title: Cloning, expression and cellular localization of Daphnia pulex senescence-associated protein, DpSAP.
abstract: Daphnia (water fleas) are small crustaceans that undergo an unusual switch from asexual to sexual reproduction that is dependent on environmental conditions. In this study, a senescence-associated protein (SAP) from the common freshwater species Daphnia pulex was cloned using primers based on homologous sequences and rapid amplification of cDNA ends (RACE). Real-time PCR was employed to quantify the expression of D. pulex SAP (DpSAP) in individual organisms. The role of DpSAP in the reproductive transformation was further investigated in both parthenogenetic and sexual females by using digoxin-labeled SAP RNA probes and RNA whole-mount in situ hybridization. DpSAP was more highly expressed in sexual females, indicating a role in growth and reproduction. Cellular localization studies using RNA whole-mount in situ hybridization showed specific expression in the second tentacle joints. These expression patterns suggest an important role for DpSAP in the reproductive transformation of D. pulex.
authors.affiliation: School of Life Science, East China Normal University, Shanghai 200241, China.
authors.forename: Ajing
authors.initials: A
authors.lastname: Liu
authors.affiliation: School of Life Science, East China Normal University, Shanghai 200241, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Kong
authors.affiliation: School of Life Science, East China Normal University, Shanghai 200241, China.
authors.forename: Mingqing
authors.initials: M
authors.lastname: Zhang
authors.affiliation: School of Life Science, East China Normal University, Shanghai 200241, China.
authors.forename: Donglei
authors.initials: D
authors.lastname: Wu
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, China.
authors.forename: Danli
authors.initials: D
authors.lastname: Wang
authors.affiliation: School of Life Science, East China Normal University, Shanghai 200241, China. Electronic address: ylzhao@bio.ecnu.edu.cn.
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D000375:Aging / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular / Q000379:methods; D018076:DNA, Complementary / Q000235:genetics; D003621:Daphnia / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005260:Female; D005618:Fresh Water; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D010802:Phylogeny; D012098:Reproduction / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary
keywords: CAT; Daphnia; Daphnia pulex SAP; DpSAP; Gene cloning; MDA; MW; NJ; ORF; PCR; POD; RACE; RNA whole-mount in situ hybridization; ROS; RT-PCR; Reproductive transformation; SAGs; SAP; SDGs; SOD; Senescence-associated protein (SAP); catalase; isoelectric point; malondialdehyde; molecular weight; neighbor-joining; open reading frame; pI; peroxidase; polymerase chain reaction; rapid amplification of cDNA ends; reactive oxygen species; reverse transcription polymerase chain reaction; senescence-associated genes; senescence-associated protein; senescence-downregulated genes; superoxide dismutase