Identification and characterization of vitellin in a hermophrodite shrimp,Pandalus kessleri

• 1.1. A female specific protein (FSP, vitellogenin) in hemolymph and its related ovarian protein (vitellin) of Pandalus kessleri were studied by means of electrophoretical and immunological procedures.
• 2.2. The vitellin was purified from vitellogenic ovaries using hydroxylapatite, DEAE cellulose and Sepharose 6B columns, consecutively.
• 3.3. The vitellin had a molecular weight of approximately 560 kD and was composed of two subunits, 81 and 110 kD, respectively.
• 4.4. The vitellogenin concentrations in the hemolymph increased as vitellogenesis in the ovarian oocytes advanced and dropped markedly after the release of mature eggs.

     

Electrophoretic patterns of yolk proteins throughout ovarian development and their relationship to vitellogenin in the rainbow trout,Oncorhynchus mykiss

• 1.1. Electrophoretic patterns of yolk proteins were investigated throughout ovarian development and their relationship to vitellogenin determined in a pulse-chase experiment with ³H-vitellogenin.
• 2.2. Using a radioimmunoassay for vitellogenin, vitellogenin/yolk protein products of vitellogenin were detected in follicles throughout ovarian development and in ovulated eggs.
• 3.3. The majority of yolk proteins in follicles measuring less than 1.0 mm in diameter appeared to be derived from sources other than vitellogenin. In contrast, in the larger follicles all of the major yolk proteins detected were derived from vitellogenin.
• 4.4. Pulse-chase with ³H-vitellogenin revealed that all of the major yolk proteins in 3.0 mm follicles were derived from vitellogenin. The major peptides eluted with molecular masses of 110 and 30 kDa under non-reducing conditions (these are very likely to represent lipovitellin 1 and lipovitellin 2), and 88, 22, 16, and 12 kDa under reducing conditions.
• 5.5. There were no apparent differences in the major yolk proteins in ovulated eggs compared to those in vitellogenic follicles, indicating that no extensive proteolysis of these proteins had occurred during maturation and/or ovulation.

     

Synthesis of vitellogenic and non-vitellogenic yolk proteins by the fat body and the ovary of Leptinotarsa decemlineata

• 1.1. Isolated ovaries of egg laying females synthesize and secrete three yolk proteins (two vitellogenins and chromoprotein 2).
• 2.2. The contribution of ovarian tissue to total yolk protein production is very small, the major site of synthesis of the three yolk proteins being the fat body.
• 3.3. There is a time lag between yolk protein synthesis by the fat body and yolk protein sequestration by the ovary.
• 4.4. In egg laying females, within 1 hr after the synthesis of both vitellogenins by the fat body, they appear in the oocytes as vitellins.

     

Vitellogenin synthesis in female larvae of the gypsy moth,Lymantria dispar (L.): suppression by juvenile hormone

• 1.1. Fat body from feeding-phase, last instar gypsy moth females incorporates l-[³⁵S]methionine in vitro into two vitellogenins with the same molecular masses (165 and 180 kDa) as the apo-vitellogenins found in teh hemolymph and the apo-vitellins in teh eggs.
• 2.2. Both apo-vitellogenins are observed in the medium of fat body cultures, but only the 180 kDa apo-vitellogenin is observed in extracts of cultured tissue.
• 3.3. Synthesis and accumulation of the apo-vitellogenins are suppressed in a dose-dependent manner by topical treatment with the juvenile hormone analog, methoprene, prior to day 4.
• 4.4. This suppression suggests that a declining juvenile hormone titre is involved in the initiation of vitellogenin synthesis.

     

Annual brown fat dynamics in Pipistrellus hesperus and Myotis californicus with special reference to winter flight activity

An examination of the annual changes in brown fat deposits of Pipistrellus hesperus and Myotis californicus reveals:

• 1.1.P. hesperus reaches peak brown fat levels in January and February, declining rapidly through March and April, then increases gradually through the remainder of the year.
• 2.2.M. californicus, on the other hand, maintains peak levels of brown fat from December through February, decreasing gradually through August, then increasing rapidly in the fall.
• 3.3.The major brown fat deposits for both species are interscapular, jugular, squamooccipitocervical and carotid bodies.
• 4.4.The interscapular deposit (which accounts for 50–70% of all brown fat) appears to be a good index of brown fat dynamics.
• 5.5.Brown fat appears to be important in maintaining body temperature during night at cold ambient temperatures.

     

Vitellogenesis in the stable fly,stomoxys calcitrans

• 1.1. No female specific proteins were found in the stable fly hemolymph by polyacrylamide gel electrophoresis.
• 2.2. Six major yolk polypeptides (YP1, YP2, YP3, YP4, YP5 and YP6) have been identified in the stable fly. Their mol. wt as determined by SDS-polyacrylamide gel electrophoresis are 41,100, 42,600, 44,100, 46,600, 48,900 and 50,600, respectively.
• 3.3. YP3 was purified and antibody made against it. By using the antibody and in vitro organ culture the stable fly yolk polypeptides were shown to be synthesized exclusively by the ovaries and not the fat body.
• 4.4. The stable fly yolk polypeptides are immunologically similar to yolk proteins of other related flies.

     

Partial characterization and subunit analysis of major phosphoproteins of egg yolk in the fish,Oryzias latipes

• 1.1. Molecular weight estimation and subunit analysis of four yolk phosphoproteins (PP1-PP4) in medaka (Oryzias latipes) eggs were performed.
• 2.2. PP1 (M_r ≈ 210,000) and PP2 (M_r ≈ 180,000) were found to be heterodimers composed of subunits of 113,000 and 94,000 and subunits of 84,000 and 72,000, respectively.
• 3.3. PP3 and PP4 [phosvitins of medaka (Murakami et al., 1990, Devl. Growth Differ.32, 619–627)], were monomeric phosphoproteins having mol. wts of about 40,000 and about 20,000, respectively.
• 4.4. Lipid composition of the mixture of PP1 and PP2, vitellogenin and yolk were found to be almost the same. PP1 and PP2 are probably lipovitellins of medaka.

     

Uptake of haemolymph glycoprotein by the fat body of Calpodes ethlius (lepidoptera). Evidence that the mechanism does not involve desialylation

• 1.1. Haemolymph and fat body of Calpodes ethlius larvae were examined for the presence of sialic acid.
• 2.2. Haemolymph contained low molecular weight substances that absorbed maximally at 549 nm after reaction with periodic acid and thiobarbituric acid (Warren assay).
• 3.3. Ion exchange chromatography of haemolymph ultrafiltrate gave two chromogenic fractions. The principal chromogen failed to give a direct Ehrlich or resorcinol test for sialic acid.
• 4.4. The thin layer chromatographic mobilities of the chromogens differed from those of N-acetylneuraminic acid.
• 5.5. No sialic acid was released by enzymatic or acid hydrolysis of haemolymph or fat body proteins.

     

Breast,hips, and buttocks revisited: Honest fatness for honest fitness

This paper comments on: Low, B. S., Alexander, R. D., and Noonan, K.M. Human hips, breast, and buttocks: Is fat deceptive? Ethology and Sociobiology 8: 249-247, 1987. In it I argue that:

• 1.1. Sexual selection has probably not been the most important selection pressure on
• 2.female human body shape.
• 3.2. Male humans in different cultures find different aspects of the female body attractive
• 4.and therefore are unlikely to have exerted consistent directional sexual selection on
• 5.the female body.
• 6.3. Breast size is not correlated with lactation success.
• 7.4. Visible hip width is not correlated with parturition success.
• 8.5. Women would lower their fitness if they tried to deceive men about their internal
• 9.pelvic dimensions.
• 10.6. There are many alternative hypothesis to explain the existence of fat onwomen's
• 11.breast, hips, and buttocks.

     

Seasonal changes of total lipids in the turtle Sternotherus odoratus

• 1.1. Seasonal variation in total lipids was examined in several body components of the turtle Sternotherus odoratus.
• 2.2. Carcass fat stores in both sexes were depleted during winter. Additionally, a decline in carcass lipids was associated with increases in gonadal mass.
• 3.3. Concentrations of liver lipids were maximal during August and minimal during winter.
• 4.4. Males showed little seasonal change in plasma lipid levels, whereas females had seasonal peaks temporally associated with ovarian development and carcass fat storage.
• 5.5. Ovarian concentrations of lipids were minimal after nesting and increased during fall.
• 6.6. Results suggest that S. odoratus uses stored fats both for reproduction and maintenance during winter.

     

Heterosynthetic origin of the major yolk protein,vitellin, in a nereid,Perinereis cultrifera (polychaete annelid)

• 1.1. An examination of proteins synthesized by Perinereis cultrifera oocytes incubated in vitro with [³H]leucine clearly shows that these cells are not capable of synthesizing the main yolk protein previously identified in this worm.
• 2.2. In addition, the detection of radiolabelled vitellin in oocytes after in vitro incubation of an oocyte-coelomocyte cell mixture in presence of [³H]leucine strongly suggests that the coelomocytes, free cells in the coelomic cavity, synthesize and secrete a vitellin precursor, vitellogenin, that is subsequently taken up by the oocytes.
• 3.3. Two native proteins differing in mol. wt but reacting with anti-vitellin antibodies have been identified in coelomocyte incubation medium. Also found in the coelomic fluid, they have been designated VG1 (M_r = 530,000) and VG2 (M_r = 320,000).
• 4.4. The two vitellogenins consist of a single type of polypeptide of M_r = 176,000 and are incorporated in the oocytes where they are apparently observed under a single molecular form corresponding to VG1, the highest mol. wt protein similar in size to the initial form of vitellin (VI, 530,000).
• 5.5. From these data, it seems likely that VG2 is a monomeric molecule that is taken up by the oocytes as a dimer of VG1.
• 6.6. We conclude that P. cultrifera accumulates vitellin heterosynthetically and that vitellogenin is produced by the coelomocytes. Moreover, a single polypeptide similar in size to the polypeptidic component of secreted vitellogenin has been detected in the coelomocytes.
• 7.7. Since this polypeptide has been identified previously as the single intraoocytic precursor of the four lower mol. wt products that make up the mature form of vitellin (V5), it appears that P. cultrifera exhibits for vitellogenin a processing pathway in which cleavage of the precursor occurs only after uptake by the oocyte.

     

Kinetic studies of vitellogenin metabolism in the elasmobranch Scyliorhinus canicula L.

• 1.1. The appearance of vitellogenin in the plasma of adult female Scyliorhinus canicula and its subsequent disappearance and conversion into yolk granules were monitored by an isotopic method. Rates of vitellogenin synthesis in different fish were compared.
• 2.2. There was considerable individual variation in the rate of synthesis and in the plasma half-life of vitellogenin; measured values of the latter ranged from 132 to 303 hr (mean 216 hr) at 7 ± 2°C.
• 3.3. Winter temperature stimulated vitellogenin synthesis in midsummer, but winter photoperiod did not do so.
• 4.4. Captivity without food for 22 days reduced the rate of vitellogenin synthesis in summer but had no effect in winter.

     

Metabolic utilization of leucine in a fat and a lean line of chicken

• 1.1. In vivo incorporation into body lipids and breast muscle proteins from l-[U-¹⁴C]leucine was studied in genetically lean or fat male chickens, fed or starved, 1 or 24 hr after intraperitoneal injection.
• 2.2. Lipogensis and portein synthesis from labelled leucine were significantly higher in fat chickens than in lean birds, particularly in those in the fed state.
• 3.3. Radioactivity in the free amino acid pool was greater in fat birds irrespective of the nutritional state.
• 4.4. However, utilization of injected l-[U-¹⁴C]leucine for lipogenesis was no more than 2%.

     

Changes in the activities of lysosomal enzymes in the fat body and midgut of two lepidopteran insects (Mamestra brassicae and Pieris brassicae) during metamorphosis

• 1.1. The activities of three lysosomal enzymes (acid phosphatase, β-galactosidase, catepsin D) was observed during metamorphosis in the fat body and midgut cells of two insects (Mamestra brassicae and Pieris brassicae).
• 2.2. The activities increased slightly during the feeding period and showed a sharp rise at the beginning of the wandering period.
• 3.3. Subsequently, a decrease was observed during the pre-pupal stage and pupation.
• 4.4. The activities increased again 2 days after the larval-pupal moult.
• 5.5. We suggest that an inhibitory mechanism works in the studied cells before pupation to protect the stored proteins from the degradation until the beginning of differentiation of imaginai cells in the pupal stage.

     

Effect of O-allyl-hydroxy amino acids on protein synthesis and secretion by cultured fat body and salivary glands in the fruit fly Ceratitis capitata

• 1.1. The amino acid analogs O-allyl-tyrosine, O-allyl-threonine, O-allyl-serine and O-allyl-homoserine, have been synthesized and their effect on protein synthesis and secretion in cultured C. capitata fat body and salivary glands have been studied.
• 2.2. The analogs had an inhibitory effect on protein synthesis in both tissues. Moreover, the analogs caused a slight increase in protein secretion in the fat body in comparison to the control.
• 3.3. The intracellular transit time of protein secretion in treated and non-treated fat body was found essentially the same (about 10 min).

     

Chemical cross-links of proteins by using bifunctional reagents

• 1.1. The chemical identification of spatial arrangements of the subunits in oligomeric proteins is exclusively achieved by the analysis of the reaction products of the protein and bifunctional reagents.
• 2.2. Since the pioneer work of Hartman and Wold (Biochemistry6, 2439–2448, 1967) the bifunctional reagent such as bis-imido-esters was first introduced into protein chemistry.
• 3.3. We have listed the non-cleavable and cleavable bis-imido-esters, the N-hydroxy-succinimido-csters and the aryl azides which once photolyzed, become the highly reactive nitrene intermediates.
• 4.4. Different reagents classified as homo- and hetero-bifunctional reagents are also listed.
• 5.5. The advantages and limits of each group as well as their chemical properties are advanced and extensively discussed.

     

Characterization of proteins from mitochondrial ribosomes of Locusta migratoria by three different two-dimensional gel electrophoretic methods and comparison with cytoplasmic ribosomal proteins

• 1.1. Proteins were isolated from subunits of mitochondrial and cytoplasmic ribosomes of Locusta migratoria and were analyzed by means of two-dimensional gel electrophoreses using three different electrophoresis systems.
• 2.2. Using the system of Czempiel et al. (1976) proteins from whole locust mitochondrial ribosomes (combined subunits) were separated into 72 spots; proteins from the large and small subunits resulted in 48 and 29 spots respectively.
• 3.3. The mol. wt distribution of mitochondrial ribosome proteins was estimated by using the electrophoresis system of O'Farrell (1975). These mol. wts are in the range of 11,000–56,000, the average mol. wt is about 29,500. Assuming one copy of protein per ribosome this gives a total mol. wt for the protein part of mitochondrial ribosomes of ca. 2.1 x 10⁶.
• 4.4. Parallel separation of cytoplasmic and mitochondrial ribosome proteins was achieved using the system of Geyl et al. (1981). Cytoplasmic ribosome proteins produced 65 spots and revealed a more alkaline character than mitochondrial ribosome proteins.

     

Proteolysis of skeletal muscle in yellowfin tuna (Thunnus albacares): Evidence of calpain activation

• 1.1. White muscle of yellowfin tuna is subject to a form of deterioration known as “burnt tuna”.
• 2.2. TEM and SDS-PAGE were used to quantify cellular differences in deteriorated white muscle of yellowfin tuna.
• 3.3. Electron micrographs showed a significant loss of Z-disc integrity and an increase in intracellular edema in burnt tuna.
• 4.4. Electrophoresis established that a specific doublet of proteins, 42 kD and 46 kD was lost.
• 5.5. Proteolysis of isolated myofibrils incubated in calpain (EC 3.4.22.17) was greatest at pH 7.5 and was selective for intermediate molecular weight proteins.
• 6.6. This evidence suggests that burnt tuna is a specific and limited proteolysis of myofibrillar structural proteins characteristic of calpain proteolysis.

     

Dose-dependent incorporation of orally infused [1-14C]oleic acid into the lipid classes of midgut,haemolymph and fat body of dragonfly larvae (Aeshna cyanea)

• 1.1. Five different doses of radioactive oleic acid (ranging from 1.87 nmoles to 5.61 μmoles) were administered to Aeshna cyanea larvae.
• 2.2. Its incorporation into the midgut epithelium, haemolymph and fat body increased with the dose and time.
• 3.3. Low doses caused up to 95% phospholipid labelling in the midgut wall, while labelled triacylglycerol was less than 1%, but increased with the doses to a maximum of 68%. The data favour the glycerophosphate pathway of oleic acid esterification.
• 4.4. At low doses oleic acid was mainly released into the haemolymph from the midgut phospholipid pool, and at high doses from the triacylglycerol pool.
• 5.5. Diacylglycerol was the most heavily labelled lipid class of the haemolymph, amounting up to 98% and slightly decreasing with time.
• 6.6. The fat body showed a dose- and time-dependent increase in labelled phospholipid and triacyl-glycerol, maximally amounting to 14 and 90%, respectively.

     

Studies on tryptophan pyrrolase of Schistocerca gregaria försk. (Orthoptera)

• 1.The trytophan pyrrolase activity of central fat bodies of S. gregoria hoppera was studied.
• 2.The enzyme system appears to be similar to that of mammalian liver.
• 3.The enzyme was localized only in central fat bodies.
• 4.Extracts of other body parts can mimic an enzyme activity because of a degradation of ommochromes in the enzyme test.