Ultrastructural observation of digestive tract and the adaptative characteristics of dietary habits for ground-dwelling and omnivorous insects.

The digestive tract of insects from mouth to anus is the crop, proventriculus, gastric caecum, midgut, ileum, colon and rectum, and the Malpighian tubules attached to the ileum belong to the excretory organs. As the main organs for digesting food and absorbing nutrients, the structure of the insect digestive tract is inevitably adapted to feeding habits. Among the Orthoptera, the digestive tracts of phytophagous locusts and carnivorous katydids have been studied for their adaptations to their food habits, while the adaptations of the digestive tracts of omnivorous insects have been less studied. In order to systematically study the adaptations of the digestive tracts of ground-nesting omnivorous insects to their feeding habits, this study was carried out with Loxoblemmus taicoun Saussure, 1877, Teleogryllus emma (Ohmachi & Matsuura, 1951), and Velarifictorus micado (Saussure, 1877). Through the use of a scanning electron microscope (SEM) and a VHX digital microscope, the digestive tract structures of these three most widespread and common omnivorous crickets in China were examined in order to better understand how omnivorous insects digestive tract structures differ from those of specialists. When we compared the morphological features of these crickets digestive tracts to those of phytophagous and carnivorous insects, we discovered six adaptive traits of omnivorous insects, including: (1) they have a shorter foregut and longer midgut and hindgut; (2) they have a well-developed muscular intestinal wall; (3) the spines in the inner wall of their crop are uniformly arranged and less chitinized; (4) the proventriculus is sclerotized and spherical, and the inner wall is accompanied by ossified large teeth; (5) they have well-developed cilia at the base of the crop and at the base of the ossified denticles; (6) they have only two lobulated gastric caeca. The study summarizes six characteristics of the digestive tract of omnivorous crickets that are compatible with their food habits, providing evidence and clues for further research on the relationship between the digestive tract and food habits in Orthoptera.

Altered expression of glycan patterns and glycan-related genes in the medial prefrontal cortex of the valproic acid rat model of autism.

Autism spectrum disorders (ASD) represent a group of neurodevelopmental defects characterized by social deficits and repetitive behaviors. Alteration in Glycosylation patterns could influence the nervous system development and contribute to the molecular mechanism of ASD. Interaction of environmental factors with susceptible genes may affect expressions of glycosylation-related genes and thus result in abnormal glycosylation patterns. Here, we used an environmental factor-induced model of autism by a single intraperitoneal injection of 400 mg/kg valproic acid (VPA) to female rats at day 12.5 post-conception. Following confirmation of reduced sociability and increased self-grooming behaviors in VPA-treated offspring, we analyzed the alterations in the expression profile of glycan patterns and glycan-related genes by lectin microarrays and RNA-seq, respectively. Lectin microarrays detected 14 significantly regulated lectins in VPA rats, with an up-regulation of high-mannose with antennary and down-regulation of Siaα2-3 Gal/GalNAc. Based on the KEGG and CAZy resources, we assembled a comprehensive list of 961 glycan-related genes to focus our analysis on specific genes. Of those, transcription results revealed that there were 107 differentially expressed glycan-related genes (DEGGs) after VPA treatment. Functional analysis of DEGGs encoding anabolic enzymes revealed that the process trimming to form core structure and glycan extension from core structure primarily changed, which is consistent with the changes in glycan patterns. In addition, the DEGGs encoding glycoconjugates were mainly related to extracellular matrix and axon guidance. This study provides insights into the underlying molecular mechanism of aberrant glycosylation after prenatal VPA exposure, which may serve as potential biomarkers for the autism diagnosis.

The rearranged mitochondrial genome of Podagrion sp. (Hymenoptera: Torymidae), a parasitoid wasp of mantis.

The complete sequence of the mitochondrial genome of Podagrion sp. (Hymenoptera: Torymidae) is described. The mitogenome was 15,845 bp in size, and contained typical sets of mitochondrial genes. The base composition of the Podagrion sp. mitogenome was also biased toward A + T bases (81.8%). The mitochondrial genome of Podagrion sp. has a weak AT skew (0.07) and a strong GC skew (-0.26). Podagrion sp. exhibits a novel rearrangement compared with the ancestral order, including six protein-coding genes (nad3, cox3, atp6, atp8, cox2 and cox1), which have inverted to the minor strand from the major strand. The A + T-rich region of Podagrion sp., which is located between trnN and trnI, have five tandem repeats. The apomorphic rearrangements, including the conserved block "cox3-atp6-atp8-cox2-cox1-nad5-nad4-nad4l-nad6-cob" and the special locations of trnV and trnA, were mapped onto the phylogeny of Proctotrupomorpha.

Genetic differentiation and forensic efficiency evaluation for Chinese Salar ethnic minority based on a 5-dye multiplex insertion and deletion panel.

The present study investigated the genetic diversities of 30 autosomal insertion and deletion (InDel) loci of Investigator DIPplex kit (Qiagen) in Chinese Salar ethnic minority and explored the genetic relationships between the studied Salar group and other populations. The allelic frequencies of deletion alleles at the 30 InDel loci were in the range of 0.1739 (HLD64) to 0.8478 (HLD39). The discrimination power, polymorphism information content and probability of exclusion ranged from 0.4101 (HLD39) to 0.6447 (HLD136), 0.2247 (HLD39) to 0.3750 (HLD92) and 0.0400 (HLD39) to 0.2806 (HLD92), respectively. The observed and expected heterozygosity were in the range of 0.2348 (HLD39) to 0.5913 (HLD92), and 0.2580 (HLD39) to 0.5000 (HLD92), respectively. The cumulative discrimination power and probability of exclusion of the 30 loci reached 0.999999999993418 and 0.99039, respectively. The results of population genetic differentiation comparisons revealed that Salar group had similar allele distributions with Qinghai Tibetan, Xibe and Yi groups. Population Bayesian cluster analysis showed that there were similar ancestry components between Salar group and most Chinese populations. Besides, the principal components analysis and phylogenetic reconstructions further indicated that Salar group had intimate genetic relationships with Qinghai Tibetan and Xibe groups. In short, the results of the current studies indicated the genetic distributions of the 30 InDel loci in Salar group were relatively high genetic polymorphisms, which could be used in forensic individual identifications and as a supplementary tool for complex paternity testing.

The complete mitochondrial genome of Euplatypus parallelus (Coleoptera: Curculionidae).

Beetles in the weevil subfamily Platypodinae are among the dominant groups of insects in wet tropical forests, which together with bark and ambrosia beetles in the subfamily Scolytinae. Easily recognised by the circle-shaped entrance holes in fallen logs and a very elongated body shape, they have earned the common name, "pinhole borers". All except two Platypodinae species are ambrosia beetles that cultivate fungi in wood tunnels as the sole food for their larvae. Platypodinae is a peculiar weevil subfamily of species that cultivate fungi in tunnels excavated in dead wood. The Platypodinae is likely the oldest known lineage of fungus-cultivating insects, with an origin of the ambrosial habit more than 80 Ma. Here, we sequenced and characterized the complete mitochondrial genome of E. parallelus, which was collected from logs imported from SierraLeone. The complete circular mitochondrial genome (mitogenome) of Euplatypus parallelus is 16,095 bp in size, containing 37 typical genes and one non-coding AT-rich region. The AT content of the AT-rich region is 87.5%. All protein-coding genes (PCGs) start with standard ATN initiation codons except for nad1and end with complete termination codons TAA except for cox1genes using an incomplete stop codon T. tRNA genes are predicted with a characteristic cloverleaf secondary structure except for trnS1(AGN) , whose dihydrouridine (DHU) arm is replaced by a simple loop. The size of the large and small ribosomal RNA genes are 1386 and 741 bp, respectively.

Validation of reference genes for quantitative real-time PCR in valproic acid rat models of autism.

Autism is a neurodevelopmental disorder, and embryonic exposure to valproic acid (VPA) in rodents is the most frequently studied environmentally triggered autism models. Valproic acid can affect gene transcription as a histone deacetylase inhibitor, and thus may alter the expression of the most genes including reference genes. The aim of the current study is to validate suitable reference genes for quantitative real-time PCR (qPCR) quantification in prefrontal cortex and hippocampus of VPA rat models of autism. Female rats received a single intraperitoneal injection of 400 mg/kg sodium VPA at day 12.5 post-conception and controls were injected with saline. Male offspring were used to observe the expression of nine commonly used reference genes by qPCR, and the data were analyzed by four commonly used reference selection program including geNorm, BestKeeper, NormFinder and RefFinder. The results showed that VPA affected the expression of these commonly used reference genes in prefrontal cortex and hippocampus on postnatal 3, 5 weeks and 80 days, Gapdh and Actin, two very frequently used reference genes, were identified as the least stable genes in VPA group. Hprt1 was selected as the most stable gene, and Hmbs and Tbp were the optimum gene pair in prefrontal cortex and hippocampus across all VPA and controls. Problematically, the use of unstable reference genes results in calculation of different PGRN mRNA expression levels. The results suggest that selection of suitable references is critical for accurate mRNA quantification, and specifically in VPA induced rat models of autism.

The complete mitochondrial genome of Coptotermes testaceus (Isoptera: Rhinotermitidae).

The complete circular mitochondrial genome (mitogenome) of Coptotermes testaceus is 15 752bp in size, containing 37 typical genes and one non-coding AT-rich region. The AT content of the AT-rich region is 68.3%. All protein coding genes (PCGs) start with standard ATN initiation codons and end with complete termination codons TAA or TAG except for cox2, atp8, and nad5 genes using an incomplete stop codon T. tRNA genes are predicted with a characteristic cloverleaf secondary structure except for trnS1(()(AGN)()), whose dihydrouridine (DHU) arm is replaced by a simple loop. The size of the large and small ribosomal RNA genes are 1315 and 818 bp, respectively. Phylogenetic analysis found that (i) the C. testaceus clade formed the sister group with another clade containing Coptotermes lacteus and Coptotermes formosanus; and (ii) Coptotermes lacteus had a close relationship with Coptotermes clade, but with lower credibility than other clades, the bootstrap value was 97%.

The complete mitochondrial genome of the American black flour beetle Tribolium audax (Coleoptera: Tenebrionidae).

Flour beetles of the genus Tribolium are all pests of stored products and cause severe economic losses every year. The American black flour beetle Tribolium audax is one of the important pest species of flour beetle, and it is also an important quarantine insect. Here we sequenced and characterized the complete mitochondrial genome of T. audax, which was intercepted by Huangpu Custom in maize from America. The complete circular mitochondrial genome (mitogenome) of T. audax was 15,924 bp in length, containing 37 typical coding genes and one non-coding AT-rich region. The mitogenome of T. audax exhibits a gene arrangement and content identical to the most common type in insects. All protein coding genes (PCGs) are start with a typical ATN initiation codon, except for the cox1, which use AAC as its start codon instead of ATN. Eleven genes use standard complete termination codon (nine TAA, two TAG), whereas the nad4 and nad5 genes end with single T. Except for trnS1 (AGN), all tRNA genes display typical secondary cloverleaf structures as those of other insects. The sizes of the large and small ribosomal RNA genes are 1288 and 780 bp, respectively. The AT content of the AT-rich region is 81.36%. The 5 bp conserved motif TACTA was found in the intergenic region between trnS2 (UCN) and nad1.

The complete mitochondrial genome of the confused flour beetle Tribolium confusum (Coleoptera: Tenebrionidae).

Flour beetles of the genus Tribolium are economically important as destructive cosmopolitan pests of stored flour, corn, peanuts, and other dried agricultural products. The confused flour beetle Tribolium confusum Jacquelin du Val (1868) is one of the most important pest species of flour beetle. Here we sequenced and characterized the complete mitochondrial genome of T. confusum, the entire sequence is 15,813 bp in size with 72.8% AT content. It consists of 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA), 2 ribosomal RNA (rRNA) genes and one major non-coding AT-rich region. The mitogenome of T. confusum exhibits a gene arrangement and content identical to the most common type in insects. All PCGs are start with a typical ATN initiation codon, except for the cox1, which use AAC as its start codon instead of ATN. Ten genes use standard complete termination codon (six TAA, three TAG), whereas the cox2, cox3, nad4 and nad5 genes end with single T. Except for trnS1 ((AGN)), all tRNA genes display typical secondary cloverleaf structures as those of other insects. The sizes of the large and small ribosomal RNA genes are 1277 and 773 bp, respectively. The AT content of the AT-rich region is 79.5%. The 5 bp conserved motif TACTA was found in the intergenic region between trnS2 ((UCN)) and nad1.

[A simple method for assessment of RNA integrity in laser capture microdissection samples].

OBJECTIVE: To develop a simple method for assessment of RNA integrity in laser capture microdissection (LCM) samples. METHODS: The total RNA were isolated from the LCM samples and the sections before and after microdissection and examined by agarose gel electrophoresis. Real-time PCR was employed to assess the RNA from LCM samples, and the quantity of RNA was theoretically estimated according to the average total RNA product in mammalian cells (10 ng/1000 cells). RESULTS: When the total RNA from the sections before and after microdissection was intact, the RNA from LCM samples also had good quality, and the 28S and 18S rRNAs were visualized by ethidium bromide staining. Real-time PCR also showed good RNA quality in the LCM samples. CONCLUSION: A simple method for quantitative and qualitative assessment of the RNA from LCM samples is established, which can also be applied to assessment of DNA or proteins in LCM samples.