title: Kisspeptin system in pejerrey fish (Odontesthes bonariensis). Characterization and gene expression pattern during early developmental stages.
abstract: In vertebrates, kisspeptins and their receptors are known to be related to puberty onset and gonadal maturation, however, there are few studies concerning their role in early development. Here, we characterize the kisspeptin system in the pejerrey, Odontesthes bonariensis, a fish with strong temperature-dependent sex determination. We reconstructed the phylogenetic history of the two ligands (kiss1 and kiss 2) and two receptors (kissr2 and kissr3) in pejerrey in the context of recent classifications of bony fishes, determined their tissue distribution and documented the early expression pattern of these ligands and receptors. Phylogenetic analysis of these gene families clearly resolved the percomorph clade and grouped pejerrey with Beloniformes. Paralogous sets of genes putatively arising from the teleost-specific genome duplication event (3R) were not detected. Kisspeptins and their receptors showed a wide tissue distribution in adult pejerrey, including tissues not related to reproduction. In larvae reared at 24°C, the four kisspeptin elements were expressed in the head from week 1 to week 8 of life, with no differences in transcript levels. Larvae kept at a female-producing temperature (17°C) did not show statistically significant differences in the transcript levels of all analyzed genes during the sex determination/differentiation period; however, in those larvae raised at male producing temperature (29°C), kiss2 levels were increased at week 4 after hatching. These results showed that all members of the kisspeptin system are expressed at this early period, and the increase of kiss2 transcripts at week 4 could be interpreted as it would be related to the differentiation of the brain-pituitary axis in male development.
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH), CONICET-UNSAM, Chascomús, Argentina.
authors.forename: M Oswaldo
authors.initials: MO
authors.lastname: Tovar Bohórquez
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH), CONICET-UNSAM, Chascomús, Argentina.
authors.forename: Alejandro S
authors.initials: AS
authors.lastname: Mechaly
authors.affiliation: Department of Biological Sciences, George Washington University, Washington, DC, USA.
authors.forename: Lily C
authors.initials: LC
authors.lastname: Hughes
authors.affiliation: Department of Biological Sciences, George Washington University, Washington, DC, USA.
authors.forename: Daniela
authors.initials: D
authors.lastname: Campanella
authors.affiliation: Department of Biological Sciences, George Washington University, Washington, DC, USA.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Ortí
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH), CONICET-UNSAM, Chascomús, Argentina.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Canosa
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH), CONICET-UNSAM, Chascomús, Argentina. Electronic address: somoza@intech.gov.ar.
authors.forename: Gustavo M
authors.initials: GM
authors.lastname: Somoza
mesh_terms: D000818:Animals; D005260:Female; D005399:Fishes / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D020440:Gene Duplication; D015870:Gene Expression; D059648:Kisspeptins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D059648:Kisspeptins; D012333:RNA, Messenger
keywords: Kisspeptin; Kisspeptin receptor; Pejerrey fish; Phylogeny; Sex differentiation