Comparative Cytogenetics and Neo-Y Formation in Small-Sized Fish Species of the Genus Pyrrhulina (Characiformes, Lebiasinidae)

Autor(es):Mostrar menos -

Rosa de Moraes, Renata Luiza ^[1] ; Sember, Alexandr ^[2] ; Carlos Bertollo, Luiz Antonio ^[1] ; de Oliveira, Ezequiel Aguiar ^{[1, 3]} ; Rab, Petr ^[2] ; Hatanaka, Terumi ^[1] ; Ferreira Marinho, Manoela Maria ^[4] ; Liehr, Thomas ^[5] ; Al-Rikabi, Ahmed B. H. ^[5] ; Feldberg, Eliana ^[6] ; Viana, Patrik F. ^[6] ; Cioffi, Marcelo de Bello ^{[5, 1]}

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos UFSCar, Dept Genet & Evolucao, Lab Citogenet Peixes, Sao Carlos, SP - Brazil

^[2] Czech Acad Sci, Inst Anim Physiol & Genet, Lab Fish Genet, Libechov - Czech Republic

^[3] Secretatia Estado Educ Mato Grosso SEDUC MT, Cuiaba - Brazil

^[4] Univ Sao Paulo, Museu Zool, Sao Paulo - Brazil

^[5] Univ Hosp Jena, Inst Human Genet, Jena - Germany

^[6] Inst Nacl de Pesquisas da Amazonia, Coordenacao Biodiversidade, Lab Genet Anim, Manaus, Amazonas - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FRONTIERS IN GENETICS; v. 10, AUG 2 2019.
• Citações Web of Science: 0

Resumo

Although fishes have traditionally been the subject of comparative evolutionary studies, few reports have concentrated on the application of multipronged modern molecular cytogenetic techniques (such as comparative genomic hybridization = CGH and whole chromosome painting = WCP) to analyze deeper the karyotype evolution of specific groups, especially the historically neglected small-sized ones. Representatives of the family Lebiasinidae (Characiformes) are a notable example, where only a few cytogenetic investigations have been conducted thus far. Here, we aim to elucidate the evolutionary processes behind the karyotype differentiation of Pyrrhulina species on a finer-scale cytogenetic level. To achieve this, we applied C-banding, repetitive DNA mapping, CGH and WCP in Pyrrhulina semifasciata and P. brevis. Our results showed 2n = 42 in both sexes of P. brevis, while the difference in 2n between male and female in P. semifasciata (male 41/female 42) stands out due to the presence of a multiple X1X2Y sex chromosome system, until now undetected in this family. As a remarkable common feature, multiple 18S and 5S rDNA sites are present, with an occasional synteny or tandem-repeat amplification. Male-vs.-female CGH experiments in P. semifasciata highlighted the accumulation of male-enriched repetitive sequences in the pericentromeric region of the Y chromosome. Inter-specific CGH experiments evidenced a divergence between both species' genomes based on the presence of several species-specific signals, highlighting their inner genomic diversity. WCP with the P. semifasciata-derived Y (PSEMI-Y) probe painted not only the entire metacentric Y chromosome in males but also the X-1 and X(2 )chromosomes in both male and female chromosomes of P. semifasciata. In the crossspecies experiments, the PSEMI-Y probe painted four acrocentric chromosomes in both males and females of the other tested Pyrrhulina species. In summary, our results show that both intra- and interchromosomal rearrangements together with the dynamics of repetitive DNA significantly contributed to the karyotype divergence among Pyrrhulina species, possibly promoted by specific populational and ecological traits and accompanied in one species by the origin of neo-sex chromosomes. The present results suggest how particular evolutionary scenarios found in fish species can help to clarify several issues related to genome organization and the karyotype evolution of vertebrates in general. (AU)

• Processo FAPESP: 15/26322-0 - Inter-relações evolutivas da família Erythrinidae (Teleostei, Characiformes) I. citogenética comparativa em Lebiasinidae, com enfoque no gênero Pyrrhulina
• Beneficiário: Renata Luiza Rosa de Moraes
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 17/09321-5 - Characiformes miniaturas (Teleostei: Ostariophysi): evolução, diversidade e biogeografia
• Beneficiário: Manoela Maria Marinho Koh
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Jovens Pesquisadores