Sheeps
Beginning: 
22/05/2017
End: 
09/05/2020
Lead researcher: 
Jorge Hugo Calvo Lacosta
Budget: 
166.000 €
Seasonal patterns of oestrous behaviour and ovulation is an important factor limiting efficiency of sheep production. Sheep breeds from Mediterranean area show reproductive seasonality, mainly regulated by variation in the photoperiod. Anoestrus period is associated with short days, with the highest percentage of ewes without ovulatory activity from February to July. This reproductive seasonality induces great variation in lamb production and, therefore, in the market price of lamb meat. Hormonal treatments are widely used in some countries to control reproductive activity outside of the breeding season, but the increasing demand for free-hormone products leads to a search for alternative methods such as the male effect or the use of genetic markers. Then, it is important to improve the knowledge about the genetic basis and the gene-male effect interaction, using sexually active males inducing strong sexual activity in rams subjecting them to photoperiod with artificial light and control males non-subjected to photoperiod with artificial light. In this project, we propose the use of the High Density Ovine SNP 680K BeadChip and Next generation sequencing (NGS) order to localize genomic regions associated with reproductive seasonality in ewes with ram effect. Finally, the study of the transcriptome will allow associating different transcriptome patterns related to sexual activation of males mediated by photoperiod. Ovine RNA seq will be used to assess changes to gene expression at the Pars tuberalis and suprachiasmatic nucleus to compare sexually active males (subjecting them to long days) and control males (non-subjecting them to long days). Such experiments will allow obtaining a biochemical profile at the RNA expression level in Pars tuberalis and suprachiasmatic nucleus.
The general aim of this project is to study the genetic bases of reproductive seasonality with ram effect in sheep using genomic tools in order to design mechanisms to select more fertile animals in anoestrus period and increase profitability and efficiency of meat livestock. The specific objectives of this project are:
  • OBJECTIVE 1: Characterization of reproductive seasonality with ram effect in Rasa aragonesa, Merino and Canaria sheep breeds using sexually active males (subjecting them to photoperiod with artificial light) and control males (non-subjecting them to photoperiod with artificial light).
  • OBJECTIVE 2: To develop a Genome wide association analysis (GWAS) in ewes for predicted reproductive seasonality with ram effect values using a High Density SNP chip (Ovine680kBeadChip) tofind genomic regions implicated in this trait.
  • OBJECTIVE 3: Characterization of sexual activity in sexually active males (subjecting them to photoperiod with artificial light) and control males (non-subjecting them to photoperiod with artificial light) in Rasa aragonesa, Merino and Canaria sheep breeds.
  • OBJECTIVE 4: Characterization of the biochemical profile at the RNA expression level in Pars tuberalis and suprachiasmatic nucleus to compare sexually active males (subjecting them to photoperiod with artificial light) and control males (non-subjecting them to photoperiod with artificial light) using RNAseq techniques.
Funder: 
INIA
Project members: 
José Luis Alabart Álvarez, Belén Lahoz Crespo, Pilar Sarto Aured, José Folch Pera, Laura Iguacel Quintana (CITA); Magdalena Serrano Noreña (INIA) Enrique Fantova Puyalto (OVIARAGÓN)