Melanesian blond hair is caused by an amino acid change in TYRP1     

Kenny EE  Timpson NJ  Sikora M  Yee MC  Moreno-Estrada A  Eng C  Huntsman S  Burchard EG  Stoneking M  Bustamante CD  Myles S 《Science (New York, N.Y.)》2012,336(6081):554

Naturally blond hair is rare in humans and found almost exclusively in Europe and Oceania. Here, we identify an arginine-to-cysteine change at a highly conserved residue in tyrosinase-related protein 1 (TYRP1) as a major determinant of blond hair in Solomon Islanders. This missense mutation is predicted to affect catalytic activity of TYRP1 and causes blond hair through a recessive mode of inheritance. The mutation is at a frequency of 26% in the Solomon Islands, is absent outside of Oceania, represents a strong common genetic effect on a complex human phenotype, and highlights the importance of examining genetic associations worldwide.  相似文献   

Chile's research planning falls short     

Astudillo P  Blondel CJ  Norambuena T  Soto K 《Science (New York, N.Y.)》2012,336(6080):412

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Foliar anatomical and morphological variation in Nothofagus pumilio seedlings under controlled irradiance and soil moisture levels     

Ivancich HS  Lencinas MV  Pastur GJ  Esteban RM  Hernández L  Lindstrom I 《Tree physiology》2012,32(5):554-564

Foliar anatomy and morphology are strongly related to physiological performance; therefore, phenotypic plasticity in leaves to variations in environmental conditions, such as irradiance and soil moisture availability, can be related to growth rate and survivorship, mainly during critical growth phases, such as establishment. The aim of this work was to analyze changes in the foliar internal anatomy (tissue proportions and cell dimensions) and external morphology (leaf length, width and area) of Nothofagus pumilio (Poepp. et Endl.) Krasser seedlings growing in a greenhouse under controlled irradiance (three levels) and soil moisture (two levels) during one growing season (measured three times), and to relate them to physiological traits. Three irradiance levels (4, 26 and 64% of the natural incident light) and two soil moisture levels (40 and 80% soil capacity) were evaluated during November, January and March. Internal foliar anatomy of seedlings was analyzed using digital photographs of histological cuttings, while leaf gross morphology was measured using digital calipers and image analysis software. Most internal anatomical variables presented significant differences under different irradiance levels during the growing season, but differences were not detected between soil moisture levels. Palisade parenchyma was the tissue most sensitive to irradiance levels, and high irradiance levels (64% natural incident light) produced greater values in most of the internal anatomical variables than lower irradiance levels (4-24% natural incident light). Complementarily, larger leaves were observed in medium and low irradiance levels, as well as under low soil moisture levels (40% soil capacity). The relationship of main results with some eco-physiological traits was discussed. Foliar internal anatomical and external morphological plasticity allows quick acclimation of seedlings to environmental changes (e.g., during harvesting). These results can be used to propose new forest practices that consider soil moisture and light availability changes to maintain high physiological performance of seedlings.  相似文献   

Pathogen translocation and histopathological lesions in an experimental model of Salmonella Dublin infection in calves receiving lactic acid bacteria and lactose supplements     

Laureano S. Frizzo  Mar��a V. Zbrun  Lorena P. Soto  Ezequiel Bertozzi  Gabriel J. Sequeira  Luis E. Marti  Marcelo L. Signorini  Roberto Rodr��guez Armesto  Marcelo R. Rosmini 《Journal of veterinary science (Suw?n-si, Korea)》2012,13(3):261-270

The purpose of this study was to evaluate the capacity of a lactic acid bacteria (LAB) inoculum to protect calves with or without lactose supplements against Salmonella Dublin infection by evaluating histopathological lesions and pathogen translocation. Fifteen calves were divided into three groups [control group (C-G), a group inoculated with LAB (LAB-G), and a group inoculated with LAB and given lactose supplements (L-LAB-G)] with five, six, and four animals, respectively. The inoculum, composed of Lactobacillus (L.) casei DSPV 318T, L. salivarius DSPV 315T, and Pediococcus acidilactici DSPV 006T, was administered with milk replacer. The LAB-G and L-LAB-G received a daily dose of 10⁹ CFU/kg body weight of each strain throughout the experiment. Lactose was provided to the L-LAB-G in doses of 100 g/day. Salmonella Dublin (2 × 10¹⁰ CFU) was orally administered to all animals on day 11 of the experiment. The microscopic lesion index values in target organs were 83%, 70%, and 64.3% (p < 0.05) for the C-G, LAB-G, and L-LAB-G, respectively. Administration of the probiotic inoculum was not fully effective against infection caused by Salmonella. Although probiotic treatment was unable to delay the arrival of pathogen to target organs, it was evident that the inoculum altered the response of animals against pathogen infection.  相似文献   

Evaluation of Efficacy and Safety of Zinc Gluconate Associated with Dimethyl Sulphoxide for Sexually Mature Canine Males Chemical Neutering     

FRM Soto  WG Viana  GCB Mucciolo  FYM Hosomi  CI Vannucchi  CP Mazzei  AR Eyherabide  C De Fátima Lúcio  RA Dias  SS De Azevedo 《Reproduction in domestic animals》2009,44(6):927-931

The aim of this research was to evaluate the efficacy of zinc gluconate associated with dimethyl sulphoxide (DMSO) for chemical neutering in canine males. Fifteen sexually mature male dogs were divided in two groups, named control and treated. An injection was administered to both testicles, at a concentration of 26.2 mg zinc gluconate per ml and 0.5% DMSO in the treated group (11 dogs). The control group was given injections of saline solution (four dogs). Clinical examination and blood collection for a haemogram were done both before and after drug injection. There were 12 spermograms performed to analyse sperm motility, sperm vigour, ejaculate volume, testicle size, pathology and sperm concentrations. Libido was also measured. An ultrasound examination and histopathology were performed at the end of the experiment. Dogs’ libido after chemical injection was reduced by over 50%. The spermogram analysis showed final mean results of 14.54% for sperm motility, 0.72 of sperm vigour and 37 150 per million spermatozoa per millilitre, values considered below the necessary levels at which fertilization can occur. Ultrasound and histopathology analyses of testicles for the treated group revealed more intense injuries when compared with the control group, with compromised testicular parenchyma and a decrease of germ cell number leading to total atrophy, indicating that the treatment reduced the fertilizing potential of male dogs, promoting a possible subfertile status.  相似文献   

Forage Production of the Argentine Pampa Region Based on Land Use and Long-Term Normalized Difference Vegetation Index Data     

Carlos M. Di Bella  Ignacio J. Negri  Gabriela Posse  Florencia R. Jaimes  Esteban G. Jobbágy  Martin F. Garbulsky  Victor A. Deregibus 《Strength and Conditioning Journal》2009,62(2):163-170

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Glyphosate resistance in perennial Sorghum halepense (Johnsongrass), endowed by reduced glyphosate translocation and leaf uptake     

Vila-Aiub MM  Balbi MC  Distéfano AJ  Fernández L  Hopp E  Yu Q  Powles SB 《Pest management science》2012,68(3):430-436

BACKGROUND: In a large cropping area of northern Argentina, Sorghum halepense (Johnsongrass) has evolved towards glyphosate resistance. This study aimed to determine the molecular and biochemical basis conferring glyphosate resistance in this species. Experiments were conducted to assess target EPSPS gene sequences and ¹⁴C‐glyphosate leaf absorption and translocation to meristematic tissues. RESULTS: Individuals of all resistant (R) accessions exhibited significantly less glyphosate translocation to root (11% versus 29%) and stem (9% versus 26%) meristems when compared with susceptible (S) plants. A notably higher proportion of the applied glyphosate remained in the treated leaves of R plants (63%) than in the treated leaves of S plants (27%). In addition, individuals of S. halepense accession R₂ consistently showed lower glyphosate absorption rates in both adaxial (10–20%) and abaxial (20–25%) leaf surfaces compared with S plants. No glyphosate resistance endowing mutations in the EPSPS gene at Pro‐101–106 residues were found in any of the evaluated R accessions. CONCLUSION: The results of the present investigation indicate that reduced glyphosate translocation to meristems is the primary mechanism endowing glyphosate resistance in S. halepense from cropping fields in Argentina. To a lesser extent, reduced glyphosate leaf uptake has also been shown to be involved in glyphosate‐resistant S. halepense . Copyright © 2011 Society of Chemical Industry  相似文献   

Molecular cloning and mRNA tissue-expression of two isoforms of the ovine costimulatory molecule CD80 (B7-1)     

Terzo EA  Alzueta M  Amorena B  de Andrés DF  de la Lastra JM 《Veterinary immunology and immunopathology》2005,103(1-2):9-19

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A Leishmania infantum multi-component antigenic protein mixed with live BCG confers protection to dogs experimentally infected with L. infantum     

Molano I  Alonso MG  Mirón C  Redondo E  Requena JM  Soto M  Nieto CG  Alonso C 《Veterinary immunology and immunopathology》2003,92(1-2):1-13

The capacity of a quimeric protein, formed by the genetic fusion of five antigenic determinants from four Leishmania proteins, formulated with BCG, to protect dogs against Leishmania infantum infection is described. The data showed that after i.v. administration of 500,000 parasites of the L. infantum M/CAN/ES/96/BCN150 strain, zymodeme MON-1, the animals became infected as suggested by the humoral response against the parasite antigens. All control unvaccinated dogs had parasites in the lymph nodes at day 150 post-infection. One of these unvaccinated infected dog was parasite negative at day 634 behaving, thus, as resistant. In contrast, only 50% of the immunized dogs had parasites in the lymph nodes at day 150 post-infection. Four of these dogs became parasite negative by day 634 post-infection. The control animals developed at various times during the follow-up period clinical symptoms associated with Leishmaniasis. The control diseased dogs developed also in the liver and spleen some of the abnormal histological features associated with natural visceral Leishmaniasis. The immunized dogs, however, were not only normal at the clinical but also at the anatomo-pathological level. A positive delayed type hypersensitivity (DTH) response was observed in nine of the immunized protected dogs. The data indicated that Q+BCG confers 90% protection against infection and at least 90% protection at the clinical level.  相似文献   

Time course of endocrine changes in the hypophysis-gonad axis induced by hypobaric hypoxia in male rats     

Farias JG  Bustos-Obregón E  Tapia PJ  Gutierrez E  Zepeda A  Juantok C  Cruz G  Soto G  Benites J  Reyes JG 《The Journal of reproduction and development》2008,54(1):18-21

Chronic hypobaric hypoxia (CHH) induces a decrease in sperm output and spermatogenesis in male rats. The mechanisms that underlie these changes in testicular function are unknown and could involve changes in the hypophysis-gonad axis. We have tested the hypothesis that changes take place in the endocrine status (FSH, follicle stimulating hormone; LH, luteinizing hormone; testosterone) of rats subjected to CHH. Male Wistar rats were maintained under normobaric or hypobaric conditions (428 torr, 4,600 m). On days 0, 5, 15 and 30 post-exposure, 12 rats were anesthetized, their body weights were measured and blood samples were collected. The testicles were fixed in 4% formaldehyde and processed for histological analysis. In this time course, the FSH levels rose by day 5 post-exposure. On subsequent days, the FSH levels decreased in rats subjected to CHH with a tendency to remain higher than the normoxic group. The LH plasma levels decreased in rats exposed to CHH. Consistent with the decrease in LH levels, the plasma testosterone level decreased significantly after 30 days of CHH exposure. Integrated analysis of hormonal changes in rats subjected to CHH and the body dehydration that occurs in HH allows us to conclude that the effects of CHH on spermatogenesis may be partially related to changes in the hypophysis-gonad hormonal axis.  相似文献