Cloning and analysis of IFRG (interferon responsive gene) in rabbit oocytes and preimplantation embryos

Although there is more evidence that shows that IFNs (interferons) plays a very important role in the early development of the embryo, the mechanism of IFNs is still unclear. Our study showed that IFRG is expressed from oocytes- through to the preimplantation embryo in rabbits. This finding provides some clues for better understanding the role of IFNs in the development of the embryo. The full length of rabbit IFRG cDNA (Accession No. AJ584672), with a 2794bp encoding 131 amino acid sequence, was cloned IFRG expression can be detected in 8 different tissues: ovary, heart, lung, liver, kidney, spleen, cerebra, and the 18-day whole-body embryo. Whole-mount in situ hybridization showed that IFRG was highly expressed in the inner-cell mass of rabbit blastula. IFRG may play an important role in embryo development and tissue differentiation.(AU)

Typological series for ovarian follicles of sexually mature Myocastor coypus (coypu)

We are herein putting forward the results derived from the careful examination of the ovary of a sexually mature Myocastor coypus which was carried out to establish a follicular typological series. Sexually mature virgin females from breeding farms were used and their ovaries were processed by routinely histological techniques. The following analysis criteria were considered for the follicular classification: size of the oocyte in follicles at different stages of development, size of the follicle regarding the number of follicular cells, and follicular morphology. Complementary characteristics were also analyzed: mean follicular diameter, presence and thickness of the pellucid zone, mean size of follicular cells, their shape in all follicular types, presence and extent of the antrum, and presence of thecas. By combining these different criteria, a follicular typological series was obtained according to Pedersen and Peters (1968) nomenclature together with a qualitative and quantitative characterization of the follicular types.(AU)

RNA metabolism in the follicle cells of Bufo arenarum oocytes: I. Biochemical studies

Se determinó la captación de 3H adenosina en células foliculares y ovocitos ováricos totalmente crecidos de Bufo arenarum, y la incorporación del trazador radioactivo en ARN total y en la fracción reistente a ribonucleasas. Se incubaron 3H adenosina en folículos y envolturas foliculares (I-FE). En el primer caso, luego de la incubación las envolturas foliculares fueron manualmente separadas (O-FE). En el primer caso, luego de la incubación las envolturas foliculares fueron manualmente separadas (O-FE) y procesadas independiente de los ovocitos . I-FE incorporó 2,9 veces más 3H adenosina que O-FE. Los medios de incubación de I-FE y O-FE fueron analizados; en el primer caso se encontró 10.2 veces más radioactividad en macromoléculas que en el segundo caso. Se realizó una caracterización parcial de la ARN recientemente sintetizada, mediante electroforesis, encontrándose diferentes patrones para ARN de I-FE y O-FE. Una posible explicación para los resultados obtenidos es que las células foliculares transfieren ARN recientemente sintetizado al ovocito y, en ausencia de esto, al medio de incubación (AU)

RNA metabolism in the follicle cells of Bufo arenarum oocytes: II. Autoradiographic studies

Se incubaron folículos ováricos, conteniendo ovocitos totalmente crecidos de Bufo arenarum en 3H adenosina por períodos de hasta 16 horas. Autorradiografías de cortes de los folículos mostraron que los núcleos de las células foliculares y los nucleolos de las vesículas germinales de los ovocitos se presentaron fuertemente marcados. El nucleoplasma y la region cortical del ovocito están más radioactivos que las zonas subcortical y la periferia de la vesícula germinal. La región cortical es la única que muestra incrementos significativos en la concentración de granos de plata luego de un período de "chase". Esto sugiere que los granos de plata de la región cortical provienen de las células foliculares y no de la vesícula germinal. El agregado de Actinomicina D a los medios de incubación reduce notablemente los depósitos de plata, indicando que las moléculas marcadas son ARN (AU)

First demonstration of the substructure of recombination nodules

Recombination nodules are submicroscopic structures that are found in all the sexually reproducing, eukaryotic organisms during the pachytene stage of meiotic prophase I. Despite many reports on their number and location, no definite substructure was previously reported in these nodules. The present observations on spread oocytes and spermatocytes of the pigeon, using an improved technique for protein preservation, shown the presence of particulate subunits or "recombinomeres" in late recombination nodules, besides an interparticle matrix. The number of subunits per each nodule ranges from 1 to 5, and this number increases with the advancement of pachytene substages. These subunits are present in recombination nodules of all the other avian species previously studied, and they may be present in other organisms as well. It is suggested that the particulate substructure of recombination nodules mirrors the multiplicity of multienzymatic complexes that are needed for the ordered series of reactions that occur at the molecular level in the sites of meiotic recombination

Morphological and cytochemical changes during nuclear maturation in Bufo arenarum oocytes

The morphological and cytochemical changes undergone by the oocyte during progesterone-induced nuclear maturation were analyzed in fully grown follicle oocytes of Bufo arenarum during the breeding period. The distribution and the staining properties of the nuclear material and of the perinuclear cytoplasm were studied. Our observations indicate that, during this complex process, the germinal vesicle (GV) undergoes migration and dissolution. The nuclear sap, which in the control has an homogeneous aspect, during maturation adopts a fibrillar appearance in the basal zone, showing basophilia and positive reaction to PAS, Feulgen and Methyl green-Pyronin staining. When the GV breakdown occurs, the nuclear contents become mixed with the cortical cytoplasm, developing a different cytoplasmic mass that disappears about 12 h after the beginning of incubation. The perinuclear cytoplasm exhibits metachromasia and orthochromasia with Toluidine Blue at pH 5.6 and a strong basophilia with PAS, suggesting the existence of acid compounds. The presence of nucleic acids such as RNA and DNA is a strong possibility because of the positive reaction to Methyl green-Pyronin, Feulgen and DAPI. This cytoplasmic mass remains until the end of the meiotic resumption process