GSE98657
Transcriptome analysis of canine (Canis familiaris) corpus luteum (CL) during non-pregnant late luteal phase compared with normal luteolyzing CL collected at prepartum progesterone (P4) decrease and following antigestagen treatment.
Next-generation sequencing (RNA-Seq) was performed on CL from the late luteal phase and compared with normally luteolyzing CL collected at the prepartum P4 decrease, and following antigestagen (Aglepristone)- treatment. The analysis of transcriptomes presented herein supports the hypothesis describing luteal regression in non-pregnant dogs as a degenerative process devoid of the acute luteolytic principle and without an acute involvement of the immune system observed prepartum. The contribution of the immune system seems, however, to be critical in the PGF2alpha-mediated active prepartum luteolysis, which appears to be an acute immune process. The antigestagen-medited effects point towards the withdrawal of the luteotropic function of P4 with lesser involvement of immune system than during natural luteolysis. In summary, a deeper insights have been obtained into possible endocrine, paracrine and autocrine mechanisms governing the luteal life span in the domestic dog during pregnancy and in non-pregnant cycles. Overall design: Corpora lutea (CL) from clinically healthy, cross-breed bitches (aged 2-8 years) were used representing the following experimental groups: (Group-1) mid-pregnancy (days 35-40); (Group-2) active prepartum luteolysis; (Group-3) antigestagen-treated mid-gestation group (days 40-45); (Group-4) non-pregnant bitches at late CL regression (day 65 after ovulation). In all dogs the time of ovulation was determined by measurements of P4 (> 5ng/ml) and by vaginal histology. Pregnant dogs were mated 2 days after ovulation (Day 0). To determine active prepartum luteolysis (Group-2), P4 concentrations in peripheral blood plasma were measured at 6 h intervals beginning on day 58 of pregnancy; when P4 levels in 3 consecutive measurements decreased below 2-3 ng/ml, the tissue material was collected. In Group 3, prepartum luteolysis/abortion was induced with the antigestagen aglepristone (Alizine; 10mg/Kg bw, 2x/24 h apart) and the tissues were collected 24h after the second application. All dogs underwent routine ovariohysterectomy. For RNA preservation, immediately after surgery the CL tissue were trimmed of surrounding ovarian tissue, washed with phosphate-buffered saline (PBS) and placed in RNAlater® (Ambion Biotechnologie GmbH, Wiesbaden, Germany) for 24 h at +4°C, and then stored at  -80°C until use.