In this paper, we address both ontological and epistemological problems related to the concept of ‘gene’. Interrupted genes, alternative splicing, overlapping genes, nested genes, genome-wide transcription and regulatory RNAs, regulatory sequences, somatic recombination in immunoglobulin genes and other molecular evidences represent a serious challenge to the classic way of framing the question ‘what is a gene?’. In the first part of the paper, after showing that the Dna polymer is an entity without bona fide boundaries, we outline ways to extract gene functionalities from it by taking into account the most recent insights of molecular biology. In particular, we argue that a gene is not merely a continuous Dna sequence, but it is an entity identifiable as a functional part of Dna which enters in a polypeptide/functional Rna/nucleus organization coding process. Thus, a gene needs not be an isolated segment of Dna, but it can be productively understood as the sum of non spatially contiguous Dna sequences, since, even if it is scattered, it still constitutes a functional unit. Moreover, a single segment of Dna can be involved in many different polypeptide/functional Rna/nucleus organization coding processes and can thus be a functional component of different genes. Conversely, distinct gene functionalities can be attributed, partially or totally, to the same Dna fragment. On the basis of this foundational analysis, we then develop an epistemological critique to expand the current popular distinction drawn by Lenny Moss (2003) between Gene-P (preformistic gene) and Gene-D (developmental gene). We argue that some uses of the concept of ‘gene’ in experimental molecular biomedicine and evolutionary biology make Moss’ distinction not exhaustive, for example in the case of so-called “reporter” genes (i.e. luciferase gene) or genes predicted by many evolutionary models (i.e. Fisher’s sex ratio) that do not align neatly along the Gene-P/Gene-D dichotomy.
|Titolo:||Gene : an entity in search of concepts?|
|Data di pubblicazione:||2008|
|Enti collegati al convegno:||Società Italiana di Logica e Filosofia della Scienza|
|Citazione:||Gene : an entity in search of concepts? / S. Giaimo, G. Testa. ((Intervento presentato al convegno SILFS Conference tenutosi a Milano nel 2007.|
|Appare nelle tipologie:||14 - Intervento a convegno non pubblicato|