Genome sequencing of large numbers of individuals promises to advance the understanding, treatment, and prevention of human diseases, among other applications. We describe a genome sequencing platform that achieves efficient imaging and low reagent consumption with combinatorial probe anchor ligation chemistry to independently assay each base from patterned nanoarrays of self-assembling DNA nanoballs. We sequenced three human genomes with this platform, generating an average of 45- to 87-fold coverage per genome and identifying 3.2 to 4.5 million sequence variants per genome. Validation of one genome data set demonstrates a sequence accuracy of about 1 false variant per 100 kilobases. The high accuracy, affordable cost of $4400 for sequencing consumables, and scalability of this platform enable complete human genome sequencing for the detection of rare variants in large-scale genetic studies.

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Intrauterine growth restriction increases the risk of perinatal complications and predisposes the infant to diabetes and cardiovascular disease in later life. Mechanisms by which maternal nutrient restriction (MNR) reduces fetal growth are poorly understood. We hypothesized that MNR decreases placental amino acid (AA) transporter activity, leading to reduced transplacental transfer of AAs. Pregnant baboons were fed either a control (ad libitum, n = 7), or MNR diet (70% of control diet, n = 7) from gestational day (GD) 30. At GD 165 (0.9 gestation), placentas (n = 7 in each group) were collected, and microvillous plasma membrane vesicles (MVM) isolated. MVM system A and system L AA transport was determined in vitro using radiolabeled substrates and rapid filtration techniques. In vivo transplacental AA transport was assessed by infusing nine (13)C- or (2)H-labeled essential AA as a bolus into the maternal circulation (n = 5 control, n = 4 MNR) at cesarean section. A fetal vein-to-maternal artery mole percent excess ratio for each essential AA was calculated. Fetal and placental weights were significantly reduced in the MNR group compared with controls (P < 0.01). The activity of system A and system L was markedly reduced by 73 and 84%, respectively, in MVM isolated from baboon placentas at GD 165 following MNR (P < 0.01). In vivo, the fetal vein-to-maternal artery mole percent excess ratio was significantly reduced for leucine, isoleucine, methionine, phenylalanine, threonine, and tryptophan in MNR baboons (P < 0.05). This is the first study to investigate placental AA transport in a nonhuman primate model of MNR. We demonstrate that the downregulation of system A and system L activity in syncytiotrophoblast MVM in MNR leads to decreased transplacental AA transport and, consequently, reduced circulating fetal AA concentrations, a potential mechanism linking maternal undernutrition to reduced fetal growth.

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A method for the preparation of N-maleoylamino acids and esters is reported. These compounds were shown to inhibit both the oxytocin-induced smooth muscle contraction in the isolated rat uterus and the vasopressin-induced water loss from the isolated toad bladder. The inhibitory ability of the maleimides in the toad bladder assay was found to be related to their corresponding partition coefficients by the equation: log 1/C = -0.055 (log P) 2 + 0.227 log P + 3.96. N-Maleoylamino acids can be coupled to peptides to form alkylating reagents which react rapidly with sulfhydryl groups. The synthesis of [1-(N-maleoylglycyl)cysteinyl]oxytocin (3) and [1=(N-maleoyl-11-aminoundecanoyl)cysteinyl]oxytocin (4) as potential affinity labeling reagents is described. These oxytocin analogs were shown to readily react with sulfhydryl-containing compounds; however, neither 3 nor 4 was seen to inhibit in the rat uterus assay at concentrations up to 3 times 10(-5)M. When tested on the mucosal and serosal surfaces of the toad bladder, assay inhibition was seen only on the mucosal surface. These results are discussed with respect to the possible existence of sulfhydryl groups at neurohypophyseal receptors.