Production of Cellulase(s) byMyricoccum albomyces

The ability ofMyricoccum albomyces to produce extracellular cellulase(s) has been studied in a stationary liquid medium. Different cellulosic carbon sources were used. The organism was able to produce cellulose 1,4-β-cellobiosidase (C₁) and cellulase (C_x) activities. The optimum temperature for C₁ and C_x activity was 45 °C. The optimum pH for C₁ activity was pH 6 while that for C_x was pH 5.     

Localization of vitellogenin and serum albumin in hepatic parenchymal cells of normal and estradiol-treated immature chickens

The localization of albumin and vitellogenin was determined in liver sections from control and estradiol-treated chickens by two different immunocytochemical techniques: (1) The sandwich technique with rabbit anti-lipovitellin or rabbit anti-albumin IgG and fluorescent goat anti-rabbit IgG and (2) the mixed aggregation immunocytochemical technique with anti-lipovitellin IgG and fluorescent lipovitellin.The results show that the antibody against albumin bound only to all liver parenchymal cells. Furthermore, the fluorescence intensity was equally strong in the portal, intermediate and central zones of the lobules.The fluorescent stain for vittelogenin was not above background in livers of control chicks but was far above background in estradiol-treated chicks. As with albumin the fluorescent stain was distributed equally among the parenchymal cells.The results were quantitatively the same 2 and 4 days after estradiol treatment. The relative rates of synthesis and the concentrations of albumin and vitellogenin correlate well with values obtained for tissue sections by immunocytochemical techniques.     

Occurrence of vitellogenin in drone honeybees (Apis mellifica)

Summary

The occurrence of vitellogenin in adult haploid drones of the honeybee, Apis mellifica, was determined by sensitive immunotechniques, i.e. two-dimensional Immunoelectrophoresis and SDS-PAGE immunoblotting using a monospecific anti-vitellogenin-serum. In drones vitellogenin is one of the minor fractions of the hemolymph proteins. Genetic and regulatory aspects of vitellogenin synthesis in male bees are discussed.     

Production of the Water-Extractable Flower-Inducing Substance(s) in Lemna

Crude water extract of Lemna paucicostata Hegelm., strain 441,had high flower-inducing activity. This activity was heat-stable,but water extract of this plant after heat treatment had verylow activity. The water extract heated immediately after homogenizationalso had low activity, and this activity increased rapidly duringincubation of the plant homogenate before heating even at 0?C.The increase in activity did not occur during separate incubationof the supernatant and pellet obtained by centrifugation ofthe homogenate; some reaction between the components of thesupernatant and pellet may be necessary for production of theheat-stable flower-inducing substance(s). Oxygen deprivation(incubation in nitrogen gas) or presence of ascorbate duringincubation of the plant homogenate markedly lowered the generationof the flower-inducing activity. These results suggest thatthe active substance(s) is produced by an oxidative reaction.No significant difference could be found between photoperiodicallyinduced and non-induced plants in the activity of the waterextract after heat treatment. (Received April 9, 1990; Accepted July 5, 1990)     

Production of amylase(s) by Schwanniomyces castellii and Endomycopsis fibuligera

Schwanniomyces castellii and Endomycopsis fibuligera Produced extracellular amylase(s) when grown on various carbon sources and at different pH values. Both yeast species showed significant amylase synthesis in the presence of either maltose or soluble starch. On the other substrates tested (glucose, cellobiose, sucrose, trehalose, melezitose, raffinose, ethanol, glycerol) differences were found regarding growth and amylase production. Free glucose in the culture medium apparently inhibited enzyme synthesis. The pH range allowing maximal growth and amylase production was 4.5–6.0 for E. fibuligera and 5.5–7.0 for S. castellii.     

Production of macrophage migration inhibitory factor(s) (MIF) by virus-transformed cells

Rodent cell lines transformed by SV40, polyoma virus and Rous sarcoma virus cultured in vitro release material into the culture medium which inhibits the migration of guinea pig macrophages. Similar macrophage migration inhibitory factors (MIF) were not detected in cell-free supernatants harvested from untransformed cell cultures. Comparison of the MIF produced by virus-transformed cells with MIF derived from peripheral lymphocytes stimulated in vitro by phytohemagglutinin (PHA) revealed that they had similar molecular weights (25 000), heat stability and were both inhibited by α-fucose and lotus agglutinin. Incubation of MIF-containing cell-free supernatants from transformed cells with pancreatic trypsin inhibitor, soybean trypsin inhibitor and diisopropylfluorophosphate eliminated the MIF activity. The possible identity of the MIF released by transformed cells as a protease is discussed with reference to a potential role in modifying the surface properties of transformed cells.     

Poly(ADP-ribose) polymerase activity in regenerating liver of hypothyroid rats

The role of PARP, a nuclear enzyme involved in DNA synthesis, repair and cell transformation, was studies during liver regeneration in hypothyroid animals. Hypothyroidism was induced by in vivo administration of propylthiouracil. In regenerating euthyroid animals PARP activity is stimulated showing an early and significant increase at 1.5 h with a maximum at 6 h after partial hepatectomy. Such an increase returns to control values within 18 h preceding the onset of DNA synthesis. A markedly different behavior, with respect to euthyroids, has been evidenced in hypothyroid rats. At first, liver PARP level was about 2-fold higher in non regenerating hypothyroid rats with respect to control euthyroids. During regeneration, PTU-treated animals show a net decrease in PARP activity, with a minimum at 6-9 h after partial hepatectomy. The activity returns to control levels within 24 days. The minimum in PARP activity anticipates, also in this case, the onset of DNA synthesis, which exhibits a maximum at 15-18 h. During liver regeneration PARP activity shows modifications related to the beginning of de novo DNA synthesis. Furthermore, these variations in turn undergo the effects of hypothyroidism.     

Relationship between interstitial fluid volume and pressure (compliance) in hypothyroid rats

There is clinical and experimental evidence that lack of thyroid hormones may affect the composition and structure of the interstitium. This can influence the relationship between volume and pressure during changes in hydration. Hypothyrosis was induced in rats by thyroidectomy 8 wk before the experiments. Overhydration was induced by infusion of acetated Ringer, 5, 10, and 20% of the body weight, while fluid was withdrawn by peritoneal dialysis with hypertonic glucose. Interstitial fluid pressure (P(i)) in euvolemia (euvolemic control situation) and experimental situation was measured with micropipettes connected to a servocontrolled counterpressure system. The corresponding interstitial fluid volume (V(i)) was found as the difference between extracellular fluid volume measured as the distribution volume of (51)Cr-labeled EDTA and plasma volume measured using (125)I-labeled human serum albumin. In euvolemia, V(i) was similar or lower in the skin and higher in skeletal muscle of hypothyroid than in euthyroid control rats, whereas the corresponding P(i) was higher in all tissues. During overhydration, P(i) rose to the same absolute level in both types of rats, whereas during peritoneal dialysis there was a linear relationship between volume and pressure in all tissues and types of rats. Interstitial compliance (C(i)), calculated as the inverse value of the slope of the curve relating changes in volume and pressure in dehydration, did not differ significantly in the hindlimb skin of hypothyroid and euthyroid rats. However, in skeletal muscle, C(i) was 1.3 and 2.0 ml. 100 g(-1). mmHg(-1) in hypothyroid and euthyroid rats (P < 0.01), with corresponding numbers for the back skin of 2.7 and 5.0 ml. 100 g(-1). mmHg(-1) (P < 0.01). These experiments suggest that lack of thyroid hormones in rats changes the interstitial matrix, again leading to reduced C(i) and reduced ability to mobilize fluid from the interstitium.     

Molecular characterization of a cDNA encoding vitellogenin in the banana shrimp, Penaeus (Litopenaeus) merguiensis and sites of vitellogenin mRNA expression

In order to determine the primary structure of banana shrimp, Penaeus merguiensis, vitellogenin (Vg), we previously purified vitellin (Vt) from the ovaries of vitellogenic females, and chemically analyzed the N-terminal amino acid sequence of its 78 kDa subunit. In this study, a cDNA from this species encoding Vg was cloned based on the N-terminal amino acid sequence of the major 78 kDa subunit of Vt and conserved sequences of Vg/Vt from other crustacean species. The complete nucleotide sequence of Vg cDNA was achieved by RT-PCR and 5' and 3' rapid amplification of cDNA ends (RACE) approaches. The full-length Vg cDNA consisted of 7,961 nucleotides. The open reading frame of this cDNA encoding a precursor peptide was comprised of 2,586 amino acid residues, with a putative processing site, R-X-K/R-R, recognized by subtilisin-like endoproteases. The deduced amino acid sequence was obtained from the Vg cDNA and its amino acid composition showed a high similarity to that of purified Vt. The deduced primary structure, of P. merguiensis Vg was 91.4% identical to the Vg of Penaeus semisulcatus and was also related to the Vg sequences of six other crustacean species with identities that ranged from 86.9% to 36.6%. In addition, the amino acid sequences corresponding to the signal peptide, N-terminal region and C-terminal region of P. merguiensis Vg were almost identical to the same sequences of the seven other reported crustacean species. Results from RT-PCR analysis showed that Vg mRNA expression was present in both the ovary and hepatopancreas of vitellogenic females but was not detected in other tissues including muscle, heart, and intestine of females or in the hepatopancreas of mature males. These results indicate that the Vg gene may be expressed only by mature P. merguiensis females and that both the ovary and hepatopancreas are possible sites for Vg synthesis in this species of shrimp.     

Induction and partial characterization of California halibut (Paralichthys californicus) vitellogenin

The egg yolk precursor protein, vitellogenin (Vg), was isolated by size exclusion and ion exchange chromatography from plasma of California halibut (Paralichthys californicus) treated with estrogen. MALDI TOF mass spectrometry (MS) analysis resulted in a molecular mass of 188 kDa. MS/MS de novo sequencing identified the protein as Vg by matching sequences of tryptic peptides to the known sequences of several other species. Matches were also made to two different forms of Vg in haddock, medaka, and mummichog, providing evidence that California halibut has more than one form of Vg. Native PAGE and Western blot with an antibody to turbot (Scophthalmus maximus) Vg confirmed the identity of the protein. Protein resolved on the SDS PAGE as a double band of approximately the same mass as determined with MALDI TOF, and two lower mass bands that were also immunoreactive. MALDI TOF and MS/MS de novo sequencing were useful for determining the molecular mass, identification, and exploring the multiplicity of Vg. The potential of using other MS methods to understand the structure and function of Vg is discussed.     

VLDL双向选择肉鸡群SSR指纹分析

对初步进行VLDL双向选择的三个世代高、低脂群肉鸡进行SSR指纹分析,评定各基因座基因频率的变化,进而判断SSR标记与肉鸡肥度性状VLDL的相关关系,为低脂肉鸡的早期选育奠定基础。5个微卫星引物一个未扩增出产物,其余4个引物扩增出14个微卫星位点。各位点在高、低脂系中的基因频率经卡方检验,一世代有一个基因座的基因频率差异显著（P<0.05）;二世代两个基因座差异显著;三世代共检测到4个基因座差异显著。 Abstract:SSR fingerprints were analyzed in three generations of fat line (FL) and lean line (LL) of broiler chickens.Changes in gene frequencies of every locus were evaluated.Thus the relationship between SSR markers and VLDL (a trait representing fat mass of broiler),which is the basis for early selection of LL broiler,was examined.Fourteen microsatellite locus were successfully amplified with 4 of 5 primers used.The results of χ2 test for the gene frequencies of every locus show that one locus was significantly different in generation 1(P<0.05),two in generation 2 and 4 in generation 3.     

Vitellogenesis in both sexes of gonochoristic mud shrimp, Upogebia major (Crustacea): analyses of vitellogenin gene expression and vitellogenin processing

The mud shrimp, Upogebia major is a gonochoristic species with distinct sexual dimorphism; however, the male has the “ovarian part of testis” in the gonad and mature-looking eggs appear in a similar reproductive cycle to the female. Vitellogenesis of U. major was investigated focusing on the characterization of vitellogenin (Vg) gene expression and Vg processing. Vg cDNA cloned by PCR-based methods was 7799 bp-long, encoding 2568 amino acids in a single open reading frame. The deduced amino acid sequence shared common characteristics conserved in other shrimp Vgs. The Vg gene was expressed in the hepatopancreas of females and males, the ovary, and the ovarian part of testis. Vitellins (Vns) were detected in the gonads of both females and males as three prominent polypeptides with apparent molecular masses of 82 kDa, 100 kDa, and 115 kDa. N-terminal amino acid sequences determined for the three polypeptides were present in the deduced amino acid sequence, demonstrating that they derived from a single long Vg polypeptide. Immunoblot analysis using polyclonal antibodies raised against two Vns (82 kDa and 100 kDa) confirmed Vg processing in the hepatopancreas, in the hemolymph and possibly in the oocytes, similarly in both sexes.     

Cloning and characterization of vitellogenin cDNA from the common Japanese conger (Conger myriaster) and vitellogenin gene expression during ovarian development

The major yolk protein precursor, vitellogenin (VTG) was detected in plasma from vitellogenic females and estradiol-17β (E₂)-treated immature females, but not in males and immature females by Western blotting in common Japanese conger Conger myriaster. Its molecular mass was approximately 180 kDa under denaturing and reducing conditions. The common Japanese conger VTG cDNA was cloned from the liver of vitellogenic female. It contains 5110 nucleotides including an open reading frame that encodes 1663 amino acids. The deduced amino acid sequence of the common Japanese conger VTG shares 80% identity with that of eel Anguilla japonica VTG-1, and 45–55%, 32–34% and 27–29% identity with the deduced amino acid sequences of other fish, amphibian and avian VTG with polyserin domain, respectively. In female common Japanese conger, VTG gene was highly expressed in the liver of this species similar with other oviparous vertebrates. The expression levels of VTG gene in the liver increased from the oil droplet stage to the tertiary yolk globule stage and were maintained until the migratory nucleus stage.