Genome-wide association study for intramuscular fatty acid composition in divergently selected rabbit lines
[EN] Intramuscular fat (IMF) content and composition are key traits determining meat quality. A divergent selection experiment for IMF content in Longissimus thoracis et lumborum muscle was carried out during nine generations in rabbits. Data from the ninth generation of selection were analysed in o...
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| Tipo de recurso: | tesis de maestría |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:riunet.upv.es:10251/148965 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/148965 |
| Access Level: | acceso abierto |
| Palabra clave: | Grasa intramuscular Ácidos grasos Selección divergente Análisis genómico Conejos Intramuscular fat Fatty acids Divergent selection Genome-wide association study Rabbits. PRODUCCION ANIMAL Máster Universitario en Mejora Genética Animal y Biotecnología de la Reproducción-Màster Universitari en Millora Genètica Animal i Biotecnologia de la Reproducció |
| Sumario: | [EN] Intramuscular fat (IMF) content and composition are key traits determining meat quality. A divergent selection experiment for IMF content in Longissimus thoracis et lumborum muscle was carried out during nine generations in rabbits. Data from the ninth generation of selection were analysed in order to evaluate the responses to selection and examine the genetic background of IMF composition. The high heritability and variability of IMF allowed its improvement through selection in rabbits. The direct response to selection for IMF was 0.51g/100g of muscle, representing 3.3 phenotypic standard deviations. Selection for IMF content generated also a correlated response on the intramuscular fatty acid composition. The correlated response to selection was positive for saturated (SFA) and monounsaturated (MUFA) fatty acids percentages, 1.71% and 3.24 %, respectively, with greater values in the high-IMF line. In contrast, it was negative for polyunsaturated fatty acids (PUFA) percentage (-4.96%), with greater values for low-IMF line. Most individual SFA were higher in high-IMF line except heptadecanoic (C17:0) and stearic (C18:0) acids. Whereas, most individual PUFA were higher in low-IMF line except ¿-linolenic acid (C18:3n3). Thus, selection for IMF content has important effects on its fatty acid composition. Association analyses were carried out on the same divergently selected rabbit lines. The aim was to identify genomic regions associated with the IMF composition and identify putative candidate genes. Our study highlighted the polygenic nature of IMF composition. An important genomic region at 34.0-37.9 Mb on OCU1 was associated with C14:0, C16:0, SFA, and C18:2n6, explaining 3.54%, 11.20%, 11.32%, and 3.18% of the genomic variance, respectively. Besides, a genomic region at 149.0-149.9 Mb on OCU3 was associated with almost all the traits (C14:0, C16:0, C18:0, C18:1, C18:2n6, C20:4n6, SFA, MUFA, PUFA, and PUFA/SFA). Another relevant genomic region was found to be associated at 46.0-48.9 Mb on OCU18, explaining up to 8% of the genomic variance of the ratio MUFA/SFA. Many genomic regions were found to be associated with the intramuscular fatty acid composition, harbouring several genes related to lipid metabolism such as SCD, PLIN2, and ERLIN1. The main genomic regions associated with the fatty acids were not previously detected for IMF content in rabbits. MTMR2 is the only gene that was associated with both the IMF content and its composition. Our study underlined the polygenic nature of IMF in rabbits and identified several candidate genes. |
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