脈胞菌節律調控網絡的魯棒性

耿瑋++殷鑫++施萌++王益

摘 要：生物鐘是生命活動以24小時左右為周期的波動，但是其一旦遭到擾亂，會導致嚴重后果。因而，保持其振蕩的魯棒性與周期長度（接近24小時）的魯棒性是生物鐘的核心問題。有研究發現，生物鐘網絡中除了一個主要的負反饋調節之外，通常都有其他的反饋調控機制，如脈胞菌的主要反饋是轉錄調控，但有額外的轉錄后調控。我們猜想：這些額外反饋調控主要用來維持生物鐘的魯棒性。我們在原有三變量脈胞菌模型基礎上，增加了額外調控項，運用數值模擬，分別對比是否有額外調控的兩種情況對環境的容忍程度，得以驗證我們的猜想。進一步我們求出在保持振蕩時，脈胞菌所能容忍的環境變化范圍的理論值，對比理論值和模擬值，引入分叉定理進行理論分析，為理解生物鐘魯棒性機理和相關疾病原因提供理論基礎。

關鍵詞：生物鐘 調控通路 數學模型 魯棒性負反饋回路

中圖分類號：TP39 文獻標識碼：A 文章編號：1674-098X（2015）02（b）-0001-04

Robustness of Rhythm Regulatory Network in Neurospora

Geng Wei Yin Xin Shi Meng Wang Yi

（Soochow University， Suzhou Jiangsu，215000，China）

Abstract：Circadian rhythm is a biological process that displays an endogenous，entrainable oscillation of about 24 hours. Circadian disruption may result in serious consequences.Therefore， maintaining the robustness of the oscillation and period length （which is close to 24 h） is a core task of circadian rhythm.After literature mining，we found that besides the primary negative feedback， there are some other auxiliary feedback loops in circadian systems.For example，there is a primary transcriptional feedback in Neurospora with an extra post-transcriptional regulation. As a result，we hypothesize that these extra feedback loops can contribute to the robustness. We establish two three-dimensional dynamical models and conduct the numerical simulation with MATLB after we add to an extra post-transcription. Through comparison of the circumstance（parameters）tolerance between two models， our assumption is verified. Furthermore， we get the theory values of range，of which Neurosppora can tolerate environmental change. Comparing the difference of theoretical and simulate values， we make some theoretical analysis of them after introducing Hopf bifurcation， which would provides theoretical basis founder standing the mechanism of the robustness of biological clock and related causes of diseases.

Key Words： The Biological Clock；Regulatory Pathway；The Mathematical Model；Robustness；The Negative Feedback Loopendprint