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Histomorphology of prepuberal ovaries in the South American fur seal [Arctocephalus australis Zimmerman, 1783]

100%

Katz H., Perez W., Bielli A., Chavez R.

Folia Morphologica

2009

tom 68

nr 4

277-286

The South American fur seal reproductive histophysiology is scarcely described. This study provides a histological description of prepuberal South American fur seal (Arctocephalus australis) ovaries as well as three-dimensional reconstructions of subcapsular crypts and primordial follicles. Ovaries from fresh dead animals were processed for histology and sliced into serial sections. A portion of the superficial cortex was photographed, and the images were processed using BioVis3d software in order to generate 3-dimensional reconstructions. A. australis prepuberal ovaries conform to the basic structure of pinnipedian species, with a subcapsular crypts system made up of interconnecting cisternae and tubules with multiple openings to the surface. Generally, the primordial follicles were arranged in a monolayer beneath the tunica albuginea and were closely associated with subcapsular crypts. The large number of interstitial cells distributed throughout the cortex was the main histological feature in comparison with previous reports in other seals. Three-dimensional reconstructions modelled the subcapsular crypts microarchitecture and showed the close spatial relationship between the crypts and the primordial follicles. Despite the fact that the general ovarian histological structure was similar to that of other pinnipeds, the large number of interstitial cells is a distinctive feature that raises the question about the origin and function in A. australis with regard to the steroidogenic activity reported in other seal species. (Folia Morphol 2009; 68, 4: 277–286)

Molecular characterization of the niaD and pyrG genes from Penicillium camemberti, and their use as transformation markers

76%

Navarrete K., Roa A., Vaca I., Espinosa Y., Navarro C., Chavez R.

Cellular and Molecular Biology Letters

2009

tom 14

nr 4

692-702

Genetic manipulation of the filamentous fungus Penicillium camemberti has been limited by a lack of suitable genetics tools for this fungus. In particular, there is no available homologous transformation system. In this study, the nitrate reductase (niaD) and orotidine-5′-monophosphate decarboxylase (pyrG) genes from Penicillium camemberti were characterized, and their suitability as metabolic molecular markers for transformation was evaluated. The genes were amplified using PCR-related techniques, and sequenced. The niaD gene is flanked by the nitrite reductase (niiA) gene in a divergent arrangement, being part of the putative nitrate assimilation cluster in P. camemberti. pyrG presents several polymorphisms compared with a previously sequenced pyrG gene from another P. camemberti strain, but almost all are silent mutations. Southern blot assays indicate that one copy of each gene is present in P. camemberti. Northern blot assays showed that the pyrG gene is expressed in minimal and rich media, and the niaD gene is expressed in nitrate, but not in reduced nitrogen sources. The functionality of the two genes as transformation markers was established by transforming A. nidulans pyrG- and niaD-deficient strains. Higher transformation efficiencies were obtained with a pyrG-containing plasmid. This is the first study yielding a molecular and functional characterization of P. camemberti genes that would be useful as molecular markers for transformation, opening the way for the future development of a non-antibiotic genetic transformation system for this fungus.

Ograniczanie wyników

1 Cellular and Molecular Biology Letters

1 Folia Morphologica

2 Chavez R.

1 Bielli A.

1 Espinosa Y.

1 Katz H.

1 Navarrete K.

1 Navarro C.

1 Perez W.

1 Roa A.

1 Vaca I.

2 2009

Wyniki wyszukiwania

Histomorphology of prepuberal ovaries in the South American fur seal [Arctocephalus australis Zimmerman, 1783]

Molecular characterization of the niaD and pyrG genes from Penicillium camemberti, and their use as transformation markers