C/EBP delta and C/EBP gamma bind the CCAAT-box in the human beta-globin promoter and modulate the activity of the CACC-box binding protein, EKLF

Developmental- and tissue-specific expression of globin genes is mediated by a few key elements within the proximal promoter of each gene. DNA-binding assays previously identified NF-Y, GATA-1, C/EBP beta and C/EBP gamma as candidate regulators of beta-globin transcription via the CCAAT-box, a promoter element situated between CACC- and TATA-boxes. We have identified C/EBP delta as an additional beta-globin CCAAT-box binding protein. In reporter assays, we show that C/EBP delta can co-operate with EKLF, a CACC-box binding protein, to activate the beta-globin promoter, whereas C/EBP gamma inhibits the transcriptional activity of EKLF in this assay. (c) 2005 Elsevier B.V. All rights reserved.

Functional characterization and genomic organization of the human Na+-sulfate cotransporter hNaS2 gene (SLC13A4)

Sulfate plays an essential role in human growth and development. Here, we characterized the functional properties of the human Na+-sulfate cotransporter (hNaS2), determined its tissue distribution, and identified its gene (SLC13A4) structure. Expression of hNaS2 protein in Xenopus oocytes led to a Na+-dependent transport of sulfate that was inhibited by thiosulfate, phosphate, molybdate. selenate and tungstate, but not by oxalate, citrate, succinate, phenol red or DIDS. Transport kinetics of hNaS2 determined a K, for sulfate of 0.38 mM, suggestive of a high affinity sulfate transporter. Na+ kinetics determined a Hill coefficient of 1.6 +/- 0.6, suggesting a Na: SO42- stoichiometry of 2:1. hNaS2 mRNA was highly expressed in placenta and testis, with intermediate levels in brain and lower levels found in the heart, thymus, and liver. The SLC13A4 gene contains 16 exons, spanning over 47 kb in length. Its 5'-flanking region contains CAAT- and GC-box motifs, and a number of putative transcription factor binding sites, including GATA-1, AP-1, and AP-2 consensus sequences. This is the first study to characterize hNaS2 transport kinetics, define its tissue distribution, and resolve its gene (SLC13A4) structure and 5' flanking region. (C) 2004 Elsevier Inc. All rights reserved.

Testicular development of Zebu bulls after chronic treatment with a gonadotropin-releasing hormone agonist

The objective was to compare testis characteristics of Zebu bulls treated with the GnRH agonist, deslorelin, at different times and for different durations during their development. An additional objective was to determine the usefulness of a stain for the transcription factor GATA-binding protein 4 (GATA-4) as a specific marker for Sertoli cell nuclei in cattle. Bulls (54) were allocated to nine groups (n = 6) and received s.c. deslorelin implants as follows: G1 = from birth to 3 mo of age; G2 = from 3 to 6 mo; G3 = from 6 to 9 mo; G4 = from 9 to 12 mo; G5 = from birth to 15 mo; G6 = from 3 to 15 mo; G7 = from 6 to 15 mo; G8 = from 12 to 15 mo; and G9 (control) = no implant. Bulls were castrated at 19 mo of age. Paraffin sections (10 mu m) were subjected to quantitative morphometry and GATA-4 immunohistochemistry. At castration, all bulls in the control group (6/6) had attained puberty (scrotal circumference ! 28 cm), whereas a smaller proportion (P < 0.05) had reached puberty in G2 (2/5) and G6 (1/ 6). Bulls in G2 and G6 also had a lesser (P < 0.05) testis weight compared with the control group. Total volume of seminiferous epithelium and total daily sperm production in G2 and G6 were only half that observed in the control group. Spermatids were observed in less than 50% of seminiferous tubules in G2, G6, and G7 compared with 82% in the control group (P < 0.05). Staining for GATA-4 was specific for and abundant in the Sertoli cell nucleus in both pre- and postpubertal bulls, and no other cell nucleus inside the seminiferous tubule was positive for GATA-4. Total number of Sertoli cells was not affected by treatment (P = 0.45), but nuclear volume was smaller in G2 and G6 (P < 0.05) compared with the control group. In conclusion, treatment of Zebu bulls with deslorelin had no apparent beneficial effect on testis development and delayed puberty when treatment was initiated at 3 mo of age. Staining for GATA-4 was a useful method for identifying and quantifying Sertoli cell nuclei in both pre- and postpubertal bulls.

Regulation of Amh during sex determination in chickens: Sox gene expression in male and female gonads

During mammalian sexual development, the SOX9 transcription factor up-regulates expression of the gene encoding anti-Mullerian hormone (AMH), but in chickens, Sox9 gene expression reportedly occurs after the onset of Amh expression. Here, we examined expression of the related gene Sox8 in chicken embryonic gonads during the sex-determining period. We found that cSox8 is expressed at similar levels in both sexes at embryonic day 6 and 7, and only at the anterior tip of the gonad, suggesting that SOX8 is not responsible for the sex-specific increase in cAmh gene expression at these stages. We also found that several other chicken Sox genes (cSox3, cSox4 and cSox11) are expressed in embryonic gonads, but at similar levels in both sexes. Our data suggest that the molecular mechanisms involved in the regulation of Amh genes of mouse and chicken are not conserved, despite similar patterns of Amh expression in both species.

Molecular cloning and characterization of the mouse Na+ sulfate cotransporter gene (Slc13a4): structure and expression

Sulfate is an essential ion required for numerous functions in mammalian physiology. Due to its hydrophilic nature, cells require sulfate transporters on their plasma membranes to allow entry of sulfate into cells. In this study, we identified a new mouse Na+-sulfate cotransporter (mNaS2), characterized its tissue distribution and determined its cDNA and gene (Slc13a4) structures. mNaS2 mRNA was expressed in placenta, brain, lung, eye, heart, testis, thymus and liver. The mouse NaS2 cDNA spans 3384 nucleotides and its open frame encodes a protein of 624 amino acids. Slc13a4 maps to mouse chromosome 6131 and contains 16 exons, spanning over 40 kb in length. Its 5'-flanking region contains CART- and GC-box motifs and a number of putative transcription factor binding sites, including GATA-1, MTF-1, STAT6 and HNF4 consensus sequences. This is the first study to define the tissue distribution of mNaS2 and resolve its cDNA and gene structures, which will allow us to investigate mNaS2 gene expression in vivo and determine its role in mammalian physiology.

Étude du mécanisme d'action du facteur bHLH hématopoïétique SCL

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Établissement d'une lignée cellulaire pro-érythroïde de souris : outil d'étude de la régulation transcriptionnelle des gènes de globine

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Étude du mécanisme d'action du facteur bHLH hématopoïétique SCL

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Établissement d'une lignée cellulaire pro-érythroïde de souris : outil d'étude de la régulation transcriptionnelle des gènes de globine

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Antropología de la Conservación en España. Balance y perspectivas

En este artículo presentamos un balance de la Antropología de la Conservación en el Estado español. Durante las últimas décadas, la protección de los espacios naturales ha aumentado de una manera exponencial en todo el mundo. A la vez que se extendía esta patrimonialización de la naturaleza, los trabajos etnográficos sobre las áreas protegidas han ido ganando terreno dentro de la disciplina y, en particular, en el campo de la Antropología Ambiental. La mencionada bibliografía ha puesto de relieve los múltiples aspectos derivados de las nuevas políticas territoriales de regulación, apropiación y mercantilización de la ‘naturaleza’. En este trabajo realizamos una revisión exhaustiva de la producción generada a raíz de este interés por las áreas protegidas en nuestro país subrayando sus principales aportaciones, características y debilidades. De este modo pretendemos reflexionar acerca de su continuidad, con el fin de evitar la mera reiteración y favorecer el avance en sus resultados.

Sobre la migración de Ciconia nigra

[ES] El día 16-X-1960 nos son mostradas las dos alas de un individuo juvenil de esta especie, cobrado por un cazador alrededor del 15-X- 1960 en las salinas del Cabo de Gata (Almería). El día 2-IX-77, a las 18:50 horas, con el sol recién puesto y a unos 11 kms. Al NE de Cehegin (Murcia), espantamos del suelo dos individuos de esta especie que se posan en un gran Pinus halepensis. Se trata de dos jóvenes, a juzgar por la coloración de patas y pico. Posteriormente emprenden vuelo hacia el S pero después de recorrer unos 500m, dan vueltas en círculos y vuelven hacia el N. observándolas en franco vuelo de aterrizaje hacia la cola del embalse de Argos, situado en las proximidades.

Clinical and molecular characterization of feline mammary carcinomas overexpressing HER2 proto-oncogene (FMC-HER2+) : new strategies for effective diagnostic and cancer therapy

Tese de Doutoramento em Ciências Veterinárias na Especialidade de Ciências Biológicas e Biomédicas

Posidonia oceanica (L.) Delile in its westernmost biogeographical limit (northwestern Alboran Sea): Meadows characterisation, phenology and flowering events

Posidonia oceanica is a Mediterranean endemic seagrass species that forms meadows covering ca. 2.5–4.5 millions of hectares, representing ca.25 % of the infralittoral and shallow circalittoral (down to 50m) bottoms of the Mediterranean. This seagrass is considered a habitat-engineer species and provides an elevated number of ecosystem services. In addition the Marine Strategy Framework Directive (MSFD, 2008/56/EC) includes seagrass like elements to evaluate the “Good Environmental Status” of the European coasts. Information about their phenological characteristic and structure of the meadows is needed for indicator estimations in order to establish their conservation status. The studied meadows are located in the westernmost limit of the P. oceanica distribution (North-western Alboran Sea) in the vecinity of the Strait of Gibraltar, an Atlantic-Mediterranean water transition area. Four sites were selected from East to West: Paraje Natural de Acantilados de Maro-Cerro Gordo (hereafter Maro), Special Area of Conservation “Calahonda” (hereafter Calahonda), Site of Community Importance Estepona (hereafter Estepona) and Punta Chullera (hereafter Chullera) where P. oceanica present their westernmost meadows. Phenological data were recorded from mid November to mid December in P. oceanica patches located at 2 – 3 m depth. At each site three types of patches (patch area <1m2, small patches; 1-2 m2, medium patches and >2 m2, large patches) were sampled. At each patch and site, 3 quadrants of 45 x 45 cm were sampled for shoot and inflorescences density measurements. In each quadrant, 10 random shoots were sampled for shoot morphology (shoot height and number of leaves). Shoot and inflorescences densities were standardized to squared meters. All the studied P. oceanica meadows develop on rocks and they present a fragmented structure with a coverage ranging between ca. 45% in Calahonda and Estepona and ca. 31% in Maro. The meadows of Chullera are reduced to a few small - medium patches with areas ranging between 0.5-1.5 m2 (Fig. 1). The meadows of Chullera and Estepona presented similar values of shoot density (ca. 752 – 662 shoots m-2, respectively) and leaf height (ca. 25 cm). Similarly, the Calahonda and Maro meadows also showed similar values of shoot density (ca. 510 – 550 shoots m-2, respectively) but displaying lower values than those of sites located closer to the Strait of Gibraltar. Regarding patch sizes and leaf height, the longest leaves (ca. 25 cm) were found in medium and large patches, but the number of leaves per shoot were higher in the small and the medium size patches (ca. 6.3 leaves per shoot). Flowering was only detected at the Calahonda meadows with maximum values of ca. 330 inflorescences m-2 (115.2 ± 98.2 inflorescences m-2, n= 9; mean ± SD) (Fig.1). Inflorescence density was not significant different among patches of different sizes. In the Alboran Sea and unlike the studied meadows, extensive beds of P. oceanica occur at the National Park of Cabo de Gata (northeastern Alboran Sea), but from east to west (Strait of Gibraltar), meadows are gradually fragmenting and their depth range decrease from 30m to 2m depth between Cabo de Gata and Chullera, respectively. Probably, the Atlantic influence and the characteristic oceanographic conditions of the Alboran Sea (i.e., higher turbidity, higher water turbulence) represent a developmental limiting factor for P. oceanica at higher depths. Similarities between the meadows located closer to Strait of Gibraltar (Chullera and Estepona) were detected as well as between those more distant (Calahonda and Maro). The first ones showed higher values of shoot densities and leaf heights than the formers, which could be relating to the higher hydrodynamic exposure found at Chullera and Estepona meadows. Regarding flowering events, sexual reproduction in P. oceanica is not common in different locations of the Mediterranean Sea. The available information seems to indicate that flowering represent an irregular event and it is related to high seawater temperature. In fact, the flowering episodes that occurred in Calahonda in November 2015, match with the warmest year ever recorded. This is the third flowering event registered in these meadows located close to the westernmost distributional limit of P. oceanica (Málaga, Alboran Sea), which could indicates that these meadows presents a healthy status. Furthermore, the absence of significant differences in relation to inflorescence density between patches of different sizes may be indicating that the fragmentation does not necessarily influence on the flowering of this seagrass species.

Distribution pattern of Galeus atlanticus in the Alborán Sea (south western Mediterranean) and some sexual character comparison with Galeus melastomus

Galeus atlanticus is a small-sized deepwater catshark living on the slope bottom of the Alborán Sea. Given its external similarities with Galeus melastomus, both species are often confused, which makes G. atlanticus a very poorly understood species both in terms of catches and biological aspects. For this study, a total of 741 G. atlanticus specimens, caught during scientific surveys from 1997 to 2003, were analysed. The distributional patterns were described and the reproductive status estimated. Galeus atlanticus occurred throughout the Alborán Sea, between the Strait of Gibraltar and Cape Gata, including the slope of the Island of Alborán. Its bathymetric range extended from 330 to 790 m and no size depth trends have been observed. Mature specimens, both males and females, were caught in all seasons of the year. Size at first maturity was significantly different between sexes, with estimates of 32.9 cm for males and 36.9 cm for females. The differential growth of some secondary sexual characteristics, such as clasper length in males and oviducal gland diameter in females, were compared with those of G. melastomus.