Comparative genomics of West Indian and South American flies

• Grant number: 07/00500-2
• Support type: Regular Research Grants
• Duration: October 01, 2007 - April 30, 2010
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal researcher: Reinaldo Otávio Alvarenga Alves de Brito
• Grantee: Reinaldo Otávio Alvarenga Alves de Brito
• Home Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The South American fruit fly Anastrepha fraterculus and the West Indian fruit fly A. obliqua are two of the greatest threats to Brazilian fruticulture. Currently we lack knowledge on biology and population history of these species, which is essential to have effective means of control of these threats. A greater availability of genetic markers and genetic maps for these species would be instrumental not only to enable the establishment of species-specific genetic markers, but also for exploratory evolutionary and population genomics. In spite of the great emphasis that evolutionary genomics has received lately, almost all such studies have come from macroevolutionary comparisons amongst mammals, insects, or Drosophila species, reinforcing the importance to broaden the sampling to different groups. Genomic studies in these two Tephritidae are theoretically relevant because they provide a greater understanding of the evolutionary genomic processes that these species have experienced. These studies are also practically relevant because of their potential applications in quantitative strategies of gene isolation and identification. In this project, we intend to use cutting edge strategies for the isolation and identification of genetic markers that will be used in the establishment of physical and genetical maps for these two species. We will use the analysis of ESTs (Expressed Sequenced Tags) obtained from the expression of individual genes to isolate and characterize genetic markers. This strategy will allow the establishment of SNPs (Single Nucleotide Polymorphisms) that will be genotyped in crosses performed among some inbred lines. The combination of linkage maps derived from the segregation of such SNPs and cursory physical maps derived from FISH of such markers will be used in evolutionary and comparative genomics of these species seeking to identify regions involved in these species’ differentiation and speciation. The use of individual genes to establishing genetic maps allows the use of synteny among genomic regions in different species, which will provide us with the means to better compare A. fraterculus and A. obliqua to themselves, but also to many other different species of Drosophila and other insects whose genome has been fully sequenced. Such synteny is important to provide a better understanding on the evolution of genomic processes that these species have experienced that may or may not have been involved with the speciation process, and greatly facilitates the comparison to other species whose genome has been sequenced. Though the identification of genes specifically involved in the speciation process of these species is not the immediate goal of this project, it is a natural follow-up of our studies in genomic evolution in these species of flies. Another noteworthy aspect of this project is the practical application of a genetic map and identification of many new molecular markers towards the understanding of the biology of fraterculus group of Anastrepha flies. At the moment we lack good molecular markers that enable us to tell most of the species of this complex apart, and even the identification using morphological markers that has been used is cumbersome, given the presence of cryptic species. Therefore, the creation of a genetic map of SNP markers for these species brings us great potential not only for the assembly of species-specific genetic markers that are easy to score, but also for studies involved in the determination of genetic differences amongst these species, paramount to our goal of establishing methods for the control of some of the most important economic pests in Brazil and worldwide. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SOBRINHO, JR., IDERVAL S.; DE BRITO, REINALDO A. Positive and Purifying Selection Influence the Evolution of Doublesex in the Anastrepha fraterculus Species Group. PLoS One, v. 7, n. 3 MAR 13 2012. Web of Science Citations: 8.

SOBRINHO, JR., IDERVAL S.; DE BRITO, REINALDO A. Evidence for positive selection in the gene fruitless in Anastrepha fruit flies. BMC Evolutionary Biology, v. 10, SEP 24 2010. Web of Science Citations: 13.