Evaluation the mechanism of luteolysis in cyclic and gestational canine corpora lutea

• Grant number: 15/23450-7
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): March 15, 2016
• Effective date (End): March 10, 2017
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Maria Denise Lopes
• Grantee: Ana Augusta Pagnano Derussi
• Supervisor: Bruce Daniel Murphy
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Research place: Université de Montréal, Canada
• Associated to the scholarship: 13/15358-8 - Luteal function in cyclic and gestational canine diestrus: a cellular approach in genic and metabolic viewpoint, BP.PD

Abstract

Abstract: In canine species, gestational and non-gestational corpora lutea (CL) have similar characteristics, especially from a steroidogenic perspective. The luteal regression period of both is considered prolonged when compared other species commonly studied, fact that making understanding of the luteolytic mechanism extremely challenging in this species. In order to investigate the variation in expression of genes related to the luteolysis process at the end of cyclical and gestational diestrus, we will evaluate the global transcriptome by the RNAseq technique and will select major gene expression mechanisms related to luteolysis in the CL that are differentially expressed between the proposed groups. We will validate the results via qRT-PCR and immunohistochemistry. In preparation, we have monitored estrous cycles and undertaken ovariohysterectomy in canine females during cyclic (control group, n = 10) and gestational (experimental group, n = 10) diestrus. The CLs were collected in both groups between days 40-44 (initial luteolysis) and 61-64 (final luteolysis) after pre-ovulatory LH signal. To analyze the genetic profiles, CLs will be subjected to RNA-seq analysis and the consequent transcriptome explored via the Galaxy platform and v.1.8.2 programs, TopHat v.2.0.1, Bowtie v. 0.12.8 for mapping and analysis of differential expression. We will align these to the canine genome. Validation of gene expression will be evaluated for normality of variance and specific comparisons made by ANOVA and Kruskal Wallis. We expect that a great number of transcripts will be expressed in both groups and many will be differentially expressed between the two models. We will undertake gene ontology analysis to establish the pathways and processes in luteal regression. We expect that the main hormone receptors involved in canine luteolysis mechanism (LH-R, PRL-R, PGF2±- R e PGE2-R) will be differentially expressed between the proposed groups. We propose to validate these and other targets by qPCR and immunohistochemistry at the CRRA (Animal Reproduction Research Centre), with supervision by Professor Bruce Murphy. (AU)