Transcriptome analysis of prenatal development in pigs

• Ano de defesa: 2020
• Autor(a) principal: Teixeira, Susana Amaral
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa; Zootecnia
• Palavras-chave em Português: Suínos - Embrião - Desenvolvimento; RNA-Seq; Organogênese; Genética e Melhoramento dos Animais Domésticos
• Link de acesso: https://locus.ufv.br//handle/123456789/30901

The conceptuses (embryos and fetuses) developmental trajectory is characterized as a highly regulated biological event at the transcriptional level, which may be influenced by sexual dimorphism and maternal nutrition. Sexual dimorphism at early developmental period, in which the phenotypic sex differentiation is not evident, is mainly related to the expression of genes linked to sex chromosomes. Maternal nutrition is the main extrinsic factor that affects developmental programming, since the molecules from dietary metabolism affects the intrauterine environment, which are important not only to provide nutrients to the conceptuses growth, but also for transcriptional regulation of genes related to placental and conceptuses development. In this context, the effects of pregnant females’ supplementation with functional amino acids, such as arginine, have been well studied under productive and reproductive aspects in pig production. However, the influence of this supplementation on global gene expression during conceptuses development is still poorly understood. The proper development and functionality of organs and tissues are events determined during embryogenesis and the fetal period, which require an adjusted control of gene expression. Although in species affected by intrauterine growth restriction, such as pigs, the knowledge about genes expression related to organogenesis can help to understand various aspects associated with prenatal development, studies addressing this event are still scarce. Currently, the gene expression, as well as the biological processes and pathways involved in its regulation, has been performed by transcriptome analysis from RNA sequencing (RNA-Seq) and functional analyses. Thus, in the present study, from the RNA-seq of pig embryos at 25 days of gestation and fetuses at 35 days of gestation, we aimed (1) the conceptuses sex determination; (2) to elucidate the effects of pregnant gilts supplemented with L-arginine on the conceptuses transcriptome; and, (3) to reveal the main molecular mechanisms involved in pig organogenesis, through the identification of genes differentially expressed between embryos and fetuses. The results of this thesis showed that Y chromosome-linked genes (DDX3Y, KDM5D, ZFY, EIF2S3Y, EIF1AY, LOC110255320, LOC110257894, LOC396706, LOC100625207 and LOC110255257) presented discrepant reads counts between the embryos and fetuses’ samples, which were used for conceptuses sex determination at early prenatal development. Dietary 1.0% L-arginine supplementation of pregnant gilts resulted in downregulation of mitochondrial genes (ND1, ND2, CYTB, COX2, ATP8, and mt-rRNA type) and upregulation of the CYP1A1 gene in embryos, showing an adjusted transcriptional control at the metabolic level, while the transcriptional program during fetal development was not affected. During the pig organogenesis, 1,705 genes were differentially expressed between embryos and fetuses, from which several biological pathways and processes related to renal, skeletal and bone muscular organogenesis, as well as the development of the cardiovascular and neuronal systems were evidenced. This thesis provided relevant information about the pig prenatal development, which can be applied in studies related to pig production efficiency, as well as greater understanding of developmental biology. Keywords: Conceptuses. Functional amino acids. Organogenesis. Pigs. Prenatal development. RNA-seq.