MOLECULAR EVOLUTION IN THE GENUS Cereus (CACTACEAE; CEREAE): POSITIVE SELECTION IN EXONIC REGIONS OF THE CACTACEAE591 PANEL

• Grant number: 23/03411-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2023
• End date: May 31, 2024
• Field of knowledge: Biological Sciences - Genetics - Plant Genetics
• Principal Investigator: Fernando de Faria Franco
• Grantee: Matheus Vieira da Silva
• Host Institution: Centro de Ciências Humanas e Biológicas (CCHB). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil

Abstract

The genus Cereus Mill. (Cactaceae) comprises approximately 31 species, most of them found in South America. Biogeographical reconstructions for this genus suggest that some geographic transitions between biomes are associated with niche evolution. Thus, natural selection may have played an important role in the evolution of the group. Recently, a molecular database of 292 exonic regions was generated using the Cactaceae591 ortholog panel for many Cereus species, representatives of the main evolutionary lineages of the genus. In the present project, this database will be used to investigate signatures of positive selection in these regions through analyses based on synonymous and non-synonymous substitution rates. Briefly, the analyses will be conducted using the MEME Suite, FUBAR, PAML, and Selecton software, using "Branch Model", "Site Model", and "Branch-site Model'' models. The expectation is that at least some of the analyzed exons may present signs of positiveselection, especially in lineages that show indicatives of niche evolution according to previous studies. Considering the potential use of the Cactaceae591 for phylogenetic studies in cacti, this study may add relevant empirical information about the level of selection found in regions sequenced using this panel.