Banca de DEFESA: ERICKA WANNESCKA DOS SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ERICKA WANNESCKA DOS SANTOS
DATE: 11/10/2021
TIME: 09:00
LOCAL: Realizada por videoconferência: Google meet
TITLE:

Karyotypic reduction in species of the Apogonidae family (Kutiformes): involved rearrangements and association with biological aspects of the group

KEY WORDS:

Karyotypic evolution; Tandem Fusion; chromosomal rearrangements, repetitive DNA, telomeric sequences.

PAGES: 64
BIG AREA: Ciências Biológicas
AREA: Genética
SUBÁREA: Genética Animal
SUMMARY:

The Apogonidae family (Kurtiformes), known as cardinals, represents a very diverse group of reef fish, present in all oceans. Some of its species exhibit the rare buccal incubation behavior of eggs, which can influence the potential for dispersal of the species. This group has karyotypes with reduced diploid values (2n = 34-46), but cytogenetic data for the family are still scarce. In this sense, the expansion of chromosomal data for the family, involving representatives from different oceans, represents a relevant evolutionary model of karyotype evolution. In order to understand the karyotypic evolution of the family, here are given the cytogenetic data that expand the phylogenetic spectrum, and allow the analysis of the dispersive potential of the species and the organization of repetitive sequences in chromosomes. For this, conventional cytogenetic techniques were used (Giemsa staining, Ag-NORs and C-banding); Fluorescent in situ mapping (FISH) of six repetitive DNA classes (18S rDNA, 5S rDNA; retrotransposon Rex3; Microsatellites (CA) 15 and (CGG) 10 and telomeric sequence), in the species Apogon americanus, Phaeoptyx pigmentaria (Atlantic Ocean), Sphaeramia nematoptera and Pterapogon kauderni (Indo-Pacific). The diploid numbers if decreased (2n = 36, A. americanus; 2n = 38, P. pigmentaria; and 2n = 46, S. nematoptera and P. kauderni), large in Atlantic species. The heterochromatic regions are reduced and the Ag-NORs / 18S rDNA regions are simple. The 18S and 5S rDNA sites are non-synthenic in the Pacific species and co-participant in the same chromosome pair in the Atlantic species. As two microsatellite sequences, as well as Rex3, they are dispersed in chromosomes. The telomeric sequences exhibited interstitial telomeric sites (ITS) in A. americanus, indicating a karyotypic reduction mediated by the tandem fusion mechanism with active participation of pericentric inversions. The family's karyotypic diversity contrasts with the numerical conservatism of other reef fish groups, suggesting a possible relationship with biological factors (buccal egg incubation), which shifts the dispersive potential and favors a karyotypic differentiation of the group. The karyotypic characteristics of Apogonidae broadens the understanding of how biological and environmental factors (extrinsic factors) contribute as triggers for a high rate of chromosomal differentiation (intrinsic factors) in some groups of marine fish.

BANKING MEMBERS:
Externo à Instituição - GIDEÃO WAGNER WERNECK FELIX DA COSTA
Externa à Instituição - KARLLA DANIELLE JORGE AMORIM
Presidente - 1199139 - WAGNER FRANCO MOLINA