having specific domain and motif characteristics. The analysis of CTL and SCRB gene families also showed that there were lineage-specific genes and specific expansion in non-pollinators. Our results showed that there were significant differences in immune recognition between pollinators and non-pollinators, and we concluded that they had undergone flexible adaptive evolution in different environments. Our study can provide more molecular evidence for future functional studies on the immune system of fig wasps.

Genomes of 12 fig wasps provide insights into the adaptation of pollinators to fig syconia.

Figs and fig pollinators are one of the few classic textbook examples of obligate pollination mutualism. The specific dependence of fig pollinators on the relatively safe living environment with sufficient food sources in the enclosed fig syconia implies that they are vulnerable to habitat changes. However, there is still no extensive genomic evidence to reveal the evolutionary footprint of this long-term mutually beneficial symbiosis in fig pollinators. In fig syconia, there are also non-pollinator species. The non-pollinator species differ in their evolutionary and life histories from pollinators. We conducted comparative analyses on 11 newly sequenced fig wasp genomes and one previously published genome. The pollinators colonized the figs approximately 66.9 million years ago, consistent with the origin of host figs. Compared with non-pollinators, many more genes in pollinators were subject to relaxed selection. Seven genes were absent in pollinators in response to environmental stress and immune activation. Pollinators had more streamlined gene repertoires in the innate immune system, chemosensory toolbox, and detoxification system. Our results provide genomic evidence for the differentiation between pollinators and nonpollinators. The data suggest that owing to the long-term adaptation to the fig, some genes related to functions no longer required are absent in pollinators.

Transcriptomic Analysis Reveals the Sexually Divergent Host-Wolbachia Interaction Patterns in a Fig Wasp.

Wolbachia are widely distributed in arthropods and nematodes, acquiring nutrients from the hosts, and inducing remarkable reproductive modulations on the hosts. To investigate the interaction of Wolbachia and insects, Wolbachia are often artificially eliminated from Wolbachia-infected hosts, which may produce negative effects of antibiotics. In the present study, based on the transcriptomic data of a fig wasp species Ceratosolen solmsi with two sibling lineages, one natively infected and the other noninfected with Wolbachia, we investigated the expression patterns of genes. The comparison results of differently expressed genes (DEGs) between Wolbachia infected and noninfected samples show that males have many more DEGs than females. The male unique upregulated genes are enriched in biological processes mainly related to biosynthesis, transport, positive regulation of I-kappaB kinase/NF-kappaB signaling, MAPK cascade, and pathogenesis; the male unique downregulated genes are enriched in biological processes mainly related to transport, oxidation-reduction, cellular responses to oxidative stress, lipid oxidation, cytoskeleton organization, actin filament-based process, and localization. In addition, for the Wolbachia's gene expression, the number of genes up-regulated in males is higher than that in females. The results revealed divergent patterns of the host-Wolbachia interactions between males and females in the fig wasp species.

Inferring the Phylogenetic Positions of Two Fig Wasp Subfamilies of Epichrysomallinae and Sycophaginae Using Transcriptomes and Mitochondrial Data.

Fig wasps are a group of insects (Hymenoptera: Chalcidoidea) that live in the compact syconia of fig trees (Moraceae: Ficus). Accurate classification and phylogenetic results are very important for studies of fig wasps, but the taxonomic statuses of some fig wasps, especially the non-pollinating subfamilies are difficult to determine, such as Epichrysomallinae and Sycophaginae. To resolve the taxonomic statuses of Epichrysomallinae and Sycophaginae, we obtained transcriptomes and mitochondrial genome (mitogenome) data for four species of fig wasps. These newly added data were combined with the data of 13 wasps (data on 11 fig wasp species were from our laboratory and two wasp species were download from NCBI). Based on the transcriptome and genome data, we obtained 145 single-copy orthologous (SCO) genes in 17 wasp species, and based on mitogenome data, we obtained 13 mitochondrial protein-coding genes (PCGs) for each of the 17 wasp species. Ultimately, we used 145 SCO genes, 13 mitochondrial PCGs and combined SCO genes and mitochondrial genes data to reconstruct the phylogenies of fig wasps using both maximum likelihood (ML) and Bayesian inference (BI) analyses. Our results suggest that both Epichrysomallinae and Sycophaginae are more closely related to Agaonidae with a high statistical support.

Genome-Wide Analysis of Peptidoglycan Recognition Protein Genes in Fig Wasps (Hymenoptera, Chalcidoidea).

The innate immunity is the most important defense against pathogen of insects, and the peptidoglycan recognition proteins (PGRPs) play an important role in the processes of immune recognition and initiation of Toll, IMD and other signal pathways. In fig wasps, pollinators and non-pollinators present different evolutionary histories and lifestyles, even though both are closely associated with fig syconia, which may indicate their different patterns in the evolution of PGRPs. By manual annotation, we got all the PGRP genes of 12 fig wasp species, containing seven pollinators and five non-pollinators, and investigated their putative different evolutionary patterns. We found that the number of PGRP genes in pollinators was significantly lower than in non-pollinators, and the number of catalytic PGRP presented a declining trend in pollinators. More importantly, PGRP-SA is associated with initiating the Toll pathway, as well as gram-negative bacteria-binding proteins (GNBPs), which were completely lost in pollinators, which led us to speculate that the initiation of Toll pathway was simpler in pollinators than in non-pollinators. We concluded that fig pollinators owned a more streamlined innate immune recognition system than non-pollinators. Our results provide molecular evidence for the adaptive evolution of innate immunity in insects of host specificity.

Transcriptome analysis of the male polymorphisms of fig wasp species Philotrypesis tridentata.

Intraspecific male polymorphism exhibiting extreme differences in morphology, behavior and life history presents good opportunities to explore adaptation mechanisms to different environments. In this study, we examined the transcriptomic differences between wingless and winged morphs of a fig wasp species Philotrypesis tridentata to investigate molecular basis to maintain polymorphisms. The winged male adults fly outside fig syconia to mate, while the wingless only stay and mate inside fig syconia where they have developed. We identified 2,391 differentially expressed genes (DEGs) with 1,396 highly expressed in winged morphs and 995 in wingless morphs. We performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses on the DEGs and differential alternative splicing genes and analyzed the top ten DEGs with the highest differential expression in each morph. The results showed that genes related to biosynthesis processes, lipid metabolism, energy production, flight and defense of the complex environments outside fig syconia were up-regulated in winged morphs. Genes involved in substance and energy metabolism and chemical reception were up-regulated in wingless morphs which might relate to their living inside fig syconia. The differences in highly expressed genes between two morphs prove adaptation of P. tridentata male polymorphism to different living environments.

[Analysis of the Composition of Atmospheric Fine Particles (PM2.5) Produced by Burning Fireworks].

Burning fireworks is one of the sources of atmospheric fine particles (PM2.5). The Chinese Spring Festival in Quanzhou City was taken as an example to study the effects of burning fireworks on the occurrence of PM2.5, and provide information on protection against air pollution caused by special pollution sources. The results showed that the concentrations of SO2, PM10, and PM2.5 increased appreciably, and the concentration of PM2.5 increased most significantly during the fireworks burning period. The peak daily average concentration in the urban area was about 4 times the annual average concentration in the urban area. The peak value of the hourly average concentration of PM2.5 in the Tushan Street station was about 21 times the annual average concentration in the urban area. At the peak of the discharge, the ratios of the characteristic elements of fireworks, such as Al, Mg, Ba, Cu, and Sr, increased rapidly, and the hourly number concentrations of Al+, Mg+, Ba+, and Cu+ were highly correlated. During the monitoring period, the main pollution sources of fine particles in Quanzhou City were fireworks and biomass burning, which accounted for more than half of the total particulate matter. The proportion of pollutants originating from coal-based and industrial process sources were relatively low, and both of them accounted for less than 10.0% of the particulate matter. The concentration of PM2.5 was up to 0.578 mg·m-3 during the fireworks burning period, the rate of contribution by fireworks increased to 58.2%. Analysis of the pollution process showed that the changes in the concentration of PM2.5 have a similar trend with the number concentration and the ratio of fireworks burning. The results indicated that the main reason of the deterioration of the atmospheric environment during the Chinese Spring Festival in Quanzhou is the centralized discharging of fireworks.

2,2'-Anhydro-1-(3',5'-di-O-acetyl-ß-D-arabinofuranosyl)uracil, a cyclouridine nucleoside with a C4'-endo furanosyl conformation.

2,2'-Anhydro-1-(3',5'-di-O-acetyl-ß-D-arabinofuranosyl)uracil, C13H14N2O7, was obtained by refluxing 2',3'-O-(methoxymethylene)uridine in acetic anhydride. The structure exhibits a nearly perfect C4'-endo ((4)E) conformation. The best four-atom plane of the five-membered furanose ring is O-C-C-C, involving the C atoms of the fused five-membered oxazolidine ring, and the torsion angle is only -0.4 (2)°. The oxazolidine ring is essentially coplanar with the six-membered uracil ring [r.m.s. deviation = 0.012 (5) Šand dihedral angle = -3.2 (3)°]. The conformation at the exocyclic C-C bond is gauche-trans which is stabilized by various C-H...π and C-O...π interactions.

1-(Phenyl-sulfon-yl)naphthalene.

In the title compound, C(16)H(12)O(2)S, the phenyl ring is nearly perpendicular to the naphthalene system [dihedral angle = 80.3 (1)°]. The packing is consolidated by a weak C-H⋯π inter-action involving neighbouring naphthalene and benzene rings. In addition, there exist two different offset π-π stacking inter-actions between benzene rings and between naphthalene systems of symmetry-related mol-ecules [centroid-centroid distances = 3.876 (9) and 3.566 (4) Å, and slippage = 1.412 and 0.554 Å, respectively.

5-{2-(4-Chloro-phen-yl)-1-[2-(4-chloro-phen-yl)-1-(3,4,5-trimeth-oxy-phen-yl)eth-oxy]eth-yl}-1,2,3-trimeth-oxy-benzene.

The title compound, C(34)H(36)Cl(2)O(7), is a by-product from the reaction of 4-chloro-benzyl-zinc chloride with 3,4,5-trimeth-oxy-benzaldehyde. In each of the two 1,2-diphenyl-ethyl moieties, the two benzene rings are arranged in a trans conformation and make C(ar)-C-C-C(ar) torsion angles of 163.64 (19) and 174.43 (18)°. The crystal structure is stabilized by van der Waals inter-actions only.