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Ribosomal RNA of the diploid amphibian species Hyla chrysoscelis and Odontophrynus americanus is structurally modified by hidden breaks. Phylogenetically polyploid related species like the tetraploid Hyla versicolor, the tetraploid Odontophrynus americanus and the octoploid Ceratophrys ornata do not show hidden breaks in ribosomal RNA. Structural modifications of rRNA molecules in diploid amphibians has no detectable effect on the ribosomal activity in vitro.

1. The polyamines spermine, spermidine and putrescine were extracted from tissues of Asterias vulgaris and quantitated using thin layer chromatography. 2. In the pyloric caeca, mean (+/- SE) levels of spermine, spermidine and putrescine were 138(15), 86(24) and 415(77) nmol/g wet wt tissue, respectively. In the testes, levels were 95(12), 13(6) and less than 6 nmol/g wet wt. In the ovaries, levels were 105(9), 11(0.8) and 15(8) nmol/g wet wt. 3. High levels of polyamines in the pyloric caeca may be related to secretion or excretion in this tissue. 4. We hypothesize that polyamines will be important in the regulation of cellular activity in these tissues during the annual reproductive cycle.

The objective of this work was to survey and compare the composition of the parts of the reproductive system of the female fowl in glycosaminoglycans and proteoglycans. Those parts analyzed were ovary, infundibulum, magnum, isthmus, shell gland and vagina. Methods of analysis included cellulose acetate electrophoresis, infrared spectroscopy, colorimetry, amino acid determination and scanning electron microscopy. Concentrations of glycosaminoglycans were higher in vagina, ovary, infundibulum and isthmus than in shell gland and magnum. Glycosaminoglycans may be important in those parts of the reproductive tract which contribute membraneous and mucosal material to the descending egg, and where fertilization of the egg occurs.

Vitellogenin was isolated by affinity chromatography and gel filtration from landlocked Atlantic salmon plasma. Vitellogenin was labelled with iodine-131 using iodogen and an homologous radioimmunoassay was developed. There was poor immunological cross-reactivity with vitellogenin or plasma from other teleosts. Parallelism of the vitellogenin standard to the displacement by plasma of vitellogenic salmon allowed the assay to be used to evaluate the seasonal concentration profile of vitellogenin in female adult salmon. Extracts of liver or ovary from female Atlantic salmon also yielded displacements parallel to the vitellogenin standard in the assay.

Seasonal variations of total lipids, free fatty acids, triglycerides, phospholipids and cholesterol content of the freshwater fish Tilapia nilotica and the marine fish Sparus auratus were investigated. Male fish of S. auratus showed higher muscular and hepatic total lipids and hepatic free fatty acids than those of T. nilotica (P less than 0.05). The mean differences in gonadal male lipids of the two species were not significant. Tilapia nilotica female fish showed a significantly higher content of hepatic free fatty acids, phospholipids and cholesterol (P less than 0.01, 0.01, 0.05 respectively) and gonadal total lipids, triglycerides, and cholesterol (P less than 0.05) than those of S. auratus females. In contrast S. auratus females exhibited higher muscular total lipids, triglycerides, phospholipids and cholesterol content (P less than 0.01, 0.05, 0.02, 0.05, respectively) and gonadal phospholipids (P less than 0.05) than those of the T. nilotica females. In general hepatic and gonadal lipids of freshwater fish T. nilotica were higher than those of the marine fish S. auratus, and in contrast the marine fish contained higher muscular lipids than the freshwater fish.

1. Gas-liquid chromatography and mass spectrometry were used to verify the presence of arachidonic acid (20:4 omega 6) in adult male and female organs of the blood-suckling bug Triatoma infestans. Fat body, gonad and head lipids were analyzed. 2. Male gonads contained the highest percentage of phospholipids and the highest percentage of arachidonic acid. 3. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine and sphingomyelin were isolated from gonads and heads of sexed insects and the fatty acid composition analyzed. 4. All the phospholipids analyzed contained relevant percentages of linoleic acid and fair percentages of arachidonic acid, except for sphingomyelin where no 20:4 omega 6 acid was found. 5. However, arachidonic acid was specifically incorporated in phosphatidylinositol since this phospholipid contained very large percentages of the acid. 6. In male gonads, phosphatidylcholine also contained a similar high percentage of the acid. Arachidonic acid is apparently incorporated, selectively, into these lipids from the blood of the host.

Total lipid and cholesterol concentrations in hepatopancreas, gonad and muscle were analyzed for 70 blue crabs. The concentrations were highest in hepatopancreas, then gonad, and muscle was the lowest. In male crabs, the concentrations decreased from the immature stage (feeding and growth stage) to the mature stage (breeding stage), and from August to September (breeding period) in mature males. In female crabs, the concentrations were comparatively high for peelers (pre-molting stage) and mature females in October (pre-spawning migration period). The total lipid and cholesterol concentrations were significantly, positively correlated in both sexes. The total lipid and cholesterol concentrations were independent of both body weight and tissue weight. Exceptions were the immature females whose concentrations in hepatopancreas were negatively correlated with both body weight and hepatopancreas weight, and the mature females whose concentrations in gonads were positively correlated with gonad weight.

1. Protein (alkali-labile) phosphorus levels are given as percentages of the dry weight of mature eggs of fishes (one elasmobranch and seven teleost species). Levels in the eggs of the five marine-spawning teleosts are much lower (10-300 times) than in the two freshwater-spawning teleosts examined. 2. The protein phosphorus content of the dry matter of developing plaice eggs decreases by a factor of 20 during the later stages of development (maturation) before ovulation. 3. It is proposed that protein-linked phosphate may be utilised, possibly as a source of energy, during the massive water uptake which accompanies egg maturation in many marine species, including plaice.