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Espressione in cellule di insetti del gene di Drosophila che codifica per alfa-fucosidasi
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The Fruit Fly Drosophila as a Powerful Tool in Teaching Life Sciences in Middle and High School Classrooms
Full text linkLiving organisms can be used as important didactic tools for students, and we report here for the first time the evaluation of a scientific laboratory on Drosophila. The aim of this work is to attract more students to wards science disciplines and a real appreciation for animal kingdom. We aimed to capture students’ interest, develop important educational experiences, and promote the basic and integrated science process skills that are involved in scientific inquiry, including direct contact to a living or ganism and authentic research on Drosophila melanogaster. We performed this experience in non-selective middle (100 students) and high school classrooms (200 students). The practical activities were carried out over three months. Initially, we decided to make homemade fly traps to catch flies, so that students could observe, recognize and have a direct contact with Drosophila . Several experiences were performed, such as the evaluation of different methods for immobilizing flies, and the observation of life cycle, sexual dimorphism, Drosophila mutants plus several species of Drosophilidae. Moreover, students prepared a procedure for fly food, and a method for anesthetizing flies. With sample questionnaires, we obtained a survey of the experiences and so we ob served a general agreement and a broad consensus (82 %), since students considered the experiences very stimulating. As a final result we obtained that students improved their attitudes towards science
Drosophila subobscura Short Sperm have no Biochemical Incompatibilities with Fertilization
No full textDrosophila obscura group species produce two distinct sizes of nucleated sperm that differ only in head and
tail lenghts. Between both sperm there is no differences in location of the acrosome and flagellum during spermiogenesis
where each sperm type develops in its own bundle. Fertile sperm accumulate in the seminal vesicles. Fertilization is exclusively
monospermic and in a previous study we suggested that both types of sperm are fertilization-competent on the
basis of similar DNA content and storage in females also if morph variations are consistent with a fertilization-related selection
for optimal sperm size. This assumption is in agreement with previous studies that demonstrated that only long
sperm fertilize eggs. In this study fertilization of Drosophila subobscura is examined using anti-sperm surface Beta-N-acetylhexosaminidases
and alfa-L-fucosidase antibodies. Beta hexosaminidases are intrinsic proteins of the sperm plasma
membrane in spermomomorphic species of the melanogaster group closely related to Drosophila melanogaster. These
enzymes had been previously identified as putative receptors for glycoconjugates of the egg surface, structurally and functionally
conserved. Here their localization has been investigated in Drosophila subobscura. Consistent with our previous
study, short and long sperm are functionally equivalent. More data are needed to clarify the consequences and adaptative
significance of morph variation
Study of the carbohydrates of the egg envelopes and of their receptors on the sperm surface in Drosophila melanogaster
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Characterization and mapping of putative egg receptors on the surface of Drosophila melanogaster spermatozoa
No full textDynamic of contribution of UBPy-sorted cargo to acrosome biogenesis : effects of its derailment in a mouse model of globozoospermia, the infertile Vps54 (L967Q) mutant
No full textThe sperm acrosome is a specialized vacuole, a member of the family of cell-specific lysosome-related organelles. Its exocytosis, the acrosome reaction, is a crucial event during fertilization. The released acrosomal contents promote sperm penetration through the investments of the oocyte, whereas the membranous components of the acrosome are involved in sperm-oocyte interaction/fusion and oocyte activation. The way that these functionally distinct acrosomal costituents reach the vacuole during its biogenesis remains poorly understood. The biosynthetic pathway and a consistent supply from the endosomal system have recently been documented. We use immunogold electron microscopy to determine the contribution of endosome cargo-sorting during step-by-step mouse acrosomogenesis. The chosen proteins of this study were UBPy (ESCRT-DUB), together with endosome compartment markers EEA1 and pallidin. The latter is described here for the first time in male germ cells. This new insight expands our knowledge of acrosomogenesis, confirming the plasticity of the endosomal system in supporting cell-type-specific functions. We also study wobbler mice, whose Vps54 mutation causes motor neuron degeneration and male infertility. Use of electron/immunoelectron microscopy and immunofluorescence enabled us to establish that the lack of an acrosome in wobbler spermatozoa is attributable to an early block in acrosome biogenesis and that the mislocalization of acrosome-destined proteins, potentially involved in the signaling events leading to oocyte activation, is possibly responsible for wobbler infertility, even after intracytoplasmic sperm injection
Plasma membrane association and characterization of Drosophila sperm surface glycosidases
No full textExpression study of an alpha-l-fucosidase gene in the Drosophilidae family
No full textThe plasma membrane of Drosophila (Sophophora) melanogaster spermatozoa contains an alpha-l-fucosidase that might be involved in fertilization by interacting with alpha-l-fucose residues on the micropyle of the eggshell. D. (S.) melanogaster has a single gene called CG6128 or Fuca encoding for a putative alpha-l-fucosidase. Two transcripts have been annotated, RA of 3514 bp, and RB of 1673 bp. While both transcripts encode an alpha-l-fucosidase, RA contains an upstream open reading frame, translated into a polypeptide containing a predicted BTB/POZ domain. We demonstrate that Fuca is expressed in male and female germ lines. RT-PCR analysis indicated a broader tissue expression. Homologous genes are expressed in the same tissues in several drosophilid flies belonging to the genera Drosophila and Scaptodrosophila. However, the long transcript is restricted to species belonging to the subgenus Sophophora. The presence of two transcripts in species of the subgenus Sophophora and only one in species belonging to the subgenus Drosophila might be related to the phylogenetic relationships of these subgenera. Immunofluorescence demonstrated that the gene product, localized to the sperm plasma membrane, is absent from Scaptodrosophila lebanonensis spermatozoa. These findings support the hypothesis that the enzyme is involved in the molecular events of primary gamete interactions that are conserved among drosophilids belonging to Drosophila genus
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