RESUMEN
BACKGROUND: Proline (Pro) accumulation is a widespread response of prokaryotic and eukaryotic cells subjected to osmotic stress or dehydration. When the cells are released from stress, Pro is degraded to glutamate by Pro-dehydrogenase (ProDH) and Pyrroline-5-carboxylate dehydrogenase (P5CDH), which are both mitochondrial enzymes in eukaryotes. While P5CDH is a single copy gene in Arabidopsis, two ProDH genes have been identified in the genome. Until now, only ProDH1 (At3g30775) had been functionally characterised. RESULTS: We demonstrate vasculature specific expression of the Arabidopsis ProDH2 gene (At5g38710) as well as enzymatic activity and mitochondrial localisation of the encoded protein. Expression levels of ProDH2 are generally low, but increased in senescent leaves and in the abscission zone of floral organs. While sucrose represses ProDH2 expression, Pro and NaCl were identified as inducers. Endogenous ProDH2 expression was not able to overcome Pro sensitivity of ProDH1 mutants, but overexpression of a GFP-tagged form of ProDH2 enabled the utilisation of Pro as single nitrogen source for growth. Amongst two intronic insertion mutants, one was identified as a null allele, whereas the other still produced native ProDH2 transcripts. CONCLUSIONS: Arabidopsis possesses two functional ProDHs, which have non-redundant, although partially overlapping physiological functions. The two ProDH isoforms differ with respect to spatial, developmental and environmental regulation of expression. While ProDH1 appears to be the dominant isoform under most conditions and in most tissues, ProDH2 was specifically upregulated during salt stress, when ProDH1 was repressed. The characterisation of ProDH2 as a functional gene requires a careful re-analysis of mutants with a deletion of ProDH1, which were so far considered to be devoid of ProDH activity. We hypothesise that ProDH2 plays an important role in Pro homeostasis in the vasculature, especially under stress conditions that promote Pro accumulation.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Prolina Oxidasa/metabolismo , Adaptación Fisiológica/efectos de los fármacos , Empalme Alternativo/efectos de los fármacos , Empalme Alternativo/genética , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Carbohidratos/farmacología , ADN Bacteriano/genética , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Técnicas de Inactivación de Genes , Prueba de Complementación Genética , Proteínas Fluorescentes Verdes/metabolismo , Intrones/genética , Isoenzimas/genética , Isoenzimas/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/enzimología , Mutación/genética , Especificidad de Órganos/efectos de los fármacos , Prolina/metabolismo , Prolina/farmacología , Prolina Oxidasa/genética , Transporte de Proteínas/efectos de los fármacos , Proteínas Recombinantes de Fusión/metabolismo , Cloruro de Sodio/farmacología , Fracciones Subcelulares/efectos de los fármacos , Fracciones Subcelulares/enzimologíaRESUMEN
Human language is a fundamentally cooperative enterprise, embodying fast-paced and extended social interactions. It has been suggested that it evolved as part of a larger adaptation of humans' species-unique forms of cooperation. Although our closest living relatives, bonobos and chimpanzees, show general cooperative abilities, their communicative interactions seem to lack the cooperative nature of human conversation. Here, we revisited this claim by conducting the first systematic comparison of communicative interactions in mother-infant dyads living in two different communities of bonobos (LuiKotale, DRC; Wamba, DRC) and chimpanzees (Taï South, Côte d'Ivoire; Kanyawara, Uganda) in the wild. Focusing on the communicative function of joint-travel-initiation, we applied parameters of conversation analysis to gestural exchanges between mothers and infants. Results showed that communicative exchanges in both species resemble cooperative turn-taking sequences in human conversation. While bonobos consistently addressed the recipient via gaze before signal initiation and used so-called overlapping responses, chimpanzees engaged in more extended negotiations, involving frequent response waiting and gestural sequences. Our results thus strengthen the hypothesis that interactional intelligence paved the way to the cooperative endeavour of human language and suggest that social matrices highly impact upon communication styles.
Asunto(s)
Comunicación Animal , Conducta Cooperativa , Pan paniscus/fisiología , Pan troglodytes/fisiología , Animales , Conducta Animal , Femenino , Gestos , Humanos , Masculino , Modelos Animales , MadresRESUMEN
Rectal gastrointestinal stromal tumors are rare. To date, 12 gastrointestinal stromal tumors have been reported as pelvic vaginal masses. We describe a rectovaginal tumor in a 39-year-old woman. The tumor frequently recurred after multiple surgical excisions and interrupted imatinib treatment without metastasizing. Magnetic resonance tomography demonstrated a partial response under imatinib. The patient was alive with stable disease under imatinib 44 months from initial diagnosis. Molecular analysis showed a somatic 6-base pair deletion in exon 11 of c-KIT (W557_K558del) in both the primary tumor and the third recurrence; the recurrence had an additional exon 17 mutation (N822K). Comparative genomic hybridization analysis of the primary tumor showed loss of 14q and gain of 1q. Recurrence showed complete loss of nuclear p16 expression. Molecular studies and p16 status confirmed the typical characteristics of gastrointestinal stromal tumors with an aggressive phenotype underscoring the need for a special interdisciplinary treatment and for achieving complete local excision with free margins.
Asunto(s)
Tumores del Estroma Gastrointestinal/genética , Tumores del Estroma Gastrointestinal/patología , Neoplasias del Recto/genética , Neoplasias del Recto/patología , Neoplasias Vaginales/genética , Neoplasias Vaginales/patología , Adulto , Antineoplásicos/uso terapéutico , Secuencia de Bases , Benzamidas , Hibridación Genómica Comparativa , Femenino , Tumores del Estroma Gastrointestinal/terapia , Humanos , Mesilato de Imatinib , Inmunohistoquímica , Biología Molecular , Datos de Secuencia Molecular , Mutación , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/terapia , Piperazinas/uso terapéutico , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas c-kit/genética , Pirimidinas/uso terapéutico , Neoplasias del Recto/terapia , Neoplasias Vaginales/terapiaRESUMEN
1. Anterior and posterior halves of 6 hour-old embryos were transplanted with or without their central egg yolk filling into the abdomens of adult females. 2. It was found that the yolk has no formative or nutritive influence on the differentiation which proceeds normally in the adult milieu.