Differential Expression of Laccase Genes in Pleurotus ostreatus and Biochemical Characterization of Laccase Isozymes Produced in Pichia pastoris

In this study, transcriptome analysis of twelve laccase genes in Pleurotus ostreatus revealed that their expression was differentially regulated at different developmental stages. Lacc5 and Lacc12 were specifically expressed in fruiting bodies and primordia, respectively, whereas Lacc6 was expressed at all developmental stages. Lacc1 and Lacc3 were specific to the mycelial stage in solid medium. In order to investigate their biochemical characteristics, these laccases were heterologously expressed in Pichia pastoris using the pPICHOLI-2 expression vector. Expression of the laccases was facilitated by intermittent addition of methanol as an inducer and sole carbon source, in order to reduce the toxic effects associated with high methanol concentration. The highest expression was observed when the recombinant yeast cells were grown for 5 days at 15degrees C with intermittent addition of 1% methanol at a 12-hr interval. Investigation of enzyme kinetics using 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) as a substrate revealed that the primordium-specific laccase Lacc12 was 5.4-fold less active than Lacc6 at low substrate concentration with respect to ABTS oxidation activity. The optimal pH and temperature of Lacc12 were 0.5 pH units and 5degrees C higher than those of Lacc6. Lacc12 showed maximal activity at pH 3.5 and 50degrees C, which may reflect the physiological conditions at the primordiation stage.

Isolation and identification of embryonic pancreatic tissues in mice / 中华内分泌外科杂志

Objective To explore the isolation technique of embryonic pancreatic tissues in mice and to identify the isolated embryonic pancreatic tissue by morphology and endocrine function test.Methods Pancreatic tissues from embryonic(E) 11.5-16.5 d C57BL/6 mouse embryos were surgically isolated under the stereomicroscope.E12.5 d,E14.5 d,E16.5 d embryonic pancreas tissues were identified by conventional HE staining,immunohistochemistry and immunofluorescence.The endocrine functions of embryonic pancreatic tissues were measured by glucose stimulation test.Results Embryonic pancreatic tissues of mice over embryonic 12.5days can be easily isolated.Embryonic pancreatic tissues of mice younger than embryonic 12.5 days were hard to achieve and these pancreatic tissues could only be isolated according to the relationship with the adjacent organs.Histological and ELISA examinations showed that early embryonic pancreatic tissues could express and secrete insulin and the insulin level was gradually increased with developmental time.Conclusion A good command of the knowledge of the development and anatomy of mouse embryo help improve isolation of embryonic pancreas,which provides therapeutic potential for embryonic pancreatic tissue transplantation.

Development of the face.

The human face develops between the fourth and eighth week after conception. Its development can be traced to five facial primordia appearing around the stomodeum in the fourth week. They are, namely, one frontonasal prominence, two maxillary and two mandibular prominences. Two nasal placodes develop on each side of the lower part of the frontonasal prominence at the end of the fourth week and further develop into the medial and lateral nasal prominences. The early development of the human face is similar to that of other mammals, such as pigs, rats and rabbits; all of which acquire branchial arches in the early stage of development. The rabbit branchial arches develop at the 4-5 mm stage and nearly disappear at the 12-14 mm stage, as the second one grows dorsally and obliterates the cervical sinus. The medial and lateral nasal prominences appear at the 4-5 mm stage. At the 12-14 mm stage the nasal cavities are more extensive than those of a 10 mm pig embryo and are of the same stage of development as a 15 mm pig embryo. Currently, we use 10 and 15 mm pig embryos as models in this study of human facial development. However, in the future, it will be more suitable to use 4-12 mm rabbit embryos because they are obtained more easily.

An Improved Compost Using Cotton Waste and Fermented Sawdust Substrate for Cultivation of Oyster Mushroom

A composting technique was assessed to enhance efficiency in oyster mushroom substrate. Poplar sawdusts and by-product of winter mushroom added by 10% of rice bran were composted outdoors at 20degrees C to 28degrees C for 12 days. The duration of fermentation was shortened 3 days in fermented sawdust plot. The yield obtained from waste cotton substrate with fermented poplar sawdust was 742 g, whereas the yield from control 663 g. In addition, the substrate with by-product of winter mushroom was the most effective to composting. It was useful to apply the fermented sawdust and by-product to waste cotton for compost and sporophore production of oyster mushroom.

Sawdust Media Affecting the Mycelial Growth and the Fruiting Body Formation of Sparassis crispa

Six strains of Sparassis crispa such as S. crispa DUM-01, DUM-02, DUM-03, DUM-04, DUM-05, and DUM-06 were tested for their mycelial growth on 6 different kinds of sawdust media and primordial formation on 10 different compositions of larch sawdust media. The highest mycelial growth was recorded on the larch sawdust. Of the 6 strains of S. crispa, S. crispa DUM-04 recorded the favorable formation of primordia. The primordial formation of S. crispa DUM-04 was more favorable on L-3 medium than 9 kinds of larch sawdust media. When S. crispa DUM-04 was cultured on the media of larch sawdust+pine sawdust, the formation of its fruiting bodies was more outstanding on the media of larch sawdust+pine sawdust than those of larch sawdust.

The role of bone morphogenetic protein in the tooth culture

Objectives : The proper development of the facial structures relies upon a sequence of tightly regulated signaling interactions between the ectoderm and mesoderm involving the participation of several families of signaling molecules. Among these, bone morphogenetic proteins (BMPs) have been suggested to be a key signal that regulates the development of the mandible and the initiation and morphogenesis of the teeth. The aim of this study was to examine the artificial development of the mandibular structures and to examine the role of BMPs on tooth morphogenesis and differentiation using an organ culture system. Materials and Methods : The tooth germs from Ed 11.5, 13.5 mice were dissected, and transplanted into the diastema of the mandible primordia. The mandibles containing the transplanted tooth germs were cultured in vitro. During this period, beads soaked with BMP4 were implanted around the transplanted tooth germs. In addition, a diastema block containing the transplanted tooth germ was dissected, then transferred to an adult mouse kidney. After the organ culture, the developing mandibular explant was removed from the kidney and prepared for the tissue specimens. Odontogeneis of the transplanted tooth germs was examined after Hematoxylin-eosin, Masson-trichrome staining. Results : Proliferation and differentiation of the tooth germs cultured in the diastema was observed. In the BMP4-treated tooth germs, the formation of the first and second molars was noted. The crown of the developing tooth showed the formation of a mature cusp with the deposition of enamel and dentin matrix. In conclusion, it was confirmed that BMP4 is involved in the formation of a dental crown and the differentiation of ameloblasts and odontoblasts of the molar tooth during the development of the transplanted tooth germs.

Effect of Fermented Sawdust on Pleurotus Spawn

A method of spawn making procedures through the application of fermented sawdust for the purpose of avoiding contamination by undesirable fungi in the course of Pleurotus ostreatus mycelial growth was evaluated. Of three kinds of supplements, rice bran was the most effective to raise temperature up to 70degrees C. Mycelial activity and density was more considerably improved in the case of using fermented sawdust supplemented with rice bran than the case of non-fermented sawdust. Primordia of Pleurotus ostreatus were formed on fermented sawdust. The substrate of fermented sawdust showed potential to prevent the growth of Trichoderma sp. which caused a symptom on mushroom mycelium, whereas there was nothing to inhibit the growth of Trichoderma sp. during 30 days after inoculation in non-fermented sawdust.

Retinoic acid and mammalian craniofacial morphogenesis.

Retinoic acid is a morphogenetic signalling molecule in vertebrate embryos, one being known to perform a specific function in organizing the body pattern along the anteroposterior axis. This molecule has especially attracted research attention because retinoic acid treatment will also induce abnormal morphogenesis, particularly in the craniofacial structures. The present review discusses recent molecular insights revealing how the retinoic acid signal is transduced within a cell, specifically focusing on the involvement of cranial neural crest cells in retinoic acid-induced abnormal morphogenesis in the mammalian head.