Background: The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm d... more Background: The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm disease beyond its native range. Their toxic eggs have virtually no predators and unusual defenses including a neurotoxic lectin and a proteinase inhibitor, presumably advertised by a warning coloration. We explored the effect of egg perivitellin fluid (PVF) ingestion on the rat small intestine morphology and physiology.
I. The inter-organ transport of free fatty acids, triacylglycerols and phospholipids in the hemol... more I. The inter-organ transport of free fatty acids, triacylglycerols and phospholipids in the hemolymph, as well as their distribution in tissues of the bivalve mollusc Diplodon delodontus, were studied. 2. Plasma, hemocytes and tissues were obtained 4~ hr after injecting labelled palmitic acid into the posterior adductor muscle. 3. Labelled palmitic acid in the free form or esterified into triacylglycerols and phospholipids, was detected in both plasma and hemocytes. 4. The free fatty acids and phospholipids are mainly transported by three plasma lipoproteins with low (LDL), high (HDL) and very high (VHDL) density characteristics, respectively. 5. Triacylglycerols circulate in hemolymph preferably associated with hematic cells and, to a lesser extent, they are also transported by plasma lipoproteins. 6. Highest specific radioactivities were observed in gills and digestive diverticula. They mainly correspond to the accumulation of free fatty acids and triacylglycerols,
The activities of the enzymatic systems involved in the activation and degradation of fatty acids... more The activities of the enzymatic systems involved in the activation and degradation of fatty acids, and in the synthesis of triacylglycerols and phospholipids were studied in vitro using total cellular homogenate and subcellular fractions of eggs of the shrimp Macrobrachium borellii at different developing stages. Egg development was divided into seven stages based on morphological features of the embryo. Palmitoyl-CoA ligase activity increased as the embryo developed and showed its maximum at stage V. An increase in the synthesis of triacylglycerols and diacylglycerols was also observed at this stage. Diacylglycerylethers were synthesized more actively during the first stages of development. The higher specific activity observed in total homogenate than in microsomal fraction suggested that their synthesis was not exclusively microsomal. Phospholipid synthesis was very active all along development, reflecting active membrane biosynthesis. The highest activity of the cytosolic triacy...
The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm disease beyon... more The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm disease beyond its native range. Their toxic eggs have virtually no predators and unusual defenses including a neurotoxic lectin and a proteinase inhibitor, presumably advertised by a warning coloration. We explored the effect of egg perivitellin fluid (PVF) ingestion on the rat small intestine morphology and physiology. Through a combination of biochemical, histochemical, histopathological, scanning electron microscopy, cell culture and feeding experiments, we analyzed intestinal morphology, growth rate, hemaglutinating activity, cytotoxicity and cell proliferation after oral administration of PVF to rats. PVF adversely affects small intestine metabolism and morphology and consequently the standard growth rate, presumably by lectin-like proteins, as suggested by PVF hemaglutinating activity and its cytotoxic effect on Caco-2 cell culture. Short-term effects of ingested PVF were studied in growing ra...
The site of synthesis of molluscs lipoproteins is little known and was investigated for the egg l... more The site of synthesis of molluscs lipoproteins is little known and was investigated for the egg lipoprotein perivitellin 1 (PV1) or ovorubin in the freshwater snail Pomacea canaliculata. Tissues (albumen gland, gonad–digestive gland complex and muscle) of vitellogenic females were incubated in vitro at 25°C for 12 h with 14C Leucine. After that, soluble proteins from tissue homogenates and medium
A novel role of ovorubin as a protection system against oxidative damage in eggs from Pomacea can... more A novel role of ovorubin as a protection system against oxidative damage in eggs from Pomacea canaliculata was investigated. Carotenoid composition, and their antioxidant capacity, as well as the carotenoid-apoprotein interaction, were studied for this lipoglycocarotenoprotein. Carotenoid extracts from ovorubin were analysed by TLC and spectrophotometry. The major carotenoid was astaxanthin in its free (40%), monoester (24%), and diester (35%)
The uptake and depuration of the water-sol‐uble fraction (WSF) of hydrocarbons of crude petroleum... more The uptake and depuration of the water-sol‐uble fraction (WSF) of hydrocarbons of crude petroleum by Atlantic salmon (Salmosalar) has previously been examined in terms of whole muscle. The hypothesis that the tainting WSF in the muscle was retained primarily by adipocytes has been investigated by the isolation of adipocytes and the subsequent analysis for hydrocarbons in adipocytes. After 96 h exposure
Energy partitioning, composition of lipids and fatty acids, and their utilization by embryos were... more Energy partitioning, composition of lipids and fatty acids, and their utilization by embryos were determined in the lecithotrophic shrimp Macrobrachium borellii during seven development stages. The biochemical composition at stage I is represented by lipids, proteins, and carbohydrates, with 29.3, 28.7, and 0.2% dry weight, respectively. The former two were identified as the major energy-providing components, contributing 131 and 60
The lipid and protein composition of the perivitelline fluid of the eggs of Pomacea canaliculata ... more The lipid and protein composition of the perivitelline fluid of the eggs of Pomacea canaliculata was investigated. Two lipoproteins (PV 1 and PV 2) and one lipoprotein fraction (PV 3) were detected for the first time in gastropods. They represent 57.0, 7.5, and 35.5% of the egg total proteins, respectively. PV 1 is a glyco-carotene-protein complex with characteristics of a very high-density lipoprotein (VHDL). It has 0.33% lipids, mainly free sterols and phospholipids. The particle has a MW of 300 Kd and is composed of three subunits of 35, 32, and 28 Kd, respectively. PV 2 particle is a VHDL of 400 Kd and 3.75% lipids. The major lipid classes are free sterols and phospholipids and also have significant quantities of energy-providing triacylglycerides and free fatty acids. It is composed of two apoproteins of 67 and 31 Kd. PV 3 density corresponds to a high-density lipoprotein (HDL). It was fractionated into two subfractions "h" and "p". Fraction "h" contains 5.16% lipids, mainly free sterols, phospholipids, and free fatty acids, and two particles of 100 and 64 Kd. Dissociating electrophoresis showed two subunits of 34 and 29 Kd. Fraction "p" is composed of a single particle of 26 Kd that contains 9.5% lipids, which represents 30% of the total egg lipids. It has high levels of a carotenoid pigment. Besides it contains free fatty acids, hydrocarbons, sterified sterols, and triacylglycerides. These three fractions are probably the major supply of lipids and amino acids for the developing embryo.
Embryo morphometry and developing time from just-laid eggs until hatching were described in the p... more Embryo morphometry and developing time from just-laid eggs until hatching were described in the palaemonid prawn, Macrobrachium borellii, using a rapid non-invasive staging method. Embryos were kept in the laboratory under controlled conditions and development divided into seven stages according to major morphological characteristics. This lecithotrophic, freshwater shrimp has a highly abbreviated type of hatching development after 39 ± 2
Background: The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm d... more Background: The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm disease beyond its native range. Their toxic eggs have virtually no predators and unusual defenses including a neurotoxic lectin and a proteinase inhibitor, presumably advertised by a warning coloration. We explored the effect of egg perivitellin fluid (PVF) ingestion on the rat small intestine morphology and physiology.
I. The inter-organ transport of free fatty acids, triacylglycerols and phospholipids in the hemol... more I. The inter-organ transport of free fatty acids, triacylglycerols and phospholipids in the hemolymph, as well as their distribution in tissues of the bivalve mollusc Diplodon delodontus, were studied. 2. Plasma, hemocytes and tissues were obtained 4~ hr after injecting labelled palmitic acid into the posterior adductor muscle. 3. Labelled palmitic acid in the free form or esterified into triacylglycerols and phospholipids, was detected in both plasma and hemocytes. 4. The free fatty acids and phospholipids are mainly transported by three plasma lipoproteins with low (LDL), high (HDL) and very high (VHDL) density characteristics, respectively. 5. Triacylglycerols circulate in hemolymph preferably associated with hematic cells and, to a lesser extent, they are also transported by plasma lipoproteins. 6. Highest specific radioactivities were observed in gills and digestive diverticula. They mainly correspond to the accumulation of free fatty acids and triacylglycerols,
The activities of the enzymatic systems involved in the activation and degradation of fatty acids... more The activities of the enzymatic systems involved in the activation and degradation of fatty acids, and in the synthesis of triacylglycerols and phospholipids were studied in vitro using total cellular homogenate and subcellular fractions of eggs of the shrimp Macrobrachium borellii at different developing stages. Egg development was divided into seven stages based on morphological features of the embryo. Palmitoyl-CoA ligase activity increased as the embryo developed and showed its maximum at stage V. An increase in the synthesis of triacylglycerols and diacylglycerols was also observed at this stage. Diacylglycerylethers were synthesized more actively during the first stages of development. The higher specific activity observed in total homogenate than in microsomal fraction suggested that their synthesis was not exclusively microsomal. Phospholipid synthesis was very active all along development, reflecting active membrane biosynthesis. The highest activity of the cytosolic triacy...
The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm disease beyon... more The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm disease beyond its native range. Their toxic eggs have virtually no predators and unusual defenses including a neurotoxic lectin and a proteinase inhibitor, presumably advertised by a warning coloration. We explored the effect of egg perivitellin fluid (PVF) ingestion on the rat small intestine morphology and physiology. Through a combination of biochemical, histochemical, histopathological, scanning electron microscopy, cell culture and feeding experiments, we analyzed intestinal morphology, growth rate, hemaglutinating activity, cytotoxicity and cell proliferation after oral administration of PVF to rats. PVF adversely affects small intestine metabolism and morphology and consequently the standard growth rate, presumably by lectin-like proteins, as suggested by PVF hemaglutinating activity and its cytotoxic effect on Caco-2 cell culture. Short-term effects of ingested PVF were studied in growing ra...
The site of synthesis of molluscs lipoproteins is little known and was investigated for the egg l... more The site of synthesis of molluscs lipoproteins is little known and was investigated for the egg lipoprotein perivitellin 1 (PV1) or ovorubin in the freshwater snail Pomacea canaliculata. Tissues (albumen gland, gonad–digestive gland complex and muscle) of vitellogenic females were incubated in vitro at 25°C for 12 h with 14C Leucine. After that, soluble proteins from tissue homogenates and medium
A novel role of ovorubin as a protection system against oxidative damage in eggs from Pomacea can... more A novel role of ovorubin as a protection system against oxidative damage in eggs from Pomacea canaliculata was investigated. Carotenoid composition, and their antioxidant capacity, as well as the carotenoid-apoprotein interaction, were studied for this lipoglycocarotenoprotein. Carotenoid extracts from ovorubin were analysed by TLC and spectrophotometry. The major carotenoid was astaxanthin in its free (40%), monoester (24%), and diester (35%)
The uptake and depuration of the water-sol‐uble fraction (WSF) of hydrocarbons of crude petroleum... more The uptake and depuration of the water-sol‐uble fraction (WSF) of hydrocarbons of crude petroleum by Atlantic salmon (Salmosalar) has previously been examined in terms of whole muscle. The hypothesis that the tainting WSF in the muscle was retained primarily by adipocytes has been investigated by the isolation of adipocytes and the subsequent analysis for hydrocarbons in adipocytes. After 96 h exposure
Energy partitioning, composition of lipids and fatty acids, and their utilization by embryos were... more Energy partitioning, composition of lipids and fatty acids, and their utilization by embryos were determined in the lecithotrophic shrimp Macrobrachium borellii during seven development stages. The biochemical composition at stage I is represented by lipids, proteins, and carbohydrates, with 29.3, 28.7, and 0.2% dry weight, respectively. The former two were identified as the major energy-providing components, contributing 131 and 60
The lipid and protein composition of the perivitelline fluid of the eggs of Pomacea canaliculata ... more The lipid and protein composition of the perivitelline fluid of the eggs of Pomacea canaliculata was investigated. Two lipoproteins (PV 1 and PV 2) and one lipoprotein fraction (PV 3) were detected for the first time in gastropods. They represent 57.0, 7.5, and 35.5% of the egg total proteins, respectively. PV 1 is a glyco-carotene-protein complex with characteristics of a very high-density lipoprotein (VHDL). It has 0.33% lipids, mainly free sterols and phospholipids. The particle has a MW of 300 Kd and is composed of three subunits of 35, 32, and 28 Kd, respectively. PV 2 particle is a VHDL of 400 Kd and 3.75% lipids. The major lipid classes are free sterols and phospholipids and also have significant quantities of energy-providing triacylglycerides and free fatty acids. It is composed of two apoproteins of 67 and 31 Kd. PV 3 density corresponds to a high-density lipoprotein (HDL). It was fractionated into two subfractions "h" and "p". Fraction "h" contains 5.16% lipids, mainly free sterols, phospholipids, and free fatty acids, and two particles of 100 and 64 Kd. Dissociating electrophoresis showed two subunits of 34 and 29 Kd. Fraction "p" is composed of a single particle of 26 Kd that contains 9.5% lipids, which represents 30% of the total egg lipids. It has high levels of a carotenoid pigment. Besides it contains free fatty acids, hydrocarbons, sterified sterols, and triacylglycerides. These three fractions are probably the major supply of lipids and amino acids for the developing embryo.
Embryo morphometry and developing time from just-laid eggs until hatching were described in the p... more Embryo morphometry and developing time from just-laid eggs until hatching were described in the palaemonid prawn, Macrobrachium borellii, using a rapid non-invasive staging method. Embryos were kept in the laboratory under controlled conditions and development divided into seven stages according to major morphological characteristics. This lecithotrophic, freshwater shrimp has a highly abbreviated type of hatching development after 39 ± 2
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