Rodolfo M Wettstein

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An ultrastructural study has been made of spermatogenesis in two species of primitive spiders having holocentric chromosomes (Dysdera crocata, ♂XO and Segestria florentia X1X2O). Analysis of the meiotic prophase shows a scarcity or absence of typical leptotene to pachytene stages. Only in D. crocata have synaptonemal complex (SC) remnants been seen, and(More)
In an electron microscopic study concerning the structure of sex chromosomes of the spider Lycosa malitiosa (male 2n=20 X1 X2O) and their behaviour during spermatogenesis, based on a detailed analysis of meiotic stages (including tridimensional reconstructions), we established: a) the existence of a special type of pairing between non-homologous sex(More)
The meiotic behaviour of the XY pair of the didelphid Lutreolina crassicaudata is analyzed by microspreading of spermatocytes for visualization of chromosomal axes and by three-dimensional reconstruction of spermatocyte nuclei from EM thin sections. The delay in pairing of sex chromosomes compared to autosomes and the absence of a synaptonemal complex(More)
Spermatogenesis is a complex differentiation process which requires the coordinate synthesis of diverse stage-specific proteins. In attempting a large-scale identification and characterization of those proteins, we have made use of the recently described mRNA differential display method (Liang and Pardee, Science 257: 967-971, 1992). This method is based on(More)
Identification of Solanum tuberosum genes responsive to culture filtrates (CF) from Erwinia carotovora subsp. carotovora led to the isolation of a full-length cDNA with high sequence similarity to several alcohol dehydrogenases. Accumulation of transcripts corresponding to this defence-related alcohol dehydrogenase (drd-1) was rapidly induced in CF-treated(More)
An ultrastructural study was performed on the sex chromosomes (male X1X2X3O) during the spermatogenesis of Tegenaria domestica (Arachnida, Agelenidae). This study was carried out using random and serially cut sections. During pachytene and diplotene the three X chromosomes are longitudinally paired. Each of these consists of a central core of condensed(More)
An electron microscope study of the spermatocytes I of Scaptericus borrelli was performed using serial sections and tridimensional reconstruction. The stages examined were: mid-pachytene, early diplotene and the so-called “diffuse stage”. At mid-pachytene the nucleolus (associated to an autosome) shows a glomerular array formed of supernumerary synaptonemal(More)
The primary spermatocytes of an Opilionid, Acanthopachylus aculeatus show (at least as a rule) two bodies which in longitudinal sections appear as integrated of up to 12 dark bands each about 300 Å wide, interlaced with one another by a curtain of thin filaments. The same bodies appear in transversal sections as formed by an hexagonal lattice the nodal(More)