The Gene Transformer of Anastrepha Fruit Flies (Diptera, Tephritidae) and Its Evolution in Insects

Author(s)

Fernanda Ruiz, Maria ^[1] ; Milano, Andreina ^[2] ; Salvemini, Marco ^[2] ; Maria Eirin-Lopez, Jose ^[3] ; Perondini, Andre L. P. ^[4] ; Selivon, Denise ^[4] ; Polito, Catello ^{[2, 5]} ; Saccone, Giuseppe ^[2] ; Sanchez, Lucas ^[1]

Affiliation

^[1] CSIC, Ctr Invest Biol, Madrid - Spain

^[2] Univ Naples Federico II, Sez Genet & Biol Mol, Dipartimento Sci Biol, Naples - Italy

^[3] Univ A Coruna, Dept Biol Celular & Mol, Coruna - Spain

^[4] Univ Sao Paulo, Inst Biociencias, Dept Genet & Biol Evolut, Sao Paulo - Brazil

^[5] CNR, Inst Genet & Biofis Adriano Buzzati Traverso ABT, I-80125 Naples - Italy

• Document type: Journal article
• Source: PLoS One; v. 2, n. 11 NOV 28 2007.
• Web of Science Citations: 62

Abstract

In the tephritids Ceratitis capitata and Bactrocera oleae, the gene transformer acts as the memory device for sex determination, via an auto-regulatory function; and functional Tra protein is produced only in females. This paper investigates the evolution of the gene tra, which was characterised in twelve tephritid species belonging to the less extensively analysed genus Anastrepha. Our study provided the following major conclusions. Firstly, the memory device mechanism used by this gene in sex determination in tephritids likely existed in the common ancestor of the Ceratitis, Bactrocera and Anastrepha phylogenetic lineages. This mechanism would represent the ancestral state with respect to the extant cascade seen in the more evolved Drosophila lineage. Secondly, Transformer2-specific binding intronic splicing silencer sites were found in the splicing regulatory region of transformer but not in doublesex pre-mRNAs in these tephritids. Thus, these sites probably provide the discriminating feature for the putative dual splicing activity of the Tra-Tra2 complex in tephritids. It acts as a splicing activator in dsx pre-mRNA splicing (its binding to the female-specific exon promotes the inclusion of this exon into the mature mRNA), and as a splicing inhibitor in tra pre-mRNA splicing (its binding to the male-specific exons prevents the inclusion of these exons into the mature mRNA). Further, a highly conserved region was found in the specific amino-terminal region of the tephritid Tra protein that might be involved in Tra auto-regulatory function and hence in its repressive splicing behaviour. Finally, the Tra proteins conserved the SR dipeptides, which are essential for Tra functionality. (AU)

• FAPESP's process: 03/02698-3 - Reproductive isolation in species of the Anastrepha fraterculus (Diptera; Tephritidae)
• Grantee: Denise Selivon Scheepmaker
• Support Opportunities: Research Projects - Thematic Grants