Impact of hormonal modulation at proestrus on ovarian responses and uterine gene expression of suckled anestrous beef cows

Manoel Francisco de Sá Filho; Angela Maria Gonella-Diaza; Mariana Sponchiado; Marcio Ferreira Mendanha; Guilherme Pugliesi; Roney Dos Santos Ramos; Sónia Cristina da Silva Andrade; Gustavo Gasparin; Luiz Lehmann Coutinho; Marcelo Demarchi Goissis; Fernando Silveira Mesquita; Pietro Sampaio Baruselli; Mario Binelli

doi:10.1186/s40104-017-0211-3

Impact of hormonal modulation at proestrus on ovarian responses and uterine gene expression of suckled anestrous beef cows

J Anim Sci Biotechnol. 2017 Nov 1:8:79. doi: 10.1186/s40104-017-0211-3. eCollection 2017.

Authors

Affiliations

¹ Departamento de Reprodução Animal, FMVZ-USP, São Paulo, SP Brazil.
² Departamento de Genética e Biologia Evolutiva, IB-USP-, São Paulo, SP Brazil.
³ Laboratório de Biotecnologia Animal, ESALQ-USP, Av Pádua Dias, Piracicaba, SP 11 Brazil.
⁴ Universidade Federal do Pampa, Uruguaiana, RS Brazil.
⁵ Universidade de São Paulo, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Reprodução Animal, Avenida Duque de Caxias Norte, 225, Pirassununga, SP Zip Code 13635900 Brazil.

Abstract

Background: This study evaluated the impact of hormonal modulation at the onset of proestrus on ovarian response and uterine gene expression of beef cows.

Methods: A total of 172 anestrous beef cows were assigned to one of four groups according to the treatment with estradiol cypionate (ECP) and/or equine chorionic gonadotropin (eCG) [CON (n = 43), ECP (n = 43), eCG (n = 44) and ECP + eCG (n = 42)].

Results: ECP-treated cows (ECP and ECP + eCG groups) presented greater occurrence of estrus (44.6% vs. 65.4%; P = 0.01) and pregnancy per AI [47.1% vs. 33.3%; P = 0.07], but similar progesterone (P4) concentration at subsequent diestrus than cows not treated with ECP (CON and eCG groups). Nonetheless, eCG-treated cows (eCG and ECP + eCG groups) presented larger follicle at timed AI (12.6 ± 0.3 vs. 13.5 ± 0.3 mm; P = 0.03), greater ovulation rate (96.5% vs. 82.6%; P = 0.008) and greater P4 concentration at d 6 (3.9 ± 0.2 vs. 4.8 ± 0.2 ng/mL; P = 0.001) than cows not treated with eCG (CON and ECP groups). Next, cows with a new corpus luteum 6 d after TAI were submitted to uterine biopsy procedure. Uterine fragments [CON (n = 6), ECP (n = 6)] were analyzed by RNA-Seq and a total of 135 transcripts were differentially expressed between groups (73 genes up-regulated by ECP treatment). Subsequently, uterine samples were analyzed by qPCR (genes associated with cell proliferation). ECP treatment induced greater abundance of PTCH2 (P = 0.07) and COL4A1 (P = 0.02), whereas suppressed EGFR (P = 0.09) expression. Conversely, eCG treatment increased abundance of HB-EGF (P = 0.06), ESR2 (P = 0.09), and ITGB3 (P = 0.05), whereas it reduced transcription of ESR1 (P = 0.05). Collectively, supplementation with ECP or eCG at the onset of proestrous of anestrous beef cows influenced ovarian responses, global and specific endometrial gene expression.

Conclusion: Proestrus estradiol regulate the endometrial transcriptome, particularly stimulating proliferative activity in the endometrium.

Keywords: Cattle; Endometrium; Estradiol; Transcriptome; eCG.