The use of GMOs (genetically modified organisms): agricultural biotechnology or agricultural biopolitics?

Agricultural biotechnologies embrace a large array of conventional and modern technologies, spanning from composting organic by-products of agriculture to innovative improvement of quality traits of about twenty out of the mostly cultivated plants. In EU a rather restrictive legislative framework has been installed for GMOs, requiring a risk assessment disproportionate with respect to conventional agriculture and organic farming products. The latter are far from being proved safe for human and animal health, and for the environment.Biotechnology of GMOs has been overtaken by biopolitics. On one side there are biotechnological challenges to be tackled, on another side there is plenty of ground for biopolitical decisions about GMOs. Perhaps the era of harsh confrontation could be fruitfully replaced by sensible cooperation, in order to get a sustainable agricultural development.     

Actin synthesis is not regulated by granulosa cells in mouse growing and preovulatory oocytes

The synthesis and intracellular distribution of actin were studied in isolated dictyate and metaphase II mouse oocytes by (1) sodium dodecyl sulfate-polyacrylamide gel electrophoresis of newly synthetized oocyte protein and (2) cytochemical F-actin labeling by fluorescent phalloidin. Unpermeabilized, fully grown oocytes bound phalloidin intensely at the level of the zona pellucida (ZP), such ZP-associated actin representing a significant portion of total actin found in these cells. In contrast, phalloidin binding to ZP was very low in growing oocytes and was undetectable in ovulated, metaphase II eggs. When ZP-associated actin of fully grown oocytes was removed by prolongedly exposing oocytes to α-chymotrypsin, the amount of newly synthesized actin displayed by cumulus-enclosed oocytes was reduced to a level comparable to that shown by oocytes isolated from granulosa cells. We demonstrate that ZP-associated actin belongs to granulosa cell processes that remain within the ZP as a consequence of oocyte isolation procedures. We conclude that actin synthesis of mouse oocytes is not regulated by granulosa cells.     

Synthesis of glycoconjugates in mouse primordial germ cells

The synthesis of protein-bound carbohydrates has been studied in primordial germ cells (PGCs) and in somatic cells of 12.5 to 13.5-days-postcoitum (dpc) fetal mouse gonads. Both cell types were shown to synthesize asparagine-linked glycopeptides and glycosaminoglycans (GAGs). In addition, PGCs also synthesize lactosaminoglycans (LAGs) although in different proportions in female and male germ cells. Female PGCs, which at 13.5 dpc are entering meiosis, synthesize mainly LAGs, and minor amounts of hyaluronic acid (HA) and chondroitin sulfate (CS). Male germ cells, on the other hand, synthesize mainly CS. Furthermore, somatic cells of fetal gonads synthesize HA as the major class of GAGs. It is suggested that the activation of LAG synthesis in developing germ cells might be related to the beginning of meiosis. Moreover, we propose that HA synthesis might be developmentally regulated in somatic cells of the gonad, in order to regulate the establishment of specific interactions with germ cells.     

Soluble peroxidase from winter wheat seedlings with phenoloxidase-like activity

Peroxidase isozymes from winter wheat (Triticum aestivum L. cv Orso) seedlings extracts showed phenoloxidase-like activity, becoming visible on polyacrylamide gels also in the absence of hydrogen peroxide. The results obtained after a characterization of the two activities, based on their substrate specificity, on their selective inhibition, and on the possible occurrence of artifacts, suggested the existence of polyfunctional peroxidase isozymes. Different isozymes possessing only phenol oxidase activity were not found in the same plant material. This appears to be the first evidence of phenoloxidase-acting isoperoxidases in winter wheat.     

Combined action of stem cell factor,leukemia inhibitory factor,and cAMP on in vitro proliferation of mouse primordial germ cells

In the present paper we investigated the effects of stem cell factor/mastocyte growth factor (SCF/MGF), leukemia inhibitory factor/differentiating inhibitory activity (LIF/DIA) (two growth factors known to affect primordial germ cell growth in vitro) and forskolin (FRSK) (an activator of adenylate cyclase in many cell types) alone or in combination on the survival and proliferation of primordial germ cells (PGCs) obtained from 8.5, 10.5, and 11.5 days post coitum (dpc) mouse embryos and cultured without pre-formed cell feeder layers. The results showed that both at 1 and 3 days of culture the addition of 100 ng/ml SCF, 20 μM FRSK, or in some instances 20 ng/ml LIF alone caused a significant increase of PGC number as compared with controls. The highest effects were obtained when SCF and/or LIF were used together with FRSK. Moreover, we found that FRSK elevated cAMP levels in purified 11.5 dpc PGCs and that this compound, but not SCF and LIF, stimulated PGC proliferation, as assessed by 5-bromo-2′-deoxyuridin (BrdU) incorporation. These results suggest a mechanism of combined action of cAMP with SCF and/or LIF in the control of proliferation of mouse PGCs in vitro. © 1993 Wiley-Liss, Inc.     

Binding of fluorescent lectins to the surface of germ cells from fetal and early postnatal mouse gonads

Fluorescent lectins were used to study the chemical nature of carbohydrate moieties present on the surface of female and male germ cells isolated from mouse gonads during fetal and early posnatal development. Concanavalin A (ConA), lens culinaris agglutinin (LCA), ricinus communis agglutinin (RCA_I) and wheat germ agglutinin (WGA) bound intensely to the germ cell plasma membrane at all stages studied. Other lectins such as ulex europaeus agglutinin (UEA_I) and agglutinin (SBA) did not bind or bound moderately (SBA to female germ cells only). Distinct developmental-related changes were observed when female germ cells were labeled with fluorescein-conjugated peanut agglutinin (PNA) or dolichos biflorus agglutinin (DBA). DBA and PNA binding was absent or weak in fetal female and male germ cells, but became intensely positive in oocytes in the immediate postnatal period. The percentage of oocytes stained with DBA increased during the first three days after birth, and from day 3–4 onwards all oocytes were strongly labeled. I suggest that these changes in lectin binding reflect changes in biochemical structure of the oocyte surface related to differentiative events occurring in the mouse ovary immediately after birth.