Multiple Genes Influence BMI on Chromosome 7q31–34: The NHLBI Family Heart Study

The National Heart, Lung, and Blood Institute Family Heart Study (FHS) genome‐wide linkage scan identified a region of chromosome 7q31–34 with a lod score of 4.9 for BMI at D7S1804 (131.9 Mb). We report the results of linkage and association to BMI in this region for two independent FHS samples. The first sample includes 225 FHS pedigrees with evidence of linkage to 7q31–34, using 1,132 single‐nucleotide polymorphisms (SNPs) and 7 microsatellites. The second represents a case–control sample (318 cases; BMI >25 and 325 controls; BMI <25) derived from unrelated FHS participants who were not part of the genome scan. The latter set was genotyped for 606 SNPs, including 37 SNPs with prior evidence for association in the linked families. Although variance components linkage analysis using only SNPs generated a peak lod score that coincided with the original linkage scan at 131.9 Mb, a conditional linkage analysis showed evidence of a second quantitative trait locus (QTL) near 143 cM influencing BMI. Three SNPs (rs161339, rs12673281, and rs1993068) located near the three genes pleiotrophin (PTN), diacylglycerol (DAG) kinase iota (DGKι), and cholinergic receptor, muscarinic 2 (CHRM2) demonstrated significant association in both linked families (P = 0.0005, 0.002, and 0.03, respectively) and the case–control sample (P = 0.01, 0.0003, and 0.03, respectively), regardless of the genetic model tested. These findings suggest that several genes may be associated with BMI in the 7q31–34 region.     

Soil phosphorus fractions and tree phosphorus resorption in pine forests along an urban-to-rural gradient in Nanchang, China

Urbanization has been rapid across the world but the responses of phosphorus (P) cycling to urbanization have not been well-investigated. This study was to understand the influences of rapid urbanization on forest P cycling in a developing country. Soil P fractions and P resportion were determined for nine slash pine (Pinus elliottii Engelm.) forests along a 30-km long urban-suburban-rural gradient in Nanchang City, southern China. The total P stocks in the surface soils in urban and suburban forests were 317% and 182% higher, respectively, than levels found in rural forests. The concentrations of soil available P, labile P, slow P, occluded P and total extractable P were also much higher in urban and suburban forests than in rural forests (P?<?0.05). Soil weathered P concentrations were highest in urban forests. Annual mean foliar P concentrations were enhanced in urban and suburban forests compared to rural forests. The P resorption efficiency (PRE) was higher in rural forests than in suburban and urban forests, while the P resorption proficiency (PRP) was lower in rural forests than in suburban and urban forests. Urbanization associated with high extraneous P inputs has altered soil P status and plant P uptake. Foliar P concentration, PRE and PRP were largely dependent on soil P availability in our study forests.     

Delta-bag cell peptide from the egg-laying hormone precursor of Aplysia. Processing, primary structure, and biological activity

The bag cells of the marine mollusk Aplysia express a gene encoding a 271-residue egg-laying hormone (ELH) precursor that is processed into at least nine peptide products. Four of the peptides have been identified in bag cell releasates and are known to act as nonsynaptic neurotransmitters in the abdominal ganglion. The isolation, primary structure, and proposed biological activity of a fifth peptide product (delta-bag cell peptide (delta-BCP)) from the ELH precursor are described. delta-BCP was established to be a 39-residue peptide: NH2-Asp-Gln-Asp-Glu-Gly-Asn-Phe-Arg-Arg-Phe-Pro-Thr-Asn-Ala-Val-Ser-Met- Ser-Ala-Asp- Glu-Asn-Ser-Pro-Phe-Asp-Leu-Ser-Asn-Glu-Asp-Gly-Ala-Val-Tyr-Gln-Arg- Asp-Leu-COOH. This sequence corresponds to residues 81-119 of the ELH prohormone and shares sequence identity with atrial gland peptides A and B. Significantly, synthetic delta-BCP stimulated Ca2+ uptake into mitochondria of secretory cells in the albumin gland in vitro, suggesting that the peptide regulates the cellular release of perivitelline fluid by the gland. Similar results were obtained with purified peptide A and a shorter version of delta-BCP (delta-BCP-(14-33)). These results indicate that delta-BCP belongs to a family of structurally related peptides with similar pharmacological activities that center at a conserved region of sequence corresponding to delta-BCP-(14-33).     

The occurrence of O-acylation during biotinylation of gonadotropin-releasing hormone and analogs. Evidence for a reactive serine.

Gonadotropin-releasing hormone (GnRH) and two of its analogs ([D-Lys6]GnRH and des-Gly10-[D-Trp6]-GnRH) were reacted with sulfonated N-hydroxysuccinimide esters of biotin that have been reported to react specifically with primary amino groups. Fractionation by reversed-phase high performance liquid chromatography demonstrated the occurrence of multiple biotinylated derivatives for each reacted peptide. These results were unexpected since GnRH and des-Gly10-[D-Trp6]GnRH contained no reactive amino groups and [D-Lys6]GnRH had only one. Reaction of the biotinylated derivatives with hydroxylamine indicated that significant O-biotinylation had occurred. Mass spectrometric analyses established the stoichiometry of biotinylation and confirmed that substantial O-biotinylation of residue Ser4, and to a minor extent Tyr5, of GnRH and the two analogs had occurred. In contrast, the biotinylation of selected peptides unrelated to GnRH under identical reaction conditions indicated no significant evidence of O-acylation of seryl residues. Strikingly, biotinylation of GnRH under denaturing conditions largely abolished O-acylation, indicating that the observed O-biotinylation was dependent on peptide conformation. All the O-biotinylated derivatives displayed significantly reduced bioactivity. Taken together, these results give strong evidence that the Ser4 hydroxyl of GnRH has a significantly elevated intrinsic reactivity, which raises new questions concerning its putative role in the conformation and mode of action of the hormone. These results also demonstrate for the first time that the N-hydroxysuccinimide-biotin esters are capable of significant O-acylation and may be generally useful reagents for detecting highly reactive hydroxyamino acid residues.     

X-ray structure determination of fully hydrated L alpha phase dipalmitoylphosphatidylcholine bilayers.

Bilayer form factors obtained from x-ray scattering data taken with high instrumental resolution are reported for multilamellar vesicles of L alpha phase lipid bilayers of dipalmitoylphosphatidylcholine at 50 degrees C under varying osmotic pressure. Artifacts in the magnitudes of the form factors due to liquid crystalline fluctuations have been eliminated by using modified Caillé theory. The Caillé fluctuation parameter eta 1 increases systematically with increasing lamellar D spacing and this explains why some higher order peaks are unobservable for the larger D spacings. The corrected form factors fall on one smooth continuous transform F(q); this shows that the bilayer does not change shape as D decreases from 67.2 A (fully hydrated) to 60.9 A. The distance between headgroup peaks is obtained from Fourier reconstruction of samples with four orders of diffraction and from electron density models that use 38 independent form factors. By combining these results with previous gel phase results, area AF per lipid molecule and other structural quantities are obtained for the fluid L alpha phase. Comparison with results that we derived from previous neutron diffraction data is excellent, and we conclude from diffraction studies that AF = 62.9 +/- 1.3 A2, which is in excellent agreement with a previous estimate from NMR data.     

Control of estrogen and androgen receptors in the rat pineal gland by catecholamine transmitter

Sucrose gradient studies of rat pineal cytosol incubated with ³H-estradiol (female pineals) or ³H-5 α -dihydrotestosterone (male pineals) revealed a radioactivity peak in the 8 S region which disappeared after superior cervical ganglionectomy or incubation with excess unlabeled hormone. Ganglionectomy decreased significantly estradiol and testosterone uptake by the pineal gland $\text{in vitro}$ as well as high affinity binding to pineal cytoplasmic and nuclear components. Norepinephrine treatment counteracted all the effects of ganglionectomy but was unable to modify hormone uptake and binding by the pineal gland of sham-operated controls. Pre-treatment with actinomycin D or propranolol but not with phentolamine impaired norepinephrine effects; propranolol blockage however was only partial. Administration of isoproterenol, L-dopa or phentolamine increased hormone uptake by denervated pineals. The effects of isoproterenol were also observed $\text{in vitro}$ and were blocked by propranolol. These results indicate that sex steroid receptors in the pinealocytes are controlled by norepinephrine via beta-adrenergic receptors and that depletion of neural norepinephrine enhanced responsiveness of pineal hormone receptors to exogenous catecholamines.     

Virulence and Pathogenesis of Yellow Fever Virus Serially Passaged in Cell Culture

Viscerotropic virulence of the Asibi strain of yellow fever virus (YFV) for monkeys has been known to be lost after serial passage in HeLa cell monolayers. This phenomenon was investigated in several other mammalian and insect tissue cell lines. Assay in monkeys of original seed virus and of virus after 7 and 11 passages in a porcine kidney cell line (PK) indicated essentially equal infectivity and mortality. Moreover, monkeys receiving the passaged virus exhibited more rapid onset of disease and death than animals infected with original seed virus. Histological changes in animals inoculated with passaged virus were identical to those in animals receiving the seed virus. Virus from later passages in PK cells was also lethal for approximately 50% of the monkeys; however, evidence for progressive attenuation was seen in these preparations. Similar results were obtained with a mosquito (Aedes aegypti) cell line. In contrast to results obtained in PK and mosquito cells, YFV became essentially avirulent (nonlethal and less infective) for monkeys after only seven passages in HeLa cell cultures.