Nature：基因与表型研究获新进展

　　

生物通报道，西班牙、芬兰与美国的科学家近期在基因型与表型研究方面取得新的进展，相关成果文章A computational model of teeth and the developmental origins of morphological variation公布在最新一期的Nature上。

 

丹麦遗传学家W.L.约翰森于1911年提出的两个遗传学名词。基因型又称遗传型,指生物的全部遗传物质(基因)组成。 但一般只表示个别或少数基因位点上的等位基因的组成。表型指生物体个别或少数性状以至全部性状的表现。基因型是生物体在适当环境条件下发育表型的内因；表型则是基因型和环境条件共同作用的结果。能遗传的是基因型，不是表型。

 

基因（基因型）与一种生物的成年形式（表现型）之间的联系并不是一对一匹配的一个简单问题。非线性的发育过程会产生干预，这取决于各种不同的基因输入及细胞间的相互作用。

 

Isaac Salazar-Ciudad和Jukka Jernvall利用一个已经得到很好研究的体系（哺乳动物牙齿），建立了一个计算模型，来在基因型与表现型之间搭起一个桥梁。基于来自海豹牙齿的数据（海豹牙齿表现出广泛的形态变化）。

 

他们发现，牙齿变化很多都可以由单一模型参数来解释。这项工作可能会成为在了解基因和发育对变化、进而对演化所做贡献方面所迈出的一步。

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A computational model of teeth and the developmental origins of morphological variation

Isaac Salazar-Ciudad1,2 & Jukka Jernvall2,3

 

Departament de Genètica i Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain

Developmental Biology Program, Institute of Biotechnology, University of Helsinki, PO Box 56, FIN-00014 Helsinki, Finland

Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York 11794, USA

Correspondence to: Isaac Salazar-Ciudad1,2Jukka Jernvall2,3 Correspondence and requests for materials should be addressed to I.S.-C. (Email: [e-mail]) or J.J. (Email: [e-mail]).

 

 

Top of pageThe relationship between the genotype and the phenotype, or the genotype–phenotype map, is generally approached with the tools of multivariate quantitative genetics and morphometrics1, 2, 3, 4. Whereas studies of development5, 6, 7 and mathematical models of development4, 8, 9, 10, 11, 12 may offer new insights into the genotype–phenotype map, the challenge is to make them useful at the level of microevolution. Here we report a computational model of mammalian tooth development that combines parameters of genetic and cellular interactions to produce a three-dimensional tooth from a simple tooth primordia. We systematically tinkered with each of the model parameters to generate phenotypic variation and used geometric morphometric analyses to identify, or developmentally ordinate, parameters best explaining population-level variation of real teeth. To model the full range of developmentally possible morphologies, we used a population sample of ringed seals (Phoca hispida ladogensis)13. Seal dentitions show a high degree of variation, typically linked to the lack of exact occlusion13, 14, 15, 16. Our model suggests that despite the complexity of development and teeth, there may be a simple basis for dental variation. Changes in single parameters regulating signalling during cusp development may explain shape variation among individuals, whereas a parameter regulating epithelial growth may explain serial, tooth-to-tooth variation along the jaw. Our study provides a step towards integrating the genotype, development and the phenotype.