Gene-controlled incorporation of haemolymph protein into the ovaries of Bombyx mori

The haemolymph protein concentration in Bombyx mori decreases normally by about one-fourth during pharate adult development. In females homozygous for the small egg gene, the concentration of haemolymph protein remained constant throughout the pupal and pharate adult stages. The sm gene does not influence the synthesis of vitellogenic female protein of pupal and pharate adult haemolymph (FP). Normal ovaries transferred to the haemocoele of sm females undergo normal vitellogenesis. In the absence of normal alleles of sm, the ovaries encounter difficulties in the incorporation of FP into their oöcytes from pharate adult haemolymph. These results suggest that an active translocation mechanism is involved in the transfer of haemolymph protein into the ovaries.     

Influence of the ovaries on JH titer in Teleogryllus commodus

Mating and availability of substrate were found to have a dramatic effect on the level of egg production and juvenile hormone III (JH III) titer in Teleogryllus commodus. Mated females with egg laying opportunity produced twice as many eggs, and exhibited an 8-fold increase in JH titer, as compared with virgin females or mated females forced to retain most of their eggs due to the absence of substrate for egg deposition. Denervation of the ovaries, or nerve cord transection, also caused accumulation of eggs and lowered the JH level, suggesting a feedback mechanism in which the state of egg depletion of the ovaries determines the level of JH secretion by the corpora allata (CA). Results from ovariectomy of mated or virgin animals suggest that the feedback mechanism includes inhibitory humoral factors secreted by the ovary.     

Gastrin-cholecystokinin-like immunoreactivity in the central nervous system of the milkweed bug,Spilostethus pandurus. Ultrastructural aspects of the reactive A cells of the brain

Summary— All the ganglia belonging to the central nervous system of adults of the milkweed bug Spilostethus pandurus (Hemiptera) were screened immunohistochemically for vertebrate gastrin-cholecystokinin (CCK-8(s))-like peptides. Several large reactive perikarya are present in the median part of the protocerebrum, their processes extending to the dorsal ‘aorta’. These cell bodies are also paraldehyde fuchsin-positive, ie they are A-type cells. In the lateral part of the protocerebrum, in the deutocerebrum and tritocerebrum, and in the suboesophageal, prothoracic and abdominal ganglia, a few immunoreactive cell bodies send axonal processes into their respective neuropiles. The A-type cells reactive to CCK antiserum were identified, at the ultrastructural level, by combining paraldehyde fuschin staining of semithin sections with a post-embedding immunogold technique carried out on adjacent ultrathin sections. The neurosecretory cells contain numerous vesicles of elevated electron density. These data suggest that members of the CCK peptide family are present in the central nervous system of Spilostethus pandurus.     

Effect of different doses of retinol acetate on the RNA and total protein content of rodent ovaries and endometrium

The effects of different doses of retinol acetate (RA) on protein synthesis by the hamster ovaries and endometrium were studied. Two groups of CBA/C57BL mice aged 3-4 months were given 3.44% oily RA per os on a daily basis for 10 days. After completion of the experiments the paraffin sections 6 micron m thin were subjected to a histochemical assay for the content of RNA and total protein in the ovaries and endometrium. RA (50 000 IU) was found to stimulate RNA and protein synthesis in all the ovarian structures and endometrium. In the ovaries, vitamin primarily affected the follicular epithelium and internal the-ca of the follicles. Administration of RA in a dose of 80 000 IU inhibited protein synthesis in the ovaries and endometrium. As for the ovarian structures the greatest changes under toxic hypervitaminosis A (80 000 IU) were experienced by the follicular epithelium and ovocytes.     

Identification of JH III in haemolymph from adults and larvae of Schistocerca gregaria

An analytical method for the separation and identification of JH III and (E,E)-methyl farnesoate from locust haemolymph is described. Using this method, JH III was identified in haemolymph from adults, but no (E,E)-methyl farnesoate was found. JH III was also identified in fourth instar hopper haemolymph fractions, which had previously been shown to be active in the Galleria pupal wax assay.     

Vitellogenin concentrations in the haemolymph and ovaries of Ixodes scapularis ticks during vitellogenesis

The vitellogenin and vitellin concentrations in the haemolymph and ovaries of Ixodes scapularis females were determined using a double sandwich enzyme-linked immunosorbent assay. The level of vitellogenin in the haemolymph began to increase just prior to tick detachment from the host and continued to increase until 2 days after detachment. There was a slight decrease in the vitellogenin level 4 days after detachment, but a second peak was observed approximately 5 days after oviposition. Subsequent to oviposition, the vitellogenin levels in the haemolymph quickly decreased. The concentration of vitellogenin in the haemolymph ranged from 1.55 to 11.48 g l^-1 during the period after dropping from the host through oviposition. The concentration of vitellin in the ovaries began to increase as the female began rapid engorgement (0.03 mg per female) and declined after oviposition (0.1 mg per female).     

Uridylylation of the PII protein from Herbaspirillum seropedicae

The PII protein is apparently involved in the control of NifA activity in Herbaspirillum seropedicae. To evaluate the probable role of PII in signal transduction, uridylylation assays were conducted with purified H. seropedicae PII and Escherichia coli GlnD, or a cell-free extract of H. seropedicae as sources of uridylylating activity. The results showed that alpha-ketoglutarate and ATP stimulate uridylylation whereas glutamine inhibits uridylylation. Deuridylylation of PII-UMP was dependent on glutamine and inhibited by ATP and alpha-ketoglutarate. PII uridylylation and (or) deuridylylation in response to these effectors suggests that PII is a nitrogen level signal transducer in H. seropedicae.     

Effect of high doses of retinol acetate on the 3-beta-ol-steroid dehydrogenase and alkaline phosphatase content in mouse ovaries

The author reports on the effects of different doses of retinol acetate on ovarian steroidogenesis. Two groups of CBA/C57BL mice with a mean body weight of 18-20 g received 3.44% oily retinol acetate per os in daily doses of 50 000 and 80 000 IU for 10 days. After completion of the experiments the quick-frozen sections of the ovaries were subjected to a histochemical assay for the content of 3-beta-ol-steroid dehydrogenase and alkaline phosphatase. Administration of 50 000 IU vitamin A was found to stimulate ovarian steroidogenesis. The effect of vitamin A was the most demonstrable in the interstitial tissue, atretic corpora, and, in the internal theca of the follicles. Administration of 80 000 IU retinol acetate inhibited ovarian steroidogenesis. The estrous cycle in animals ceased. Administration of vitamin A (80 000) primarily affected the follicular apparatus of the ovaries, namely the epithelium of the follicles and yellow bodies. At the same time secretory function of atretic corpora and interstitial tissue remained within normal, which was regarded as a compensatory-adaptive mechanism under toxic hypervitaminosis A.     

The role of PII conformations in the calculation of peptide fractional helix content.

Changes in the temperature, pH, ionic strength, or denaturant concentration of aqueous solutions of the monomeric non-alpha-helical peptide acetylYEAAAKEAPAKEAAAKAamide generate changes in its dichroic spectrum characteristic for a conformational transition. This transition has the characteristic features of a residue PII/unstructured conformational equilibrium in which PII denotes an extended left-handed helical conformation and unstructured denotes all the remaining conformations in a random coil ensemble. Replacement of the proline residue facilitates population of residues in an alpha-helical conformation. However, the ellipticity values for these non-proline peptides merge with the ellipticity of the proline peptide as the population of residues in the alpha-helix conformation is diminished. This convergence suggests that all residues in a host/guest peptide series of the same length share a common PII/unstructured conformational equilibrium in a given solvent. We propose that the fractional helix content of peptides within such a series may be estimated by using a two-state calculation in which the ellipticity for the non-alpha-helix conformations is provided by a peptide having a central proline guest residue.     

Effect of antibiotics on the structure and function of the ovaries

Streptomycin, penicillin, levomycetin, florimycin, cycloserin, erythromycin, sekazin, novobiocin, tetracyclines and neomycins had a stimulating effect on the sexual organs of the tests animals during the 1st decade of their administration. With long-term use some of the drugs induced dystrophic changes in the ovary. The signs of stimulation in the ovary were evident from increased activity of the oxidation-reduction enzymes in the inner membrane of the follicles and the interstitial cells of the stroma, as well as in an increase in the number of the maturating follicles. With long-term long use of erythromycin, sekasin or novobiocin, disappearance of the primordial follicles, an increase in the number of the atretic follicles and death of the ovocytes in the mature follicles were observed in the ovary.     

A larval haemolymph protein in the eggs of Rhynchosciara americana

In Rhynchosciara americana larvae, a protein referred to as “protein 10” comprises one of the major plasma protein of the last instar. This protein was purified and an antiserum against it shows that an identical protein is present in the eggs from this fly. Protein 10 has an estimated molecular weight of 43,000 and an isoelectric pH of 6.6. Examination of protein 10 from eggs and from haemolymph by limited proteolysis indicates that the two are structurally identical. Protein 10 is synthesized in large amounts by the larval fat bodies up until the end of the feeding stage. Estimation by radial immunodiffusion shows that protein 10 is stored in the larval haemolymph, attaining a maximum level at the end of feeding stage and then decreasing until very little remains in the young adult. By the middle of the pupal stage the ovaries begin to sequester and acummulate the protein 10 which is deposited in the eggs.     

Effect of temperature on the protein and nucleic acid content of thermotolerant yeasts

Summary The effect of growth at 30°, 35° and 40° on the biomass yield and on the nucleic acid and protein content of twelve isolates of yeast has been studied. Although yields of 41.6% and a true protein content of 34% were obtained, each of the strains exhibited a lower yield and protein content at 40° than at the lower temperatures. Nucleic acid levels were also reduced at 40°.