title: Intake of Erythrocytes Required for Reproductive Development of Female Schistosoma japonicum.
abstract: The reproductive development and maturation of female schistosomes are crucial since their released eggs are responsible for the host immunopathology and transmission of schistosomiasis. However, little is known about the nutrients required by female Schistosoma japonicum during its sexual maturation. We evaluated the promoting effect of several nutrients (calf serum, red blood cells (RBCs), ATP and hypoxanthine) on the reproductive development of pre-adult females at 18 days post infection (dpi) from mixed infections and at 50 dpi from unisexual infections of laboratory mice in basic medium RPMI-1640. We found RBCs, rather than other nutrients, promoted the female sexual maturation and egg production with significant morphological changes. In 27% of females (18 dpi) from mixed infections that paired with males in vitro on day 14, vitelline glands could be positively stained by Fast Blue B; and in 35% of females (50 dpi) from unisexual infections on day 21, mature vitelline cells were observed. Infertile eggs were detected among both groups. To analyze which component of mouse RBCs possesses the stimulating effect, RBCs were fractionated and included in media. However, the RBC fractions failed to stimulate development of the female reproductive organs. In addition, bovine hemoglobin hydrolysate, digested by neutral protease, was found to exhibit the promoting activity instead of untreated bovine hemoglobin. The other protein hydrolysate, lactalbumin hydrolysate, exhibited a similar effect with bovine hemoglobin hydrolysate. Using quantitative RT-PCR, we found the expression levels of four reproduction-related genes were significantly stimulated by RBCs. These data indicate that RBCs provide essential nutrients for the sexual maturation of female S. japonicum and that the protein component of RBCs appeared to constitute the key nutrient. These findings would improve laboratory culture of pre-adult schistosomes to adult worms in medium with well-defined components, which is important to investigate the function of genes related to female sexual maturation.
authors.affiliation: Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China.
authors.forename: Jipeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China.
authors.forename: Shuqi
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China.
authors.forename: Xiufeng
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Parasite and Vector Biology of Ministry of Public Health, Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.affiliation: Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China.
authors.forename: Riyi
authors.initials: R
authors.lastname: Chai
authors.affiliation: Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China.
authors.forename: Pan
authors.initials: P
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Parasite and Vector Biology of Ministry of Public Health, Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Ju
authors.affiliation: Institute for Infectious Diseases and Vaccine development, Tongji University School of Medicine, Shanghai, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Microbiology, Immunology & Tropical Medicine, and Research Center for the Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, DC, United States of America.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Brindley
authors.affiliation: Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China; Key Laboratory of Parasite and Vector Biology of Ministry of Public Health, Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
mesh_terms: D000818:Animals; D002417:Cattle; D003470:Culture Media; D004912:Erythrocytes / Q000469:parasitology*; D005260:Female; D015870:Gene Expression / Q000502:physiology; D005836:Genitalia, Female / Q000254:growth & development; D006454:Hemoglobins / Q000378:metabolism; D008297:Male; D051379:Mice; D018613:Microscopy, Confocal; D016133:Polymerase Chain Reaction; D012549:Schistosoma japonicum / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D012554:Schistosomiasis japonica / Q000469:parasitology; D012741:Sexual Maturation / Q000235:genetics / Q000502:physiology*
chemical_list: D003470:Culture Media; D006454:Hemoglobins