ORCID Profile
0000-0002-1351-0291
Current Organisation
University of Adelaide
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Publisher: Cambridge University Press (CUP)
Date: 22-12-2020
DOI: 10.1017/S2040174420001257
Abstract: Intrauterine growth restriction (IUGR) due to uteroplacental insufficiency results in a placenta that is unable to provide adequate nutrients and oxygen to the fetus. These growth-restricted babies have an increased risk of hypertension and chronic kidney disease later in life. In rats, both male and female growth-restricted offspring have nephron deficits but only males develop kidney dysfunction and high blood pressure. In addition, there is transgenerational transmission of nephron deficits and hypertension risk. Therefore, epigenetic mechanisms may explain the sex-specific programming and multigenerational transmission of IUGR-related phenotypes. Expression of DNA methyltransferases ( Dnmt1 and Dnmt3a ) and imprinted genes ( Peg3, Snrpn, Kcnq1 , and Cdkn1c ) were investigated in kidney tissues of sham and IUGR rats in F1 (embryonic day 20 (E20) and postnatal day 1 (PN1)) and F2 (6 and 12 months of age, paternal and maternal lines) generations ( n = 6–13/group). In comparison to sham offspring, F1 IUGR rats had a 19% decrease in Dnmt3a expression at E20 ( P 0.05), with decreased Cdkn1c (19%, P 0.05) and increased Kcnq1 (1.6-fold, P 0.01) at PN1. There was a sex-specific difference in Cdkn1c and Snrpn expression at E20, with 29% and 34% higher expression in IUGR males compared to females, respectively ( P 0.05). Peg3 sex-specific expression was lost in the F2 IUGR offspring, only in the maternal line. These findings suggest that epigenetic mechanisms may be altered in renal embryonic and/or fetal development in growth-restricted offspring, which could alter kidney function, predisposing these offspring to kidney disease later in life.
Publisher: Springer Science and Business Media LLC
Date: 25-06-2022
DOI: 10.1038/S41598-022-14893-5
Abstract: Oryza australiensis is a wild rice native to monsoonal northern Australia. The International Oryza Map Alignment Project emphasises its significance as the sole representative of the EE genome clade. Assembly of the O. australiensis genome has previously been challenging due to its high Long Terminal Repeat (LTR) retrotransposon (RT) content. Oxford Nanopore long reads were combined with Illumina short reads to generate a high-quality ~ 858 Mbp genome assembly within 850 contigs with 46× long read coverage. Reference-guided scaffolding increased genome contiguity, placing 88.2% of contigs into 12 pseudomolecules. After alignment to the Oryza sativa cv. Nipponbare genome, we observed several structural variations. PacBio Iso-Seq data were generated for five distinct tissues to improve the functional annotation of 34,587 protein-coding genes and 42,329 transcripts. We also report SNV numbers for three additional O. australiensis genotypes based on Illumina re-sequencing. Although genetic similarity reflected geographical separation, the density of SNVs also correlated with our previous report on variations in salinity tolerance. This genome re-confirms the genetic remoteness of the O. australiensis lineage within the O. officinalis genome complex. Assembly of a high-quality genome for O. australiensis provides an important resource for the discovery of critical genes involved in development and stress tolerance.
Publisher: Walter de Gruyter GmbH
Date: 22-09-2015
Abstract: In spring 2014, thousands of green algal balls were washed up at Dee Why Beach, Sydney, New South Wales, Australia. Reports of algal balls are uncommon in marine systems, and mass strandings on beaches are even more rare, sparking both public and scientific interest. We identified the algal masses as Chaetomorpha linum by using light microscopy and DNA sequencing. We characterize the size and composition of the balls from Dee Why Beach and compare them to previous records of marine algal balls. We describe the environmental conditions that could explain their appearance, given the ecophysiology of C. linum .
Publisher: Elsevier BV
Date: 05-2023
Publisher: Springer Science and Business Media LLC
Date: 08-01-2022
DOI: 10.1007/S11103-021-01210-3
Abstract: A wild relative of rice from the Australian savannah was compared with cultivated rice, revealing thermotolerance in growth and photosynthetic processes and a more robust carbon economy in extreme heat. Above ~ 32 °C, impaired photosynthesis compromises the productivity of rice. We compared leaf tissues from heat-tolerant wild rice ( Oryza australiensis ) with temperate-adapted O . sativa after sustained exposure to heat, as well as diurnal heat shock. Leaf elongation and shoot biomass in O . australiensis were unimpaired at 45 °C, and soluble sugar concentrations trebled during 10 h of a 45 °C shock treatment. By contrast, 45 °C slowed growth strongly in O. sativa . Chloroplastic CO 2 concentrations eliminated CO 2 supply to chloroplasts as the basis of differential heat tolerance. This directed our attention to carboxylation and the abundance of the heat-sensitive chaperone Rubisco activase (Rca) in each species. Surprisingly, O . australiensis leaves at 45 °C had 50% less Rca per unit Rubisco, even though CO 2 assimilation was faster than at 30 °C. By contrast, Rca per unit Rubisco doubled in O. sativa at 45 °C while CO 2 assimilation was slower, reflecting its inferior Rca thermostability. Plants grown at 45 °C were simultaneously exposed to 700 ppm CO 2 to enhance the CO 2 supply to Rubisco. Growth at 45 °C responded to CO 2 enrichment in O. australiensis but not O. sativa , reflecting more robust carboxylation capacity and thermal tolerance in the wild rice relative.
Location: Australia
No related grants have been discovered for Aaron Phillips.