The Role of Early Life Gut Mycobiome on Child Health.

The human gut microbiota is composed of bacteria (microbiota or microbiome), fungi (mycobiome), viruses, and archaea, but most of the research is primarily focused on the bacterial component of this ecosystem. Besides bacteria, fungi have been shown to play a role in host health and physiologic functions. However, studies on mycobiota composition during infancy, the factors that might shape infant gut mycobiota, and implications to child health and development are limited. In this review, we discuss the factors likely shaping gut mycobiota, interkingdom interactions, and associations with child health outcomes and highlight the gaps in our current knowledge of this ecosystem.

Maternal Exercise Prior to and during Gestation Induces Sex-Specific Alterations in the Mouse Placenta.

While exercise (EX) during pregnancy is beneficial for both mother and child, little is known about the mechanisms by which maternal exercise mediates changes in utero. Six-week-old female C57BL/6 mice were divided into two groups: with (exercise, EX; N = 7) or without (sedentary, SED; N = 8) access to voluntary running wheels. EX was provided via 24 h access to wheels for 10 weeks prior to conception until late pregnancy (18.5 days post coitum). Sex-stratified placentas and fetal livers were collected. Microarray analysis of SED and EX placentas revealed that EX affected gene transcript expression of 283 and 661 transcripts in male and female placentas, respectively (±1.4-fold, p < 0.05). Gene Set Enrichment and Ingenuity Pathway Analyses of male placentas showed that EX led to inhibition of signaling pathways, biological functions, and down-regulation of transcripts related to lipid and steroid metabolism, while EX in female placentas led to activation of pathways, biological functions, and gene expression related to muscle growth, brain, vascular development, and growth factors. Overall, our results suggest that the effects of maternal EX on the placenta and presumably on the offspring are sexually dimorphic.

Ovarian stimulation with excessive FSH doses causes cumulus cell and oocyte dysfunction in small ovarian reserve heifers.

Excessive FSH doses during ovarian stimulation in the small ovarian reserve heifer (SORH) cause premature cumulus expansion and follicular hyperstimulation dysgenesis (FHD) in nearly all ovulatory-size follicles with predicted disruptions in cell-signaling pathways in cumulus cells and oocytes (before ovulatory hCG stimulation). These observations support the hypothesis that excessive FSH dysregulates cumulus cell function and oocyte maturation. To test this hypothesis, we determined whether excessive FSH-induced differentially expressed genes (DEGs) in cumulus cells identified in our previously published transcriptome analysis were altered independent of extreme phenotypic differences observed amongst ovulatory-size follicles, and assessed predicted roles of these DEGs in cumulus and oocyte biology. We also determined if excessive FSH alters cumulus cell morphology, and oocyte nuclear maturation before (premature) or after an ovulatory hCG stimulus or during IVM. Excessive FSH doses increased expression of 17 cumulus DEGs with known roles in cumulus cell and oocyte functions (responsiveness to gonadotrophins, survival, expansion, and oocyte maturation). Excessive FSH also induced premature cumulus expansion and oocyte maturation but inhibited cumulus expansion and oocyte maturation post-hCG and diminished the ability of oocytes with prematurely expanded cumulus cells to undergo IVF or nuclear maturation during IVM. Ovarian stimulation with excessive FSH is concluded to disrupt cumulus cell and oocyte functions by inducing premature cumulus expansion and dysregulating oocyte maturation without an ovulatory hCG stimulus yielding poor-quality cumulus-oocyte complexes that may be incorrectly judged morphologically as suitable for IVF during ART.

Maternal nutritional status modifies heat-associated growth restriction in women with chronic malnutrition.

Rapid changes in the global climate are deepening existing health disparities from resource scarcity and malnutrition. Rising ambient temperatures represent an imminent risk to pregnant women and infants. Both maternal malnutrition and heat stress during pregnancy contribute to poor fetal growth, the leading cause of diminished child development in low-resource settings. However, studies explicitly examining interactions between these two important environmental factors are lacking. We leveraged maternal and neonatal anthropometry data from a randomized controlled trial focused on improving preconception maternal nutrition (Women First Preconception Nutrition trial) conducted in Thatta, Pakistan, where both nutritional deficits and heat stress are prevalent. Multiple linear regression of ambient temperature and neonatal anthropometry at birth (n = 459) showed a negative association between daily maximal temperatures in the first trimester and Z-scores of birth length and head circumference. Placental mRNA-sequencing and protein analysis showed transcriptomic changes in protein translation, ribosomal proteins, and mTORC1 signaling components in term placenta exposed to excessive heat in the first trimester. Targeted metabolomic analysis indicated ambient temperature associated alterations in maternal circulation with decreases in choline concentrations. Notably, negative impacts of heat on birth length were in part mitigated in women randomized to comprehensive maternal nutritional supplementation before pregnancy suggesting potential interactions between heat stress and nutritional status of the mother. Collectively, the findings bridge critical gaps in our current understanding of how maternal nutrition may provide resilience against adverse effects of heat stress in pregnancy.

Effects of early lactation body condition loss in dairy cows on serum lipid profiles and on oocyte and cumulus cell transcriptomes.

The objective of this study was to determine the effect of early lactation body condition (BC) loss in multiparous dairy cows on serum lipids and the effect of these changes on oocyte and cumulus cell transcriptomes. Body condition loss in dairy cattle after parturition is associated with reduced fertility and increased pregnancy loss. The complex interplay between BC, nutrition, dry matter intake, milk production, and time of calving has presented a barrier to understanding mechanisms leading to reduced fertility. We identified cows that lost BC (L group; n = 10) or maintained or gained BC (M/G group; n = 8) during the first 27 to 33 d in milk and investigated changes in serum fatty acids and oocyte and cumulus cell transcriptomes at 75 to 81 d in milk. The L group had increased serum levels of nonesterified fatty acids and mead acid, and reduced serum levels of petroselaidic acid and behenic acid. Transcriptome analyses revealed 38 differentially expressed genes (DEG) in oocytes and 71 DEG in cumulus cells of L (n = 3) compared with M/G group (n = 3). Network analysis connected serum fatty acid changes to downstream effects including reduced inflammatory response and mitochondrial membrane depolarization, increased production of reactive oxygen species, and functions related to fatty acid metabolism and cytoplasmic organization in oocytes. These effects were associated with predicted effects on signaling in oocytes through calcium, insulin, O-GlcNAcase (OGA), fibroblast growth factor receptor 4 (FGF4R), peroxisome proliferator activated receptor gamma coactivator 1 α (PPARGC1A), and phospholipase D2 (PLD2) pathways, with a connection to the cumulus cell via calcium signaling. These results connect BC loss following parturition to changes in serum lipid levels, and changes potentially affecting oocyte quality; thus, these results provide new insight into mechanism of reduced fertility.

Follicular Hyperstimulation Dysgenesis: New Explanation for Adverse Effects of Excessive FSH in Ovarian Stimulation.

High follicle-stimulating hormone (FSH) doses during ovarian stimulation protocols for assisted reproductive technologies (ART) are detrimental to ovulatory follicle function and oocyte quality. However, the mechanisms are unclear. In a small ovarian reserve heifer model, excessive FSH doses lead to phenotypic heterogeneity of ovulatory size follicles, with most follicles displaying signs of premature luteinization and a range in severity of abnormalities. By performing whole transcriptome analyses of granulosa cells, cumulus cells, and oocytes from individual follicles of animals given standard or excessive FSH doses, we identified progressive changes in the transcriptomes of the 3 cell types, with increasing severity of follicular abnormality with the excessive doses. The granulosa and cumulus cells each diverged progressively from their normal phenotypes and became highly similar to each other in the more severely affected follicles. Pathway analysis indicates a possible dysregulation of the final stages of folliculogenesis, with processes characteristic of ovulation and luteinization occurring concurrently rather than sequentially in the most severely affected follicles. These changes were associated with disruptions in key pathways in granulosa and cumulus cells, which may account for previously reported reduced estradiol production, enhanced progesterone and oxytocin production and diminished ovulation rates. Predicted deficiencies in oocyte survival, stress response, and fertilization suggest likely reductions in oocyte health, which could further compromise oocyte quality and ART outcomes.

Associations between maternal obesity and offspring gut microbiome in the first year of life.

BACKGROUND: Maternal obesity is an important determinant of offspring obesity risk, which may be mediated via changes in the infant microbiome. OBJECTIVES: We examined infant faecal microbiome, short-chain fatty acids (SCFA), and maternal human milk oligosaccharides (HMO) in mothers with overweight/obese body mass index (BMI) (OW) compared with normal weight (NW) (Clinicaltrials.gov NCT01131117). METHODS: Infant stool samples at 1, 6, and 12 months were analysed by 16S rRNA sequencing. Maternal (BODPOD) and infant (quantitative nuclear magnetic resonance [QMR]) adiposity were measured. HMOs at 2 months postpartum and faecal SCFAs at 1 month were also assessed. Statistical analyses included multivariable and mixed linear models for assessment of microbiome diversity, composition, and associations of taxonomic abundance with metabolic and anthropometric variables. RESULTS: At 1 month, offspring of women with obesity had lower abundance of SCFA-producing bacteria (including Ruminococcus and Turicibacter) and lower faecal butyric acid levels. Lachnospiraceae abundance was lower in OW group at 6 months, and infant fat mass was negatively associated with the levels of Sutterella. Gradient boosting machine models indicated that higher α-diversity and specific microbial taxa at 1 month predicted elevated adiposity at 12 months with overall accuracy of 76.5%. Associations between maternal HMO concentrations and infant bacterial taxa differed between NW and OW groups. CONCLUSIONS: Elevated maternal BMI is associated with relative depletion of butyrate-producing microbes and faecal butyrate in the early infant faecal microbiome. Overall microbial richness may aid in prediction of elevated adiposity in later infancy.

Excessive follicle-stimulating hormone during ovarian stimulation of cattle may induce premature luteinization of most ovulatory-size follicles†.

High follicle-stimulating hormone (FSH) doses during ovarian stimulation are detrimental to ovulatory follicle function and decrease live birth rate in cattle and women. However, the mechanism whereby excessive FSH causes ovarian dysfunction is unknown. This study tested the hypothesis that excessive FSH during ovarian stimulation induces premature luteinization of ovulatory-size follicles. Small ovarian reserve heifers were injected twice daily for 4 days with 70 IU (N = 7 heifers) or 210 IU (N = 6 heifers) Folltropin-V [commercial FSH-enriched preparation of porcine pituitary glands with minor (<1%) luteinizing hormone (LH) contamination, cpFSH]. Ovulatory-size (≥10 mm) follicles were excised from ovaries after the last cpFSH injection and hormone concentrations in follicular fluid (FF) were determined using ELISA. Luteinization was monitored by assessing cumulus cell-oocyte complex (COC) morphology and measuring concentrations of estradiol (E), progesterone (P), and oxytocin (O) in FF. COCs were classified as having compact (cCOC) or expanded (eCOC) cumulus cell layers, and as estrogen-active (E:P in FF ≥1), estrogen-inactive (EI, E:P in FF ≤1 > 0.1), or extreme-estrogen-inactive (EEI, E:P in FF ≤0.1). A high proportion (72%) of ovulatory-size follicles in 210 IU, but not 70 IU, dose heifers displayed eCOCs. The high doses also produced higher proportions of EI or EEI follicles which had lower E:P ratio and/or E but higher P and/or O concentrations compared with the 70 IU dose heifers. In conclusion, excessive cpFSH doses during ovarian stimulation may induce premature luteinization of most ovulatory-size follicles in heifers with small ovarian reserves.

Associations between Maternal Diet, Body Composition and Gut Microbial Ecology in Pregnancy.

Maternal body composition, gestational weight gain (GWG) and diet quality influence offspring obesity risk. While the gut microbiome is thought to play a crucial role, it is understudied in pregnancy. Using a longitudinal pregnancy cohort, maternal anthropometrics, body composition, fecal microbiome and dietary intake were assessed at 12, 24 and 36 weeks of gestation. Fecal samples (n = 101, 98 and 107, at each trimester, respectively) were utilized for microbiome analysis via 16S rRNA amplicon sequencing. Data analysis included alpha- and beta-diversity measures and assessment of compositional changes using MaAsLin2. Correlation analyses of serum metabolic and anthropometric markers were performed against bacterial abundance and predicted functional pathways. α-diversity was unaltered by pregnancy stage or maternal obesity status. Actinobacteria, Lachnospiraceae, Akkermansia, Bifidobacterium, Streptococcus and Anaerotuncus abundances were associated with gestation stage. Maternal obesity status was associated with increased abundance of Lachnospiraceae, Bilophila, Dialister and Roseburia. Maternal BMI, fat mass, triglyceride and insulin levels were positively associated with Bilophila. Correlations of bacterial abundance with diet intake showed that Ruminococcus and Paraprevotella were associated with total fat and unsaturated fatty acid intake, while Collinsella and Anaerostipes were associated with protein intake. While causal relationships remain unclear, collectively, these findings indicate pregnancy- and maternal obesity-dependent interactions between dietary factors and the maternal gut microbiome.

Shared aspects of mRNA expression associated with oocyte maturation failure in humans and rhesus monkeys indicating compromised oocyte quality.

Oocyte maturation failure observed in assisted reproduction technology (ART) cycles can limit the number of quality oocytes obtained and present a pronounced barrier for some patients. The potential exists to use unmatured oocytes for ART through in vitro maturation. Understanding the molecular basis of oocyte maturation failure is pertinent to minimizing this loss of oocytes and considerations of whether such oocytes can be used safely for ART. We identified shared transcriptome abnormalities for rhesus monkey and human failed-to-mature (FTM) oocytes relative to healthy matured MII stage oocytes. We discovered that, although the number of shared affected genes was comparatively small, FTM oocytes in both species shared effects for several pathways and functions, including predicted activation of oxidative phosphorylation (OxPhos) with additional effects on mitochondrial function, lipid metabolism, transcription, nucleotide excision repair, endoplasmic reticulum stress, unfolded protein response, and cell viability. RICTOR emerged as a prominent upstream regulator with predicted inhibition across all analyses. Alterations in KDM5A, MTOR, MTORC1, INSR, CAB39L, and STK11 activities were implicated along with RICTOR in modulating mitochondrial activity and OxPhos. Defects in cell cycle progression were not a prominent feature of FTM oocytes. These results identify a common set of transcriptome abnormalities associated with oocyte maturation failure. While our results do not demonstrate causality, they indicate that fundamental aspects of cellular function are abnormal in FTM oocytes and raise significant concerns about the potential risks of using FTM oocytes for ART.

Listening to mother: Long-term maternal effects in mammalian development.

The oocyte is a complex cell that executes many crucial and unique functions at the start of each life. These functions are fulfilled by a unique collection of macromolecules and other factors, all of which collectively support meiosis, oocyte activation, and embryo development. This review focuses on the effects of oocyte components on developmental processes that occur after the initial stages of embryogenesis. These include long-term effects on genome function, metabolism, lineage allocation, postnatal progeny health, and even subsequent generations. Factors that regulate chromatin structure, genome programming, and mitochondrial function are elements that contribute to these oocyte functions.

Maternal Adiposity is Associated with Fat Mass Accretion in Female but not Male Offspring During the First 2 Years of Life.

OBJECTIVE: This study investigated which antenatal and postnatal factors determine offspring adiposity during the first 2 years of life. METHODS: Participants were mother and child pairs (N = 224). Offspring percent fat mass (%FM) was obtained using quantitative nuclear magnetic resonance at 11 time points between ages 0.5 and 24 months. Independent variables included race, age, gestational weight gain, first-trimester %FM, delivery mode, gestational measures of resting energy expenditure, respiratory exchange ratio, physical activity, serum cytokines and lipids, and dietary intake for the mothers, as well as sex, birth weight and length, breastfeeding duration, and physical activity at age 2 years for the children. Linear mixed models were used to construct the best-fitted models for the entire cohort and for each sex. RESULTS: Maternal %FM (P = 0.006), high-density lipoprotein (HDL) (P < 0.001), and breastfeeding duration (P = 0.023) were positively associated with female offspring adiposity, whereas maternal dietary fiber intake (P = 0.016) had a negative association. Birth weight (P = 0.004), maternal HDL (P = 0.013), and breastfeeding duration (P = 0.015) were all positively associated with male offspring adiposity. CONCLUSIONS: Antenatal and postnatal factors differentially impact male and female offspring adiposity during the first 2 years of life.

Parental adiposity differentially associates with newborn body composition.

BACKGROUND: Maternal obesity increases offspring's obesity risk. However, studies have not often considered maternal metabolic and exercise patterns as well as paternal adiposity as potential covariates. OBJECTIVE: To assess the relationship between parental and newborn adiposity. METHODS: Participants were mother-child pairs (n = 209) and mother-father-offspring triads (n = 136). Parental (during gestation) and offspring (2 weeks old) percent fat mass (FM) were obtained using air displacement plethysmography. Maternal race, age, resting energy expenditure (indirect calorimetry), physical activity (accelerometry), gestational weight gain (GWG), gestational age (GA), delivery mode, infant's sex and infant feeding method were incorporated in multiple linear regression analyses. The association between parental FM and offspring insulin-like growth factor 1 (IGF-1) was assessed at age 2 years. RESULTS: Maternal adiposity was positively-associated with male (ß = 0.11, P = .015) and female (ß = 0.13, P = .008) infant FM, whereas paternal adiposity was negatively-associated with male newborn adiposity (ß = -0.09, P = .014). Breastfeeding, female sex, GA and GWG positively associated with newborn adiposity. Vaginal and C-section delivery methods associated with greater adiposity than vaginal induced delivery method. Plasma IGF-1 of 2-year-old boys and girls positively associated with their respective fathers' and mothers' FM. CONCLUSIONS: Maternal and paternal adiposity differentially associate with newborn adiposity. The mechanisms of this finding remain to be determined.

A New Role for SMCHD1 in Life's Master Switch and Beyond.

Structural maintenance of chromosomes flexible hinge-domain containing protein 1 (SMCHD1) has emerged as a key regulator of embryonic genome function. Its functions have now extended well beyond the initial findings of effects on X chromosome inactivation associated with lethality in female embryos homozygous for a null allele. Autosomal dominant effects impact stem cell properties as well as postnatal health. Recent studies have revealed that SMCHD1 plays an important role as a maternal effect gene that regulates the master switch of life, namely embryonic genome activation, as well as subsequent preimplantation development and term viability. These discoveries mark SMCHD1 as a major regulator linking developmental processes to adult disorders including a form of muscular dystrophy.

SMCHD1 terminates the first embryonic genome activation event in mouse two-cell embryos and contributes to a transcriptionally repressive state.

Embryonic genome activation (EGA) in mammals begins with transient expression of a large group of genes (EGA1). Importantly, entry into and exit from the 2C/EGA state is essential for viability. Dux family member genes play an integral role in EGA1 by activating other EGA marker genes such as Zscan4 family members. We previously reported that structural maintenance of chromosomes flexible hinge domain-containing protein 1 (Smchd1) is expressed at the mRNA and protein levels in mouse oocytes and early embryos and that elimination of Smchd1 expression inhibits inner cell mass formation, blastocyst formation and hatching, and term development. We extend these observations here by showing that siRNA knockdown of Smchd1 in zygotes results in overexpression of Dux and Zscan4 in two-cell embryos, with continued overexpression of Dux at least through the eight-cell stage as well as prolonged expression of Zscan4. These results are consistent with a role for SMCHD1 in promoting exit from the EGA1 state and establishing SMCHD1 as a maternal effect gene and the first chromatin regulatory factor identified with this role. Additionally, bioinformatics analysis reveals that SMCHD1 also contributes to the creation of a transcriptionally repressive state to allow correct gene regulation.

Temporal patterns of gene regulation and upstream regulators contributing to major developmental transitions during Rhesus macaque preimplantation development.

The preimplantation period of life in mammals encompasses a tremendous amount of restructuring and remodeling of the embryonic genome and reprogramming of gene expression. These vast changes support metabolic activation and cellular processes that drive early cleavage divisions and enable the creation of the earliest primitive cell lineages. A major question in mammalian embryology is how such vast, sweeping changes in gene expression are orchestrated, so that changes in gene expression are exactly appropriate to meet the developmental needs of the embryo over time. Using the rhesus macaque as an experimentally tractable model species closely related to the human, we combined high quality RNA-seq libraries, in-depth sequencing and advanced systems analysis to discover the underlying mechanisms that drive major changes in gene regulation during preimplantation development. We identified the major changes in mRNA population and the biological pathways and processes impacted by those changes. Most importantly, we identified 24 key upstream regulators that are themselves modulated during development and that are associated with the regulation of over 1000 downstream genes. Through their roles in extensive gene networks, these 24 upstream regulators are situated to either drive major changes in target gene expression or modify the cellular environment in which other genes function, thereby directing major developmental transitions in the preimplantation embryo. The data presented here highlight some of the specific molecular features that likely drive preimplantation development in a nonhuman primate species and provides an extensive database for novel hypothesis-driven studies.

Obesity leads to distinct metabolomic signatures in follicular fluid of women undergoing in vitro fertilization.

Although obesity negatively influences the metabolic homeostasis of cells within a broad range of tissues, its impact on oocyte metabolism is not fully understood. Prior evidence suggests that obesity increases expression of oocyte genes associated with inflammation, oxidative stress, and lipid metabolism; however, the metabolic impact of these genetic differences is not known. To address this gap, we conducted an exploratory assessment of the follicular fluid (FF) metabolome in eight overweight/obese (OW) and nine normal-weight (NW) women undergoing in vitro fertilization. FF and serum were collected and analyzed by untargeted metabolomics using gas chromatography-quadrupole time-of-flight mass spectrometry and charged-surface hybrid column-electrospray ionization quadrupole time-of-flight tandem mass spectrometry. Untargeted metabolomics identified obesity-associated changes in FF metabolites related to oxidative stress/antioxidant capacity, xenometabolism/amino acid biosynthesis, and lipid metabolism. Discriminant FF metabolites included elevated uric acid, isothreonic acid, one unknown primary metabolite, and six unknown complex lipids in OW compared with NW women. Conversely, 2-ketoglucose dimethylacetal, aminomalonate, two unknown primary metabolites, and two unknown complex lipids were decreased in FF of OW relative to NW women. Indole-3-propionic acid (IPA), a bacteria-derived metabolite, was also decreased in both FF and serum of OW women ( P < 0.05). The significant correlation between antioxidant IPA in serum and FF ( R = 0.95, P < 0.0001) suggests a potential serum biomarker of FF antioxidant status or reflection of the gut metabolism interaction with the follicle. These results suggest that obesity has important consequences for the follicular environment during the preconception period, a window of time that may be important for lifestyle interventions to ameliorate obesity-associated risk factors.

Transcriptome analysis of rhesus monkey failed-to-mature oocytes: deficiencies in transcriptional regulation and cytoplasmic maturation of the oocyte mRNA population.

STUDY QUESTION: Which different pathways and functions are altered in rhesus monkey oocytes that fail to mature after an ovulatory stimulus? SUMMARY ANSWER: Failed to mature (FTM) oocytes complete a large portion of the transition in transcriptome composition associated with normal maturation, but also manifest numerous differences that indicate incomplete transcriptional repression and cytoplasmic maturation affecting multiple processes. WHAT IS KNOWN ALREADY: Oocyte maturation defects contribute to unexplained female infertility. Failure of some oocytes to undergo germinal vesicle breakdown or progress to second meiotic metaphase in response to an ovulatory stimulus can limit the number of high quality oocytes available for ART. STUDY DESIGN, SIZE, DURATION: The transcriptome of rhesus monkey oocytes that failed to mature (FTM; n = 11, 5 donors) in response to an ovulatory stimulus in vivo was compared to those of normal germinal vesicle stage (GV, n = 7, 2 donors) and metaphase II stage (MII, n = 7, 5 donors) oocytes by RNA-sequencing (RNAseq). PARTICIPANTS/MATERIALS, SETTING, METHODS: Female rhesus monkeys of normal breeding age (6-12 years old) and with regular menstrual cycles were used. Animals underwent a controlled ovarian stimulation protocol for the collection of oocytes by ultrasound-guided needle aspiration of follicles. MAIN RESULTS AND THE ROLE OF CHANCE: We obtained a high quality RNAseq dataset consisting of n = 7, n = 7, and n = 11 libraries for normal GV, normal MII and FTM oocytes, respectively. Total reads acquired were an average of 34 million for each GV sample, 41 million for each FTM sample and 59 million for each MII oocyte sample. Approximately 44% of the total reads were exonic reads that successfully aligned to the rhesus monkey genome as unique non-rRNA gene transcript sequences, providing high depth of coverage. Approximately 44% of the mRNAs that undergo changes in abundance during normal maturation display partial modulations to intermediate abundances, and 9.2% fail to diverge significantly from GV stage oocytes. Additionally, a small group of mRNAs are grossly mis-regulated in the FTM oocyte. Differential expression was seen for mRNAs associated with mitochondrial functions, fatty acid beta oxidation, lipid accumulation, meiosis, zona pellucida formation, Hippo pathway signaling, and maternal mRNA regulation. A deficiency DNA methyltransferase one mRNA expression indicates a potential defect in transcriptional silencing. LARGE SCALE DATA: All RNAseq data are published in the Gene Expression Omnibus Database (GSE112536). LIMITATIONS, REASONS FOR CAUTION: These results do not establish cause of maturation failure but reveal novel correlates of incompetence to mature. Transcriptome studies likely do not capture all post-transcriptional or post-translational events that inhibit maturation, but do reveal mRNA expression changes that lie downstream of such events or that are related to effects on upstream regulators. The use of an animal model allows the study of oocyte maturation failure independent of covariates and confounders, such as pre-existing conditions of the female, which is a significant concern in human studies. Depending on the legislation, it may not be possible to collect and study oocytes from healthy women; and using surplus oocytes from patients undergoing ART may introduce confounders that vary from case to case. FTM oocytes were at various stages of meiotic progression, so correlates of specific times of arrest are not revealed. All the FTM oocytes failed to respond appropriately to an ovulatory stimulus in vivo. Therefore, this analysis informs us about common transcriptome features associated with meiotic incompetence. WIDER IMPLICATIONS OF THE FINDINGS: These results reveal that some diagnostic markers of oocyte quality may not reflect developmental competence because even meiotically incompetent oocytes display many normal gene expression features. The results also reveal potential mechanisms by which maternal and environmental factors may impact transcriptional repression and cytoplasmic maturation, and prevent oocyte maturation. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by grants from the National Institutes of Health Office of Research Infrastructure Programs Division of Comparative Medicine Grants R24 [OD012221 to K.E.L., OD011107/RR00169 (California National Primate Research Center), and OD010967/RR025880 to C.A.V.]; the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health under the award number T32HD087166; MSU AgBioResearch, Michigan State University. Authors have nothing to disclose.

Obesity Modulates Inflammation and Lipid Metabolism Oocyte Gene Expression: A Single-Cell Transcriptome Perspective.

Context: It is hypothesized that obesity adversely affects the ovarian environment, which can disrupt oocyte maturation and embryonic development. Objective: This study aimed to compare oocyte gene expression profiles and follicular fluid (FF) content from overweight/obese (OW) women and normal-weight (NW) women who were undergoing fertility treatments. Design: Using single-cell transcriptomic analyses, we investigated oocyte gene expression using RNA sequencing. Patients or Other Participants: Eleven OW women and 13 NW women undergoing fertility treatments were enrolled. Main Outcome Measures: Oocyte messenger RNA profiles as well as serum and FF hormone and lipid levels were assessed. Results: OW women had significantly higher body mass index, body fat percentage, and serum homeostatic model assessment-insulin resistance index compared with NW women (P < 0.01). Serum leptin and C-reactive protein (CRP) levels as well as FF leptin, CRP, and triglyceride levels were increased (P < 0.05) in OW compared with NW women. Oocytes from OW women had increased expression of proinflammatory (CXCL2; P = 0.071) and oxidative stress-related (DUSP1; P = 0.051) genes but had decreased expression of GAS7 (fat metabolism; P = 0.065), TXNIP (oxidative stress; P = 0.055), and transcription factors ID3 (P = 0.075) and TWIST1 (P = 0.099) compared with NW women. Conclusions: These findings provide evidence for the significant influence of body composition on oocyte transcript abundance in women undergoing hormonal induction to retrieve oocytes. They further identify the potential for maternal diet to influence oocyte gene expression. The preconception period is, therefore, an important window of opportunity to consider for lifestyle interventions.

Hepatic steatosis development with four weeks of physical inactivity in previously active, hyperphagic OLETF rats.

Physical activity-induced prevention of hepatic steatosis is maintained during short-term (7-day) transitions to an inactive state; however, whether these protective effects are present under a longer duration of physical inactivity is largely unknown. Here, we sought to determine whether previous physical activity had protective effects on hepatic steatosis and metabolic health following 4 wk of physical inactivity. Four-week old, hyperphagic, male Otsuka Long-Evans Tokushima fatty (OLETF) rats were randomly assigned to either a sedentary group for 16 wk (OLETF-SED), given access to running wheels for 16 wk with wheels locked 5 h (OLETF-WL5hr) or given access to running wheels for 12 wk with wheels locked 4 wk (OLETF-WL4wk) prior to death. Four weeks of physical inactivity caused hepatic steatosis development, but liver triglycerides remained 60% lower than OLETF-SED (P < 0.01), and this was associated with only a partial loss in activity-induced improvements in body composition, serum lipids, and glycemic control. Total hepatic mitochondrial palmitate oxidation, citrate synthase, and ß-HAD activity returned to SED levels following 4 wk of inactivity, whereas markers of fatty acid uptake and lipogenesis remained relatively suppressed following 4 wk of inactivity. In addition, 4 wk of inactivity caused a complete loss of activity-induced increases in serum IL-6 and reductions in regulated upon activation, normal T-cell expressed, and secreted (RANTES), and a partial loss in reductions in leptin, monocyte chemoattractant protein-1, and TNF-α. In conclusion, 4 wk of physical inactivity does not result in a complete loss in physical activity-induced benefits but does cause deterioration in the liver phenotype and overall metabolic health in hyperphagic OLETF rats.