RESUMEN
Here I report the complete mitochondrial genome of the African palm civet, (Nandinia binotata) as sequenced from overlapping PCR products. The genome is 17,103 bp in length and contains the 37 genes found in a typical mammalian genome: 13 protein-coding genes, 22 transfer RNA genes and 2 ribosomal RNA genes. The control region of N. binotata includes both RS2 and RS3 tandem repeats. The overall base composition on the L-strand is A: 33.6%, C: 27.3%, G: 13.0%, and T: 26.1%.
Asunto(s)
ADN Mitocondrial/genética , Genoma Mitocondrial/genética , Mitocondrias/genética , Nandiniidae/genética , Análisis de Secuencia de ADN/veterinaria , África , Animales , Composición de Base/genética , Secuencia de Bases , Tamaño del Genoma , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa/veterinaria , ARN Ribosómico/genética , ARN de Transferencia/genética , Secuencias Repetidas en Tándem/genéticaRESUMEN
Oil palm, a plantation crop of major economic importance in Southeast Asia, is the predominant source of edible oil worldwide. We report the identification of the virescens (VIR) gene, which controls fruit exocarp colour and is an indicator of ripeness. VIR is a R2R3-MYB transcription factor with homology to Lilium LhMYB12 and similarity to Arabidopsis production of anthocyanin pigment1 (PAP1). We identify five independent mutant alleles of VIR in over 400 accessions from sub-Saharan Africa that account for the dominant-negative virescens phenotype. Each mutation results in premature termination of the carboxy-terminal domain of VIR, resembling McClintock's C1-I allele in maize. The abundance of alleles likely reflects cultural practices, by which fruits were venerated for magical and medicinal properties. The identification of VIR will allow selection of the trait at the seed or early-nursery stage, 3-6 years before fruits are produced, greatly advancing introgression into elite breeding material.
Asunto(s)
Frutas/crecimiento & desarrollo , Regulación de la Expresión Génica de las Plantas , Nandiniidae/metabolismo , Proteínas de Plantas/metabolismo , Secuencia de Aminoácidos , Animales , Frutas/genética , Frutas/metabolismo , Regulación del Desarrollo de la Expresión Génica , Datos de Secuencia Molecular , Nandiniidae/clasificación , Nandiniidae/genética , Proteínas Asociadas a Pancreatitis , Filogenia , Proteínas de Plantas/genética , Plantas/clasificación , Plantas/genéticaRESUMEN
We compared the effects of the extract from fruits of Nandina domestica Thunberg (NDE) and its constituents, higenamine and nantenine, on contractile responses in isolated guinea-pig trachea. NDE (1 mg/ml) caused biphasic relaxation of the trachea precontracted with high-K(+) stimulation: the fast component was blocked by propranolol and mimicked by higenamine; and the slow was resistant to propranolol and mimicked by nantenine. Ca(2+)-induced contraction under high-K(+) stimulation was antagonized by nantenine or NDE + propranolol. These results suggest that NDE relaxes the trachea quickly through ß-adrenoceptor stimulation by higenamine and slowly through Ca(2+) antagonism by nantenine.
Asunto(s)
Agonistas Adrenérgicos beta/farmacología , Alcaloides/farmacología , Aporfinas/farmacología , Nandiniidae , Tetrahidroisoquinolinas/farmacología , Tráquea/efectos de los fármacos , Antagonistas Adrenérgicos beta/farmacología , Animales , Calcio/metabolismo , Frutas , Cobayas , Masculino , Relajación Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Potasio/metabolismo , Propranolol/farmacología , Tráquea/fisiologíaRESUMEN
Despite the impact of some trypanosome species on human and livestock health, the full diversity of trypanosomes in Africa is poorly understood. A recent study examined the prevalence of trypanosomes among a wide variety of wild vertebrates in Cameroon using species-specific PCR tests, but six trypanosome isolates remained unidentified. Here they have been re-examined using fluorescent fragment length barcoding (FFLB) and phylogenetic analysis of glycosomal glyceraldehyde phosphate dehydrogenase gGAPDH and 18S ribosomal RNA (rDNA) genes. Isolates from a monkey (Cercopithecus nictitans) and a palm civet (Nandinia binotata) belonged to the Trypanosoma cruzi clade, known previously only from New World and Australian terrestrial mammals, and bats from Africa, Europe and South America. Of the four other isolates, three from antelope were identified as Trypanosoma theileri, and one from a crocodile as T. grayi. This is the first report of trypanosomes of the T. cruzi clade in African terrestrial mammals and expands the clade's known global distribution in terrestrial mammals. Previously it has been hypothesized that African and New World trypanosomes diverged after continental separation, dating the divergence to around 100 million years ago. The new evidence instead suggests that intercontinental transfer occurred well after this, possibly via bats or rodents, allowing these trypanosomes to establish and evolve in African terrestrial mammals, and questioning the validity of calibrating trypanosome molecular trees using continental separation.
Asunto(s)
Genes Protozoarios , Mamíferos/parasitología , Filogenia , Trypanosoma cruzi/genética , Trypanosoma/clasificación , Trypanosoma/genética , Tripanosomiasis Africana/veterinaria , Caimanes y Cocodrilos/parasitología , Animales , Antílopes/parasitología , Camerún , Cercopithecus/parasitología , ADN Ribosómico/genética , Evolución Molecular , Variación Genética , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Humanos , Datos de Secuencia Molecular , Nandiniidae/parasitología , ARN Ribosómico 18S/genética , Alineación de Secuencia , Trypanosoma cruzi/clasificación , Tripanosomiasis Africana/parasitologíaRESUMEN
The severe acute respiratory syndrome coronavirus (SARS-CoV) caused a worldwide epidemic in late 2002/early 2003 and a second outbreak in the winter of 2003/2004 by an independent animal-to-human transmission. The GD03 strain, which was isolated from an index patient of the second outbreak, was reported to resist neutralization by the human monoclonal antibodies (hmAbs) 80R and S3.1, which can potently neutralize isolates from the first outbreak. Here we report that two hmAbs, m396 and S230.15, potently neutralized GD03 and representative isolates from the first SARS outbreak (Urbani, Tor2) and from palm civets (SZ3, SZ16). These antibodies also protected mice challenged with the Urbani or recombinant viruses bearing the GD03 and SZ16 spike (S) glycoproteins. Both antibodies competed with the SARS-CoV receptor, ACE2, for binding to the receptor-binding domain (RBD), suggesting a mechanism of neutralization that involves interference with the SARS-CoV-ACE2 interaction. Two putative hot-spot residues in the RBD (Ile-489 and Tyr-491) were identified within the SARS-CoV spike that likely contribute to most of the m396-binding energy. Residues Ile-489 and Tyr-491 are highly conserved within the SARS-CoV spike, indicating a possible mechanism of the m396 cross-reactivity. Sequence analysis and mutagenesis data show that m396 might neutralize all zoonotic and epidemic SARS-CoV isolates with known sequences, except strains derived from bats. These antibodies exhibit cross-reactivity against isolates from the two SARS outbreaks and palm civets and could have potential applications for diagnosis, prophylaxis, and treatment of SARS-CoV infections.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/inmunología , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/aislamiento & purificación , Animales , Unión Competitiva , Fusión Celular , Reacciones Cruzadas , Modelos Animales de Enfermedad , Brotes de Enfermedades , Humanos , Modelos Biológicos , Modelos Moleculares , Mutagénesis , Nandiniidae/virología , Pruebas de Neutralización , Estructura Terciaria de Proteína , Receptores de Superficie Celular/química , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/fisiología , Síndrome Respiratorio Agudo Grave/epidemiología , Síndrome Respiratorio Agudo Grave/inmunología , Síndrome Respiratorio Agudo Grave/virología , Proteínas Virales/metabolismo , Internalización del Virus , Replicación ViralRESUMEN
BACKGROUND: Experimental animal data show that protection against severe acute respiratory syndrome coronavirus (SARS-CoV) infection with human monoclonal antibodies (mAbs) is feasible. For an effective immune prophylaxis in humans, broad coverage of different strains of SARS-CoV and control of potential neutralization escape variants will be required. Combinations of virus-neutralizing, noncompeting mAbs may have these properties. METHODS AND FINDINGS: Human mAb CR3014 has been shown to completely prevent lung pathology and abolish pharyngeal shedding of SARS-CoV in infected ferrets. We generated in vitro SARS-CoV variants escaping neutralization by CR3014, which all had a single P462L mutation in the glycoprotein spike (S) of the escape virus. In vitro experiments confirmed that binding of CR3014 to a recombinant S fragment (amino acid residues 318-510) harboring this mutation was abolished. We therefore screened an antibody-phage library derived from blood of a convalescent SARS patient for antibodies complementary to CR3014. A novel mAb, CR3022, was identified that neutralized CR3014 escape viruses, did not compete with CR3014 for binding to recombinant S1 fragments, and bound to S1 fragments derived from the civet cat SARS-CoV-like strain SZ3. No escape variants could be generated with CR3022. The mixture of both mAbs showed neutralization of SARS-CoV in a synergistic fashion by recognizing different epitopes on the receptor-binding domain. Dose reduction indices of 4.5 and 20.5 were observed for CR3014 and CR3022, respectively, at 100% neutralization. Because enhancement of SARS-CoV infection by subneutralizing antibody concentrations is of concern, we show here that anti-SARS-CoV antibodies do not convert the abortive infection of primary human macrophages by SARS-CoV into a productive one. CONCLUSIONS: The combination of two noncompeting human mAbs CR3014 and CR3022 potentially controls immune escape and extends the breadth of protection. At the same time, synergy between CR3014 and CR3022 may allow for a lower total antibody dose to be administered for passive immune prophylaxis of SARS-CoV infection.