A dynamical model of growth and maturation in Drosophila

The decision to stop growing and mature into an adult is a critical point in development that determines adult body size, impacting multiple aspects of an adult’s biology. In many animals, growth-cessation is a consequence of hormone release that appears to be tied to attainment of particular body size or condition. Nevertheless, the size-sensing mechanism animals use to initiate hormone synthesis is poorly understood. Here we develop a simple mathematical model of growth cessation in Drosophila melanogaster, which is ostensibly triggered by attainment of a critical weight early in the last instar. Attainment of critical weight is correlated with synthesis of the steroid hormone ecdysone, which causes a larva to stop growing, pupate and metamorphose into the adult form. Our model suggests that, contrary to expectation, the size-sensing mechanism that initiates metamorphosis occurs before the larva reaches critical weight; that is, the critical-weight phenomenon is a downstream consequen..., The experimental data were collected as detailed in B. C. Stieper, M. Kupershtok, M. V. Driscoll, A. W. Shingleton, Imaginal discs regulate developmental timing in Drosophila melanogaster. Dev Biol 321, 18 26 (2008). The simulated data were generated using the deposited XPP-Auto and Simulink/Matlab scripts. , , # A dynamical model of growth and maturation in Drosophila The data comprise experimental data used to parametrize the model, and example simulations generated by the model. The experimental data are the relationship between body mass (mg) and time to pupariation (TTP) for fed and starved third-instar *Drosophila* larvae (experimental_data_fed.csv and experimental_data_stvd.csv). The simulated data are the simulated relationship between body mass and TTP for fed and starved larvae without scatter (simulated_data_fed_ln.csv and simulated_data_stvd_ln.csv) and with scatter (simulated_data_fed_sct.csv and simulated_data_stvd_sct.csv). ## Description of the data and file structure All the data files contain two columns: one for body mass and a second for the time to pupariation in hours. ## Code/Software The R-script (Tyson_et_al_analysis.R) is the code used to analyze these data using loess regression and segmented regression. Script was prepared and run on R version 4.0.3. The XPP...停止生长并发育为成虫的决策是发育过程中的关键节点，该节点决定成虫体型，并影响成虫生物学特性的多个方面。在众多动物中，生长停止是激素释放的结果，而该激素释放似乎与个体达到特定体型或生理状态相关。然而，动物用于启动激素合成的体型感知机制仍不甚明晰。 本研究针对黑腹果蝇（Drosophila melanogaster）构建了生长停止的简易数学模型，该模型显示生长停止表面上由幼虫最后龄期早期达到临界体重（critical weight）所触发。临界体重的达成与类固醇激素蜕皮激素（ecdysone）的合成相关，该激素可促使幼虫停止生长、化蛹并变态发育为成虫。本研究模型显示，与预期相悖的是，启动变态发育的体型感知机制在幼虫达到临界体重之前就已发挥作用；换言之，临界体重现象是下游的后续结果…… 实验数据的采集细节参见B. C. Stieper、M. Kupershtok、M. V. Driscoll、A. W. Shingleton于2008年发表在《Developmental Biology》第321卷18-26页的论文《Imaginal discs regulate developmental timing in Drosophila melanogaster》。模拟数据通过已存档的XPP-Auto及Simulink/Matlab脚本生成。 # 黑腹果蝇生长与发育的动力学模型 本数据集包含用于模型参数化的实验数据，以及模型生成的示例模拟数据。实验数据为喂食组与饥饿组三龄黑腹果蝇幼虫的体重（单位：毫克，mg）与化蛹时间（Time to Pupariation, TTP）之间的对应关系，对应数据文件为experimental_data_fed.csv与experimental_data_stvd.csv。模拟数据则为喂食组与饥饿组幼虫的体重与化蛹时间（TTP）的模拟对应关系，包含无离散误差的数据集（simulated_data_fed_ln.csv与simulated_data_stvd_ln.csv）以及带离散误差的数据集（simulated_data_fed_sct.csv与simulated_data_stvd_sct.csv）。 ## 数据与文件结构说明 所有数据文件均包含两列：一列记录体重数据，另一列记录化蛹时间（单位：小时）。 ## 代码与软件 R脚本（Tyson_et_al_analysis.R）为用于通过局部加权回归（LOESS）与分段回归分析本数据集的代码，该脚本基于R 4.0.3版本编写并运行。 XPP相关脚本……