title: Molecular cloning and expression analysis of dmrt1 and sox9 during gonad development and male reproductive cycle in the lambari fish, Astyanax altiparanae.
abstract: BACKGROUND
  The dmrt1 and sox9 genes have a well conserved function related to testis formation in vertebrates, and the group of fish presents a great diversity of species and reproductive mechanisms. The lambari fish (Astyanax altiparanae) is an important Neotropical species, where studies on molecular level of sex determination and gonad maturation are scarce.
  
  
  METHODS
  Here, we employed molecular cloning techniques to analyze the cDNA sequences of the dmrt1 and sox9 genes, and describe the expression pattern of those genes during development and the male reproductive cycle by qRT-PCR, and related to histology of the gonad.
  
  
  RESULTS
  Phylogenetic analyses of predicted amino acid sequences of dmrt1 and sox9 clustered A. altiparanae in the Ostariophysi group, which is consistent with the morphological phylogeny of this species. Studies of the gonad development revealed that ovary formation occurred at 58 days after hatching (dah), 2 weeks earlier than testis formation. Expression studies of sox9 and dmrt1 in different tissues of adult males and females and during development revealed specific expression in the testis, indicating that both genes also have a male-specific role in the adult. During the period of gonad sex differentiation, dmrt1 seems to have a more significant role than sox9. During the male reproductive cycle dmrt1 and sox9 are down-regulated after spermiation, indicating a role of these genes in spermatogenesis.
  
  
  CONCLUSIONS
  For the first time the dmrt1 and sox9 were cloned in a Characiformes species. We show that both genes have a conserved structure and expression, evidencing their role in sex determination, sex differentiation and the male reproductive cycle in A. altiparanae. These findings contribute to a better understanding of the molecular mechanisms of sex determination and differentiation in fish.
authors.affiliation: Department of Cell and Developmental Biology, Institute of Biomedical Science, University de São Paulo, São Paulo, SP, Brazil. mateus.adolfi@biozentrum.uni-wuerzburg.de.
authors.forename: Mateus C
authors.initials: MC
authors.lastname: Adolfi
authors.forename: Ana Co
authors.initials: AC
authors.lastname: Carreira
authors.forename: Lázaro Wo
authors.initials: LW
authors.lastname: Jesus
authors.forename: Jan
authors.initials: J
authors.lastname: Bogerd
authors.forename: Rejane M
authors.initials: RM
authors.lastname: Funes
authors.forename: Manfred
authors.initials: M
authors.lastname: Schartl
authors.forename: Mari C
authors.initials: MC
authors.lastname: Sogayar
authors.forename: Maria I
authors.initials: MI
authors.lastname: Borella
mesh_terms: D000818:Animals; D060125:Characiformes / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D003001:Cloning, Molecular; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006066:Gonads / Q000254:growth & development* / Q000378:metabolism; D008297:Male; D012098:Reproduction / Q000235:genetics*; D055758:SOX9 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D012733:Sex Differentiation / Q000235:genetics; D013091:Spermatogenesis / Q000235:genetics; D013737:Testis / Q000254:growth & development / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: C110547:DMRT1 protein; D055758:SOX9 Transcription Factor; D014157:Transcription Factors