Body Yolk Research Articles

Analysis of pteridines inPyrrhocoris apterus (L.) (heteroptera, pyrrhocoridae) during development and in body-color mutants

By using thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC), five different pteridines have been quantified in extracts from Pyrrhocoris apterus: neopterin, isoxanthopterin, isoxantholumazine (violapterin), 7-methylxanthopterin, and erythropterin. Biopterin was also detected using HPLC. Pteridines have been analyzed separately in bodies and eyes of the wild type regarding developmental stage and sex. The pteridine content in both bodies and eyes increased from nymphs to 2-day-old adults. After this period, the concentration of pteridines in the eyes of adults remained approximately constant, while in the bodies isoxantholumazine, 7-methylxanthopterin, and isoxanthopterin kept increasing until 20 days. Considering the total amount of pteridines per insect, no qualitative or quantitative differences between males and females have been observed except a lower concentration of erythropterin in female bodies. But when pteridines are analyzed per unit body weight, a lower amount of pteridines is always detected in females due to its bigger size. A new body-color mutant, the yolk body mutant, that goes through developmental colour changes, was also analyzed during development, showing a general deficient accumulation of all pteridines, especially of 7-methylxanthopterin and isoxantholumazine in adult bodies. The effect on pteridine content of three other recessive (white, yellow, mosaic) and two dominant (Pale and Apricot) body-color mutations, has also been studied. A specific pteridine pattern different from the wild type was obtained for each mutant. © 1997 Wiley-Liss, Inc.

Changes induced by pineal indoles in post-implantation mouse embryos

1. 1. A subcutaneous injection of hydroxyindoleacetic acid (HIAA), melatonin (MEL), methoxytryptophol (MTP) or methoxytryptamine (MTA) (1 mg/25 g body wt/injection) at 8.5 days post-coitum (p.c.) did not produce any effect on the development of embryos in utero at 10.5 days p.c. 2. 2. Two subcutaneous injections (3 mg/25 g body wt/injection) of MTP, but not HIAA, MEL nor MTP, at 7.5 and 8.5 days p.c. brought about a decrease in gravid uterine weight and number of live fetuses and an increased incidence of early resorptions at 17.5 days p.c. 3. 3. MEL at doses 100 and 200 μg/ml, MTP at doses 50 and 100 μg/ml and MTA at 25, 50 and 100 μg/ml brought about an increase in the number of abnormal embryos cultured in vitro and an increased incidence of abnormal yolk sac circulation, body axis, optic and otic placodes, branchial apparatus, forelimb buds and cranial neural tube. 4. 4. The findings show that melatonin, methoxytryptamine and methoxytryptophol produced an embryotoxic effect on embryos at the early somite stage in vitro while only methoxytryptamine had an adverse effect on embryonic development in vivo.

Differential abilities of the ribosome inactivating proteins luffaculin, luffins and momorcochin to induce abnormalities in developing mouse embryos in vitro

1. Possible teratogenic activity in the ribosome inactivating proteins luffaculin, luffin-a, luffin-b and momorcochin was tested using cultured mouse embryos. 2. At a dosage of 200 μg/ml culture medium, luffin-a and momorcochin did not affect organogenesis in embryos. 3. Luffin-b at a dosage of 100 μg/ml brought about decreases in embryo somite number and axial length and induced defects in yolk sac circulation, body axis, optic placodes, branchial apparatus, forelimb buds and cranial neural tube. 4. Luffaculin at a dosage of 100 μg/ml caused only reductions in embryo somite number and axial length, but at 200 μg/ml produced all of the aforementioned teratogenic effects and defects in otic placodes. 5. The data indicate that ribosome inactivating proteins differ in their potencies as teratogens.

Lipophorin lipase from the yolk of Manduca sexta eggs: identification and partial characterization.

In the hawkmoth Manduca sexta high density lipophorin from adult insects (HDLp-A) delivers lipids to developing oocytes. During this lipid delivery HDLp-A is taken up by the oocyte and converted to a very high density lipophorin (VHDLp), which is stored in protein storage granules (yolk bodies). A membrane-free lysate of isolated M. sexta yolk bodies was demonstrated to contain lipoprotein lipase activity that hydrolyses the diacylglycerol of HDLp-A. With HDLp-A as a substrate yolk body lipophorin lipase (YBLpL) activity was shown to be maximal between pH 9 and pH 9.5. NaCl concentration was optimal between 0.7 M and 1 M. YBLpL activity required neither bovine serum albumin nor calcium ions but appeared to be stimulated by 5 mM EDTA. Diisopropyl fluorophosphate effectively inhibited YBLpL activity, indicating the presence of a serine in the active site of the enzyme. The identified lipase activity co-eluted with lipophorins and vitellins from the yolk in the void volume of a Sephadex G-75 gel filtration column. This observation suggests that the lipase has a Mr of more than 80,000, or that the enzyme is associated with the lipoproteins. Incubation of HDLp-A with yolk body lysate converted HDLp-A to two classes of higher density lipophorins. The highest density lipophorins produced during this incubation approached the density of VHDLp as it is isolated from mature eggs. The possible role of YBLpL activity in the delivery of lipids to developing oocytes is discussed.

Pathologic alterations in early life stages of lake trout, Salvelinus namaycush, exposed to 2,3,7,8-tetrachlorodibenzo- p-dioxin as

Fertilized lake trout eggs exposed to vehicle or graded concentrations of [ 3H]-2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) in water for 48 h accumulated 0, < 15, 40, or 400 ppt (parts per trillion) [ 3H]-TCDD. The exposed eggs were then transferred to flowing [ 3H]-TCDD free water where they remained throughout early development. Lake trout embryos developed normally in all groups until one week prior to hatch. At this time retrobulbar, meningeal and subcutaneous hemorrhages were evident in many embryos and sac fry that were derived from eggs containing 400 ppt [ 3H]-TCDD. High mortality prior to or during hatching accompanied these lesions. All sac fry which survived hatching in the 400 ppt TCDD group developed severe subcutaneous edema, with cessation of blood circulation in the yolk sac and body. Necrosis of the retina, brain, and spinal cord occurred in morbid embryos and sac fry. All sac fry in the 400 ppt TCDD group showed arrested development from the time of hatching and all died prior to swim-up. One percent of sac fry in the vehicle control and < 15 ppt TCDD groups, and 2% in the 40 ppt TCDD group, exhibited blue-sac disease, an edematous syndrome identical grossly and nearly identical microscopically to that observed in the 400 ppt TCDD group. Thus, the cardiovascular system appears to be the initial tissue affected in both the TCDD toxicity syndrome and in blue-sac disease of developing lake trout. Lesions in other organs including brain, retina and liver develop as a result of circulatory derangements, anemia and hypoxia.

Monoclonal antibodies as probes for processing of the mosquito yolk protein; a high-resolution immunolocalization of secretory and accumulative pathways

A library of monoclonal antibodies (mAB) directed against yolk polypeptides of the mosquito Aedes aegypti was utilized to visualize the secretory pathway of these polypeptides in the fat body and their accumulative pathway in developing oocytes. Single and double immunolabelling using mABs and colloidal gold of different sizes confirmed biochemical observation that 200 ± 5 and 65 ± 3 kDa polypeptides represent subunits of the yolk protein. This immunocytochemical analysis showed that, in trophocytes of the fat body, both the subunits of the yolk protein were routed simultaneously through the Golgi complex into secretory granules and were subsequently secreted. The yolk protein subunits were also directed together through all the steps of the accumulative pathway in the oocyte. Double immunogold labelling revealed that the subunits were present together during their binding to the oocyte membrane, transportation into and accumulation in the transitional yolk body, and, finally, crystallization in the mature yolk body. Electron microscopical immunocytochemistry also confirmed immunofluorescent data and showed that mABs directed against different steps in the biosynthetic processing of the yolk protein in the fat body, as well as in its accumulative pathway in oocytes.

Internalized proteins directed into accumulative compartments of mosquito oocytes by the specific ligand, vitellogenin

We have investigated the internalization pathways for a specific protein, vitellogenin, and a non-specific protein, horseradish peroxidase, in the mosquito oocyte in vivo. The internalized proteins were localized by electron microscopical immunocytochemistry or autoradiography; the relationship of their destination compartments with lysosomes was monitored by visualization of acid phosphatase. Proteins internalized by the oocyte follow either a specific accumulative route or a lysosomal degradative route. Via coated vesicles, both proteins enter the same compartment, the endosome, where they dissociate from membrane-binding sites. The route to their final destination depends on the presence of the specific ligand. In its absence, the degradative route is followed, and the endosome with non-specific protein fuses with lysosomes. In the presence of the specific ligand, the accumulative route is followed, and both specific and non-specific proteins are delivered into an accumulative compartment, the transitional yolk body. During the transformation of the transitional yolk body into the final storage compartment, a mature yolk body, vitellogenin undergoes crystallization, whereas the non-specific protein is concentrated in small vesicular extensions of the compartmental membrane. These vesicles are separated from the yolk bodies and apparently deliver the non-specific protein into the lysosomal system. We concluded that any protein bound to the membrane would be internalized by the oocyte, but only binding of the specific ligand to its receptor serves as a transmembrane signal stimulating the formation of accumulative compartments.

EXTRA-CAPSULAR YOLK BODIES IN THE EGG MASSES OF SOME TROPICAL OPISTHOBRANCHIA

Seventeen species of opisthobranch molluscs from Enewetak, Marshall Islands were found to deposit bodies of yolk within their gelatinous egg masses external to the capsules which surround the ova. These observations bring the total number of opisthobranch species in which extra-capsular yolk is known to 26. This study reviews previous reports of extra-capsular yolk and contributes new data on the egg masses and developmental characteristics of species in which it is known to occur. The various types of yolk body found are detailed and categorized, and original observations on the deposition of yolk bodies and their fate during, and subsequent to embryonic development presented. To date, extra-capsular yolk bodies have been found only within the egg masses of species of Chromodoris and Cadlinella (Nudibranchia: Chromodorididae), Elysia (Sacoglossa: Elysiidae), and Bosellia (Sacoglossa: Polybranchiidae). Three types of yolk body are recognized: (1) cap-like yolk bodies associated with individual capsules, (2) discrete yolk bodies strewn throughout the egg mass, and (3) continuous or discontinuous yolk strings. Direct consumption of yolk bodies by newlyhatched veligers of Chromodoris albopunctatus (Garrett) is described. In most other species, the yolk disappears during the course of development and is probably of nutritive value to the embryos. The available data suggest that chromodorid species which utilize extra-capsular yolk during the course of development produce relatively larger larvae than species with comparably sized ova that do not.

An ultrastructural study of oogenesis inStreblospio benedicti (spionidae), with remarks on diversity of vitellogenic mechanisms in polychaeta

The ultrastructural features of oogenesis were examined in the spionid polychaeteStreblospio benedicti. Paired ovaries are attached to the genital blood vessels extending into the coelomic space from the circumintestinal sinus. The genital blood vessel wall is composed of flattened, peritoneal cells, large follicle cells and developing oocytes. Vitellogenesis occurs while the oocytes are attached to the blood vessel wall. Two morphologically distinguishable types of yolk are synthesized. Type I is synthesized first by an autosynthetic process apparently involving pinocytosis and the conjoined efforts of the Golgi complex and rough endoplasmic reticulum. Type II yolk appears later through a heterosynthetic process involving the infolding of the oolemma and the sequestering of materials from the blood vessel lumen by endocytosis. During this process, blood pigment molecules appear to be incorporated into endocytotic pits, vesicles and eventually the forming yolk body. The significance of heterosynthetic yolk formation to the general reproductive strategies of polychaetous annelids is discussed.

An electron microscope study on the developing oocytes of the crab Cancer pagurus L. with special reference to yolk formation (Crustacea)

The developing oocytes of the crab Cancer pagurus L. were studied with the light and electron microscope. Protein yolk formation was found to take place in two different ways. Yolk precursors of type 1 accumulate within the cisternae of an extensively developed granular endoplasmic reticulum. Also further growth and transformation into the definite yolk body occur within the reticular membranes. There is no structural indication that any other cell organelle contributes to the synthesis of this type of yolk building. Protein yolk formation of type 2 involves accumulation and transformation of material within a limiting membrane of the smooth type. The enclosed material is presumably derived from micropinocytosis, enclosed cellular elements and vesicles originating from the Golgi complex. It thus appears that the cell organelles play an important role in the process of drotein yolk formation in the growing oocytes of Cancer pagurus.

Cytochemical and fine structural analysis of oogenesis in the gastropod, Ilyanassa obsoleta.

AbstractAn analysis of differentiating oocytes of the gastropod, Ilyanassa obsoleta, has been made by techniques of light and electron microscopy. Early previtellogenic oocytes are limited by a smooth surfaced oolemma and are associated with each other by maculae adhaerentes. Previtellogenic oocytes are also distinguished by a large nucleus containing randomly dispersed aggregates of chromatin. Within the ooplasm are Golgi complexes, mitochondria and a few cisternae of the rough endoplasmic reticulum. When vitellogenesis begins, the oolemma becomes morphologically specialized by the formation of microvilli. One also notices an increase in the number of organelles and inclusions such as lipid droplets. During vitellogenesis there is a dilation of the saccules of the Golgi complexes and cisternae of the endoplasmic reticulum. Associated with the Golgi complexes are small protein‐carbohydrate yolk precursors encompassed by a membrane. These increase in size by fusing with each other. The “mature” yolk body is a membrane‐bounded structure with a central striated core and a granular periphery. At maturity a major portion of the ooplasmic constituents such as as mitochondria and lipid droplets occupy the animal region while the bulk of the population of yolk bodies are situated in the vegetal hemisphere.The follicle cells incompletely encompass the developing oocyte. In addition to the regularly occurring organelles, follicle cells are characterized by the presence of large quantities of rough endoplasmic reticulum and Golgi complexes whose saccules are filled with a dense substance. Associated with the Golgi saccules are secretory droplets of varied size.Amongst the differentiating oocytes and follicle cells are Leydig cells. These cells are characterized by a large vacuole containing glycogen. A possible function for the follicle and Leydig cells is discussed.

Fatty Acid Composition of Egg Yolk and Adipose Tissue as Influenced by Dietary Fat and Strain of Hen

CONSIDERABLE information has been gathered concerning the influence of dietary fat on fatty acid composition of egg yolk fat and body fat of the chicken (Cruickshank, 1934; Fisher and Leveille, 1957; Feigenbaum and Fisher, 1959; Ostwald et al., 1962; and Sell and Hodgson, 1963). However, there is only limited information available about the variation existing among chickens due to genetic differences, with regard to fatty acid composition of egg fat and adipose tissue (Edwards, 1964; and Chen et al., 1965).The objectives of this study were to determine the influence of dietary rapeseed oil and soybean oil on the fatty acid composition of egg fat and adipose tissue, and to obtain information about potential variation among strains of hens with respect to composition of egg and body fat.EXPERIMENTAL PROCEDUREThe experimental animals and conditions were as described by Kondra et al. (1968) in the preceding paper. Rapeseed oil and .

Effect of Cholesterol with Different Dietary Fats on the Fatty Acid Composition of Egg Yolk and Various Body Tissues

THERE is extensive evidence that dietary fats influence the fatty acids of chicken tissue, blood (Machlin et al., 1962; Evans et al., 1962; Adamson et al., 1961; Menge et al., 1964; Isaacks et al., 1964) and egg yolk lipids (Fisher and Leveille, 1957; Choudhury and Reiser, 1959 Wheeler et al., 1959; Evans et al., 1963 Machlin et al., 1962; Chen et al., 1965). Fatty acid changes in tissue lipids resulting from cholesterol feeding have been described in rats (Okey et al., 1961; Patil and Magar, 1960), rabbits (Swell et al., 1961, 1962; Evrard et al., 1962) and chickens (Machlin and Gordon, 1961; Dam and Nielson, 1957; Leveille et al., 1963; Blomstrand and Christensen, 1961). Chung et al. (1965) reported that the iodine number values of egg yolk and liver lipids were increased when cholesterol was consumed. Chung et al. (1966) showed that cholesterol in diets varying widely in linoleic acid …

The Effect of Dietary Cholesterol and Different Dietary Fats on Cholesterol Content and Lipid Composition of Egg Yolk and Various Body Tissues

THE effect of dietary lipids on the lipid composition of the egg and tissues of the hen has recently received much attention. The type or amount of dietary fat appears to have no effect on total lipid content of egg yolk according to Reiser et al. (1951), and Marion and Edwards (1962). Dietary fat also has very little influence on cholesterol deposition in the egg yolk (Reiser et al., 1951; Fisher and Leveille, 1957; Wheeler et al., 1959; Daghir et al., 1960; Edwards et al., 1962). However, when cholesterol is included in the diet of the hen, the egg yolk cholesterol level is increased according to the findings of Dam (1928), Budowski et al. (1961), Wood et al. (1961) and Harris and Wilcox (1963).Leveille and Fisher (1958) found that the iodine number of egg fat from hens receiving dietary corn oil was significantly higher than when animal fat or…

Effects of early handicaps on chickens as measured by yolk absorption and body weight to twenty weeks of age

Abstract does not appear. First page follows. General Problem and Literature That growth is markedly influenced by environmental factors is well known. The precise effects and optimum conditions have been the subject of so many investigations that reference can be made only to those which have the most direct bearing on the experiments reported here. Most of the previous investigations have been concerned with the results obtained when the experimental subjects were kept continuously under the particular environmental conditions. The point with which the present experiments are primarily concerned is the question of how permanent the effects of environmental handicaps are, when those handicaps are maintained for only a short time, during the early life of the subjects.

Studies on the shape of the Golgi apparatus

1. The cytoplasmic inclusions of the egg-follicle ofCulex fatigans have been studied in fresh coverslip preparations and also in sections prepared by the current technique for theGolgi apparatus and the mitochondria. 2. In the youngest follicle in which the oocyte is not differentiated from the nurse cells theGolgi elements consist of a number of vesicles, each showing an osmiophilic or argentophilic rim and an osmiophobic or argentophobic central area. The contents of these vesicles are non-fatty. 3. The contents of theGolgi vesicles on the nurse cells and of the follicular epithelial cells remain non-fatty throughout the growth period of the egg-follicle, while those of the majority of the oocyte vesicles become fatty. 4. Immediately after the mosquito has bad a feed on blood the proteid yolk bodies start appearing in the cytoplasm of the oocyte. 5. If an egg is ruptured and its contents studied under the microscope theGolgi vesicles are seen performing a very interesting dancing movement while the proteid yolk bodies are stationary. The presence of free fat inside the interior of theGolgi vesicles raises their refractive index and enables one to study them in fresh eggs with the utmost ease. 6. The youngest proteid yolk body is larger than aGolgi vesicle. 7. The egg contains only two types of inclusions, theGolgi vesicles and the proteid yolk bodies. Even the most diligent search has failed to bring out any granules etc. either in the oocyte or in the nurse cells and the follicular epithelium which could be assigned to the category of mitochondria. 8. In a centrifuged egg the albuminous yolk bodies are thrown to one pole of the egg and the fattyGolgi vesicles go to the opposite pole. The central area is occupied by the undifferentiated hyaloplasm which also contains the nucleus. The non-fattyGolgi vesicles remain uniformly distributed throughout the cytoplasm. 9. It has been shown that the oocyte nucleus ofCulex does not branch like that ofAnopheles as claimed byNicholson and that the “amoeboid” appearance of the nucleus results from the rupturing of its membrance by the brittle albuminous yolk spheres.