Progestogen Profiling Over the Course of Diapause and Resumption of Embryo Development in the European Roe Deer

Abstract

Progesterone (P4) plays a pivotal role in maintenance of pregnancy in many mammalian species. Species-specific P4 metabolites have been shown to function as primary acting progestogen and the receptor binding capacity varies between species. The European roe deer (Capreolus capreolus) displays a 4-5 month period of embryonic diapause, which decouples fertilization from implantation. The majority of roe deer have two corpora lutea that secrete P4. No changes in P4 concentrations have been observed during pre-implantation embryo development. As 5α-DHP is known to play a major role during pregnancy in elephants and horses, we hypothesized that 5α-DHP functions as additional progestogen facilitating embryo reactivation. The profile of 11 progestogens was quantified in roe deer plasma over the course of diapause and resumption of embryo development including P4, 3α- and 3β-DHP, 20α- and 20β-DHP, 5α- and 5β-DHP, 3α,5α- and 3α,5β-THP, as well as 3β,5α- and 3β,5β-THP. While P4 was most abundant during diapause and resumption of development, 20α-DHP was the most abundant P4 metabolite. This is different than in pregnant elephants, where 5α-DHP was most abundant, and the luteal phase in cattle, where 3α,5α-THP was most abundant. With the exception of a weak correlation of 3β,5α-THP, none of the progestogens significantly correlated with embryonic development in the roe deer. Thus, plasma 5α-DHP does not seem to play a role in embryo reactivation. We propose that progestogens might contribute to priming the endometrium for supporting embryo development and preparation for implantation.

Amino acids activate mTORC1 to release roe deer embryos from decelerated proliferation during diapause

“…E2-induced cell proliferation via CREB1 has previously been shown ( 42 ), thereby providing evidence for a potential regulatory role of E2. Previously, we have substantiated a lack of variation in both maternal plasma and endometrial steroid hormones, specifically E2 and P4, during this period of development of the roe deer embryo ( 40 , 41 ). Thus, a possible explanation is that local intracellular E2 metabolism may occur as observed in mice ( 43 ).…”

“…Given the lack of maternal plasma IGF1 and insulin changes in nonfasted animals, we suspect that environmental changes such as food availability have little effect on the regulation of embryonic diapause. Despite the continuous presence of progesterone ( 40 , 41 ), it remains intuitive to assume that the daylight length via melatonin may play a pivotal role in the regulation of the gonadotropic axis. We identified estrogens as an in silico–predicted upstream regulator of both the observed LE and embryonic transcriptome changes.…”

Distribution Pattern of SN in Qinghai-Tibet Plateau and Its Relationship with Environmental Factors

“…Many scholars have conducted in-depth studies on the distribution characteristics of SN and the driving force behind its formation (Hemu et al, 2018;Mulenga and Siziya, 2019;Nematollahi et al, 2018;Oyola-Guzmán and Oyola-Morales, 2018;Weijden et al, 2019). Someone analyzed the distribution characteristics of SN (including STN and SAN) and the driving forces of climate factors on SN formation in northeast china (Lv et al, 2010;Wang et al, 2002;Cao et al, 2007).…”

Embryonic diapause in mammals and dormancy in embryonic stem cells with the European roe deer as experimental model

“…Maternal factors involved in governing the cell cycle may be elucidated. They may further our understanding of molecular factors in the uterine microenvironment that play a role in stem cell pluripotency (Drews et al 2019;van der Weijden et al 2019avan der Weijden et al , 2019bvan der Weijden et al , 2019c. The findings may be translatable to other species, including bovine and human.…”