title: [In-vitro differentiation of human testicular round spermatids to elongating spermatids].
abstract: OBJECTIVE
  To investigate the differentiation of human testicular spermatogenic cells during in vitro culture.
  
  
  METHODS
  Testicular cells of obstructive azoospermic patients' testis biopsies were dispersed employing mechanic methods. Then, (1) mixed testicular cells were applied to in vitro culture, and changes of the ratio of elongating spermatids and all round cells were analyzed during mixed cell culture; (2) round spermatids were picked up from the mixed cells employing micromanipulator, followed by differentiation of the isolated round spermatids during microdrop culture.
  
  
  RESULTS
  The ratio of the elongating spermatids increased significantly (P < 0.05) after 24 hours of mixed cell culture in HTF medium supplemented with FSH and testosterone. During single round spermatid culture, transformation of the round spermatid to elongating spermatid with newly formed flagellum was observed, and the transformation ratio within 48 hours of microdrop culture was 3.54%. The differentiation of human testicular spermatogenic cells cultured in Vero cell conditioned medium was similar to that cultured in HTF medium.
  
  
  CONCLUSIONS
  Human testicular round spermatids can differentiate to elongating spermatids during in vitro culture. Vero cell conditioned medium does not promote the differentiation of human testicular round spermatids to elongating spermatids.
authors.affiliation: Laboratory of Male Reproduction, Center of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, China.
authors.forename: Zhi-ming
authors.initials: ZM
authors.lastname: Cai
authors.forename: Min
authors.initials: M
authors.lastname: Shi
authors.forename: Yun
authors.initials: Y
authors.lastname: Long
authors.forename: Bo
authors.initials: B
authors.lastname: Song
authors.forename: Yong-yan
authors.initials: YY
authors.lastname: Cui
authors.forename: Hui
authors.initials: H
authors.lastname: Zhu
authors.forename: Yao-ting
authors.initials: YT
authors.lastname: Gui
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D006801:Humans; D007248:Infertility, Male / Q000473:pathology; D008297:Male; D013087:Spermatids / Q000166:cytology*; D013737:Testis / Q000166:cytology*; D014709:Vero Cells