title: Identification and characterization of a Masculinizer (Masc) gene involved in sex differentiation in Artemia.
abstract: The sex of relatively primitive animals such as invertebrates is mostly determined by environmental factors and chromosome ploidy. Heteromorphic chromosomes may also play an important role, as in the ZW system in lepidopterans. However, the mechanisms of these various sex determination systems are still largely undefined. In the present study, a Masculinizer gene (Ar-Masc) was identified in the crustacean Artemia franciscana Kellogg 1906. Sequence analysis revealed that the 1140-bp full-length open reading frame of Ar-Masc encodes a 380-aa protein containing two CCCH-type zinc finger domains having a high degree of shared identities with the MASC protein characterized in the silkworm Bombyx mori, which has been determined to participate in the production of male-specific splice variants. Furthermore, although Ar-Masc could be detected in almost all stages in both sexual and parthenogenetic Artemia, there were significant variations in expression between these two reproductive modes. Firstly, qRT-PCR and Western blot analysis showed that levels of both Ar-Masc mRNA and protein in sexual nauplii were much higher than in parthenogenetic nauplii throughout the hatching process. Secondly, both sexual and parthenogenetic Artemia had decreased levels of Ar-Masc along with the embryonic developmental stages, while the sexual ones had a relatively higher and more stable expression than those of parthenogenetic ones. Thirdly, immunofluorescence analysis determined that sexual individuals had higher levels of Ar-MASC protein than parthenogenetic individuals during embryonic development. Lastly, RNA interference with dsRNA showed that gene silencing of Ar-Masc in sexual A. franciscana caused the female-male ratio of progeny to be 2.19:1. These data suggest that Ar-Masc participates in the process of sex determination in A. franciscana, and provide insight into the evolution of sex determination in sexual organisms.
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
authors.forename: Dong-Rui
authors.initials: DR
authors.lastname: Li
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
authors.forename: Hui-Li
authors.initials: HL
authors.lastname: Ye
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
authors.forename: Jin-Shu
authors.initials: JS
authors.lastname: Yang
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: Tianjin Key Laboratory of Aqua-Ecology and Aquaculture, Department of Fisheries Science, Tianjin Agricultural University, People's Republic of China.
authors.forename: Mo-Ran
authors.initials: MR
authors.lastname: Wang
authors.affiliation: Laboratory of Aquaculture &Artemia Reference center, Ghent University, Belgium.
authors.forename: Stephanie
authors.initials: S
authors.lastname: De Vos
authors.affiliation: Laboratory of Aquaculture &Artemia Reference center, Ghent University, Belgium.
authors.forename: Marnik
authors.initials: M
authors.lastname: Vuylsteke
authors.affiliation: Laboratory of Aquaculture &Artemia Reference center, Ghent University, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Sorgeloos
authors.affiliation: Laboratory of Aquaculture &Artemia Reference center, Ghent University, Belgium.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Van Stappen
authors.affiliation: Laboratory of Aquaculture &Artemia Reference center, Ghent University, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Bossier
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China. Electronic address: w_jyang@zju.edu.cn.
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Yang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001156:Artemia / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D060829:Arthropod Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D015153:Blotting, Western; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007814:Larva / Q000235:genetics; D008297:Male; D010312:Parthenogenesis / Q000235:genetics; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D019849:Sex Determination Processes / Q000235:genetics*; D012733:Sex Differentiation / Q000235:genetics*; D013997:Time Factors
chemical_list: D060829:Arthropod Proteins
keywords: Masculinizer; Parthenogenetic Artemia; RNA interference; Sexual Artemia; Sexual determination