Methods: Two complementary approaches, saturated transposon mutagenesis and spontaneous mutation induction with high concentrations of colistin and polymyxin B, were employed to select for mutations associated with resistance to polymyxins. Mutants were identified using transposon-directed insertion-site sequencing or Illumina WGS. A resistance phenotype was confirmed by MIC and further investigated using RT-PCR. Competitive growth assays were used to measure fitness cost.

Results: A transposon insertion at nucleotide 41 of the pmrB gene (EC958pmrB41-Tn5) enhanced its transcript level, resulting in a 64- and 32-fold increased MIC of colistin and polymyxin B, respectively. Three spontaneous mutations, also located within the pmrB gene, conferred resistance to both colistin and polymyxin B with a corresponding increase in transcription of the pmrCAB genes. All three mutations incurred a fitness cost in the absence of colistin and polymyxin B.

RESULTS: The present report is a continuing study from our previous published transcriptomic profiling of oil palm seedlings against G. boninense. We focused on identifying differentially expressed genes (DEGs) encoding transcription factors (TFs) from the same RNA-seq data; resulting in 106 upregulated and 108 downregulated TFs being identified. The DEGs are involved in four established defense-related pathways responsible for cell wall modification, reactive oxygen species (ROS)-mediated signaling, programmed cell death (PCD) and plant innate immunity. We discovered upregulation of JUNGBRUNNEN 1 (EgJUB1) during the fungal biotrophic phase while Ethylene Responsive Factor 113 (EgERF113) demonstrated prominent upregulation when the palm switches to defense against necrotrophic phase. EgJUB1 was shown to have a binding activity to a 19 bp palindromic SNBE1 element, WNNYBTNNNNNNNAMGNHW found in the promoter region of co-expressing EgHSFC-2b. Further in silico analysis of promoter regions revealed co-expression of EgJUB1 with TFs containing SNBE1 element with single nucleotide change at either the 5th or 18th position. Meanwhile, EgERF113 binds to both GCC and DRE/CRT elements promoting plasticity in upregulating the downstream defense-related genes. Both TFs were proven to be nuclear-localized based on subcellular localization experiment using onion epidermal cells.

PATIENTS AND METHODS: We report two siblings of a healthy but consanguineous Malaysian family presenting with severe short stature caused by CPHD with a variable phenotype. Importantly, at the beginning the girl presented with isolated GHD, whereas the boy was hypothyroid. As the most common gene alterations responsible for CPHD are within either the PROP-1- or the POU1F1- (PIT-1)-gene these two genes were further studied.

RESULTS: Subsequent sequencing of the six exons of the POU1F1-gene allowed the identification of a new N-terminal mutation (Q4ter) in these two children. A substitution of C to T induced a change from a glutamine (CAA) to a stop codon (TAA) in exon 1 of the PIT-1 protein. Both affected children were homozygous for the mutation, whereas the mother and father were heterozygous.

METHODS: Female rats were treated with quercetin (10, 25 and 50mg/kg/day) subcutaneously beginning from day-1 pregnancy. Uterus was harvested at day-4 (following three days quercetin treatment) for morphological, ultra-structural, protein and mRNA expressional changes and plasma sex-steroid levels analyses. In another cohort of rats, implantation rate was determined at day-6 (following five days quercetin treatment).

RESULTS: Administration of 50mg/kg/day quercetin causes increased in uterine fluid volume and CFTR expression but decreased in γ-ENaC, AQP-5, AQP-9 claudin-4, occludin, E-cadherin, integrin αnβЗ, FGF, Ihh and Msx-1expression in the uterus. Pinopodes were poorly develop, tight junctions appear less complex and implantation rate decreased. Serum estradiol levels increased but serum progesterone levels decreased.