ABSTRACT
To identify downstream and/or interactive factors of the nsdD gene, which encodes a positive regulator of sexual development of Aspergillus nidulans, suppressor mutants displaying a self-fertile phenotype were isolated from a sterile nsdD deletion mutant. At least five different loci (sndA-E) were identified and genetically analyzed. In the nsdD (+) background, most of the suppressors showed a marked increment of sexual development, even under the stress conditions that normally inhibited sexual development. The common phenotype of the suppressor mutants suggested the involvement of the snd genes in the negative regulation of sexual development in response to the environmental factors.
Subject(s)
Aspergillus nidulans/genetics , Aspergillus nidulans/physiology , Fungal Proteins/genetics , Gene Deletion , Suppression, Genetic , Aspergillus nidulans/growth & development , Fungal Proteins/metabolism , Gene Expression Regulation, Developmental , Reproduction , Reproduction, AsexualABSTRACT
We have expressed human erythropoietin (EPO) in transgenic mice using a recombinant EPO cDNA combined with a partial TPO construct. The gene was microinjected using standard techniques and five mice were detected as transgenic by PCR and further used as founders. The life span of the transgenic founders was much shorter than that of their normal littermates. Most of the tissues of the transgenic founders contained human EPO transcripts as judged by RT-PCR. Especially high expression levels were seen in the liver and lung. EPO protein levels in serum were examined by ELISA and ranged from 266, 414 mIU/ml. The number of red blood cell, white blood cell and hemoglobin in the hEPO transgenic mice was higher than in normal mice. These results indicate that overexpression of hEPO is deleterious and can provoke lung failure and erythrocytosis.
Subject(s)
Erythropoietin/metabolism , Lung Diseases/pathology , Polycythemia/pathology , Animals , Blood Cell Count , Cattle , Cell Count , Erythropoietin/blood , Erythropoietin/genetics , Gene Expression Regulation , Humans , Lung Diseases/chemically induced , Mice , Mice, Inbred C57BL , Mice, Transgenic , Pedigree , Polycythemia/chemically induced , RNA, Messenger/genetics , RNA, Messenger/metabolism , Recombinant Proteins , TransgenesABSTRACT
To determine whether the mammary gland can be used to secrete large quantities of a bioactive heterodimeric protein into milk, we used a bovine beta-casein promoter to target and express human follicle-stimulating hormone (hFSH) in the mammary gland into the milk of transgenic mice. We also identified the effects of hFSH leaked into the bloodstream. Transgenic mice produced a high level (up to 300 mIU/ml) of recombinant hFSH in the mammary gland. Human FSH was expressed in the mammary gland and brain, as determined by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. In vitro bioactivity was also identified by cyclic AMP (cAMP) assay. The highest activity was showed in the transgenic mice line 11. However, hFSH leaked into the bloodstream was a powerful factor in the generation of breast and ovarian tumors from the transgenic mice line 11. These results suggest that change of endogenous hormones (FSH and progesterone) may affect the morphology and blood cell counts of peripheral blood and, especially, provoke breast and ovarian tumors.
