Mapping the expression of the sex determining factor Doublesex1 in Daphnia magna using a knock-in reporter

• Published in: Scientific reports 2017-11, Vol.7 (1), p.13521-13, Article 13521
• Main Authors: Nong, Quang Dang, Mohamad Ishak, Nur Syafiqah, Matsuura, Tomoaki, Kato, Yasuhiko, Watanabe, Hajime
• Format: Article
• Language: English
• Subjects: 14/35; 38/35; 42/35; 42/41; 45/41; 631/181/2806; 631/208/182; Animals; Arthropod Proteins - genetics; Arthropod Proteins - metabolism; Biotechnology; Crustaceans; Daphnia; Daphnia magna; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Embryogenesis; Embryonic growth stage; Embryonic Stem Cells - cytology; Embryonic Stem Cells - metabolism; Evolution; Female; Females; Gastrulation; Gender differences; Gene Expression Regulation, Developmental; Genes; Genes, Reporter; Genomes; Humanities and Social Sciences; Insects; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Male; Males; multidisciplinary; Ovulation; Progenitor cells; Red Fluorescent Protein; Science; Science (multidisciplinary); Sex; Sexual dimorphism; Stem cells
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-13730-4

Sexually dimorphic traits are common and widespread among animals. The expression of the Doublesex-/Mab-3-domain (DM-domain) gene family has been widely studied in model organisms and has been proven to be essential for the development and maintenance of sex-specific traits. However, little is known about the detailed expression patterns in non-model organisms. In the present study, we demonstrated the spatiotemporal expression of the DM-domain gene, doublesex1 ( dsx1 ), in the crustacean Daphnia magna , which parthenogenetically produces males in response to environmental cues. We developed a dsx1 reporter strain to track dsx1 activity in vivo by inserting the mCherry gene into the dsx1 locus using the TALEN-mediated knock-in approach. After confirming dsx1 expression in male-specific traits in juveniles and adults, we performed time-lapse imaging of embryogenesis. Shortly after gastrulation stage, a presumptive primary organiser, named cumulus, first showed male-specific dsx1 expression. This cell mass moved to the posterior growth zone that distributes dsx1- expressing progenitor cells across the body during axial elongation, before embryos start male-specific dsx1 expression in sexually dimorphic structures. The present study demonstrated the sex-specific dsx1 expression in cell populations involved in basal body formation.