Molecular basis of the silkworm mutant rel causing red egg color and embryonic death.

The coloration and hatchability of insect eggs can affect individual and population survival. However, few genetic loci have been documented to affect both traits, and the genes involved in regulating these two traits are unclear. The silkworm recessive mutant rel shows both red egg color and embryo mortality. We studied the molecular basis of the rel phenotype formation. Through genetic analysis, gene screening and sequencing, we found that two closely linked genes, BGIBMGA003497 (Bm-re) and BGIBMGA003697 (BmSema1a), control egg color and embryo mortality, respectively. Six base pairs of the Bm-re gene are deleted in its open reading frame, and BmSema1a is expressed at abnormally low levels in mutant rel . BmSema1a gene function verification was performed using RNA interference and clustered randomly interspersed palindromic repeats (CRISPR)/CRISPR-associate protein 9. Deficiency of the BmSema1a gene can cause the death of silkworm embryos. This study revealed the molecular basis of silkworm rel mutant formation and indicated that the Sema1a gene is essential for insect embryo development.

BmBlimp-1 gene encoding a C2H2 zinc finger protein is required for wing development in the silkworm Bombyx mori.

Cys2-His2 zinc finger (C2H2-ZF) proteins represent the most common class of transcription factors. These factors have great potential for the management of developmental progression by regulating the specific spatiotemporal expression of genes. In this study, we cloned one C2H2-ZF protein gene of Bombyx mori, BGIBMGA000319, that is orthologous to B-lymphocyte-induced maturation protein-1 (Blimp-1); we thus named it as Bombyx mori Blimp-1 (BmBlimp-1). In the silkworm, the BmBlimp-1 gene is specifically upregulated during day 2 of the pupal to adult stage and is highly expressed in wing discs on day 3 of the pupa. Knockdown of its expression level in the pupal stage results in a crumpled-winged silkworm moth. Using the predicted DNA-binding sequences of BmBlimp-1 to search the silkworm genome to screen target genes of BmBlimp-1, 7049 genes were identified to have at least one binding site of BmBlimp-1 on their 1 kb upstream and downstream genome regions. Comparisons of those genes with a reported pupal wing disc transcriptome data resulted in 4065 overlapping genes being retrieved. GO enrichment analysis of the overlapping genes showed that most of the genes were enriched in the binding term. Combining functional annotation and real-time quantitative PCR, 15 genes were identified as the candidate target genes of BmBlimp-1, including several wing cuticular protein genes, chitin synthase A, and wing disc development genes, such as Wnt1, cubitus interruptus (ci) and engrailed (en). Moreover, the amino acid sequence of the zinc finger motif of Blimp-1 gene was highly conserved among the 15 insect species. We propose that BmBlimp-1 is an important regulatory factor in silkworm wing development.

[Effects and significance of gas explosion on expression of NF-kappaB and ICAM1 in lung tissue of rats].

OBJECTIVE: To explore the expression of NF-kappaB and ICAM-1 in the gas explosion wounded lung of rats and the relationship. METHODS: Digoxin labeled NF-kappaB was used as probe. In situ hybridization was performed to detect the NF-kappaB mRNA. Immunohistochemistry was used to detect the expression of NF-kappaB and ICAM-1. RESULTS: The levels of NF-kappaB mRNA, the expression of NF-kappaB and ICAM-1 in the wounded rats were significantly increased and reached their peak two hours after injury. Pathology of lung tissue showed that some crachea epithelium mucosae were desquamated; congestion, edema of trachea wall and infiltration of neutrophilic granulocytes were found; hemorrhage, edema and infiltration of lots of inflammatory cells were present in alveolus cells. Electron microscope showed that type I, especially type II alveolus epithelia had degeneration and desquamation. CONCLUSION: The injury of gas explosion can activate NF-kappaB, which has close correlation with the acute injury to lung.

[A study on relationship between rat brain tissues hurts of the gas explosion and the expression of protein kinase CamRNA and c-fos gene.].

OBJECTIVES: To explore relationship between rat brain tissues hurts of gas explosion and the expression of Protein Kinase C alpha mRNA. METHODS: Build up rat hurt model of gas explosion. In Situ Hybridization (IDH) technique was used to test Protein Kinase C alpha mRNA. Immunohistochemical Assays (IHA) was used to determine c-fos gene protein. RESULTS: Only a little a mount expression of PKC alpha mRNA and c-fos of the control group was detected. The expression of the cerebral cortex and hippocampus of PKC alpha mRNA 24 h, 48 h and the 48 h increased obviously, and the 48 h reached the peak of expression; (t = 4.12 P < 0.01). The expression of c-fos protein of the cerebral cortex and hippocampus started to increase obviously at 0.5 h and the 4 h reached the peak, then the strength lowered gradually and the expression level came back normal level on fifth day. CONCLUSION: The anoxia of brain tissues due to the gas explosion may promote the expression of PKCamRNA, and PKCamRNA could regulate the expression of the gene of c-fos. Both PKCamRNA and the gene of c-fos are involved in harmful processes to the nerve cells.