Do workers with B chromosomes exhibit greater asymmetry in size and wing shape? A case study: Partamona helleri (Hymenoptera: Apidae: Meliponini).

• Grant number: 23/16283-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2024
• End date: February 28, 2025
• Field of knowledge: Biological Sciences - Morphology
• Principal Investigator: Marco Antonio Del Lama
• Grantee: Henrique Setem Schimidt
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Some species of the genus Partamona (Schwarz, 1939) exhibit a peculiar characteristic - the presence of supernumerary chromosomes or Bs. An analysis conducted in our laboratory with samples from 841 colonies from 123 sites of thirteen species of the genus, using a specific Sequence Characterized Amplified Region (SCAR) marker for Partamona's B chromosomes, determined the frequency of this chromosome in Partamona helleri, six species from the cupira clade, and two species from the pearsoni clade. Additionally, we investigated the transmission rate of these chromosomes in three of these species, observing a regular meiotic behavior in the transmission of B chromosomes from the queen to the offspring and indicating that in these species, no meiotic drive occurs to favor transmission. In this study, after identifying colonies of P. helleri in which segregation of the B chromosome occurs in the progeny, we intend to verify if workers with the B chromosome are more asymmetrical than their sisters without the B chromosome. Asymmetry will be estimated through geometric wing morphometry, a methodology capable of characterizing subtle differences in morphology. Thus, the study aims to contribute to establishing whether the presence of supernumerary chromosomes induces phenotypic alterations in their carriers.