Preliminary Study on the Gene Characteristics of Oidiomycetes Mutant Strains Like Bacterial Morphology / 现代检验医学杂志

Objective To further explore the genetic characteristics of oidiomycetes mutant strains like bacterial morphology on the basis of the study on morphology and structure of mutated candida.Methods The standard strains of candida albicans were induced by low temperature and under the condition of low temperature and nutrient deficiency.Variation of standard strains of Candida albicans were induced by clinical antifungal drugs such as fluconazole with different concentration gradient.Fungal gene template was prepared by boiling method,sequences of 16SRNA and 18SRNA were amplified using bacteria conservative gene sequence of 16SRNA and fungal conserved gene sequence of 18SRNA,and observed and recorded the results agarose gel electrophoresis.At the same time,the amplified fragment of bacterial conservative gene 16SRNA was sequenced,and the sequence was analyzed by BLAST comparison.Results the 16SRNA sequences of candida variant were amplified positive,while the standard strain of candida albicans did not show the corresponding amplification band.Except 2 strains which showed a faint band,the other variants of the 18SRNA sequences did not amplified the target band,while the standard strains of candida albicans showed a corresponding amplification bands.Suggested that proportion of 18SRNA sequences in the genome of oidiomycetes mutant strains like bacterial morphology was not much even lack.The 16SRNA fragments amplified of oidiomycetes mutant strains like bacterial morphology did determination of DNA sequence after purification.BLAST comparison analysis,it was found that sequence of oidiomycetes mutant strains like bacterial morphology had higher similarity with bacterial sequences in the database.Conclusion Oidiomycetes mutant strains like bacterial morphology contained bacterial and a small amount of fungus conservative gene.Oidiomycetes mutant strains like bacterial morphology with original nuclear biological character are ones from eukaryotes.This study is great significance in biological evolution,especially in the evolution of prokaryotic cells and eukaryotic cells.

Preparation of catalitaxol-deficient defective strains by using ultraviolet mutagenesis / 生物工程学报

Secondary metabolites of endophytic fungi FSN002 from Juglans mandshurica Maxim have excellent liver cancer resistance. Preparation of mutant strains is an important means to study the biosynthesis mechanism of catalitaxol. Fungal spores germinating young hyphae with 4 to 6 cells after culturing for 13 hours were used as starting materials of ultraviolet (UV) mutagenesis. UV light intensity and irradiation time have a linear relationship with fungal mortality. The two factors had no obvious interactions. When UV light was 90 000 μJ/cm2 and irradiation time for 6 s, the mortality of fungi was around 95%. Under the optimization mutation condition, two mutant strains were obtained, of which one lost the synthesis ability of catalitaxol completely, and the another synthetized only 16% catalitaxol of the wild strain. Our findings may serve basis for further study on the biosynthesis mechanism and efficient production of catalitaxol.

Cdc20 mutation promotes development of colon cancer in APCmin/+ mice / 肿瘤研究与临床

Objective To demonstrate the relationship between Cdc20 mutation and the promotion of colon cancer via Cdc20loxp/+ APCmin/+ villin-cre+/-compound mutant mice.Methods Cdc20loxp/+ APCmin/+ villin-cre+/-compound mutant mice and APCmin/+ mutant mice were generated by mice mating strategy.The colon tumors of two group mice were compared by phenotypic analysis and histology analysis.Results Phenotypic analysis showed that the number of tumors in Cdc20loxp/+ APCmin/+ villin-cre+/-compound mutant mice group and APCmin/+ mutant mice group was 1.2±0.5 and 1.6±0.5, respectively (t =0.215, P =0.588), and the maximum diameter of tumors was (2.7±0.3) cm and (2.5±0.2) cm, respectively (t =0.568, P =0.575).Pathologic type of Cdc20loxp/+ APCmin/+ villin-cre+/-compound mutant mice was adenocarcinoma, while that of APCmin/+ mice was tubular adenoma.Conclusion Cdc20 carrying a null allele can accelerate the promotion of colon cancer in APCmin/+ mice without influence on the tumor number and size.

Study on Biological Characters and Genetic Characteristics of Oidiomycetes Mutant Strains Like Bacterial Morphology / 现代检验医学杂志

Objective To investigate the changes of the morphology,structure and biological characters of mutated Candida and through its genetic characteristics,research and reveal the mechanism of the variation at the molecular level.Methods Used different nutritional conditions,different growth conditions and different azole antifungal agents to induce mutation of the standard strains of Candida albicans.In clinical study,Candida mutant strains was isolated from vaginal secretions,pleu-ral effusion and gastric juice samples in patients of poor effect with Antifungal therapy,and studied on the morphological characteristics,and the nuclear structure,the biochemical reaction,the drug resistance,the bacterial composition and the ge-netic characteristics of above variants,etc.Results Mycelial?morphology:Candida were prone to mutation like bacteria, mutant bacteria could show G+ Aureus shape,G+ Bacillus,G+ long filamentous,G- Aureus shape,G- Bacillus and G- long filamentous;Nuclear structure:Candida mutant strains changed like prokaryotes under the electron microscope because it lost the original structure of eukaryotic cells.Biochemical reaction:there were 5 different items in 20 biochemical test ob-served.Drug sensitivity test:Candida mutated to antifungal drugs being originally sensitive was completely resistant,sensi-tive and resistant originally was completely sensitive,and the same as ordinary bacteria resistant.The cell component chan-ges:there was significantly different in Candida variant strain and the atavism of variant strain identified by mass spectrome-try.The most conservative fungalgene expression:Candida mutated had conservative gene expression of eukaryotes.It could be demonstrated that oidiomycetes mutant strains like bacterial morphology with prokaryotic cell biological characteristics was derived from Candida with eukaryotic cells.Conclusion Candida was prone to variation like bacterial morphology.The biological characteristics of mutant resembled prokaryote.There was a qualitative change among the standard strains of Can-dida albicans,mutant strains of oidiomycetes like bacterial morphology and the atavism of variant strain with clear genetic re-lationship under the electron microscope in the form of nuclear matter.The study on biological evolution,especially contact in prokaryotic cells and eukaryotic evolution has very important significance.

Current research in animal models of dry age-related macular degeneration / 中华实验眼科杂志

Age-related macular degeneration (AMD) is the leading cause of the irreversible vision loss in population over 55 years of age.With the increasingly serious problem of aging,the prevalence of AMD is rising year by year.However,as the pathogenesis of dry AMD is largely unknown,the effective therapy still is lack.Given that there was a lack of proper animal models,it brought about obstacles to researches about molecular mechanism underlying dry AMD.Nowadays,lots of murine models of dry AMD have been established and developed,which provide suitable tools for relevant researches.But,different dry AM D models show varied pathogenesis features,and a reasonable choice of models is very important for different studies.The characteristics of different dry models were reviewed in this article.

Processamento intracelular da fibrilina-1 mutada na síndrome de Marfan: escape do controle de qualidade pela dissulfeto isomerase proteica / Mutated fibrillin-1 intracellular processing in Marfan syndrome: bypass of a protein disulfide isomerase-mediated quality control

A Síndrome de Marfan (SMF) é a enfermidade hereditária mais comum dentre as que afetam o sistema conjuntivo, causada por mutações da glicoproteína fibrilina-1, o principal componente estrutural das microfibrilas elásticas da matriz extracelular. As manifestações fenotípicas da SMF são sistêmicas e acometem tipicamente os sistemas ocular, esquelético e cardiovascular, este uma importante causa de morbi-mortalidade. Entretanto, não está claro como a mutação induz a doença. Estudos anteriores sugerem anomalias morfológicas do retículo endoplasmático (RE) ou retenção intracelular da fibrilina-1 nos estágios avançados da SMF. Entretanto, a contribuição do enovelamento da fibrilina-1 mutada e do estresse do RE na fisiopatologia celular da SMF não é conhecida. Proteínas mal-enoveladas podem levar à retenção intracelular e/ou aumento da degradação através da via de degradação associada ao RE (ERAD), além da indução da resposta a proteínas mal-enoveladas (UPR), ambas com potencial contribuição à fisiopatologia de doenças, incluindo a SMF. Assim, estudamos em fibroblastos embrionários isolados de camundongos (MEFs) com SMF se a fibrilina-1 mutada é reconhecida pelo controle de qualidade do RE pelo seu mal- enovelamento e induz estresse do RE por sua retenção intracelular. Demonstramos que a mutação na fibrilina-1 per se não promoveu chaperonas marcadoras de UPR ou geração de oxidantes. Além disso, não levou a uma maior sensibilização das células à indução exógena de estresse do RE, nem promoveu maior morte celular após inibição do proteassoma. Além disso, não foi observada retenção intracelular da fibrilina-1 nas células SMF, e mesmo após inibição da via secretora ou indução de estresse do RE, a inibição da secreção da fibrilina-1 foi similar nos MEFs SMF e wild-type (WT). A dissulfeto isomerase proteica (PDI), uma importante chaperona redox do RE, interage com fibrilina-1, e seu silenciamento levou a um aumento na secreção da fibrilina-1 pelos MEFs WT...

Marfan syndrome (MFS) is the most common connective tissue hereditary disease, caused by mutations in the glycoprotein fibrillin-1, the main structural component of extracellular matrix elastic microfibrils. MFS phenotypic manifestations are systemic and typically involve the ocular, skeletal and cardiovascular systems, the latter a major cause of morbidity/mortality. However, how gene mutation induxes disease is yet unclear. Previous studies suggest endoplasmic reticulum (ER) morphological abnormalities or fibrillin-1 intracellular retention in advanced MFS stages. However, the contribution of mutated fibrillin-1 folding and ER stress to MFS cellular pathophysiology is unknown. Un/misfolded proteins may associate with their intracellular retention and/or increased degradation through ER-associated degradation (ERAD), in addition to inducing the unfolded protein response (UPR), both sharing potential contributions to disease pathophysiology, including MFS. Thus, we studied in embryonic fibroblasts (MEFs) isolated from WT and MFS mice, if mutated fibrillin-1 can be recognized by ER quality control as a misfolded protein, able to induce ER stress due to its intracellular retention. We showed that fibrillin-1 mutation by itself did not promote UPR chaperone markers or oxidant generation. Moreover, it did not sensitize cells to exogenous ER stress nor affected cell survival curves after proteasome inhibition. Furthermore, no intracellular retention of fibrillin-1 was observed in MFS cells, and even after secretory pathway inhibition or ER stress induction, fibrillin-1 secretion inhibition was similar in MFS and wild-type (WT) MEFs. Protein disulfide isomerase (PDI), an important ER redox chaperone, interacts with fibrillin-1 and its silencing induced an increased fibrillin-1 secretion in WT...

Insulin 3-like hormone and its role in epididymo-testicular descent

PURPOSE: The role of insulin 3-like (Insl3) hormone signaling in the testicular descent process has been demonstrated. The purpose of the present study was to evaluate epididymal development in Insl3-deficient mice. MATERIALS AND METHODS: Heterozygous and homozygous Insl3 mutants of a mixed CD1 X 129/Sv genetic background were generated by breeding Insl3-/- females with Insl3+/- males, and their genotypes were determined by polymerase chain reaction. On the first postnatal day, newborn males were sacrificed, embedded in paraffin, and cut in 4 µm sections. Sections were stained with hematoxylin/eosin and immunoreacted with anti-± actin antibody. RESULTS: An analysis of stained sections indicated an arrest in the development of the epididymis in all homozygous mice. The cauda and corpus of the epididymis were undersized. Compared to the heterozygous epididymis, the homozygous epididymis had fewer peritubular layers and dwarfish musculature. We confirmed this with immunostaining with monoclonal antibodies against ± -smooth muscle actin. CONCLUSION: Defective development of the smooth musculature in the epididymis of Insl3 homozygous mutant mice, combined with its high intraabdominal undescended position, supports previous observations regarding the importance of intact epididymis morphology and function for descent of the epididymo-testicular unit.

Alzheimer disease associated phenotypes in PDAP_(SW) transgenic mice / 中华神经科杂志

Objective In order to study the role of APP SW mutation in the aetiology of Alzheimer′s disease(AD), the phenotypes of the PDAP SW transgenic mice were investigated. Methods Body weight, coat color and reproducibility of transgenic mice were observed;The pathological changes in the brain of the transgenic mice were examined using immunohistochemistry; Behavioral changes of transgenic mice were examined by Y-maze. Result At 3 month′s age, the mean body weight of the transgenic mice was (31.0?3.7) g, that of non-transgenic was (34.0?2.9) g;while the mean body weight of F1 transgenic mice was (32.0?3.3) g, of negative mice was (31.0?4.2) g. There were no significant difference between these two groups. There were three transgenic mice with abnormal coat and one male was infertile. The transgenic mice had amyloid deposit in their brains. In the Y-maze test, transgenic mice showed an increased number of arm entered (53?7 versus 37?4) and an impaired spontaneous alternation. The frequency of alternation was 48.2% in the transgenic mice and 76.4% in the non-transgenic mice,respectively.Conclusion The PDAP SW transgenic mice had typical pathological and behavioral changes similar to that of AD and could be used as an animal model for studying AD.

In vitro and in vivo nitrogenase activity of Rhizobium mutants and their symbiotic effectivity.

A slow growing nitrogen-fixing strain of Vigna radiata var. aureus (mung bean) Rhizobium which expressed nitrogenase activity in a synthetic medium was isolated from its native population. Mutants with decreased and increased nitrogenase activity were derived from this strain by treatment with acridine orange and ethidium bromide. These mutants were tested for symbiotic effectivity in vivo. The effectivity of mutants with decreased nitrogenase activity in the culture medium was lower than the parent strain; however, the effectivity of mutants with higher nitrogenase activity did not increase above that of the parent. This suggests that the plant is perhaps a limiting factor in the full expression of rhizobial nitrogenase in the nodules.