Banca de DEFESA: SIMIÃO ALEFE SOARES DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : SIMIÃO ALEFE SOARES DA SILVA
DATE: 30/08/2024
TIME: 14:00
LOCAL: https://meet.google.com/swb-dqca-nqu
TITLE:

Karyotypic evolution in cichlids (Cichlidae; Percomorpha): biogeographic context and role in reproductive isolation 

KEY WORDS:

Karyotypic evolution, chromosomal rearrangements, rDNA, allopatric speciation, sympatric speciation.

PAGES: 71
BIG AREA: Ciências Biológicas
AREA: Genética
SUBÁREA: Genética Animal
SUMMARY:

The Cichlidae family is one of the most diverse groups of fish, with nearly two thousand species globally distributed across hydrographic regions in the Americas, Africa, Madagascar, India, Sri Lanka, and the Middle East. The diversification of this group is driven both by extensive allopatric processes and rapid sympatric radiative explosions. Although many cytogenetic aspects of the group have been studied, the understanding of how biogeographic and phyletic diversification processes contribute to karyotype evolution remains less explored. In this context, we conducted comparative cytogenomic analyses on a substantial set of multicontinental species within the Cichlidae family to contribute to understanding evolutionary trends associated with biogeography and diversification processes. Chromosomal patterns were conspicuously differentiated between Neotropical species groups (Central and South America) and Afro-Tropical groups (Africa), regions that harbor the greatest species diversity. Indeed, in addition to specificities in the organization of repetitive DNA sequences, the modal diploid number in Neotropical species reflects a basal condition with 48 chromosomes and notable structural karyotype variation, while Afro-Tropical species exhibited reduced karyotypes, with 2n=44, and conserved karyotype structures. Multiple and sometimes syntenic rDNA sites, along with other repetitive sequences, indicate intense internal chromosomal rearrangements. The biogeographic context of cytogenetic diversification suggests that allopatric multipartitions, involving rivers in Central America and the Amazon Basin in South America, drive significant structural changes in karyotypes, influencing species evolution. In contrast, rapid sympatric adaptive radiation processes due to ecological partitioning, occurring in the large African lakes, maintain significant karyotypic conservatism in Afro-Tropical species

COMMITTEE MEMBERS:
Presidente - 1199139 - WAGNER FRANCO MOLINA
Externo à Instituição - GIDEÃO WAGNER WERNECK FELIX DA COSTA
Externa à Instituição - KARLLA DANIELLE JORGE AMORIM
Externo à Instituição - MARCELO MOREIRA DE CARVALHO
Externo à Instituição - PAULO AUGUSTO DE LIMA FILHO