Location: Animal Disease Research
Project Number: 2090-32000-046-002-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2020
End Date: Aug 31, 2025
Objective:
The objectives of this cooperative sheep genomics and animal health research are to: 1) perform genetic and genomic analyses to validate and fine map underlying genes influencing nasal shedding of Mycoplasma ovipneumoniae; 2) leverage existing data to perform additional genome-wide association analyses with sheep individual and maternal traits and additional genomic selection evaluations of sheep individual and maternal traits.
Approach:
The USDA, Agricultural Research Service (ARS) and University of Idaho (UI) are collaborating to advance ovine genomics and animal health research that will be conducted and used by both ARS and UI scientists. Existing collaborative work between ARS and UI has identified genomic regions associated with sheep nasal shedding of Mycoplasma ovipneumoniae. The boundaries of these genomic regions have been defined in terms of chromosome segments usually consisting of multiple genes in length. One need is to refine the positions of the underlying mutations at within gene resolution through genetic fine mapping. Furthermore, these major genetic loci have been identified only in specific individual populations. Thus, validating the results in different animals and possibly different but related breeds would serve to validate findings.
This primary purpose (Obj. 1) of this agreement is to facilitate validation of multiple associated genomic regions identified in existing work and genetic fine-mapping of associated genomic regions. The secondary purpose (Obj. 2) of this agreement is to make available ancillary genotype data to facilitate industry- and program-wide efforts in developing/fine-tuning genetic breeding values and genomically-enhanced estimating breeding values.
For Objective 1, approximately 200 Targhee and 400 Rambouillet ewes from the ARS, Range Sheep Production Efficiency Research (RSPER) unit (Dubois, Idaho) flocks will be enrolled in a 2-year sampling program, where each ewe will be sampled 5 times. Venous (jugular)-blood and nasal-swab samples will be collected by RSPER and subsequently analyzed at ADRU for qPCR as a measure of nasal shedding of Mycoplasma ovipneumoniae. Genotype data will be generated using state-of-the-art methods at the time of analysis. Sampling timepoints will be pre-lambing, post-lambing, and at weaning. Initial ages for the ewes will range from 1 to 5 years.
For Objective 2, ADRU will provide cooperator and RSPER with genotype information obtained from accomplishment of Objective 1 and 2; previous genotype information obtained in the original work; and new genotype data from additional RSPER ewes.
