Aspectos moleculares da diferencia????o sexual em tambaqui (Colossoma macropomum): identifica????o de vias n??o convencionais em uma esp??cie neotropical

Autor: Paix??o, R??mulo Veiga, https://orcid.org/0000-0002-7242-7391
Přispěvatelé: Souza, Fl??via Kelly Siqueira de, O'Sullivan, Fernanda Loureiro de Almeida, Artoni, Roberto Ferreira, Ribolli, Josiane, Hashimoto, Diogo Teruo, Castro, Lu??s Filipe C.
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Biblioteca Digital de Teses e Dissertações da UFAM
Universidade Federal do Amazonas (UFAM)
instacron:UFAM
Popis: Submitted by R??mulo Paix??o (romulo.veiga.paixao@gmail.com) on 2022-12-12T18:15:22Z No. of bitstreams: 2 Tese vers??o final - R??mulo Veiga Paix??o.pdf: 13478142 bytes, checksum: 386e4a88019f4893aa97d9f7fb8260cd (MD5) CartaEncaminhamentoTCC-TESE-DISSERTAC??A??O.pdf: 119680 bytes, checksum: 66db43d34fdfece70936850a99086ae2 (MD5) Approved for entry into archive by Ci??ncia Animal e Recursos Pesqueiros PPGCARP (ppgcarpsecretaria@ufam.edu.br) on 2023-01-12T19:19:05Z (GMT) No. of bitstreams: 2 Tese vers??o final - R??mulo Veiga Paix??o.pdf: 13478142 bytes, checksum: 386e4a88019f4893aa97d9f7fb8260cd (MD5) CartaEncaminhamentoTCC-TESE-DISSERTAC??A??O.pdf: 119680 bytes, checksum: 66db43d34fdfece70936850a99086ae2 (MD5) Approved for entry into archive by Divis??o de Documenta????o/BC Biblioteca Central (ddbc@ufam.edu.br) on 2023-01-18T21:24:44Z (GMT) No. of bitstreams: 2 Tese vers??o final - R??mulo Veiga Paix??o.pdf: 13478142 bytes, checksum: 386e4a88019f4893aa97d9f7fb8260cd (MD5) CartaEncaminhamentoTCC-TESE-DISSERTAC??A??O.pdf: 119680 bytes, checksum: 66db43d34fdfece70936850a99086ae2 (MD5) Made available in DSpace on 2023-01-18T21:24:44Z (GMT). No. of bitstreams: 2 Tese vers??o final - R??mulo Veiga Paix??o.pdf: 13478142 bytes, checksum: 386e4a88019f4893aa97d9f7fb8260cd (MD5) CartaEncaminhamentoTCC-TESE-DISSERTAC??A??O.pdf: 119680 bytes, checksum: 66db43d34fdfece70936850a99086ae2 (MD5) Previous issue date: 2022-03-28 FAPEAM - Funda????o de Amparo ?? Pesquisa do Estado do Amazonas CAPES - Coordena????o de Aperfei??oamento de Pessoal de N??vel Superior Fish exhibit a wide variety of mechanisms of sex determination and sexual differentiation, which are topics of great scientific interest and also relevant to the fish industry, specifically when the exploitation of one sex is more advantageous in species of economic importance. The tambaqui Colossoma macropomum is a prominent neotropical species in Brazilian aquaculture. Still, the mechanism of sex determination of tambaqui has not yet been properly identified and characterized, despite efforts using omic technologies such as sequencing the genome of males and females, and also juvenile transcriptomes during the sexually undifferentiated phase. Seeking to expand the scientific knowledge about the mechanisms involved in the tambaqui sexual differentiation process, this thesis had as main objective to identify and evaluate, by in silico and in vivo analyses, the molecular mechanisms involved in this process, mainly those related to steroid hormones and their precursors as well as fatty acids. In the Chapter 1, we show that fish diversity is not restricted to the top of the sex-determining cascade, but also to the different genetic, hormonal and molecular pathways necessary for the development of reproductive organs and the behavior of males and females of the species. Unexpected results about the expression of genes involved in the production of estradiol, such as cyp19a1a and cyp19a1b, and estradiol receptors, which have been recently reported in fish of the order Characiformes, indicate that estradiol possibly has a different role in this lineage, compared to classically established in the literature. Our results from chapter 2 suggest that the substantial variations in the function of gonadal and brain aromatase in tambaqui may be a consequence of the drastic changes in the cis and trans-regulatory region resulted from the rearrangements evidenced in the genomic sequence where these genes are located, when compared to species phylogenetically more distant species such as zebrafish, tilapia, medaka and arowana. Furthermore, the gene expression analysis of aromatase cyp19a1a and cyp19a1b during sexual differentiation and in adulthood, together with the unexpected lack of effect of endocrine disruptors on tambaqui sex ratio, reinforce that estradiol may have a less critical role in the ovarian development or it might be fundamental for the development and maintenance of the gonads in both sexes of this species. In chapter 3, the remarkable differential expression of genes belonging to the elovl family, more expressed in males in the pre-differentiation phase, suggests that fatty acid metabolism plays an important role in sex differentiation in tambaqui. Os peixes exibem uma grande variedade de mecanismos de determina????o sexual e diferencia????o sexual, que s??o t??picos de grande interesse cient??fico e tamb??m relev??ncia para o setor produtivo, quando a explora????o de um sexo ?? mais vantajosa em esp??cies de import??ncia econ??mica. O tambaqui Colossoma macropomum ?? uma esp??cie neotropical de destaque na aquicultura nativa brasileira, e seu mecanismo gen??tico de determina????o sexual ainda n??o foi propriamente identificado e caracterizado, apesar dos esfor??os utilizando-se de tecnologias ??micas como sequenciamento do genoma de machos e f??meas, e tamb??m transcriptomas de juvenis durante a fase sexualmente indiferenciada. Buscando ampliar os conhecimentos cient??ficos sobre os mecanismos envolvidos no processo de diferencia????o sexual do tambaqui, esta tese teve como principal objetivo identificar e avaliar, por an??lises in silico e in vivo, os mecanismos moleculares envolvidos neste processo, principalmente os relacionados a horm??nios ester??ides e seus precursores, bem como os ??cidos graxos. No cap??tulo 1, mostramos que a diversidade de peixes n??o se restringe ao topo da cascata determinante do sexo, mas tamb??m nas diferentes vias genicas, hormonais e moleculares necess??rias para a desenvolvimento de ??rg??os reprodutivos e comportamento de machos e f??meas da esp??cie. Resultados inesperados acerca da express??o de genes envolvidos na produ????o e a????o do estradiol, como cyp19a1a e cyp19a1b, e receptores de estradiol, que t??m sido recentemente reportados em peixes da ordem Characiformes, indicam que o estradiol possivelmente tenha um papel diferenciado nessa linhagem, se comparado ao classicamente estabelecido na literatura. Nossos resultados do cap??tulo 2 sugerem que as varia????es substanciais na fun????o das aromatases gonadal e cerebral em tambaqui podem ser reflexo das dr??sticas modifica????es na regi??o cis e trans-regulat??rias provenientes dos rearranjos evidenciados na sequ??ncia gen??mica onde estes genes se econtram localizados, quando comparados com esp??cies filogeneticamente mais distantes como zebrafish, til??pia, medaka e aruan??. Al??m disso, as an??lises de express??o g??nica das aromatases cyp19a1a e cyp19a1b durante a diferencia????o sexual e na fase adulta, em conjunto com a inesperada falta de efeito dos disruptores end??crinos na raz??o sexual do tambaqui, refor??am que o estradiol possa ter um papel menos cr??tico no desenvolvimento ovariano ou ainda que seja fundamental para o desenvolvimento gonadal e manuten????o dos ??rg??os sexuais em ambos os sexos desta esp??cie. No cap??tulo 3, a not??vel express??o diferencial dos genes pertencentes ?? fam??lia elovl, mais expressos nos machos em fase de pr??-diferencia????o sexual, sugere que o metabolismo dos ??cidos graxos tenha um papel importante na diferencia????o sexual em tambaqui.
Databáze: OpenAIRE
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