Genomic associations integrated with transcriptome and proteome analyses for reproductive precocity in Nelore cattle.

• Grant number: 25/25870-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2025
• End date: November 30, 2027
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Genetics and Improvement of Domestic Animals
• Principal Investigator: Claudia Cristina Paro de Paz
• Grantee: Letícia Silva Pereira
• Host Institution: Instituto de Zootecnia. Agência Paulista de Tecnologia dos Agronegócios (APTA). Nova Odessa , SP, Brazil
• Associated research grant: 21/11922-2 - Science Center for the Development of Climate Neutrality for Beef in Tropical Regions, AP.CCD

Abstract

Brazilian beef production plays an important role in the global economy, as it is one of the world's leading beef suppliers, particularly in its fresh form. The high and constant demand for beef meat, coupled with the challenges posed by climate change, is essential to sustain elevated levels of meat production. Therefore, enhancing the efficiency of the cattle system is critical for maintaining competitiveness and sustainability. Early weaning is an effective strategy for improving the condition of lactating cows and the performance of calves. Understanding the genetic and epigenetic mechanisms behind early weaning is vital for developing sustainable and innovative strategies to increase beef production. The experiment will be conducted with approximately 100 male calves of the Nellore breed and to verify the proteomic, transcriptomic and epigenetic profiles associated with male Nellore calves during the post-weaning and finishing phases 30 animals will be used, 15 for each treatment: T1) calves weaned at 120 days and T2) calves weaned at 240 days. In each treatment, the animals will be divided into three paddocks (5 calves per paddock). The calves will be submitted to muscle tissue biopsy during the breeding, rearing and fattening phases, on the left side of the 13th rib, in the Longissimus lumborum muscle and the samples will be immediately frozen and stored in an ultrafreezer. RNA samples will be obtained from muscular tissue, and the total RNA and miRNA libraries will be constructed and sequenced by NextSeq (Illumina). The proteomic analyzes will be performed by gel electrophoresis (SDS-PAGE) and mass spectrometry (LC-MS/MS). To achieve this goal, this proposal aims to analyze divergent transcriptomic and proteomic profiles of the muscle tissue of Nellore calves at different post-weaning ages (120 and 240 days). This proposal also aims to integrate omics data to shed light on biological mechanics and help elucidate regulatory elements, genes, and proteins associated with early wearing. Omics integration approaches can provide insights into the complex biology of early weaning. Additionally, these approaches can help identify molecular markers and essential proteins crucial for this phenotype variation. They can be helpful in animal breeding and gene editing programs to select superior animals. This proposal aims to investigate the molecular mechanisms associated with the early weaning of Nellore calves through an integrated approach using proteomics and transcriptomics. (AU)