Gene expression quantification at mRNA level is very important for post‐genomic studies, as gene expression level is the reflection of the special biological function of the target gene. Methods used for gene expression quantification, such as microarray or quantitative real‐time polymerase chain reaction (qRT‐PCR), require stable expressed reference genes. Thus, finding suitable control genes is essential for gene quantification. In this study, a genome‐wide survey of reference genes during metamorphism was performed on silkworm Bombyx mori. Twelve genes were chosen as putative reference genes based on a whole genome oligonucleotide microarray normalized by external controls. Then, qRT‐PCR was employed for further validation and selection of potential reference gene candidates. The results were analyzed, and stable genes were selected using geNorm 3.4 and NormFinder software. Finally, considering factors from every aspect, translation initiation factor 4A, translation initiation factor 3 subunit 4, and translation initiation factor 3 subunit 5 (represented by sw22934, swl4876, and swl3956) were selected as reliable internal controls across the examined developmental stages, while cytoplasmic actin (sw22671), the commonly used reference gene in a previous study was shown to vary drastically throughout the examined developmental stages. For future research, we recommend the use of the geometric mean of those three stable reference genes as an accurate normalization factor for data normalization of different developmental stages during metamorphism.

Background: MicroRNAs (miRNAs) are expressed by a wide range of eukaryotic organisms, and function in diverse biological processes. Numerous miRNAs have been identified in Bombyx mori, but the temporal expression profiles of miRNAs corresponding to each stage transition over the entire life cycle of the silkworm remain to be established. To obtain a comprehensive overview of the correlation between miRNA expression and stage transitions, we performed a whole-life test and subsequent stage-by-stage examinations on nearly one hundred miRNAs in the silkworm.

Anemia is commonly seen in preterm infants. It may reduce the capacity of hemoglobin to transport oxygen throughout the body and may result in tissue and organ dysfunction. This study aimed to investigate the effect of anemia on the development of bronchopulmonary dysplasia (BPD) in preterm infants. 243 infants who were admitted to BaYi Children’s Hospital Affiliated to Clinical Medical College in Beijing Military General Hospital with gestational age (GA) less than 32 weeks from February, 2014 to February, 2015 were included in the study. Maternal and infant data were recorded. Multivarariate logistic regression analysis was performed to determine the association between anemia and BPD. Of 243 preterm infants, the incidence of anemia was higher in BPD patients than non-BPD patients (p < 0.001). Mean Hct in BPD patients was lower than non-BPD patients at different time points in 1d, 7d, 14d, and 21d. Controlling for other confounding factors, early anemia was associated with an increased risk of BPD. Number of transfusions is also a significant risk factor for BPD (p = 0.001). Therefore, prevention and treatment of early anemia is necessary and reducing number of transfusions may reduce the incidence of BPD in preterm infants.