Thermal evolution of gene expression profiles in Drosophila subobscura
Laayouni, Hafid (Universitat Autònoma de Barcelona. Departament de Genètica i de Microbiologia)
García-Franco, Francisco (Universitat Autònoma de Barcelona. Departament de Genètica i de Microbiologia)
Chávez Sandoval, Blanca Estela (Universitat Autònoma de Barcelona. Departament de Genètica i de Microbiologia)
Trotta, Vincenzo (Università di Bologna (Itàlia). Dipartimento di Biologia Evoluzionistica Sperimentale)
Beltran i Agulló, Sergi (Universitat de Barcelona. Departament de Genètica)
Santos, Mauro (Universitat Autònoma de Barcelona. Departament de Genètica i de Microbiologia)
Corominas, Montserrat (Universitat de Barcelona. Departament de Genètica)

Data:	2007
Resum:	Background: Despite its pervasiveness, the genetic basis of adaptation resulting in variation directly or indirectly related to temperature (climatic) gradients is poorly understood. By using 3-fold replicated laboratory thermal stocks covering much of the physiologically tolerable temperature range for the temperate (i. e. , cold tolerant) species Drosophila subobscura we have assessed whole-genome transcriptional responses after three years of thermal adaptation, when the populations had already diverged for inversion frequencies, pre-adult life history components, and morphological traits. Total mRNA from each population was compared to a reference pool mRNA in a standard, highly replicated two-colour competitive hybridization experiment using cDNA microarrays. Results: A total of 306 (6. 6%) cDNA clones were identified as 'differentially expressed' (following a false discovery rate correction) after contrasting the two furthest apart thermal selection regimes (i. e. , 13°C vs . 22°C), also including four previously reported candidate genes for thermotolerance in Drosophila (Hsp26, Hsp68, Fst, and Treh). On the other hand, correlated patterns of gene expression were similar in cold- and warm-adapted populations. Analysis of functional categories defined by the Gene Ontology project point to an overrepresentation of genes involved in carbohydrate metabolism, nucleic acids metabolism and regulation of transcription among other categories. Although the location of differently expressed genes was approximately at random with respect to chromosomes, a physical mapping of 88 probes to the polytene chromosomes of D. subobscura has shown that a larger than expected number mapped inside inverted chromosomal segments. Conclusion: Our data suggest that a sizeable number of genes appear to be involved in thermal adaptation in Drosophila, with a substantial fraction implicated in metabolism. This apparently illustrates the formidable challenge to understanding the adaptive evolution of complex trait variation. Furthermore, some clustering of genes within inverted chromosomal sections was detected. Disentangling the effects of inversions will be obviously required in any future approach if we want to identify the relevant candidate genes.
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Llengua:	Anglès
Document:	Article ; Versió publicada
Publicat a:	BMC evolutionary biology, Vol. 7, N. 42 (March 2007) , p. 1-15, ISSN 1471-2148

DOI: 10.1186/1471-2148-7-42
PMID: 17371595

15 p, 522.3 KB

El registre apareix a les col·leccions:
Articles > Articles publicats