Maternally derived avian corticosterone affects offspring genome-wide DNA methylation in a passerine species.

Avian embryos develop in an egg composition which reflects both maternal condition and the recent environment of their mother. In birds, yolk corticosterone (CORT) influences development by impacting pre- and postnatal growth, as well as nestling stress responses and development. One possible mechanism through which maternal CORT may affect offspring development is via changes to offspring DNA methylation. We sought to investigate this, for the first time in birds, by quantifying the impact of manipulations to maternal CORT on offspring DNA methylation. We non-invasively manipulated plasma CORT concentrations of egg-laying female zebra finches (Taeniopygia castanotis) with an acute dose of CORT administered around the time of ovulation and collected their eggs. We then assessed DNA methylation in the resulting embryonic tissue and in their associated vitelline membrane blood vessels, during early development (5 days after lay), using two established methods - liquid chromatography-mass spectrometry (LC-MS) and methylation-sensitive amplification fragment length polymorphism (MS-AFLP). LC-MS analysis showed that global DNA methylation was lower in embryos from CORT-treated mothers, compared to control embryos. In contrast, blood vessel DNA from eggs from CORT-treated mothers showed global methylation increases, compared to control samples. There was a higher proportion of global DNA methylation in the embryonic DNA of second clutches, compared to first clutches. Locus-specific analyses using MS-AFLP did not reveal a treatment effect. Our results indicate that an acute elevation of maternal CORT around ovulation impacts DNA methylation patterns in their offspring. This could provide a mechanistic understanding of how a mother's experience can affect her offspring's phenotype.

The Plight of the Metabolite: Oxidative Stress and Tear Film Destabilisation Evident in Ocular Allergy Sufferers across Seasons in Victoria, Australia.

Ocular allergy (OA) is characterised by ocular surface itchiness, redness, and inflammation in response to allergen exposure. The primary aim of this study was to assess differences in the human tear metabolome and lipidome between OA and healthy controls (HCs) across peak allergy (spring-summer) and off-peak (autumn-winter) seasons in Victoria, Australia. A total of 19 participants (14 OA, 5 HCs) aged 18-45 were recruited and grouped by allergy questionnaire score. Metabolites and lipids from tear samples were analysed using mass spectrometry. Data were analysed using TraceFinder and Metaboanalyst. Metabolomics analysis showed 12 differentially expressed (DE) metabolites between those with OA and the HCs during the peak allergy season, and 24 DE metabolites were found in the off-peak season. The expression of niacinamide was upregulated in OA sufferers vs. HCs across both seasons (p ≤ 0.05). A total of 6 DE lipids were DE between those with OA and the HCs during the peak season, and 24 were DE in the off-peak season. Dysregulated metabolites affected oxidative stress, inflammation, and homeostasis across seasons, suggesting a link between OA-associated itch and ocular surface damage via eye rubbing. Tear lipidome changes were minimal between but suggested tear film destabilisation and thinning. Such metabolipodome findings may pave new and exciting ways for effective diagnostics and therapeutics for OA sufferers in the future.

Development of bio-composite mulch film from cotton gin wastes: Study of pesticide residue and outdoor stability and degradation.

Non-degradable plastic mulch films used in agriculture are polluting the environment by leaving residues and microplastics in the soil. They are also difficult to recycle due to contamination during their use. Biodegradable mulch films are needed as alternatives so that they can be used effectively during the growing season and later be ploughed to be degraded in soil. However, market-available so-called biodegradable mulch films are very slow to degrade in the natural environment and thus do not fit with crop rotation demands or annual cultivation. In this study, we have developed mulch films from cotton gin trash (CGT) and/or gin motes (GM) in combination with biodegradable polycaprolactone and demonstrated their effectiveness over 3 months in outdoor conditions. Both the stability and degradation behaviours of mulch film samples were observed when they were placed on top of the soil and buried in the soil, respectively. Pesticide residue analysis also was carried out on CGT powder to identify and quantify individual pesticides against a matrix of known pesticides. The mulch films prepared in this study showed comparable and stable mechanical properties compared to commercial biodegradable mulch film, though were much quicker to degrade when buried in the soil. No pesticides were detected in the CGT samples. The films produced were vapour-permeable and may be useful in practical agricultural settings by being able to maintain consistent soil moisture and allowing precipitation to penetrate gradually. The lab-scale production cost for the film was 98.8 AUD/kg, which could be lowered by integrating a continuous film line in large-scale production.

Creatine and pregnancy outcomes: a prospective cohort study of creatine metabolism in low-risk pregnant females.

BACKGROUND: Physiological adaptations during pregnancy alter nutrient and energy metabolism. Creatine may be important for maintaining cellular energy homeostasis throughout pregnancy. However, the impact of pregnancy on endogenous and exogenous creatine availability has never been comprehensively explored. OBJECTIVES: To undertake a prospective cohort study and determine the physiological ranges of creatine and associated metabolites throughout human pregnancy. METHODS: Females with a singleton low-risk pregnancy were recruited at an Australian health service. Maternal blood and urine were collected at 5-time points from 10-36 weeks of gestation, and cord blood and placental samples were collected at birth. Creatine and associated amino acids and metabolites of creatine synthesis were analyzed. Dietary data were captured to determine effects of exogenous creatine intake. Associations between creatine metabolism and neonatal growth parameters were examined. RESULTS: Two hundred and eighty-two females were included. Maternal plasma creatine remained stable throughout pregnancy [ß: -0.003 µM; 95% confidence interval (CI): -0.07, 0.07; P = 0.94], though urinary creatine declined in late gestation (ß: 0.38 µM/mmol/L creatinine (CRN); 95% CI: -0.47, -0.29; P < 0.0001). Plasma guanidinoacetate (GAA; the precursor to creatine during endogenous synthesis) fell from 10-29 weeks of gestation before rising until birth (ß: -0.38 µM/mmol/L CRN; 95% CI: -0.47, -0.29; P < 0.0001). Urinary GAA followed an opposing pattern (ß: 2.52 µM/mmol/L CRN; 95% CI: 1.47, 3.58, P < 0.001). Animal protein intake was positively correlated with maternal plasma creatine until ∼32 weeks of gestation (ß: 0.07-0.18 µM; 95% CI: 0.006, 0.25; P ≤ 0.001). There were no links between creatine and neonatal growth, but increased urinary GAA in early pregnancy was associated with a slight reduction in head circumference at birth (ß: -0.01 cm; 95% CI: -0.02, -0.004; P = 0.003). CONCLUSIONS: Although maternal plasma creatine concentrations were highly conserved, creatine metabolism appears to adjust throughout pregnancy. An ability to maintain creatine concentrations through diet and shifts in endogenous synthesis may impact fetal growth. This trial was registered at [registry name] as ACTRN12618001558213.