Maternal metabolism during pregnancy impacts the developing fetus, affecting offspring birth weight and adiposity. This has important implications for metabolic health later in life (e.g., offspring ...of mothers with pre-existing or gestational diabetes mellitus have an increased risk of metabolic disorders in childhood). To identify genetic loci associated with measures of maternal metabolism obtained during an oral glucose tolerance test at ∼28 weeks' gestation, we performed a genome-wide association study of 4,437 pregnant mothers of European (n = 1,367), Thai (n = 1,178), Afro-Caribbean (n = 1,075), and Hispanic (n = 817) ancestry, along with replication of top signals in three additional European ancestry cohorts. In addition to identifying associations with genes previously implicated with measures of glucose metabolism in nonpregnant populations, we identified two novel genome-wide significant associations: 2-h plasma glucose and HKDC1, and fasting C-peptide and BACE2. These results suggest that the genetic architecture underlying glucose metabolism may differ, in part, in pregnancy.
Many diverse systems for sex determination have evolved in plants and animals. One involves physically distinct (heteromorphic) sex chromosomes (X and Y, or Z and W) that are homozygous in one sex ...(usually female) and heterozygous in the other (usually male). Sex chromosome evolution is thought to involve suppression of recombination around the sex determination genes, rendering permanently heterozygous a chromosomal region that may then accumulate deleterious recessive mutations by Muller's ratchet, and fix deleterious mutations by hitchhiking as nearby favourable mutations are selected on the Y chromosome. Over time, these processes may cause the Y chromosome to degenerate and to diverge from the X chromosome over much of its length; for example, only 5% of the human Y chromosome still shows X-Y recombination. Here we show that papaya contains a primitive Y chromosome, with a male-specific region that accounts for only about 10% of the chromosome but has undergone severe recombination suppression and DNA sequence degeneration. This finding provides direct evidence for the origin of sex chromosomes from autosomes.
About half of people with trisomy 21 have a congenital heart defect (CHD), whereas the remainder have a structurally normal heart, demonstrating that trisomy 21 is a significant risk factor but is ...not causal for abnormal heart development. Atrioventricular septal defects (AVSD) are the most commonly occurring heart defects in Down syndrome (DS), and ∼65% of all AVSD is associated with DS. We used a candidate-gene approach among individuals with DS and complete AVSD (cases = 141) and DS with no CHD (controls = 141) to determine whether rare genetic variants in genes involved in atrioventricular valvuloseptal morphogenesis contribute to AVSD in this sensitized population. We found a significant excess (p < 0.0001) of variants predicted to be deleterious in cases compared to controls. At the most stringent level of filtering, we found potentially damaging variants in nearly 20% of cases but fewer than 3% of controls. The variants with the highest probability of being damaging in cases only were found in six genes: COL6A1, COL6A2, CRELD1, FBLN2, FRZB, and GATA5. Several of the case-specific variants were recurrent in unrelated individuals, occurring in 10% of cases studied. No variants with an equal probability of being damaging were found in controls, demonstrating a highly specific association with AVSD. Of note, all of these genes are in the VEGF-A pathway, even though the candidate genes analyzed in this study represented numerous biochemical and developmental pathways, suggesting that rare variants in the VEGF-A pathway might contribute to the genetic underpinnings of AVSD in humans.
Newborns characterized as large and small for gestational age are at risk for increased mortality and morbidity during the first year of life as well as for obesity and dysglycemia as children and ...adults. The intrauterine environment and fetal genes contribute to the fetal size at birth. To define the genetic architecture underlying the newborn size, we performed a genome-wide association study (GWAS) in 4281 newborns in four ethnic groups from the Hyperglycemia and Adverse Pregnancy Outcome Study. We tested for association with newborn anthropometric traits (birth length, head circumference, birth weight, percent fat mass and sum of skinfolds) and newborn metabolic traits (cord glucose and C-peptide) under three models. Model 1 adjusted for field center, ancestry, neonatal gender, gestational age at delivery, parity, maternal age at oral glucose tolerance test (OGTT); Model 2 adjusted for Model 1 covariates, maternal body mass index (BMI) at OGTT, maternal height at OGTT, maternal mean arterial pressure at OGTT, maternal smoking and drinking; Model 3 adjusted for Model 2 covariates, maternal glucose and C-peptide at OGTT. Strong evidence for association was observed with measures of newborn adiposity (sum of skinfolds model 3 Z-score 7.356, P = 1.90×10⁻¹³, and to a lesser degree fat mass and birth weight) and a region on Chr3q25.31 mapping between CCNL and LEKR1. These findings were replicated in an independent cohort of 2296 newborns. This region has previously been shown to be associated with birth weight in Europeans. The current study suggests that association of this locus with birth weight is secondary to an effect on fat as opposed to lean body mass.
The androgen receptor (AR) is important in reproductive organ development, as well as tissue homeostasis of the pancreas, liver, and skeletal muscle in adulthood. The trinucleotide (CAG)n repeat ...polymorphism in exon 1 of the AR gene is thought to regulate AR activity, with longer alleles conferring reduced receptor activity. Therefore, the evaluation of the allelic distribution of the AR (CAG)n repeat in various ethnic groups is crucial in understanding the interindividual variability in AR activity. We evaluated ethnic variation of this AR polymorphism by genotyping individuals from the multiethnic Hyperglycemia and Adverse Pregnancy Outcome study cohort. We genotyped 4421 Caucasian mothers and 3365 offspring of European ancestry; 1494 Thai mothers and 1742 offspring; 1119 Afro‐Caribbean mothers and 1142 offspring; and 780 Hispanic mothers and 770 offspring of Mexican ancestry from Bellflower, California. The distributions of (CAG)n alleles among all 4 ethnic groups are significantly different (P < .0001). Pairwise tests confirmed significant differences between each pair of ethnicities tested (P < 10−28). The relative AR (CAG)n repeat length in the different groups was as follows: Afro‐Caribbean (shortest repeat lengths and greatest predicted AR activity) < Caucasian < Hispanic < Thai (longest repeat length and lowest predicted AR activity). Significant interethnic differences in the allele frequencies of the AR exon 1 (CAG)n polymorphism exist. Our results suggest that there may be potential ethnic differences in androgenic pathway activity and androgen sensitivity.
Since mediators of inflammation are associated with insulin resistance, and the risk of developing diabetes mellitus and gestational diabetes, we hypothesized that genetic variation in members of the ...inflammatory gene pathway impact glucose levels and related phenotypes in pregnancy. We evaluated this hypothesis by testing for association between genetic variants in 31 inflammatory pathway genes in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) cohort, a large multiethnic multicenter study designed to address the impact of glycemia less than overt diabetes on pregnancy outcome.
Fasting, 1-hour, and 2-hour glucose, fasting and 1-hour C-peptide, and HbA1c levels were measured in blood samples obtained from HAPO participants during an oral glucose tolerance test at 24-32 weeks gestation. We tested for association between 458 SNPs mapping to 31 genes in the inflammatory pathway and metabolic phenotypes in 3836 European ancestry and 1713 Thai pregnant women. The strongest evidence for association was observed with TNF alpha and HbA1c (rs1052248; 0.04% increase per allele C; p-value = 4.4×10(-5)), RETN and fasting plasma glucose (rs1423096; 0.7 mg/dl decrease per allele A; p-value = 1.1×10(-4)), IL8 and 1 hr plasma glucose (rs2886920; 2.6 mg/dl decrease per allele T; p-value = 1.3×10(-4)), ADIPOR2 and fasting C-peptide (rs2041139; 0.55 ug/L decrease per allele A; p-value = 1.4×10(-4)), LEPR and 1-hour C-peptide (rs1171278; 0.62 ug/L decrease per allele T; p-value = 2.4×10(-4)), and IL6 and 1-hour plasma glucose (rs6954897; -2.29 mg/dl decrease per allele G, p-value = 4.3×10(-4)).
Based on the genes surveyed in this study the inflammatory pathway is unlikely to have a strong impact on maternal metabolic phenotypes in pregnancy although variation in individual members of the pathway (e.g. RETN, IL8, ADIPOR2, LEPR, IL6, and TNF alpha,) may contribute to metabolic phenotypes in pregnant women.
In the ABC model of flower development, B function organ-identity genes act in the second and third whorls of the flower to control petal and stamen identity. The trioecious papaya has male, female, ...and hermaphrodite flowers and is an ideal system for testing the B-class gene expression patterns in trioecious plants. We cloned papaya B-class genes, CpTM6-1, CpTM6-2, and CpPI, using MADS box gene specific degenerate primers followed by cDNA library screening and sequencing of positive clones. While phylogenetic analyses show that CpPI is the ortholog of the Arabidopsis gene PI, the CpTM6-1 and CpTM6-2 loci are representatives of the paralogous TM6 lineage that contain paleoAP3 motifs unlike the euAP3 gene observed in Arabidopsis. These two paralogs appeared to have originated from a tandem duplication occurred approximately 13.4 million year ago (mya) (bootstrap range 13.36 ± 2.42). In-situ hybridization and RT-PCR showed that the papaya B-class genes were highly expressed in young flowers across all floral organ primordia. As the flower organs developed, all three B-class genes were highly expressed in petals of all three-sex types and in stamens of hermaphrodite and male flowers. CpTM6-1 expressed at low levels in sepals and carpels, whereas CpTM6-2 expressed at a low level in sepals and at a high level in leaves. Our results showed that B-class gene homologs could function as predicted by the ABC model in trioecous flowers but differential expressions of CpTM6-1, and CpTM6-2, and CpPI suggested the diversification of their functions after the duplication events.
Common genetic variants in GCK and TCF7L2 are associated with higher fasting glucose and type 2 diabetes in nonpregnant populations. However, their associations with glucose levels from oral glucose ...tolerance tests (OGTTs) in pregnancy have not been assessed in a large sample. We hypothesized that these variants are associated with quantitative measures of glycemia in pregnancy.
We analyzed the associations between variants rs1799884 (GCK) and rs7903146 (TCF7L2) and OGTT outcomes at 24-32 weeks' gestation in 3,811 mothers of European (U.K. and Australia) and 1,706 mothers of Asian (Thailand) ancestry from the HAPO cohort. We also tested associations with offspring birth anthropometrics.
The maternal GCK variant was associated with higher fasting glucose in Europeans (P = 0.001) and Thais (P < 0.0001), 1-h glucose in Europeans (P = 0.001), and 2-h glucose in Thais (P = 0.005). It was also associated with higher European offspring birth weight, fat mass, and skinfold thicknesses (P < 0.05). The TCF7L2 variant was associated with all three maternal glucose outcomes (P = 0.03, P < 0.0001, and P < 0.0001 for fasting and 1-h and 2-h glucose, respectively) in the Europeans but not in the Thais (P > 0.05). In both populations, both variants were associated with higher odds of gestational diabetes mellitus according to the new International Association of Diabetes and Pregnancy Study Groups recommendations (P = 0.001-0.08).
Maternal GCK and TCF7L2 variants are associated with glucose levels known to carry an increased risk of adverse pregnancy outcome in women without overt diabetes. Further studies will be important to determine the variance in maternal glucose explained by all known genetic variants.
Biological treatment of rheumatoid arthritis (RA) is one of the cornerstones of current treatment strategies for the disease. Surprisingly little information exists on whether the route of ...administration affects patients' treatment satisfaction. It is equally unclear whether rheumatologists are able to accurately perceive their patients' appreciation. Thus, the Belgian Be-raise survey aimed to examine whether RA patient's experience of their current biological treatment coincided with the treating physician's perception. A nationwide cross-sectional survey was conducted by 67 Belgian rheumatologists providing data obtained from 550 RA patients. Patients under stable dose of biologics for at least 6 months, were enrolled consecutively and all completed questionnaires. Separate questionnaires were completed by the treating rheumatologist which evaluated their patient's perception of the route of treatment administration. This study therefore evaluates whether a treating physician perceives the satisfaction with the route of administration to the same degree as the patient. Completed questionnaires were obtained from 293 and 257 patients who obtained treatment via the intravenous (IV) or subcutaneous (SC) route of administration, respectively. 58.4% of patients were in DAS28-CRP(3) remission. Patient satisfaction with disease control was higher (44% scored greater than or equal to 9) than that of the treating physician (35%), regardless of the route of administration (p< 0.01). No differences were seen for the patients treated with an IV as opposed to a SC route of administration. The physician's perception of patient's satisfaction with disease control was markedly lower for IV treated patients as opposed to SC treated patients (p< 0.001).
Inserts and insert sites in transgenic, papaya ringspot virus (PRSV)-resistant commercial papaya Rainbow and SunUp, were characterized as part of a petition to Japan to allow import of fresh fruit of ...these cultivars from the U.S. and to provide data for a larger study aimed at understanding the global impact of DNA transformation on whole genome structure. The number and types of inserts were determined by Southern analysis using probes spanning the entire transformation plasmid and their sequences determined from corresponding clones or sequence reads from the whole-genome shotgun (WGS) sequence of SunUp papaya. All the functional transgenes, coding for the PRSV coat protein (
CP
), neophosphotransferase (
nptII
) and β-glucuronidase (
uidA
) were found in a single 9,789 basepair (bp) insert. Only two other inserts, one consisting of a 290 bp nonfunctional fragment of the
nptII
gene and a 1,533 bp plasmid-derived fragment containing a nonfunctional 222 bp segment of the
tetA
gene were detected in Rainbow and SunUp. Detection of the same three inserts in samples representing transgenic generations five to eight (R5 to R8) suggests that the three inserts are stably inherited. Five out of the six genomic DNA segments flanking the three inserts were nuclear plastid sequences (nupts). From the biosafety standpoint, no changes to endogenous gene function based on sequence structure of the transformation plasmid DNA insertion sites could be determined and no allergenic or toxic proteins were predicted from analysis of the insertion site and flanking genomic DNA.