Evidence of peripheral olfactory impairment in the domestic silkworms: insight from the comparative transcriptome and population genetics.

BACKGROUND: The insect olfactory system is a highly specific and sensitive chemical detector, which plays important roles in feeding, mating and finding an appropriate oviposition site. The ecological niche of Bombyx mori has changed greatly since domestication from B. mandarina, and its olfactory response to environmental odorants clearly decreased. However, the mechanisms that result in the olfactory impairment are largely unknown. RESULTS: The antennal transcriptomes were compared between the domestic and wild silkworms. Comparison of the same sex between the domestic and wild silkworms revealed 1410 and 1173 differentially expressed genes (DEGs) in males and females, respectively. To understand the olfactory impairment, we mainly focused on the olfactory-related genes. In total, 30 olfactory genes and 19 odorant-degrading enzymes (ODEs) showed differential expression in the two comparisons, in which 19 and 14 were down-regulated in the domestic silkworm, respectively. Based on population genomic data, the down-regulated odorant receptors (ORs) showed a higher ratio of unique non-synonymous polymorphisms to synonymous polymorphisms (N/S ratio) in the domestic populations than that in the wild silkworms. Furthermore, one deleterious mutation was found in OR30 of the domestic population, which was located in transmembrane helix 6 (TM6). CONCLUSIONS: Our results suggested that down-regulation of the olfactory-related genes and relaxed selection might be the major reasons for olfactory impairment of the domestic silkworm reared completely indoor environment. Reversely, wild silkworm may increase expression and remove deleterious polymorphisms of olfactory-related genes to retain sensitive olfaction.

MT1JP inhibits glioma progression via negative regulation of miR-24.

Long noncoding RNAs have been reported to be dysregulated and have pivotal roles in various human malignancies, including glioma. Previous studies revealed that metallothionein 1J (MT1JP) has important regulatory functions in the development of gastric cancer. However, the biological role and potential mechanism of MT1JP in glioma remain unknown. The present study suggested that MT1JP expression was significantly downregulated in glioma tissues and glioma cell lines, and the decreased expression of MT1JP was associated with glioma progression and poor survival of patients with glioma. Additionally, overexpression of MT1JP significantly inhibited the proliferation and invasion of glioma cells. Furthermore, it was revealed that MT1JP interacted with microRNA-24 (miR-24), which has previously been reported as an oncogene in glioma, negatively regulating its expression level. Rescue experiments revealed that the tumor suppressive functions of MT1JP may be mediated by the negative regulation of miR-24. Collectively, the data suggested that MT1JP inhibited the progression of glioma by negatively regulating miR-24 and may serve as a novel diagnostic biomarker and therapeutic target for glioma.

Penetrating transorbital injury by a coloring pencil in a 3-year-old child: A case report.

A transorbital penetrating injury by a foreign body is an extremely rare type of injury, and its severity is often difficult to estimate by examination of the superficial wound alone. Thus, such injuries are challenging for neurosurgeons to investigate and manage. We herein present a peculiar case involving a 3-year-old girl with a penetrating transorbital skull-base injury caused by a coloring pencil and discuss the anatomical location of the foreign body, radiological examination findings, diagnosis, and treatment strategy. The pencil was completely removed by manual extraction. Follow-up investigations confirmed a good outcome. Multidisciplinary cooperation, radiological examination, correct diagnosis, timely treatment, and detailed follow-up studies are necessary to manage penetrating transorbital skull-base injuries caused by foreign bodies. The orbital walls are very thin in children, and the orbital roof and superior orbital fissure are often penetrated by foreign bodies in cases such as that described herein. The anatomical location of the foreign body influences the clinical management strategy.

Decreased CDKL2 expression is correlated with the progression and poor prognosis of glioma.

Glioma is the most common form of malignant intracranial tumors. Cyclin-dependent kinase-like 2 (CDKL2) was observed in various regions of the brain, but the specific role of CDKL2 in glioma has not been reported yet. In the present study, the expression of CDKL2 mRNA was detected by real-time QPCR in freshly collected glioma and para-carcinoma tissues, and we collected genomic and clinical data from The Cancer Genome Atlas to determine mRNA expression levels of CDKL2 in the normal brain and glioma samples. Moreover, western blot assay and immunohistochemistry experiments were implemented to identify CDKL2 protein expression, and clinical pathology characteristics from 151 glioma cases and thirty-four para-carcinoma tissues were also examined. The relationship between the levels of CDKL2 expression and clinical data was analyzed. Low mRNA and protein expression of CDKL2 was observed in glioma tissues compared to non-cancerous tissues. In addition, low levels of CDKL2 correlated with Astrocytic type, higher clinical WHO grade, and higher Ki-67 expression in glioma. Low mRNA and protein expression of CDKL2 in glioma predicted an observably shorter overall survival time than high expression. However, as revealed by multivariate analysis, CDKL2 protein expression was not an independent prognostic biomarker for the survival of patients with glioma. Our study firstly determined that low levels of CDKL2 expression are associated with poor clinical diagnosis. Thus, CDKL2 may serve as a prognostic factor of glioma.

A Comparison of Co-expression Networks in Silk Gland Reveals the Causes of Silk Yield Increase During Silkworm Domestication.

Long-term domestication and selective breeding have increased the silk yield of the domestic silkworm (Bombyx mori) by several times the amount of the silk yield of its wild ancestor (Bombyx mandarina). However, little is known about the molecular mechanisms behind the increase in silk yield during domestication. Based on dynamic patterns of functional divergence in the silk gland between domestic and wild silkworms, we found that at early and intermediate stages of silk gland development, the up-regulated genes of the domestic silkworm were mainly involved in DNA integration, nucleic acid binding, and transporter activity, which are related to the division and growth of cells. This has led to the posterior silk gland (PSG) of the domestic silkworm having significantly more cells ("factories" of fibroin protein synthesis) than that of the wild silkworm. At the late stage of silk gland development, the up-regulated genes in the domestic silkworm was enriched in protein processing and ribosome pathways, suggesting protein synthesis efficiency is greatly improved during silkworm domestication. While there was an increase in fibroin protein synthesis, the production of sericin protein was simultaneously reduced in the silk gland of the domestic silkworm. This reflects that domestic and wild silkworms have been under different selection pressures. Importantly, we found that the network co-expressed with the silk-coding genes of the domestic silkworm was larger than that of the wild silkworm. Furthermore, many more genes co-expressed with silk-coding genes in the domestic silkworm were subjected to artificial selection than those in the wild silkworm. Our results revealed that the increase of silk yield during silkworm domestication is involved in improvement of a biological system which includes not only expansion of "factories" (cells of PSG) of protein synthesis, but also a high expression of silk-coding genes and silk production-related genes such as biological energy, transport, and ribosome pathway genes.