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Young squirrel monkeys (Saimiri sciureus) were reported grooming an adult female uakari (Cacajao calvus rubicundus) on four different occasions. Furthermore, the uakari was noted grooming two squirrel monkeys in separate instances. These observations took place in a seminatural rainforest (The Monkey Jungle; Goulds, Florida, U.S.A.) where provisions are provided. Some possible hypostheses tendered to account for this unusual behavior included (a) the unaverted interaction of food-seeking and fur-cleaning behavior, and (b) the compatibility of play-curiosity activities by squirrel monkeys with the uakaris' need for social contact.  相似文献   
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Ultraconserved elements in the human genome likely harbor important biological functions as they are dosage sensitive and are able to direct tissue-specific expression. Because they are under purifying selection, variants in these elements may have a lower frequency in the population but a higher likelihood of association with complex traits. We tested a set of highly constrained SNPs (hcSNPs) distributed genome-wide among ultraconserved and nearly ultraconserved elements for association with seven traits related to reproductive (age at natural menopause, number of children, age at first child, and age at last child) and overall [longevity, body mass index (BMI), and height] fitness. Using up to 24,047 European-American samples from the National Heart, Lung, and Blood Institute Candidate Gene Association Resource (CARe), we observed an excess of associations with BMI and height. In an independent replication panel the most strongly associated SNPs showed an 8.4-fold enrichment of associations at the nominal level, including three variants in previously identified loci and one in a locus (DENND1A) previously shown to be associated with polycystic ovary syndrome. Finally, using 1430 family trios, we showed that the transmissions from heterozygous parents to offspring of the derived alleles of rare (frequency ≤0.5%) hcSNPs are not biased, particularly after adjusting for the rates of genotype missingness and error in the data. The lack of transmission bias ruled out an immediately and strongly deleterious effect due to the rare derived alleles, consistent with the observation that mice homozygous for the deletion of ultraconserved elements showed no overt phenotype. Our study also illustrated the importance of carefully modeling potential technical confounders when analyzing genotype data of rare variants.  相似文献   
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The replication enzyme of RNA viruses must preferentially recognize their RNAs in an environment that contains an abundance of cellular RNAs. The factors responsible for specific RNA recognition are not well understood, in part because viral RNA synthesis takes place within enzyme complexes associated with modified cellular membrane compartments. Recombinant RNA-dependent RNA polymerases (RdRps) from the human norovirus and the murine norovirus (MNV) were found to preferentially recognize RNA segments that contain the promoter and a short template sequence for subgenomic RNA synthesis. Both the promoter and template sequence contribute to stable RdRp binding, accurate initiation of the subgenomic RNAs and efficient RNA synthesis. Using a method that combines RNA crosslinking and mass spectrometry, residues near the template channel of the MNV RdRp were found to contact the hairpin RNA motif. Mutations in the hairpin contact site in the MNV RdRp reduced MNV replication and virus production in cells. This work demonstrates that the specific recognition of the norovirus subgenomic promoter is through binding by the viral RdRp.  相似文献   
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The neuropeptides, pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) are implicated in the regulation of gene expression and hormone secretion in mammalian melanotrope cells and a mammalian pro-opiomelanocortin (POMC)-producing tumor cell line, but the physiological relevance of this regulation is elusive. The purpose of the present study was to establish if these peptides affect biosynthetic and secretory processes in a well-established physiological model for endocrine cell functioning, the pituitary melanotrope cells of the amphibian Xenopus laevis, which hormonally control the process of skin color adaptation to background illumination. We show that both PACAP and VIP are capable of stimulating the secretory process of the Xenopus melanotrope cell. As the peptides are equipotent, they may exert their actions via a VPAC receptor. Moreover, PACAP stimulated POMC biosynthesis and POMC gene expression. Strong anti-PACAP immunoreactivity was found in the pituitary pars nervosa (PN), suggesting that this neurohemal organ is a source of neurohormonal PACAP action on the melanotropes in the intermediate pituitary. We propose that the PACAP/VIP family of peptides has a physiological function in regulating Xenopus melanotrope cell activity during the process of skin color adaptation.  相似文献   
67.
Review of Florida Red Tide and Human Health Effects   总被引:1,自引:0,他引:1  
This paper reviews the literature describing research performed over the past decade on the known and possible exposures and human health effects associated with Florida red tides. These harmful algal blooms are caused by the dinoflagellate, Karenia brevis, and similar organisms, all of which produce a suite of natural toxins known as brevetoxins. Florida red tide research has benefited from a consistently funded, long term research program, that has allowed an interdisciplinary team of researchers to focus their attention on this specific environmental issue-one that is critically important to Gulf of Mexico and other coastal communities. This long-term interdisciplinary approach has allowed the team to engage the local community, identify measures to protect public health, take emerging technologies into the field, forge advances in natural products chemistry, and develop a valuable pharmaceutical product. The Review includes a brief discussion of the Florida red tide organisms and their toxins, and then focuses on the effects of these toxins on animals and humans, including how these effects predict what we might expect to see in exposed people.  相似文献   
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A Clostridium botulinum type A strain (A661222) in our culture collection was found to produce the botulinum neurotoxin subtype A5 (BoNT/A5). Its neurotoxin gene was sequenced to determine its degree of similarity to available sequences of BoNT/A5 and the well-studied BoNT/A1. Thirty-six amino acid differences were observed between BoNT/A5 and BoNT/A1, with the predominant number being located in the heavy chain. The amino acid chain of the BoNT/A from the A661222 strain was superimposed over the crystal structure of the known structure of BoNT/A1 to assess the potential significance of these differences--specifically how they would affect antibody neutralization. The BoNT/A5 neurotoxin was purified to homogeneity and evaluated for certain properties, including specific toxicity and antibody neutralization. This study reports the first purification of BoNTA5 and describes distinct differences in properties between BoNT/A5 and BoNT/A1.  相似文献   
69.
Unlocking the barley genome by chromosomal and comparative genomics   总被引:2,自引:0,他引:2  
We used a novel approach that incorporated chromosome sorting, next-generation sequencing, array hybridization, and systematic exploitation of conserved synteny with model grasses to assign ~86% of the estimated ~32,000 barley (Hordeum vulgare) genes to individual chromosome arms. Using a series of bioinformatically constructed genome zippers that integrate gene indices of rice (Oryza sativa), sorghum (Sorghum bicolor), and Brachypodium distachyon in a conserved synteny model, we were able to assemble 21,766 barley genes in a putative linear order. We show that the barley (H) genome displays a mosaic of structural similarity to hexaploid bread wheat (Triticum aestivum) A, B, and D subgenomes and that orthologous genes in different grasses exhibit signatures of positive selection in different lineages. We present an ordered, information-rich scaffold of the barley genome that provides a valuable and robust framework for the development of novel strategies in cereal breeding.  相似文献   
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