The FOXO Transcription Factor Controls Insect Growth and Development by Regulating Juvenile Hormone Degradation in the Silkworm, \u3cem\u3eBombyx mori\u3c/em\u3e

Forkhead box O (FOXO) functions as the terminal transcription factor of the insulin signaling pathway and regulates multiple physiological processes in many organisms, including lifespan in insects. However, how FOXO interacts with hormone signaling to modulate insect growth and development is largely unknown. Here, using the transgene-based CRISPR/Cas9 system, we generated and characterized mutants of the silkworm Bombyx mori FOXO (BmFOXO) to elucidate its physiological functions during development of this lepidopteran insect. The BmFOXO mutant (FOXO-M) exhibited growth delays from the first larval stage and showed precocious metamorphosis, pupating at the end of the fourth instar (trimolter) rather than at the end of the fifth instar as in the wild-type (WT) animals. However, different from previous reports on precocious metamorphosis caused by juvenile hormone (JH) deficiency in silkworm mutants, the total developmental time of the larval period in the FOXO-M was comparable with that of the WT. Exogenous application of 20-hydroxyecdysone (20E) or of the JH analog rescued the trimolter phenotype. RNA-seq and gene expression analyses indicated that genes involved in JH degradation but not in JH biosynthesis were up-regulated in the FOXO-M compared with the WT animals. Moreover, we identified several FOXO-binding sites in the promoter of genes coding for JH-degradation enzymes. These results suggest that FOXO regulates JH degradation rather than its biosynthesis, which further modulates hormone homeostasis to control growth and development in B. mori. In conclusion, we have uncovered a pivotal role for FOXO in regulating JH signaling to control insect development

A multicenter study of fetal chromosomal abnormalities in Chinese women of advanced maternal age

AbstractObjectiveThis study aimed to determine the rates of different fetal chromosomal abnormalities among women of advanced maternal age in China and to discuss the possible misdiagnosis risks of newer molecular techniques, for selection of appropriate prenatal screening and diagnostic technologies.Materials and MethodsSecond trimester amniocentesis and fetal karyotype results of 46,258 women were retrospectively reviewed. All women were ≥ 35 years old with singleton pregnancies. The rates of clinically significant chromosomal abnormalities (CSCAs), incidence of chromosomal abnormalities, and correlations with age were determined.ResultsFrom 2001 to 2010, the proportion of women of advanced maternal age undergoing prenatal diagnosis increased from 20% to 46%. The mean age was 37.4 years (range, 35–46 years). A total of 708 cases of CSCAs, with a rate of 1.53% were found. Trisomy 21 was the most common single chromosome abnormality and accounted for 55.9% of all CSCAs with an incidence of 0.86%. Trisomy 13, trisomy 18, and trisomy 21, the most common chromosome autosomal aneuploidies, accounted for 73.6% of all CSCAs, with a rate of 1.13%. As a group, the most common chromosomal aneuploidies (13/18/21/X/Y) accounted for 93.9% of all abnormalities, with a rate of 1.44%. The incidence of trisomy 21, trisomy 13/18/21 as a group, and 13/18/21/X/Y as a group was significantly greater in women aged 39 years and older (p < 0.001), but was not different between women aged 35 years, 36 years, 37 years, and 38 years.ConclusionThese findings may assist in genetic counseling of advanced maternal age pregnant women, and provide a basis for the selection of prenatal screening and diagnostic technologies

Efficient estimation of nonparametric genetic risk function with censored data

With an increasing number of causal genes discovered for complex human disorders, it is crucial to assess the genetic risk of disease onset for individuals who are carriers of these causal mutations and compare the distribution of age-at-onset with that in non-carriers. In many genetic epidemiological studies aiming at estimating causal gene effect on disease, the age-at-onset of disease is subject to censoring. In addition, some individuals’ mutation carrier or non-carrier status can be unknown due to the high cost of in-person ascertainment to collect DNA samples or death in older individuals. Instead, the probability of these individuals’ mutation status can be obtained from various sources. When mutation status is missing, the available data take the form of censored mixture data. Recently, various methods have been proposed for risk estimation from such data, but none is efficient for estimating a nonparametric distribution. We propose a fully efficient sieve maximum likelihood estimation method, in which we estimate the logarithm of the hazard ratio between genetic mutation groups using B-splines, while applying nonparametric maximum likelihood estimation for the reference baseline hazard function. Our estimator can be calculated via an expectation-maximization algorithm which is much faster than existing methods. We show that our estimator is consistent and semiparametrically efficient and establish its asymptotic distribution. Simulation studies demonstrate superior performance of the proposed method, which is applied to the estimation of the distribution of the age-at-onset of Parkinson's disease for carriers of mutations in the leucine-rich repeat kinase 2 gene

Electrically Assisted Stretch Bending of Aluminum Extruded Profile

Aluminum extruded profile is widely applied in aircraft frame parts whose forming quality is directly related to the assembly accuracy, aerodynamic shape and the service life of aircraft. However, it normally faces difficulties of large springback and low forming limit while forming at room temperature by stretch bending method. Here, electricity was applied in stretch bending process to heat aluminum profile aiming at improving the formability and reducing the springback by using electrically assisted stretch bending machine which is consisted of electrical power with the capability of 10000A and 40000kN stretching force for each hydraulic cylinder. In this research, a set of uniaxial tension tests was performed at different temperature to determine the relationship between the deformation behavior of aluminum profile and temperature. Then, a series of stretch bending tests were conducted to investigate the springback law of the aluminum profile. The corresponding stretch bending parts were obtained under different conditions. The experiment results show that, the plasticity of aluminum profile can be improved when the temperature rises, and the springback of aluminum profile can be reduced even more due to the electrical heating effect compared to the cold stretch bending process. Therefore, the forming accuracy of aluminum profile can be improved in electrically assisted stretch bending process

Electrically Assisted Stretch Bending of Aluminum Extruded Profile

Aluminum extruded profile is widely applied in aircraft frame parts whose forming quality is directly related to the assembly accuracy, aerodynamic shape and the service life of aircraft. However, it normally faces difficulties of large springback and low forming limit while forming at room temperature by stretch bending method. Here, electricity was applied in stretch bending process to heat aluminum profile aiming at improving the formability and reducing the springback by using electrically assisted stretch bending machine which is consisted of electrical power with the capability of 10000A and 40000kN stretching force for each hydraulic cylinder. In this research, a set of uniaxial tension tests was performed at different temperature to determine the relationship between the deformation behavior of aluminum profile and temperature. Then, a series of stretch bending tests were conducted to investigate the springback law of the aluminum profile. The corresponding stretch bending parts were obtained under different conditions. The experiment results show that, the plasticity of aluminum profile can be improved when the temperature rises, and the springback of aluminum profile can be reduced even more due to the electrical heating effect compared to the cold stretch bending process. Therefore, the forming accuracy of aluminum profile can be improved in electrically assisted stretch bending process

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dFOXO dependent changes on transposon siRNAs in total abundance and Ago2 RISC.

Small RNAs from wildtype or dFOXO-null flies collected from whole lysate and Ago2 RISC were sequenced, size selected to 21 nt in silico, mapped to known Drosophila miRNAs and transposons, and normalized by total mapped reads (n = 2). (A) Many transposon siRNAs in total small RNA at either or both young (Y) and old (O) age have differential abundance dependent on dFOXO in males and (B) females. (C) Most of these transposons also have differential abundance dependent on dFOXO in Ago2 RISC as well in males and (D) females. Ninja was not detected in the male wildtype Ago2 RISC old timepoint.</p

20 transposon siRNAs make up the majority of transposon siRNAs detected in total small RNA and Ago2 RISC.

Small RNAs from whole flies, Ago1 RISC immunoprecipitation (IP), or Ago2 RISC IP were sequenced, size selected in silico, mapped to known Drosophila miRNAs and transposons, and normalized as a percent of total reads mapped (n = 2). Transposon siRNA reads were then normalized by total transposon siRNA reads and shown here. (A) The 20 most abundant transposon siRNAs in young wildtype males make up 57 to 88 percent of the total transposon siRNA reads in male total small RNA and Ago2 RISC. (B) The 20 most abundant transposon siRNAs in young wildtype females make up 55 to 66 percent of the total transposon siRNA reads in the female total small RNA and Ago2 RISC. (PDF)</p

Survival curves of animals used in this work.

Percent survival of wildtype (wDAH) and dFOXO-null (wDAH; foxoΔ94) flies were recorded 2–3 times weekly. (A) Mated wildtype males had a median lifespan of 90 days and a maximum survival of 105 days while mated dFOXO-null males had a median lifespan of 45 days and a maximum survival of 65 days. (B) Mated wildtype females had a median lifespan of 90 days and a maximum survival of 110 days while mated dFOXO-null females had a median lifespan of 55 days and a maximum survival of 70 days. (TIFF)</p

The abundance of most miRNAs and transposon siRNAs is stable with age.

(A) Small RNAs from whole wildtype fly lysate were sequenced, mapped to known Drosophila miRNAs and transposons, and normalized by total mapped reads (n = 2). miRNA abundance is plotted as percent of reads mapped miRNAs and transposons in young (5–6 day old) and old (31 day old) males and (B) females (n = 2). Plotted in log10 scale. Top 20 miRNAs are boxed and top miRNAs that changed more than 2-fold are shown in black. (C) siRNA abundance from males and (D) females.</p