RFRP3 influences basal lamina degradation, cellular death, and progesterone secretion in cultured preantral ovarian follicles from the domestic cat.

The hypothalamic neuropeptide RFRP3 can suppress hypothalamic GnRH neuron activation and inhibit gonadotropin release from the anterior pituitary. RFRP3 is also produced locally in the ovary and can inhibit steroidogenesis and follicle development in many vertebrates. However, almost nothing is known about the presence and regulatory action of RFRP3 in gonads of any carnivore species. Such knowledge is important for developing captive breeding programs for endangered carnivores and for inhibiting reproduction in feral species. Using the domestic cat as a model, our objectives were to (1) demonstrate the expression of feline RFRP3 (fRFRP3) and its receptor in the cat ovary and (2) assess the influence of fRFRP3 on ovarian follicle integrity, survival, and steroidogenesis in vitro. We first confirmed that fRFRP3 and its receptors (NPFFR1 and NPFFR2) were expressed in cat ovaries by sequencing PCR products from ovarian RNA. We then isolated and cultured preantral ovarian follicles in the presence of 10 or 1 µM fRFRP3 + FSH (1 µg/mL). We recorded the percentage of morphologically viable follicles (basal lamina integrity) over 8 days and calculated percentage survival of follicles on Day 8 (using fluorescent markers for cell survival and death). Last, we quantified progesterone accumulation in media. 10 µM fRFRP3 had no observable effect on viability, survival, or steroid production compared to follicles exposed to only FSH. However, 1 µM fRFRP3 decreased the percentage of morphologically viable follicles and the percentage of surviving follicles on Day 8. At the same time, 1 µM fRFRP3 increased the accumulation of progesterone in media. Our study shows, for the first time, direct action of RFRP3 on the follicle as a functional unit, and it is the first in a carnivore species. More broadly, our results support a conserved, inhibitory action of RFRP3 on ovarian follicle development and underscore the importance of comparative functional studies

Does adaptation to high altitude affect hypoxia-dependent structural plasticity of the placenta?

High altitude residence causes fetal growth restriction (FGR) during pregnancy in lowland mammals. Highland-adapted mammals do not experience this altitude-dependent FGR, suggesting that adaptation to altitude has produced some protective mechanisms. However, the specific mechanisms by which highland-adapted mammals preserve fetal growth at altitude remain unknown. We hypothesized that highland-adapted populations protect fetal growth through structural changes to the placenta that increase surface area for nutrient and gas exchange. We tested this hypothesis using deer mice (Peromyscus maniculatus), from populations native to low [400 m, Lincoln, NE] and high [4300 m, Mt. Evans, CO] altitudes. We predicted structural adaptation would occur via increases to the relative size of the labyrinth zone (LZ), the layer within the rodent placenta where nutrient and gas exchange occur. Placentas were collected from lowland and highland deer mice undergoing pregnancy under normoxia or hypoxia (60 kPa) to understand how hypoxia-dependent structural plasticity might interact with adaptive remodeling of the placenta (N = 5-7 per strain and treatment). Using immunohistochemistry, we quantified the size of each placenta zone. Our preliminary results show that highlanders have relatively larger placental arteries and LZs under both normoxia and hypoxia (P \u3c 0.05 in generalized linear mixed model), suggesting that blood delivery and area for exchange (as determined by the LZ size) may protect fetal growth in highlanders. Future work will pair histological characterization of placental structure with transcriptomics to guide a mechanistic understanding of how placentation constrains to fetal growth under hypoxia

Conference Scheduling Undermines Diversity Efforts

We assessed diversity-focused programming at 29 major biology conferences from 2010 to 2019, noting events tailored to three underrepresented and marginalized groups in biology: women, ethnic and racial minority groups, and the LGBTQ+ community (see Supplementary Information for further methods). Since 2010, diversity-focused events have become more common but frequently address only a subset of URG communities. In general, the percentage of conferences with diversity-focused events increased from 75% in 2019. On average, women were the most frequent focus of these events and the LGBTQ+ community was the least frequent focus (Fig. 1a)

A Push for Inclusive Data Collection in STEM Organizations

Professional organizations in STEM (science, technology, engineering, and mathematics) can use demographic data to quantify recruitment and retention (R&R) of underrepresented groups within their memberships. However, variation in the types of demographic data collected can influence the targeting and perceived impacts of R&R efforts - e.g., giving false signals of R&R for some groups. We obtained demographic surveys from 73 U.S.-affiliated STEM organizations, collectively representing 712,000 members and conference-attendees. We found large differences in the demographic categories surveyed (e.g., disability status, sexual orientation) and the available response options. These discrepancies indicate a lack of consensus regarding the demographic groups that should be recognized and, for groups that are omitted from surveys, an inability of organizations to prioritize and evaluate R&R initiatives. Aligning inclusive demographic surveys across organizations can provide baseline data that can be used to target and evaluate R&R initiatives to better serve underrepresented groups throughout STEM

現代日本語における敬語の命令形

千葉大学社会文化科学研究科研究プロジェクト報告書第123集『語彙と文法の相関-比較･対照研究の視点から』所

Regulation of the female reproductive system in comparative mammalian models

Reproduction is a critical component of an animal’s fitness, but it is also energetically intensive. In order to maximize reproductive fitness, organisms modulate their reproductive investment or timing in response to environmental cues that provide information about resource availability or other indicators of reproductive success. Physiologic systems that monitor these cues then influence both reproductive readiness and more scaled measures of investment, including number of offspring or offspring provisioning effort. This kind of physiologic modulation is especially salient to mammals, for whom reproduction (gestation and lactation) is exceptionally intensive, and there is extensive documentation of variation in reproductive effort and success under specific environmental and physiological challenges. Still, the underlying mechanisms that coordinate these shifts in investment remain poorly defined and understood. This dissertation identifies novel endocrine and paracrine mechanisms that regulate ovarian and uterine function in the context of reproductive success. Chapter 1 summarizes our current understanding of female reproductive function and modulation, ultimately identifying 4 key areas of modulation for which the molecular mechanisms are poorly understood or defined: (1) evaluating autonomic nervous system regulation of reproductive organs in ecophysiological contexts, (2) identifying new signals regulating ovary and uterine function; (3) determining the extent to which reproductive stage (e.g., pregnancy) alters regulatory networks and sensitivity; and (4) scaling function of specific cell types or organs to organism-level reproductive outcomes. Chapters 2-5 address areas 2-4 by identifying new mechanisms of mammalian reproductive system control in the ovary and uterus and by evaluating the function of established signaling networks in other reproductive states. Chapter 2 interrogates the direct sensitivity of the ovary to physiological cues using mouse ovarian explants. By using pharmacologic inhibition of glucose metabolism, these experiments identify novel glucose sensitivity in the ovary. Chapter 3 examines the effect of neuropeptide gonadotropin inhibitory hormone (GnIH) on ovarian follicle growth, survival, and steroidogenesis in the domestic cat. As has been shown in other mammals to-date, GnIH promotes follicle degradation in vitro. These findings support a conserved role for GnIH in vertebrate ovarian folliculogenesis. Together, these chapters provide new paracrine and endocrine mechanisms of ovarian regulation that adds to our molecular understanding of how reproductive effort and investment are modulated.Chapter 4 explores the sensitivity of feline uterine endometrial epithelial cells to sex steroids. We demonstrate that sex steroids stimulate morphological changes to endometrial epithelial cell 3D growth in vitro, and that morphological changes are associated with functional changes in gene expression. Though often manipulated as part of normal fertility treatment, we do not have a good understanding of how these hormones facilitate uterine preparedness for implantation and pregnancy in felines. Chapter 4 thus identifies specific mechanisms of reproductive modulation in the feline uterus and also beings to flesh out molecular mechanisms underlying reproductive failure at the organism level. Our results have direct application to endangered felid breeding programs, which utilize in vitro follicle maturation and in vivo hormones treatments to promote breeding success of genetically-important individuals. Finally, chapter 5 uses a classic stress physiology paradigm to identify the mechanism(s) by which psychological stress inhibits ovarian steroid synthesis during pregnancy in mice. These experiments demonstrate that stress-dependent inhibition of ovarian function does not occur through classical, hypothalamic inhibition, emphasizing the dynamic shifts in endocrine function across mammalian pregnancy. These studies add to our comparative understanding of reproductive function, which is critical because of its fundamental connection to organismal fitness. Taken together, these studies also highlight the utility of in vitro approaches for experimentally approaching the challenge of connecting molecular variation to organismal function. We summarize the results and their ultimate importance to female reproductive physiology research in Chapter 6

Regulation of the female reproductive system in comparative mammalian models

Reproduction is a critical component of an animal’s fitness, but it is also energetically intensive. In order to maximize reproductive fitness, organisms modulate their reproductive investment or timing in response to environmental cues that provide information about resource availability or other indicators of reproductive success. Physiologic systems that monitor these cues then influence both reproductive readiness and more scaled measures of investment, including number of offspring or offspring provisioning effort. This kind of physiologic modulation is especially salient to mammals, for whom reproduction (gestation and lactation) is exceptionally intensive, and there is extensive documentation of variation in reproductive effort and success under specific environmental and physiological challenges. Still, the underlying mechanisms that coordinate these shifts in investment remain poorly defined and understood. This dissertation identifies novel endocrine and paracrine mechanisms that regulate ovarian and uterine function in the context of reproductive success. Chapter 1 summarizes our current understanding of female reproductive function and modulation, ultimately identifying 4 key areas of modulation for which the molecular mechanisms are poorly understood or defined: (1) evaluating autonomic nervous system regulation of reproductive organs in ecophysiological contexts, (2) identifying new signals regulating ovary and uterine function; (3) determining the extent to which reproductive stage (e.g., pregnancy) alters regulatory networks and sensitivity; and (4) scaling function of specific cell types or organs to organism-level reproductive outcomes. Chapters 2-5 address areas 2-4 by identifying new mechanisms of mammalian reproductive system control in the ovary and uterus and by evaluating the function of established signaling networks in other reproductive states. Chapter 2 interrogates the direct sensitivity of the ovary to physiological cues using mouse ovarian explants. By using pharmacologic inhibition of glucose metabolism, these experiments identify novel glucose sensitivity in the ovary. Chapter 3 examines the effect of neuropeptide gonadotropin inhibitory hormone (GnIH) on ovarian follicle growth, survival, and steroidogenesis in the domestic cat. As has been shown in other mammals to-date, GnIH promotes follicle degradation in vitro. These findings support a conserved role for GnIH in vertebrate ovarian folliculogenesis. Together, these chapters provide new paracrine and endocrine mechanisms of ovarian regulation that adds to our molecular understanding of how reproductive effort and investment are modulated.Chapter 4 explores the sensitivity of feline uterine endometrial epithelial cells to sex steroids. We demonstrate that sex steroids stimulate morphological changes to endometrial epithelial cell 3D growth in vitro, and that morphological changes are associated with functional changes in gene expression. Though often manipulated as part of normal fertility treatment, we do not have a good understanding of how these hormones facilitate uterine preparedness for implantation and pregnancy in felines. Chapter 4 thus identifies specific mechanisms of reproductive modulation in the feline uterus and also beings to flesh out molecular mechanisms underlying reproductive failure at the organism level. Our results have direct application to endangered felid breeding programs, which utilize in vitro follicle maturation and in vivo hormones treatments to promote breeding success of genetically-important individuals. Finally, chapter 5 uses a classic stress physiology paradigm to identify the mechanism(s) by which psychological stress inhibits ovarian steroid synthesis during pregnancy in mice. These experiments demonstrate that stress-dependent inhibition of ovarian function does not occur through classical, hypothalamic inhibition, emphasizing the dynamic shifts in endocrine function across mammalian pregnancy. These studies add to our comparative understanding of reproductive function, which is critical because of its fundamental connection to organismal fitness. Taken together, these studies also highlight the utility of in vitro approaches for experimentally approaching the challenge of connecting molecular variation to organismal function. We summarize the results and their ultimate importance to female reproductive physiology research in Chapter 6

The Timing of Embryonic Exposure to Elevated Temperature Alters Stress Endocrinology in Domestic Chickens (Gallus domesticus)

Patterns of glucocorticoid (GC) release in response to stimuli vary both among individuals and within individuals across their lifetime. While much work has focused on how the prenatal steroid environment can affect GC release, relatively little is known about how environmental parameters, such as incubation temperature affect GCs. We tested the hypothesis that variation and timing of elevated incubation temperature within the thermoneutral zone can alter the pattern of GC release. We incubated domestic chicken eggs (Gallus domesticus) at the optimal incubation temperature (37.5°C) or at a slightly higher temperature (+1.1°C) either early, late, or throughout incubation. At three weeks post-hatch, all birds were (i) exposed to a capture-restraint stress to measure stress-induced GC release (naive). Three days following the naive stressor, birds were (ii) exposed to a heat challenge, which was followed the next day by a second capture-restraint stress (post-heat challenge). Regardless of treatment, birds had similar patterns of GC release following the naive stress series. However, during the post-heat challenge stress series, birds incubated at optimal temperatures increased their peak GC release. In contrast, birds exposed to slightly elevated temperatures for any period of development failed to increase peak GC release, and their specific response varied with timing of exposure to the elevated incubation temperature. Our results demonstrate that subtle variation in the embryonic environment, such as elevated incubation temperature within the thermoneutral zone, can impact the pattern of GC release of offspring. Further work is needed to understand the mechanisms underlying these changes and the relationship between fitness and environmentally-altered phenotypes. Copyright 2015 Elsevier Inc. All rights reserved

Evidence for a Coupled Oscillator Model of Endocrine Ultradian Rhythms

Whereas long-period temporal structures in endocrine dynamics have been well studied, endocrine rhythms on the scale of hours are relatively unexplored. The study of these ultradian rhythms (URs) has remained nascent, in part, because a theoretical framework unifying ultradian patterns across systems has not been established. The present overview proposes a conceptual coupled oscillator network model of URs in which oscillating hormonal outputs, or nodes, are connected by edges representing the strength of node-node coupling. We propose that variable-strength coupling exists both within and across classic hormonal axes. Because coupled oscillators synchronize, such a model implies that changes across hormonal systems could be inferred by surveying accessible nodes in the network. This implication would at once simplify the study of URs and open new avenues of exploration into conditions affecting coupling. In support of this proposed framework, we review mammalian evidence for (1) URs of the gut-brain axis and the hypothalamo-pituitary-thyroid, -adrenal, and -gonadal axes, (2) UR coupling within and across these axes; and (3) the relation of these URs to body temperature. URs across these systems exhibit behavior broadly consistent with a coupled oscillator network, maintaining both consistent URs and coupling within and across axes. This model may aid the exploration of mammalian physiology at high temporal resolution and improve the understanding of endocrine system dynamics within individuals