Abstract #M472

# M472
An NGS-based gene expression profile study in the goat mammary gland: Effect of undernutrition in two breeds with different levels of adaptation to nutritional stress.
José Parreira1,2, Joana R. Lérias1, Lorenzo E. Hernández-Castellano3,4, Mariana Palma2, Noemi Castro4, Anastasio Argüello4, Juan Capote5, Susana S. Araújo1,2, André M. de Almeida*1, 1Instituto de Biologia Experimental Tecnológica, Oeiras, Portugal, 2Instituto de Tecnologia Química e Biológica (I.T.Q.B.), Universidade Nova de Lisboa, Oeiras, Portugal, 3Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland, 4Department of Animal Science, Universidad de Las Palmas de Gran Canaria, Arucas, Canary Islands, Spain, 5Instituto Canario de Investigaciones Agrarias, Valle Guerra, Canary Islands, Spain.

Goat milk has a high relevance worldwide, particularly in the tropics. Consequently, dairy goat productivity performance is very important for animal production and the dairy industry. Undernutrition during the dry season causes Seasonal Weight Loss (SWL), a relevant constraint for animal production. Knowledge on the genetic factors regulating milk production is limited and the impact of feed restriction, in this mechanism has been poorly addressed. A Systems Biology approach can provide a new and comprehensive insight on the molecular mechanisms underlying milk production, under feed restriction, as well as the regulation of the several biological processes involved. With such strategy, the identification of specific biomarkers and metabolic pathways involved could be used to develop new strategies to overcome this constraint. The objective of this work is to understand the molecular mechanisms by which goat breeds are adapted to SWL. We report a preliminary study of a quantitative differential analysis of mammary glands transcriptome using the Illumina high-throughput transcriptome sequencing (RNA-Seq). Two Canary Island (Spain) goat breeds were used; Majorera (SWL tolerant) and Palmera (SWL susceptible), with different productivity performances. We studied the impact of nutritional restriction on the transcriptome of mammary gland secretory tissue. Results show that a concerted reprograming of genes expression occurs as result of the stress imposed, irrespective to the breed. Also suggesting a different behavior of both breeds in response to the treatment applied. Moreover, an enrichment analysis of the differentially expressed genes provided some insight into what biological processes are related with the response to SWL during lactation. Finally, a validation of the RNA-Seq assay using RT-qPCR was performed on candidate genes differentially expressed, for instance glycerol kinase (GK) and adrenoreceptor β 2 (ADRB2). The knowledge obtained through this project will be useful to release new genomic resources as well as shed some light into the genes and regulatory networks underlying milk production under nutritional stress.

Key Words: dairy goat, undernutrition, transcriptomics