RING Finger Protein 38 Is a Neuronal Protein in the Brain of Nile Tilapia, Oreochromis niloticus

Abstract

Really interesting new gene (RING) finger protein is a type of zinc-binding motif found in a large family of functionally distinct proteins. RING finger proteins are involved in diverse cellular processes including apoptosis, DNA repair, cell cycle, signal transduction, tumour suppressor, vesicular transport, and peroxisomal biogenesis. RING finger protein 38 (RNF38) is a member of the family whose functions remain unknown. To gain insight into the putative effects of RNF38 in the central nervous system, we localised its expression. The aim of this study was to identify the neuroanatomical location(s) of rnf38 mRNA and its peptide, determine the type of RNF38-expressing cells, and measure rnf38 gene expression in the brain of male tilapia. The distributions of rnf38 mRNA and its peptide were visualised using in situ hybridisation with digoxigenin-labelled RNA antisense and immunocytochemistry, respectively. Both were identically distributed throughout the brain, including the telencephalon, preoptic area, optic tectum, hypothalamus, cerebellum, and the hindbrain. Double-labelling immunocytochemistry for RNF38 and the neuronal marker HuC/D showed that most but not all RNF38 protein was expressed in neuronal nuclei. Quantitative real-time polymerase chain reaction showed the highest level of rnf38 mRNA in the midbrain, followed by the preoptic area, cerebellum, optic tectum, telencephalon, hindbrain and hypothalamus. These findings reveal a differential spatial pattern of RNF38 in the tilapia brain, suggesting that it has potentially diverse functions related to neuronal activity.

Expression of Repressor Element 1 Silencing Transcription Factor (REST) in Serotonin Neurons in the Adult Male Nile Tilapia (Oreochromis niloticus)

“…Compound (Sakura Finetek USA, Inc., Torrance, CA, USA) for brain microdissection, then stored at −80°C until use. Microdissected brain samples were prepared using a cryostat (Cham et al, 2017 ). Briefly, frozen coronal sections (60 μm) were taken from the cryostat (Leica CM1860) followed by mounting onto microscope slides (Sail Boat Lab Company, Zhejiang, China).…”

Expression of RING Finger Protein 38 in Serotonergic Neurons in the Brain of Nile Tilapia, Oreochromis niloticus

“…Antigen-antibody complexes were visualised with Streptavidin, Alexa Fluor 488 conjugate (1:500; S32354, RRID:AB_2315383, Thermo Fisher Scientific, Waltham, MA, United States). The specificity of the RNF38 antibody was tested in the brain of tilapia in a previous study (Cham et al, 2017).…”

“…Rnf38 mRNA is found in the brain, spleen, liver, heart, testis, and placenta (Eisenberg et al, 2002), and its protein is a nuclear protein capable of mediating ubiquitination of the p53 tumour-suppressor protein (Sheren and Kassenbrock, 2013), thus acting as an E3 ubiquitin ligase. In the brain, rnf38 mRNA and its protein are widely distributed, including the telencephalon, preoptic area, optic tectum, hypothalamus, cerebellum and the hindbrain in male tilapia (Cham et al, 2017). Furthermore, the same study showed that RNF38 protein is absent in astroglial cells, but is expressed in the nucleus of neuronal cells (Cham et al, 2017), suggesting that RNF38 may be involved in neuronal functions by interacting with various proteins.…”

“…In the brain, rnf38 mRNA and its protein are widely distributed, including the telencephalon, preoptic area, optic tectum, hypothalamus, cerebellum and the hindbrain in male tilapia (Cham et al, 2017). Furthermore, the same study showed that RNF38 protein is absent in astroglial cells, but is expressed in the nucleus of neuronal cells (Cham et al, 2017), suggesting that RNF38 may be involved in neuronal functions by interacting with various proteins. RNF38 is also linked to cancerous diseases and ageing (Fu et al, 2006; Nacheva et al, 2010; Sato et al, 2013; Xiong et al, 2018).…”

Dissecting the localization ofTilapia tilapinevirusin the brain of the experimentally infected Nile tilapia (Oreochromis niloticus)

“…Localization of TiLV was interpreted in parallel with the slides of TiLV-specific probes, negative controls (unrelated probe and no probe), and H&E stained sections. TiLV signal density in the brain was subjectively scored on a four-point scale as follows: + + + (high signal), + + (moderate signal), + (low signal), and -(absent signal) followingCham et al (2017). Nomenclatures for the brain area(Table 1) were based on those described byWullimann et al (1996),Simoes et al (2012),Ogawa et al (2016), andCham et al (2017).…”