RESUMEN
The recovering of trivalent Lanthanides from aqueous solutions, by biosorption process onto Galdieria sulphuraria lifeless cells, was investigated. Potentiometry, UV-Vis, FTIR-ATR spectroscopy and SEM-EDS analysis were used. All the experiments were performed at 25 °C, in 0.5 M NaCl. Ln3+ biosorption is greater in the 5-6 pH range with values ranging from 80 µmol/g to 130 µmol/g (dry weight). The adsorbed Ln3+ ions can be recovered at higher acidity (pH<1) and the biosorbent can be reused. Specific molecular interactions between Ln3+ ions and the functional groups on G. sulphuraria surface were highlighted. Particularly, proteins are involved if Ln3+=Pr3+, Sm3+, Eu3+, Tb3+, Dy3+, Tm3+, while Ce3+, Ho3+, Er3+ form bonds with carbohydrates. Finally, both proteins and carbohydrates are involved if Gd3+ and Yb3+. A Surface Complexation approach, with a good graphical fitting to potentiometric experimental collected data, was used to describe the biosorption mechanism. This study could be of great applicative utility for removing of trivalent actinides, from waste aqueous solutions, by biosorption. As well known the lanthanides were used as model to simulate the chemical behaviour of actinides in the same oxidation state.
Asunto(s)
Elementos de Series Actinoides , Elementos de la Serie de los Lantanoides , Rhodophyta , Elementos de la Serie de los Lantanoides/química , IonesRESUMEN
<b>Background and Objective:</b> Ras cheese is one of the important dairy products that are consumed in great quantities. But this cheese is vulnerable to the growth of fungi during ripening and selling until consumption. Therefore, research aimed to detect fungi contaminating Ras cheese and try to resist them. <b>Materials and Methods:</b> The effect of various concentrations (0.25, 0.5, 1, 2 and 3%) of essential oils emulsions of clove (<i>Syzygium aromaticum</i>), thyme (<i>Thymus vulgaris</i>) and peppermint (<i>Mentha piperita</i>) severally on the mycelial growth of the isolated fungi as compared to the control sample was tested <i>in vitro.</i> <b>Results:</b> The results indicated that many fungal species belonging to the genera <i>Aspergillus</i>, <i>Mucor</i>, <i>Eurotium</i> and <i>Mortierella</i> were isolated from the infected Ras cheese. Ochratoxin A was found in two samples whereas recorded the highest level in sample number 1 (2.1 µg kg<sup>1</sup>). Aflatoxin M1 was found in few levels ranged between 0.012 and 0.360 µg kg<sup>1</sup>in cheese samples, while aflatoxin B1 and B2 weren't detected in all samples. Clove essential oil emulsion completely inhibited the growth of all tested fungi at the concentration of 0.5%, followed by thyme essential oil emulsion which inhibited the fungal growth of all fungi at the concentration of 1%, while peppermint essential oil emulsion was less effective. <b>Conclusion:</b> The research recommends that clove and thyme essential oils emulsions can be used to resist the fungi of Ras cheese. Also, suggests that more research could be done on these essential oils emulsions to produce safe foods free of fungi.
Asunto(s)
Queso/análisis , Hongos/efectos de los fármacos , Aceites Volátiles/farmacología , Antifúngicos/administración & dosificación , Antifúngicos/farmacología , Queso/microbiología , Hongos/metabolismo , Hongos/patogenicidad , Aceites Volátiles/administración & dosificaciónRESUMEN
BACKGROUND: School feeding program (SFP) increases access to education and to better health. This study aims to evaluate the effects of SFP on physical growth, cognitive development, psychosocial behavior, and learning achievement of school children. METHODS: A quasi-experimental study was conducted. The intervention group included 903 pupils in the fifth grade receiving the school meal, while the control group included 886 pupils, matched for age and sex, without meal. The meal consisted of a pie made of flour fortified with vitamins A, B6, B12, C, thiamin, riboflavin, niacin, folate, calcium, iron, zinc, and phosphorus. Socioeconomic position, nutritional status, and dietary behavior were evaluated. Neuropsychological tests were done. Psychosocial behavior was rated and educational achievement was recorded. Post hoc and independent sample t tests were used to detect the association of the studied parameters with the intake of school snack. RESULTS: Children who took the meal had better scores on visual memory, auditory vigilance tests (9.71 ± 2.80 vs. 7.45 ± 3.25; 25.02 ± 3.36 vs. 10.82 ± 8.92, respectively, P < 0.001), the afternoon attention and working memory test (8.20 ± 2.21vs. 7.75 ± 3.05) (P < 0.001), but less score of externalizing behavior (P < 0.001) than the control group. No significant changes of children's nutritional status were detected between the two groups. School meal was the main predictor of visual memory and auditory vigilance (P < 0.001), and was the strongest predictor of academic achievements when combined with family size and meals' frequency (P < 0.001). CONCLUSION: School meal improves academic achievements of school children.
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Desarrollo del Adolescente , Desarrollo Infantil , Escolaridad , Asistencia Alimentaria , Adolescente , Niño , Conducta Infantil , Cognición , Egipto , Femenino , Humanos , Estudios Longitudinales , Masculino , Instituciones AcadémicasRESUMEN
Several lines of evidence have implicated long interspersed nuclear element-1 (LINE-1) retroelement in the onset and progression of lung cancer. Retrotransposition-dependent mechanisms leading to DNA mobilization give rise to insertion mutations and DNA deletions, whereas retrotransposition-independent mechanisms disrupt epithelial programming and differentiation. Previous work by our group established that tobacco carcinogens such as benzo(a)pyrene (BaP) reactivate LINE-1 in bronchial epithelial cells through displacement of nucleosome remodeling and deacetylase (NuRD) corepressor complexes and interference with retinoblastoma-regulated epigenetic signaling. Whether LINE-1 in coordination with other genes within its regulatory network contributes to the in vivo genotoxic response to BaP remains largely unknown. Evidence is presented here that intratracheal instillation of ORFeusLSL mice with BaP alone or in combination with adenovirus (adeno)-CRE recombinase is genotoxic to the lung and associated with activation of the human LINE-1 transgene present in these mice. LINE-1 reactivation modulated the expression of genes involved in oncogenic signaling, and these responses were most pronounced in female mice compared with males and synergized by adeno-CRE recombinase. This is the first report linking LINE-1 and genes within its oncogenic regulatory network with early sexually dimorphic responses of the lung in vivo.
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Benzo(a)pireno/toxicidad , Daño del ADN , Redes Reguladoras de Genes , Elementos de Nucleótido Esparcido Largo/genética , Neoplasias Pulmonares/patología , Pulmón/patología , Transgenes/fisiología , Animales , Carcinógenos/toxicidad , Reprogramación Celular , Humanos , Integrasas/metabolismo , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Neoplasias Pulmonares/inducido químicamente , Neoplasias Pulmonares/genética , RatonesRESUMEN
Long interspersed nuclear elements-1 (Line-1 or L1) accounts for approximately 17% of the human genome. The majority of L1s are inactive, but â¼100 remain retrotransposon competent (RC-L1) and able to retrotranspose through RNA intermediates to different locations of the genome. L1 is involved in both disease initiation and progression via retrotransposition dependent and independent mechanisms. Retrotransposed L1 sequences disrupt genetic loci at sites of insertion, while the activities of L1 si/piRNAs, mRNAs, and ORF1 and ORF2 proteins, and have been implicated in the etiology and progression of several human diseases. Despite these relationships, little is known about the clinical utility of L1 as a biomarker of disease initiation and progression, or the utility of small molecules to inhibit and reverse the harmful effects of L1. In this review, we discuss the life cycle of L1, somatic and germline inhibitions, the mechanisms of L1 retrotransposition dependent and independent disease initiation and progression, clinical utilities, and potential of L1s as pharmacologic targets for the treatment of cancer.
Asunto(s)
Genoma Humano/genética , Elementos de Nucleótido Esparcido Largo/genética , Terapia Molecular Dirigida , Neoplasias/genética , Endonucleasas/genética , Humanos , Neoplasias/terapia , Proteínas/genética , ARN Interferente Pequeño/genética , ADN Polimerasa Dirigida por ARN/genéticaRESUMEN
Varicocele is the most common abnormality identified in men being evaluated for subfertility. In this comprehensive review of the pathophysiology of varicocele, we will shed light on novel pathophysiological findings and their clinical implications that may direct future researches; we will shed light on the impact of transient scrotal hyperthermia and the roles of inflammation and differential protein expression and androgen expression in spermatozoa on inducing pathophysiological findings. Furthermore, we will clarify the linked processes contributing to the pathophysiology of varicocele and the impact of genetics on the induction of these processes. Spermatogenesis is a temperature-sensitive process, and heat stress of varicocele is considered the most plausible cause of impaired spermatogenesis. The three processes associated with the presence of varicocele - heat stress, excess reactive oxygen species, and increased apoptosis - appear to be linked; heat stress is associated with increased levels of reactive oxygen species and oxidative stress, which can induce apoptosis. The genetic role should not be overlooked as a contributing factor in the induction of heat stress, excess reactive oxygen species/oxidative stress, and apoptosis; this is evidenced by the association of varicocele with decreased expression of heat-shock proteins, higher polymorphism of glutathione S transferase and nitric oxide synthase genes, and increased BAX and decreased BCL2 genes and proteins. In this article, we will highlight the need of application of novel diagnostic techniques that can provide a precise pathophysiological diagnosis to guide potential specific innovative therapies. Innovative therapies can counteract the varicocele-induced stasis, suppress the degenerative effects of testicular hyperthermia, reduce the varicocele-induced apoptosis, and target the elevated-neutrophil products aiming at abrogating the testicular damage caused by the induced varicocele in rats/mice. In conclusion, on the basis of the novel scientific research, it may be possible to formulate new treatments and achieve the appropriate selection of patients who can benefit from these treatments.
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Varicocele/fisiopatología , Animales , Apoptosis , Temperatura Corporal , Cadmio/metabolismo , Daño del ADN , Humanos , Infertilidad Masculina/metabolismo , Inflamación , Masculino , Especies Reactivas de Oxígeno/metabolismo , Receptores Androgénicos/metabolismo , Espermatogénesis , Testículo/fisiopatología , Varicocele/genética , Varicocele/metabolismo , Varicocele/terapiaRESUMEN
Penile curvature (PC) is bothersome to the patient. PC is either congenital or acquired. In most of the circulatory system, blood flows in a laminar profile with minimal energy expenditure. When a fluid passes in a curved tube, the laminar profile is disturbed and changed into a turbulent flow. It increases the energy expenditure and reduces the flow. Turbulent flow may have a role in the development of an atherosclerotic plaque and in localizing its site. The aim of this research was to study penile hemodynamics before and after correction of PC. This prospective study included 20 participants, with PC more than 30°. For each participant, preoperative color duplex doppler ultrasonography (CDDU), correction of the curvature using 16 dot plication technique and post-operative CDDU were done. Furhtermore, arterial systolic velocity was estimated distal to the site of curvature/correction every 5 min for 25 min. The degree of curvature ranged from 30° to 90° with a mean of 55±18.98. Comparative study between the preoperative and post-operative data proved a significantly higher postoperative peak systolic velocity distal to the site of correction, whereas CDDU data had insignificant differences. We concluded that correction of PC is associated with improvement of penile arterial blood flow distal to the site of correction.
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Hemodinámica , Pene/anomalías , Pene/irrigación sanguínea , Adulto , Anciano , Egipto , Humanos , Masculino , Persona de Mediana Edad , Pene/diagnóstico por imagen , Pene/cirugía , Proyectos Piloto , Periodo Posoperatorio , Estudios Prospectivos , Ultrasonografía Doppler en Color , Adulto JovenRESUMEN
The aim of the present study was to assess female sexual function in an obese group (250 women) and to compare it with a control group (100 women), among 25-35-year-old uncircumcised Egyptian women, using female sexual function index (FSFI) score. FSFI total score of ⩽ 26.55 was considered diagnostic of Female Sexual Dysfunction (FSD). The percentage of FSD in the obese group was 73.6% while it was 71% in the control group, which was statistically insignificant (P > 0.05). The difference between both groups regarding the total (FSFI) score was insignificant (P > 0.05), but arousal and satisfaction domains scores were significantly lower in the obese group. In the obese group, a strong negative correlation between body mass index and arousal, orgasm and the total FSFI score was found. Women with excessive obesity had the lowest total FSFI score. In the obese group, college graduates had the highest total scores and all domain scores of FSFI followed by high school graduates while the least educated women had the lowest scores and when these subgroups were compared, significant differences were found among them. We conclude that in uncircumcised 25-35-year-old Egyptian women, obesity is not a major detrimental factor for FSD, but it may affect some sexual domains such as arousal and satisfaction, although excessive obesity is associated with FSD. Also, educational and cultural factors may have an impact on perception of sex and pleasure.
Asunto(s)
Obesidad/psicología , Orgasmo , Satisfacción Personal , Conducta Sexual/psicología , Disfunciones Sexuales Fisiológicas/psicología , Disfunciones Sexuales Psicológicas/psicología , Adulto , Estudios Transversales , Egipto , Femenino , Humanos , Obesidad/complicaciones , Disfunciones Sexuales Fisiológicas/complicaciones , Disfunciones Sexuales Psicológicas/complicacionesRESUMEN
UNLABELLED: Many procedures have been proposed for the management of sacrococcygeal pilonidal sinus disease. The aim of this work is to evaluate the superiorly based flap (used before for reconstruction of pressure sore) for reconstruction after excision of sacrococcygeal pilonidal sinus. PATIENTS AND METHODS: Between January 2004 and February 2007, 25 male patients of ages between 14 and 29 years(median age: 23 years), who had recurrent pilonidal sinus, underwent surgical treatment by the Limberg flap technique. The mean duration of symptoms was 5.2 + or - 4.5 years (range 3-6 years). Rhombic-shaped excision of the sinus-bearing skin and subcutaneous tissue up to the presacral fascia guided by electrocautery was performed, followed by reconstruction of the defect by perforator-based Limberg flap (based on the superior gluteal and sacral perforators). RESULTS: Primary healing occurred in 22 patients. Two patients (8%) had seroma with negative bacterial cultures, which healed completely with bedside drainage and conservative treatment. Another patient (4%) had superficial wound infection that were treated by appropriate antimicrobial therapy. Complete healing of all cases occurred without recurrence during the follow-up period. The mean operative time was 40min (ranging between 30 and 45min according to the size of the lesion). There was no ischaemia or necrosis of the flaps, and all flaps remained viable. The mean length of hospital stay was 2 days, ranging between 1 and 6 days. CONCLUSION: The use of superiorly based Limberg flap in reconstruction after excision of sacrococcygeal pilonidal sinus is reliable, easily performed, associated with complete cure and low postoperative complications.
Asunto(s)
Seno Pilonidal/cirugía , Procedimientos de Cirugía Plástica/métodos , Colgajos Quirúrgicos/irrigación sanguínea , Adolescente , Adulto , Humanos , Masculino , Complicaciones Posoperatorias , Recurrencia , Región Sacrococcígea/cirugía , Cicatrización de Heridas , Adulto JovenRESUMEN
Previous morphological and molecular analyses failed to resolve the phylogenetic position of the critically endangered saola (Pseudoryx nghetinhensis) with respect to its placement in Bovina (cattle, bison, and yak) or Bubalina (Asian and African buffaloes). In the present study, G- and C-banding, Ag-staining and FISH with 28S and telomeric probes was undertaken for 17 bovid species. An analysis of these data allowed us to identify 49 structural rearrangements that included autosomes, gonosomes and 17 different NOR sites. The combined data set was subjected to a cladistic analysis aimed at: (i) providing new insights on phylogenetic relationships of the saola and other species within the subfamily Bovinae, and (ii) testing the suitability of different classes of chromosomal characters for phylogenetic reconstruction of the family Bovidae. The study revealed that nucleolar organizing regions (NORs) are phylogenetically informative. It was shown that at least one, or sometimes two of these characters punctuate divergences that include nodes that are the most basal in the tree, to those that are the most recent. In this context, the shared presence of three NORs in saola and species of Syncerus and Bubalus strongly suggests the saola's placement within the subtribe Bubalina. This contrasts with Robertsonian rearrangements which are informative only at the generic level. These findings suggest that NORs are an important and frequently overlooked source of additional phylogenetic information within the Bovidae that may also have applicability at higher taxonomic levels, possibly even for Pecora.
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Filogenia , Rumiantes/clasificación , Rumiantes/genética , Animales , Evolución Biológica , Bison/clasificación , Bison/genética , Búfalos/clasificación , Búfalos/genética , Bovinos/clasificación , Bovinos/genética , Bandeo Cromosómico , Citogenética , Femenino , Cabras/clasificación , Cabras/genética , Hibridación Fluorescente in Situ , Cariotipificación , Masculino , Región Organizadora del Nucléolo/genética , Ovinos/clasificación , Ovinos/genética , Especificidad de la Especie , Translocación Genética , Cromosoma X/genéticaRESUMEN
We assessed the long-term immunity to hepatitis B among 242 Egyptian children aged 6-12 years who had received a full vaccination course in infancy, and investigated the factors associated with immunity. Only 39.4% of the children had protective (> or = 10 lU/L) hepatitis B surface antibody levels (HBsAb). This proportion decreased with age but the decrease was not statistically significant. The mean level of HBsAb decreased significantly with increasing age (P = 0.026). A significant negative correlation was found between current age and HBsAb levels (r = -0.31, P = 0.041). Age and weight-for-age were found to be significant predictors of non-protective HBsAb levels.
Asunto(s)
Anticuerpos contra la Hepatitis B/sangre , Vacunas contra Hepatitis B/inmunología , Vacunación , Factores de Edad , Peso Corporal , Niño , Estudios Transversales , Egipto , Femenino , Necesidades y Demandas de Servicios de Salud , Antígenos de Superficie de la Hepatitis B/inmunología , Humanos , Inmunidad Activa , Esquemas de Inmunización , Inmunización Secundaria , Modelos Logísticos , Masculino , Análisis Multivariante , Programas Nacionales de Salud , Factores de Riesgo , Estudios Seroepidemiológicos , Factores Socioeconómicos , Encuestas y Cuestionarios , Salud Urbana/estadística & datos numéricos , Vacunación/métodosRESUMEN
To determine seroprevalence of anti-hepatitis A virus (HAV) antibodies and potential risk factors for and age of contracting symptomatic hepatitis A infection among children of different socioeconomic status (SES) in Cairo, we carried out a cross-sectional study on 426 children aged 3-18 years from low SES areas and 142 from high SES areas. Seroprevalence was significantly higher with age. Seropositivity to anti-HAV antibodies was significantly higher among children of low and very low SES, 90%, compared to children of high SES, 50%. Water supply and sewage disposal were the most significant risk factors for HAV seropositivity in children of low SES. Children of high SES were more likely to be vulnerable to infection in adolescence than those of low SES.
Asunto(s)
Protección a la Infancia/estadística & datos numéricos , Hepatitis A/epidemiología , Clase Social , Salud Urbana/estadística & datos numéricos , Adolescente , Distribución por Edad , Alanina Transaminasa/sangre , Niño , Preescolar , Estudios Transversales , Egipto/epidemiología , Enfermedades Endémicas/estadística & datos numéricos , Femenino , Hepatitis A/inmunología , Hepatitis A/metabolismo , Anticuerpos de Hepatitis A/sangre , Virus de la Hepatitis A Humana/inmunología , Humanos , Masculino , Vigilancia de la Población , Eliminación de Residuos/estadística & datos numéricos , Características de la Residencia/estadística & datos numéricos , Factores de Riesgo , Estudios Seroepidemiológicos , Distribución por Sexo , Factores Socioeconómicos , Abastecimiento de Agua/estadística & datos numéricosRESUMEN
Golden moles (Chrysochloridae) are poorly known subterranean mammals endemic to Southern Africa that are part of the superordinal clade Afrotheria. Using G-banding and chromosome painting we provide a comprehensive comparison of the karyotypes of five species representing five of the nine recognized genera: Amblysomus hottentotus, Chrysochloris asiatica, Chrysospalax trevelyani, Cryptochloris zyli and Eremitalpa granti. The species are karyotypically highly conserved. In total, only four changes were detected among them. Eremitalpa granti has the most derived karyotype with 2n = 26 and differs from the remaining species (all of whom have 2n = 30) by one centric and one telomere:telomere fusion. In addition, two intrachromosomal rearrangements were detected in A. hottentotus. The painting probes also suggest the presence of a unique satellite DNA family located on chromosomes 11 and 12 of both C. asiatica and C. zyli. This represents a synapomorphy linking these two sympatric species as sister taxa. A molecular clock was calibrated adopting a relaxed Bayesian approach for multigene data sets comprising publicly available sequences derived from five gene fragments representative of three golden moles and 39 other eutherian species. The data suggest that golden moles diverged from a common ancestor approximately 28.5 mya (95% credibility interval = 21.5-36.5 mya). Based on an inferred chrysochlorid ancestral karyotype of 2n = 30, the estimated rate of 0.7 rearrangements per 10 my (95% Credibility Interval = 0.54-0.93) differs from the 'default rate' of mammalian chromosomal evolution which has been estimated at one change per 10 million years, thus placing the Chrysochloridae among the slower-evolving chromosomal lineages thus far recorded.
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Pintura Cromosómica , Cromosomas de los Mamíferos/genética , Evolución Molecular , Topos/genética , Animales , Células Cultivadas , Bandeo Cromosómico , Hibridación Fluorescente in SituRESUMEN
Gulls (Aves: Laridae) constitute a recent and cosmopolite family of well-studied seabirds for which a robust phylogeny is needed to perform comparative and biogeographical analyses. The present study, the first molecular phylogeny of all Larids species (N=53), is based on a combined segment of mtDNA (partial cytochrome b and control region). We discuss our phylogenetic tree in the light of previous suggestions based on morphological, behavioral, and plumage characters. Although the phylogeny is not fully resolved, it highlights several robust species groups and confirms or identifies for the first time some sister relationships that had never been suggested before. The Dolphin Gull (Leucophaeus scoresbii) for instance, is identified as the sister species of the Grey Gull (Larus modestus) and the Ross's Gull (Rhodostethia rosea) forms a monophyletic group with the Little Gull (Larus minutus). Our results clearly demonstrate that the genus Larus as currently defined is not monophyletic, since current taxonomy of gulls is based on the use of convergent phenotypic characters. We propose a new systematic arrangement that better reflects their evolutionary history.
Asunto(s)
Charadriiformes/genética , Filogenia , Animales , Secuencia de Bases , Teorema de Bayes , Charadriiformes/clasificación , Cartilla de ADN , ADN Mitocondrial/genética , Funciones de Verosimilitud , Modelos Genéticos , Datos de Secuencia Molecular , Análisis de Secuencia de ADNRESUMEN
In 1993, several horns of an unknown mammal were collected in the south of Vietnam. Due to the unusual characteristics of its horns, the 'linh duong', as named by Vietnamese hunters, was quickly described as belonging to a new monospecific genus of bovid, i.e. Pseudonovibos spiralis Peter & Feiler, 1994. The taxonomic status of Pseudonovibos was a highly controversial subject, and it has been suggested that this enigmatic species may be related to three different groups of Bovidae: Antilopini (gazelles), Bovini (cattle, bisons, buffaloes), and Caprini sensu lato (goats, sheep and allies). To assess the phylogenetic relationships of the linh duong within the family Bovidae, two different DNA markers, the nuclear lactoferrin and the mitochondrial cytochrome b genes, were sequenced from bone samples of four trophies collected during 1925 in Indochina. Results show that the mysterious horns of linh duong belong to domestic cattle (Bos taurus). Thus, the linh duong is not a new mammal and the scientific name Pseudonovibos spiralis should be abandoned.
Asunto(s)
ADN/química , Rumiantes/clasificación , Rumiantes/genética , Animales , Secuencia de Bases , Huesos/química , Bovinos/anatomía & histología , Bovinos/genética , Grupo Citocromo b/genética , Cuernos/química , Lactoferrina/genética , Datos de Secuencia Molecular , Filogenia , Rumiantes/anatomía & histología , Alineación de Secuencia/veterinaria , VietnamRESUMEN
In 1993, the discovery of several pairs of lyre-shaped horns with corrugations was recorded in Vietnam and regarded as evidence for a new, large bovid, later referred to as Pseudonovibos spiralis Peter & Feiler, 1994. Despite numerous field investigations made since 1994 in Vietnam and Cambodia, no new anatomical evidence has ever been found, except for two frontlets with their horn cores and horn sheaths. A new investigation has been carried out on six frontlets and based on a histological analysis of the keratin. It shows that the horns of P. spiralis are merely a skillful forgery made by carving and distorting ordinary cow horns. The horns of Pseudonovibos spiralis were, in some cases, positioned back onto the corresponding horn cores of domestic cow frontlets. The name Pseudonovibos spiralis is thus a junior synonym of Bos taurus, yet it remains valid and available.
Asunto(s)
ADN/química , Cuernos/química , Rumiantes/clasificación , Rumiantes/genética , Animales , Secuencia de Bases , Huesos/química , Bovinos , Grupo Citocromo b/genética , Lactoferrina/genética , Datos de Secuencia Molecular , Filogenia , Rumiantes/anatomía & histología , Alineación de Secuencia , VietnamRESUMEN
We have isolated and characterized a cDNA (DNA complementary to RNA) clone (Rf69) from the vestimentiferan Riftia pachyptila. The cDNA insert consists of 1169 base pairs. The aminoacid sequence deduced from the longest reading frame is 193 residues in length, and clearly characterized it as a myosin regulatory light chain (RLC). The RLC primary structure is described in relation to its function in muscle contraction. The comparison with other RLCs suggested that Riftia myosin is probably regulated through its RLC either by phosphorylation like the vertebrate smooth muscle myosins, and/or by Ca2+-binding like the mollusk myosins. Riftia RLC possesses a N-terminal extension lacking in all other species besides the earthworm Lumbricus terrestris. Aminoacid sequence comparisons with a number of RLCs from vertebrates and invertebrates revealed a relatively high identity score (64%) between Riftia RLC and the homologous gene from Lumbricus. The relationships between the members of the myosin RLCs were examined by two phylogenetic methods, i.e. distance matrix and maximum parsimony. The resulting trees depict the grouping of the RLCs according to their role in myosin activity regulation. In all trees, Riftia RLC groups with RLCs that depend on Ca2+-binding for myosin activity regulation.
Asunto(s)
Cadenas Ligeras de Miosina/genética , Poliquetos/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión , Cationes/metabolismo , ADN Complementario/química , ADN Complementario/genética , Datos de Secuencia Molecular , Cadenas Ligeras de Miosina/metabolismo , Fosforilación , Filogenia , Unión Proteica , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia de AminoácidoRESUMEN
The Ig and T cell receptor (TCR) loci have an exceptionally dynamic evolutionary history, but the mechanisms responsible remain a subject of speculation. Ig and TCR genes are unique in vertebrates in that they are assembled from V, D, and J segments by site-specific recombination in developing lymphocytes. Here we examine the extent to which the V(D)J recombination in germline cells may have been responsible for remodeling Ig and TCR loci in mammals by asking whether gene segments have evolved as a unit, or whether, instead, recombination signal sequences (RSSs) and coding sequences have different phylogenies. Four distinct types of RSS have been defined in the human Ig heavy-chain variable region (Vh) locus, namely H1, H2, H3, and H5, and no other RSS type has been detected in other mammalian species. There is a well-supported discrepancy between the evolutionary history of the RSSs as compared with the Vh coding sequences: the RSS type H2 of one Vh gene segment has clearly become replaced by a RSS type H3 during mammalian evolution, between 115 and 65 million years ago. Two general models might explain the RSS swap: the first involves an unequal crossing over, and the second implicates germline activation of V(D)J recombination. The Vh-H2/RSS-H3 recombination product has likely been selected during the evolution of mammals because it provides better V(D)J recombination efficiency.
Asunto(s)
Evolución Molecular , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Señales de Clasificación de Proteína/genética , Recombinación Genética , Secuencia de Bases , ADN , Humanos , Datos de Secuencia Molecular , Filogenia , Homología de Secuencia de Ácido NucleicoRESUMEN
The "Linh Duong" (Pseudonovibos spiralis), a newly described Vietnamese bovid, has been shown to be related to the Caprinae on the basis of the mitochondrial cytochrome b gene sequencing from horn fragments. To integrate the greatest available biodiversity we performed a new phylogenetic analysis including all genera of Caprinae. Unexpectedly, Pseudonovibos is found to be robustly associated with Rupicapra, and closer to the Alpine than to the Pyrenean chamois. Several clues led us to interpret this result as a carry-over DNA contamination of Pseudonovibos by Rupicapra.
Asunto(s)
Grupo Citocromo b/genética , Filogenia , Rumiantes/clasificación , Rumiantes/genética , Animales , ADN Mitocondrial/genética , Ecosistema , VietnamRESUMEN
The nucleotide sequence of the complete mitochondrial cytochrome b gene has been determined and compared for 51 species of the family Bovidae and 10 potential pecoran and tragulid outgroups. A detailed saturation analysis at each codon position relative to the maximum parsimony procedure indicates that all transitions on third codon positions do not accumulate in a similar fashion: C-T are more saturated than A-G substitutions. The same trend is observed for second positions but not for first positions where A-G and C-T transitions exhibit roughly the same levels of saturation. Maximum parsimony reconstructions were weighted according to these observations. Maximum parsimony, maximum likelihood, and distance phylogenetic reconstructions all depict a major split within Bovidae. The subfamily Bovinae includes four multifurcating tribes and subtribes: Boselaphini, Tragelaphini, cattle-Bovini (Bos and Bison), and buffalo-Bovini (Bubalus and Syncerus). Its sister group is the subfamily Antilopinae, i.e., all non-Bovinae taxa, represented by seven lineages: Antilopini (including Saiga), Caprini sensu lato (i. e., Caprinae including Pantholops), Hippotragini, Alcelaphini, Reduncini (including Pelea), Aepyceros possibly linked to Neotragus, and Cephalophini possibly linked to Oreotragus (the suni and the klipspringer being members of a polyphyletic Neotragini). These various tribes and major lineages were produced by two noteworthy explosive radiations, which occurred simultaneously between 12.0 and 15.3 MY (Middle Miocene) in the subfamilies Bovinae and Antilopinae.