The Juvenile-Hormone-Responsive Factor AmKr-h1 Regulates Caste Differentiation in Honey Bees.

Honey bees are typical model organisms for the study of caste differentiation, and the juvenile hormone (JH) is a crucial link in the regulatory network of caste differentiation in honey bees. To investigate the mechanism of JH-mediated caste differentiation, we analyzed the effect of the JH response gene AmKr-h1 on this process. We observed that AmKr-h1 expression levels were significantly higher in queen larvae than in worker larvae at the 48 h, 84 h, and 120 h larval stages, and were regulated by JH. Inhibiting AmKr-h1 expression in honey bee larvae using RNAi could lead to the development of larvae toward workers. We also analyzed the transcriptome changes in honey bee larvae after AmKr-h1 RNAi and identified 191 differentially expressed genes (DEGs) and 682 differentially expressed alternative splicing events (DEASEs); of these, many were related to honey bee caste differentiation. Our results indicate that AmKr-h1 regulates caste differentiation in honey bees by acting as a JH-responsive gene.

A Global Survey of the Full-Length Transcriptome of Apis mellifera by Single-Molecule Long-Read Sequencing.

As important pollinators, honey bees play a crucial role in both maintaining the ecological balance and providing products for humans. Although several versions of the western honey bee genome have already been published, its transcriptome information still needs to be refined. In this study, PacBio single-molecule sequencing technology was used to sequence the full-length transcriptome of mixed samples from many developmental time points and tissues of A. mellifera queens, workers and drones. A total of 116,535 transcripts corresponding to 30,045 genes were obtained. Of these, 92,477 transcripts were annotated. Compared to the annotated genes and transcripts on the reference genome, 18,915 gene loci and 96,176 transcripts were newly identified. From these transcripts, 136,554 alternative splicing (AS) events, 23,376 alternative polyadenylation (APA) sites and 21,813 lncRNAs were detected. In addition, based on the full-length transcripts, we identified many differentially expressed transcripts (DETs) between queen, worker and drone. Our results provide a complete set of reference transcripts for A. mellifera that dramatically expand our understanding of the complexity and diversity of the honey bee transcriptome.

Transcriptome changes of Apis mellifera female embryos with fem gene knockout by CRISPR/Cas9.

The sex of honey bees is decided by a regulatory cascade comprising of csd, fem and Amdsx. In order to further identify other genes involved in sex determination and differentiation of honey bees in the early stages of embryo development, the CRISPR/Cas9 method was used to knock out fem gene in the embryonic stage of diploid western honey bees, and RNA-seq was used to analyze gene expression changes in the embryo after fem knockout. Finally, we found that the bees had undergone gender changes due to fem knockout. A total of 155 differentially expressed genes (DEGs) were obtained, with 48 up-regulated and 107 down-regulated DEGs in the mutant group compared to the control group. Of them, many genes are related to sex development or differentiation. In addition, 1502 differentially expressed alternative splicing events (DEASEs) related to 1011 genes, including the main honey bee sex-determining genes csd, tra2, fem, and Amdsx, were identified between the mutant group and control group, indicating that fem regulates alternative splicing of a large number of downstream genes. Our results provide valuable clues for further investigating the molecular mechanism of sex determination and differentiation in honey bees.

[Clinical controlled trial on the treatment of comminuted clavicular fracture with acromioclavicular external fixator and clavicle anatomic DCP internal fixation].

OBJECTIVE: To explore the different therapeutic effects of comminuted clavicular fracture with acromioclavicular external fixtatior and DCP internal fixation. METHODS: There were 768 cases of comminuted clavicular fracture involved in the study. Among them, 528 patients (321 male and 207 female, aged from 15 to 82 years) treated with acromioclavicular external fixator, in which there were 165 cases of three parts fracture and 363 cases of more than three parts fracture; 240 patients (152 males and 88 females, aged from 17 to 64 years) treated with the internal fixation, in which there were 178 cases of three parts fracture and 62 cases of more than three parts fracture. The time between injury and treatment was 1.3 days (range, 2 h to 8 days). The results were evaluated according to Neer scoring system. RESULTS: All the cases were followed up from 8 to 24 months. For treatment of fracture more than three parts, there was significant difference between acromioclavicular external fixation group and internal fixation group in nonunion rate (chi2=44.17, P<0.05) and in Neer scores (t=5.284, P<0.05). CONCLUSION: Treatment with DCP internal fixation which matching the AO principles can obtain anatomic reduction, firm fixation and early functional exercise; however, treatment with self-designed acromioclavicular external fixator is an ideal therapeutic method as it has, early union of the fracture and good functional outcome with seldom complications.