Maternal Deposition Research Articles

Evolution of maternal and zygotic mRNA complements in the early Drosophila embryo

The earliest stages of animal development are controlled by maternally deposited mRNA transcripts and proteins. Once the zygote is able to transcribe its own genome, maternal transcripts are degraded, in a tightly regulated process known as the maternal to zygotic transition (MZT). While this process has been well-studied within model species, we have little knowledge of how the pools of maternal and zygotic transcripts evolve. To characterize the evolutionary dynamics and functional constraints on early embryonic expression, we created a transcriptomic dataset for 14 Drosophila species spanning over 50 million years of evolution, at developmental stages before and after the MZT, and compared our results with a previously published Aedes aegypti developmental time course. We found deep conservation over 250 million years of a core set of genes transcribed only by the zygote. This select group is highly enriched in transcription factors that play critical roles in early development. However, we also identify a surprisingly high level of change in the transcripts represented at both stages over the phylogeny. While mRNA levels of genes with maternally deposited transcripts are more highly conserved than zygotic genes, those maternal transcripts that are completely degraded at the MZT vary dramatically between species. We also show that hundreds of genes have different isoform usage between the maternal and zygotic genomes. Our work suggests that maternal transcript deposition and early zygotic transcription are remarkably dynamic over evolutionary time, despite the widespread conservation of early developmental processes.

Maternal mRNA input of growth and stress-response-related genes in cichlids in relation to egg size and trophic specialization

BackgroundEgg size represents an important form of maternal effect determined by a complex interplay of long-term adaptation and short-term plasticity balancing egg size with brood size. Haplochromine cichlids are maternal mouthbrooders showing differential parental investment in different species, manifested in great variation in egg size, brood size and duration of maternal care. Little is known about maternally determined molecular characters of eggs in fishes and their relation to egg size and trophic specialization. Here we investigate maternal mRNA inputs of selected growth- and stress-related genes in eggs of mouthbrooding cichlid fishes adapted to different trophic niches from Lake Tanganyika, Lake Malawi, Lake Victoria and compare them to their riverine allies.ResultsWe first identified two reference genes, atf7ip and mid1ip1, to be suitable for cross-species quantification of mRNA abundance via qRT-PCR in the cichlid eggs. Using these reference genes, we found substantial variation in maternal mRNA input for a set of candidate genes related to growth and stress response across species and lakes. We observed negative correlation of mRNA abundance between two of growth hormone receptor paralogs (ghr1 and ghr2) across all haplochromine cichlid species which also differentiate the species in the two younger lakes, Malawi and Lake Victoria, from those in Lake Tanganyika and ancestral riverine species. Furthermore, we found correlations between egg size and maternal mRNA abundance of two growth-related genes igf2 and ghr2 across the haplochromine cichlids as well as distinct clustering of the species based on their trophic specialization using maternal mRNA abundance of five genes (ghr1, ghr2, igf2, gr and sgk1).ConclusionsThese findings indicate that variations in egg size in closely related cichlid species can be linked to differences in maternal RNA deposition of key growth-related genes. In addition, the cichlid species with contrasting trophic specialization deposit different levels of maternal mRNAs in their eggs for particular growth-related genes; however, it is unclear whether such differences contribute to differential morphogenesis at later stages of development. Our results provide first insights into this aspect of gene activation, as a basis for future studies targeting their role during ecomorphological specialization and adaptive radiation.

Social density, but not sex ratio, drives ecdysteroid hormone provisioning to eggs by female house crickets (Acheta domesticus).

Social environment profoundly influences the fitness of animals, affecting their probability of survival to adulthood, longevity, and reproductive output. The social conditions experienced by parents at the time of reproduction can predict the social environments that offspring will face. Despite clear challenges in predicting future environmental conditions, adaptive maternal effects provide a mechanism of passing environmental information from parent to offspring and are now considered pervasive in natural systems. Maternal effects have been widely studied in vertebrates, especially in the context of social environment, and are often mediated by steroid hormone (SH) deposition to eggs. In insects, although many species dramatically alter phenotype and life‐history traits in response to social density, the mechanisms of these alterations, and the role of hormone deposition by insect mothers into their eggs, remains unknown. In the experiments described here, we assess the effects of social environment on maternal hormone deposition to eggs in house crickets (Acheta domesticus). Specifically, we tested the hypotheses that variable deposition of ecdysteroid hormones (ESH) to eggs is affected by both maternal (a) social density and (b) social composition. We found that while maternal hormone deposition to eggs does not respond to social composition (sex ratio), it does reflect social density; females provision their eggs with higher ESH doses under low‐density conditions. This finding is consistent with the interpretation that variable ESH provisioning is an adaptive maternal response to social environment and congruent with similar patterns of variable maternal provisioning across the tree of life. Moreover, our results confirm that maternal hormone provisioning may mediate delayed density dependence by introducing a time lag in the response of offspring phenotype to population size.

Estimated energy requirements increase across pregnancy in healthy women with dichorionic twins

Estimated energy requirement (EER) has not been defined for twin pregnancy. This study was designed to determine the EER of healthy women with dichorionic-diamniotic (DCDA) twin pregnancies. We aimed to estimate energy deposition from changes in maternal body protein and fat; to measure resting energy expenditure (REE), physical activity level (PAL), and total energy expenditure (TEE) throughout pregnancy and postpartum; and to define the EER based on the sum of TEE and energy deposition for twin gestation. This is a prospective study of 20 women with DCDA twin gestations. Maternal EER, energy deposition, REE, TEE, and PAL were obtained during the first, second, and third trimesters of pregnancy and immediately postpartum. A mixed-effects linear regression model for repeated measures with random intercept was used to test for the effects of BMI groups and time. Gains in total body protein (mean±SD: 2.1±0.7 kg) and fat mass (5.9±2.8 kg) resulted in total energy deposition of 67,042±25,586 kcal between 0 and 30-32 weeks of gestation. REE increased 26% from 1392±162 to 1752±172 kcal/d across the 3 trimesters, whereas TEE increased 17% from 2141±283 to 2515±337 kcal/d. Physical activity decreased steadily throughout pregnancy. Reductions in physical activity did not compensate for the rise in REE and energy deposition, thus requiring an increase in dietary energy intake as pregnancy progressed. EER increased 29% from 2257±325 kcal/d in the first trimester to 2941±407 kcal/d in the second trimester, and stayed consistent at 2906±350 kcal/d in the third trimester. Increased energy intake, on average ∼700 kcal/d in the second and third trimesters when compared with the first trimester, is required to support gestational weight gain and the rise in energy expenditure of DCDA twin pregnancies.

A new method for measuring thyroid hormones using nano-LC-MS/MS

This paper describes a novel mass spectrometry based analytical method for analyzing thyroid hormones (THs). Thyroid hormones play a critical role in the regulation of many biological processes such as growth, metabolism and development. Several analytical methods using liquid chromatography-mass spectrometry (LC–MS) and tandem mass spectrometry (LC–MS/MS) have previously been developed to measure THs, especially in humans. For biomedical and toxicological research using small animal models, and in ecophysiological research using wild species where sample volume is limiting, sensitive methods are needed. In this study, we developed a nano-LC-MS/MS method enabling quantification of low concentrations of two key THs, thyroxine (T4) and 3,3′,5-triiodothyronine (T3). The method was tested with egg yolk samples. We used a low flow rate (300 nl/min) to obtain maximal sensitivity of the method. The limit of quantitation was 10.6 amol for T4 and 17.9 amol for T3. The method shows good linearity (r > 0.99), repeatability and reproducibility (CVs <10%). We also reanalyzed yolk samples with radioimmunoassay for a comparison of the newly developed and previously used methods. Finally, we applied the methodology to measure hormones in egg yolk extracts in multiple avian species, and report interesting variation in maternal TH deposition. The newly developed nano-LC-MS/MS method is thus suitable for measuring THs in low concentrations and across species.

Partitioning components of maternal growth to determine efficiency of feed use in gestating sows.

The objective of this study was to evaluate the effect of parity and stage of gestation on predicted maternal weight gain and efficiency of feed use in gestating sows from a commercial sow farm. A total of 712 females (Camborough, PIC, Hendersonville, TN) were group-housed from days 5 to 112 of gestation and individually fed with electronic sow feeders (ESF). Feed intake and body weight (BW) were recorded daily throughout gestation via the ESF and a scale located in an alleyway just after sows exited the feeding station. Gilts (parity 1) and sows received 6,450 or 7,418 kcal ME, respectively, whereas 12 thin females received 9,675 kcal ME per day. Maternal weight gain, not including products of conceptus, and feed efficiency were predicted using a series of equations to model nutrient utilization in gestation. Data were divided into 3 parity groups: 1, 2, and 3+, and gestation was divided into 3 periods: days 5 to 39, 40 to 74, and 75 to 109. After dividing energy requirements into tissue pools for maintenance, growth (maternal protein and fat deposition), and products of conceptus, the greatest portion of the energy requirement was for maintenance and maternal growth. The predicted energy used for maternal protein and fat deposition decreased (P < 0.05) in each period of gestation, regardless of parity group. Parity 2 sows had the greatest (P < 0.05) energy use for maternal protein and fat deposition in all stages of gestation, whereas parity 1 sows had a negative energy balance during the final stage of gestation. Parity 1 sow BW increased (P < 0.05) in each period of gestation; however, parity 2 and 3+ sow BW remained static from days 75 to 109 of gestation. Parity 3+ sows had the greatest (P < 0.05) maternal BW throughout the course of gestation compared with other parity groups. Regardless of parity, maternal ADG decreased (P < 0.05) from days 40 to 74 before increasing (P < 0.05) during the final stage of gestation. Parity 1 sows had the greatest (P < 0.05) ADG in all gestation periods. Parity 1 sow G:F decreased (P < 0.05) in each sequential period of gestation. Parity 2 and 3+ sow G:F decreased (P < 0.05) from days 40 to 74 but improved (P < 0.05) during the final period of gestation. Parity 1 sow G:F was greater than parity 2 and 3+ sows in most gestation periods. Overall, this study and subsequent prediction models show how stage of gestation and parity affect the growth of different tissue pools, sow maternal BW, and feed usage throughout the course of gestation.

Effect of Larval Nutrition on Maternal mRNA Contribution to the Drosophila Egg.

Embryonic development begins under the control of maternal gene products, mRNAs and proteins that the mother deposits into the egg; the zygotic genome is activated some time later. Maternal control of early development is conserved across metazoans. Gene products contributed by mothers are critical to many early developmental processes, and set up trajectories for the rest of development. Maternal deposition of these factors is an often-overlooked aspect of parental investment. If the mother experiences challenging environmental conditions, such as poor nutrition, previous studies in Drosophila melanogaster have demonstrated a plastic response wherein these mothers may produce larger eggs to buffer the offspring against the same difficult environment. This additional investment can produce offspring that are more fit in the challenging environment. With this study, we ask whether D. melanogaster mothers who experience poor nutrition during their own development change their gene product contribution to the egg. We perform mRNA-Seq on eggs at a stage where all mRNAs are maternally derived, from mothers with different degrees of nutritional limitation. We find that nutritional limitation produces similar transcript changes at all degrees of limitation tested. Genes that have lower transcript abundance in nutritionally limited mothers are those involved in translation, which is likely one of the most energetically costly processes occurring in the early embryo. We find an increase in transcripts for transport and localization of macromolecules, and for the electron transport chain. The eggs produced by nutrition-limited mothers show a plastic response in mRNA deposition, which may better prepare the future embryo for development in a nutrition-limited environment.

Effects of Plasmodium falciparum on Placental Expression of Inflammatory and Coagulation Factors

Plasmodium falciparum infection during pregnancy, which can develop into placental malaria (PM), is estimated to cause over 200,000 infant deaths annually. PM is characterized by sequestration of parasite infected red blood cells (iRBCs) and deposition of hemozoin (HZ) in the maternal blood (intervillous) space of the placenta. HZ is an insoluble, iron‐containing by‐product of the parasite's digestion of hemoglobin. Additionally, accumulation of maternal immune cells and excessive deposition of fibrin are seen in the intervillous space. The role of the syncytiotrophoblast (ST), the outermost cell layer of the placenta, during PM pathogenesis remains unclear. It is hypothesized that the ST responds to iRBCs, HZ, and inflammatory cytokines like tumor necrosis factor (TNF) produced by maternal immune cells to attenuate infection. However, it is ultimately harmed by its own response. Mechanistically, it is predicted that TNF leads to activation of tissue factor (TF), the initiator of the extrinsic coagulation pathway, which ultimately results in fibrin deposition. In addition to TNF, HZ released from iRBCs may also upregulate TF. Downstream coagulation factors activate protease activated receptors (PARs), which are G‐protein coupled receptors highly expressed on the ST. Activated PARs increase expression of TNF, propagating what is known as “the inflammation‐coagulation cycle”. The cycle's propagation adversely affects nutrient and gas exchange between the maternal blood and the ST, resulting in growth restriction, low birth weight, and occasionally death of the fetus. Using a human choriocarcinoma cell line, BeWo, and isolated human trophoblast cells, in vivo host (ST)‐parasite interactions are simulated. BeWos and human trophoblasts are left unstimulated or stimulated over a physiologically relevant time‐course with (1) lipopolysaccharide (LPS; positive control), (2) natural HZ, (3) TNF, or (4) natural HZ/TNF. RNA isolation is followed by cDNA generation and qPCR for TF, PAR‐1, and PAR‐2. Results indicate that BeWos respond to LPS and HZ with a modest upregulation of TF and PAR‐1 between 2 to 4 hours. Response to TNF occurs at 2 hours with a modest upregulation of TF. Gene expression of PAR‐2 was not found to be significant over the time‐course. qPCR results with cDNA generated from time‐course experiments using human trophoblast cells are forthcoming. Identifying the extent to which the ST is involved in PM pathogenesis will advanced the understanding of how this syndrome impacts fetal development and outcome.Support or Funding InformationThis work is supported by National Institutes of Health grant 1R21AI111242 to Dr. Julie M. Moore.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Maternal and fetal genetic contribution to gestational weight gain

Background:Clinical recommendations to limit gestational weight gain (GWG) imply high GWG is causally related to adverse outcomes in mother or offspring, but GWG is the sum of several inter-related complex phenotypes (maternal fat deposition and vascular expansion, placenta, amniotic fluid and fetal growth). Understanding the genetic contribution to GWG could help clarify the potential effect of its different components on maternal and offspring health. Here we explore the genetic contribution to total, early and late GWG.Participants and methods:A genome-wide association study was used to identify maternal and fetal variants contributing to GWG in up to 10 543 mothers and 16 317 offspring of European origin, with replication in 10 660 mothers and 7561 offspring. Additional analyses determined the proportion of variability in GWG from maternal and fetal common genetic variants and the overlap of established genome-wide significant variants for phenotypes relevant to GWG (for example, maternal body mass index (BMI) and glucose, birth weight).Results:Approximately 20% of the variability in GWG was tagged by common maternal genetic variants, and the fetal genome made a surprisingly minor contribution to explain variation in GWG. Variants near the pregnancy-specific beta-1 glycoprotein 5 (PSG5) gene reached genome-wide significance (P=1.71 × 10−8) for total GWG in the offspring genome, but did not replicate. Some established variants associated with increased BMI, fasting glucose and type 2 diabetes were associated with lower early, and higher later GWG. Maternal variants related to higher systolic blood pressure were related to lower late GWG. Established maternal and fetal birth weight variants were largely unrelated to GWG.Conclusions:We found a modest contribution of maternal common variants to GWG and some overlap of maternal BMI, glucose and type 2 diabetes variants with GWG. These findings suggest that associations between GWG and later offspring/maternal outcomes may be due to the relationship of maternal BMI and diabetes with GWG.

Zoning of the Bazhenov suite and clinoforms of Neocomian according to the density resources of shale and primaryly-accumulated oil (Nurol megadepression as an example)

Complex representation of the methodology, of search criteria and basis for the use of data of Geothermal technology for solution of the problem of forecasting oil and gas potential has been given. The technology is based on the method paleotemperature modeling, allowing to reconstruct the thermal history of maternal deposits and allocate geothermal criteria and mapping the source of oils generation. The resource estimate is determined by an integral indicator, which is directly dependent on the time of maternal suite location in the main zone of oil generation and on geo-temperature of the zone. Perspective areas and plots for search of the shale (accumulated in situ) Bazhenov oil and of primaryly accumulated oil of terrigenous Achimov Neocomian reservoir Nurol megadepression (Western Siberia) have been identified. Consistency of zoning has been argued by the oil shows and flows of oil in deep wells of the intervals of the parent rocks and clastic reservoirs Shale resource potential of the Bazhenov Formation and difficult-to-determine resources of Neocomian are the subject to priority economic development in accordance with the new strategy of development of hydrocarbon resource base of the Russian Federation.

Speckled and plain regions of avian eggshells differ in maternal deposition of calcium and metals: A hitherto overlooked chemical aspect of egg maculation

ABSTRACT Although it has been strongly implied that studies on structural function might resolve certain conflicting theories regarding the huge variability of coloration in avian eggs, including maculation, the fundamental physiological question about the functional role of eggshell speckling in the maternal deposition of micronutrients into maculated (pigment spots) and plain (unpigmented) eggshell regions remains largely unanswered. We measured (within the same egg) the concentrations of 2 micronutrients, the staple components of avian eggshells (calcium and magnesium), and 6 trace elements (copper, manganese, iron, cobalt, cadmium, and lead) in maculated (a superficial layer of brown pigment) and unpigmented areas of eggshells in 2 groups of Japanese Quail (Coturnix coturnix japonica) eggs representing 2 extremes of eggshell coloration: those with darker eggshells and more extensive pigment spots vs. those with bright eggshells and small, more clearly demarcated pigment spots. We found evidence that t...

Gene Disruption of Zebrafish Sbds Phenocopies Human Shwachman-Diamond Syndrome but Suggests More Global and Lineage Defects

Introduction: Shwachman-Diamond Syndrome (SDS) is a complex disorder resulting in short stature, neutropenia, bony dysplasia, and pancreatic malabsorption. Individuals with SDS are also at increased risk for developing myelodysplastic syndrome and/or acute myeloid leukemia (AML). Its estimated incidence of 1 in 77,000 births makes SDS difficult to study and develop newer therapies. SDS results from mutations in the SBDS gene. Genetic ablation of Sbds results in early embryonic lethality (ED 7.5) in mice. Zebrafish provide an attractive, alternative model organism to study human diseases. Genome analysis of zebrafish (Danio rerio) revealed the presence of a single sbds gene, encoding a protein 90% identical to the human orthologue.Methods: We used CRISPR/Cas9 genome editing technique to generate indel mutations in sbds andestablished multiple zebrafish lines. We used zebrafish sbds mutants to analyze the function of this gene during vertebrate development and in the pathophysiology of SDS.Results: Western blotting showed progressive decrease of Sbds expression with no detectable protein at 8 days post fertilization (dpf). These results suggest that the presence of Sbds during early stages of the development is due to maternal deposition, which was confirmed by qPCR and immunoblot demonstration of sbds transcript and proteins in in all stages of the development including the 1 cell-stage. Unlike Sbds-/- mice, homozygous mutant sbdsnu132live up to 6 weeks. They display marked growth retardation. We also observed a significantly low number of neutrophils at 5 dpf and 15 dpf. No differences were found in macrophages and hemoglobinization. Interestingly, multiple organs, especially the pancreas, liver, digestive tract and eye showed histologic evidence of atrophy at 21 dpf. Differences were also observed in fat deposition and bone formation. These defects were not seen at 15 dpf, suggesting a critical stage in development dependent on functional sbds.Conclusions: To our knowledge, we established the first zebrafish model of SDS, making it a highly relevant model to investigate its pathophysiology and develop new small molecule therapies. Comparison of null states between mice and zebrafish suggest that loss of Sbds results in two phenotypes: an early embryonic stage required for viability and development and a post-embryonic (larval) stage critical for granulocyte production and normal size. Data will be presented on bone formation, neutrophil chemotaxis, metabolomics, and RNAseq in the zebrafish model.This work was supported by grants from the NIH R21CA15920, Shwachman-Diamond Syndrome Foundation and the Alex Turnquist Memorial Research fund of Shwachman-Diamond America. DisclosuresNo relevant conflicts of interest to declare.

МОРФОЛОГІЧНІ ОСОБЛИВОСТІ ПЛАЦЕНТИ ПРИ БАГАТОПЛІДНІЙ ВАГІТНОСТІ.

Проведено клініко-імунологічне дослідження послідів жінок з багатоплідною вагітністю, відзначено наявність морфофункціональних, імунопатологічних змін різного ступеня вираженості. Доведено, що у жінок з невиношуванням вагітності при багатоплідності ступінь фетоплацентарної недостатності залежить від кровопостачання плаценти і характеру запальних проявів. Вивчено морфологічну картину плацентарних порушень при невиношуванні вагітності. Виявлено, що морфологічними ознаками фетоплацентарної недостатності при неінфекційних факторах невиношування вагітності є: ранні зміни в судинах децидуальної оболонки у вигляді спазму, облітерації просвіту спіральних артерій, зменшення обсягу судинного русла ворсинчастого дерева, зменшення обсягу хоріонального епітелію і периферичного трофобласта, збільшення відкладень материнського і плодового фібриноїду. Проведені дослідження дозволяють сформувати чітку концепцію патогенетично обґрунтованої терапії пренатальних ускладнень, що виникають при багатоплідній вагітності.

Clinical observation study of Chinese massage combined with low-frequency pulse electrical stimulation therapy in treatment of milk siltation breasts

Objective To observe the traditional Chinese medicine massage in breasts joint French PHENIX-USB4 neuromuscular stimulation electrical stimulation therapy treatment of postpartum milk siltation, and provide the basis for clinical. Methods 120 patients with a diagnosis of milk deposition were selected according to random number table method, who were divided into control group and observation group, with 60 cases in each group.The patients in the control group were administrated with the traditional hot compress and breast massage technique treatment, and the patients in the observation group were administrated with low frequency pulse electrical stimulation treatment based on that in the control group, the clinical efficacy of the two groups were compared. Results The therapy efficacy rate of the observation group was 100.0%, which was significantly higher than 80.0%of control group(χ2=16.51, P 0.78). The case of mild pain in the observation group was significantly more than that in the control group (χ2=40.98, P<0.05). The cases of moderate pain and severe pain in the observation group were significantly less than those in the control group (χ2=4.48, 10.21, all P<0.05); After treatment of milk deposition for 1 day, 2 days and 3 days, the milk siltation in the observation group were significantly lighter than those in the control group (χ2=31.58, 23.52, 37.33, all P<0.05). Conclusion Breast massage of traditional Chinese medicine combined with low-frequency pulse electrical stimulation of acupuncture treatment of postpartum maternal milk deposition has the very good curative effect, the treatment is relatively simple, which is easy to operate, safe, noninvasive, relatively low incidence of adverse reactions, it can enhance the confidence of breastfeeding, and is worth of clinical promotion. Key words: Low frequency pulsed electrical stimulation; Points; Analgesia; TCM massage; Milk siltation

Non-Mendelian Dominant Maternal Effects Caused by CRISPR/Cas9 Transgenic Components in Drosophila melanogaster.

The CRISPR/Cas9 system has revolutionized genomic editing. The Cas9 endonuclease targets DNA via an experimentally determined guide RNA (gRNA). This results in a double-strand break at the target site . We generated transgenic Drosophila melanogaster in which the CRISPR/Cas9 system was used to target a GAL4 transgene in vivo. To our surprise, progeny whose genomes did not contain CRISPR/Cas9 components were still capable of mutating GAL4 sequences. We demonstrate this effect was caused by maternal deposition of Cas9 and gRNAs into the embryo, leading to extensive GAL4 mutations in both somatic and germline tissues. This serves as a cautionary observation on the effects of maternal contributions when conducting experiments using genomically encoded CRISPR/Cas9 components. These results also highlight a mode of artificial inheritance in which maternal contributions of DNA editing components lead to transmissible mutant defects even in animals whose genomes lack the editing components. We suggest calling this a dominant maternal effect to reflect it is caused by the gain of maternally contributed products. Models of CRISPR-mediated gene drive will need to incorporate dominant maternal effects in order to accurately predict the efficiency and dynamics of gene drive in a population.

Influences of Neo-Pleistocene permafrost on thermal history of petromaternal Lower Jurassic Togur suite (Tomsk region)

Based on paleotemperature modeling, evaluation of Neo-Pleistocene permafrost rock thickness impact on geothermal regime of the petromaternal Togur deposits has been performed within the territory of oil fields of the Tomsk region (the southeast of Western Siberia). It has been stated that paleopermafrost with the thickness of about 300 m must be considered for appropriate reconstruction of geothermal history of petromaternal rocks in the south-east areas of West Siberia. This condition is relevant to a consistent consideration of thermal history of maternal deposits in course of assessment of resources by a volumetric- genetic method.

The Effect of Early Excessive Weight Gain on the Development of Hypertension in Pregnancy.

Background Previous studies have shown an association between total excessive gestational weight gain and hypertension in pregnancy. However, this may be a reflection of excessive water retention associated with the pathophysiology of hypertensive disorders of pregnancy. Early excessive weight gain, prior to the third trimester, results in greater maternal fat deposition and inflammation, which has also been associated with the development of hypertension. By focusing on early excessive weight gain, the association between maternal weight gain and the future development of hypertension can be examined. Objective To evaluate the association between early excessive maternal weight gain and the development of hypertension during pregnancy. Study Design This was a secondary analysis of a longitudinal cohort study of 1,441 women without chronic hypertension who were enrolled in a prospective study evaluating maternal angiogenic factors and the prediction of preeclampsia. Initial body mass index (BMI) was calculated by weight and height at the first study visit. Early excessive maternal weight gain was defined as weight gain by 28 weeks that exceeded the Institute of Medicine (IOM) guidelines and was calculated utilizing the maximum amount of weight gain per week recommended by the IOM based on the patient's starting BMI (normal: 0.45 kg; overweight: 0.32 kg; obese: 0.27 kg). Hypertension was defined as a sustained systolic blood pressure of ≥140 mm Hg or a diastolic blood pressure of ≥90 mm Hg. Logistic regression was used to determine the association between early excessive weight gain, initial BMI, and the development of hypertension, including gestational hypertension and preeclampsia, during pregnancy. Results Of 1,441 women, 767 (53.2%) had weight gain that exceeded the IOM guidelines in the first 28 weeks and 154 (10.8%) developed hypertension during pregnancy. Women whose weight gain exceeded the IOM guidelines were more likely to develop hypertension even after adjusting for relevant confounders (12.5 vs. 8.6%; p = 0.02; adjusted odds ratio [OR] = 1.70; 95% confidence interval [CI]: 1.18-2.44; p < 0.01). Obese women had a 2.4-fold increased risk of developing hypertension, even after controlling for excessive weight gain (adjusted OR = 2.44; 95% CI: 1.66-3.59; p < 0.01) Conclusions Early excessive maternal weight gain and initial BMI are independently associated with the diagnosis of a hypertensive disorder of pregnancy. Women should be counseled regarding the benefits of achieving a normal BMI prior to pregnancy and appropriate weight gain during pregnancy, as well as the potential harms of excessive weight gain related to perinatal outcomes.

Maternal corticosterone deposition in avian yolk: Influence of laying order and group size in a joint-nesting, cooperatively breeding species

Glucocorticoid hormones play a key role in day-to-day adjustments to fluctuating metabolic needs. These hormones also mediate physiological and behavioral responses to stressful events, allowing individuals to cope with stressors. Various environmental insults, such as a food shortages, predation attempts, and agonistic encounters often elevate plasma glucocorticoid levels in vertebrates. Because exposure to maternally-derived (via circulation or egg) glucocorticoids may be detrimental to the developing embryo, maternal stress can have negative carryover effects on offspring fitness. We examined corticosterone, the primary avian glucocorticoid, concentrations in egg yolk in a plural-breeding, joint-nesting species, the smooth-billed ani (Crotophaga ani), in which females compete among themselves to lay eggs in the final incubated clutch. We investigated whether yolk corticosterone levels varied with laying order and group size. Because egg-laying competition leads to physiological and social stress that is intensified with group size and laying order, we predicted that yolk corticosterone levels should increase from the early to the late egg-laying period and from single female to multi-female groups. In this two-year field study, we found that yolk corticosterone levels of late-laid eggs within the communal clutch were higher in multi-female groups than in single female groups. Results from this study suggest that laying females experience higher levels of stress in multi-female groups and that this maternal stress influences yolk corticosterone concentrations. This study identifies a novel cost of group-living in plural-breeding cooperatively breeding birds, namely an increase in yolk corticosterone levels with group size that may result in detrimental effects on offspring development.

Impacts of prenatal nanomaterial exposure on male adult Sprague-Dawley rat behavior and cognition

ABSTRACTIt is generally accepted that gestational xenobiotic exposures result in systemic consequences in the adult F1 generation. However, data on detailed behavioral and cognitive consequences remain limited. Using our whole-body nanoparticle inhalation facility, pregnant Sprague-Dawley rats (gestational day [GD] 7) were exposed 4 d/wk to either filtered air (control) or nano-titanium dioxide aerosols (nano-TiO2; count median aerodynamic diameter of 170.9 ± 6.4 nm, 10.4 ± 0.4 mg/m3, 5 h/d) for 7.8 ± 0.5 d of the remaining gestational period. All rats received their final exposure on GD 20 prior to delivery. The calculated daily maternal deposition was 13.9 ± 0.5 µg. Subsequently, at 5 mo of age, behavior and cognitive functions of these pups were evaluated employing a standard battery of locomotion, learning, and anxiety tests. These assessments revealed significant working impairments, especially under maximal mnemonic challenge, and possible deficits in initial motivation in male F1 adults. Evidence indicates that maternal engineered nanomaterial exposure during gestation produces psychological deficits that persist into adulthood in male rats.

Mineral metabolism of pregnant goats under feed restriction

We examined the effects of feed restriction on calcium, phosphorus, magnesium, sodium and potassium metabolism in Oberhasli and Saanen goats during gestation. The 63 goats were distributed into groups that were divided into three levels of feed restriction (0%, 20% and 40% restriction) and slaughtered at different pregnancy stages (80, 110 and 140 days of gestation), in a randomised block design with a 2 × 3 × 3 factorial arrangement. The mineral balance was determined at ~80, 110 and 140 days of gestation. The serum levels of minerals and alkaline phosphatase activity were determined during pregnancy. Mineral retention in the maternal body, femur, empty uterus, mammary gland, fetus and fetal fluid was also determined during gestation. Bone mineral density was measured in the femur. Mixed models with days of gestation, levels of feed restriction, breed and their interactions as fixed effects and blocks as random effect were used for data analysis. In response to the reduction in feed intake, the maternal body uses its mineral reserves to maintain gestation. Physiological adjustments of the goats subjected to 20% feed restriction avoided a decrease in fetal mineral deposition. More severe feed restriction, however, compromised concentrations of phosphorus, sodium and potassium in the fetus, which were the main minerals used by the maternal body, whereas calcium and magnesium deposition in fetuses remained unaffected. At 40% feed restriction, the retention of all minerals in the body decreased, and the fetal dry mass was on average also less than those fetuses from goats without feed restriction. The fetal deposition of phosphorus, sodium and potassium was also lower during 40% restriction.