Cloning and characterization of wnt4a gene and evidence for positive selection in half-smooth tongue sole (Cynoglossus semilaevis)

Abstract

Wnt4 gene plays a role in developmental processes in mammals. However, little is known regarding its function in teleosts. We cloned and characterized the full-length half-smooth tongue sole (Cynoglossus semilaevis) wnt4a gene (CS-wnt4a). CS-wnt4a cDNA was 1746 bp in length encoding 353aa. CS-wnt4a expression level was highest in the testis, and gradually increased in the developing gonads until 1 year of age. In situ hybridization revealed that CS-wnt4a expression level was highest in stage II oocytes and sperm in the adult ovary and testis, respectively. CS-wnt4a expression level was significantly up-regulated in the gonads after exposure to high temperature. The level of methylation of the CS-wnt4a first exon was negatively correlated with the expression of CS-wnt4a. The branch-site model suggested that vertebrate wnt4a differed significantly from that of wnt4b, and that the selective pressures differed between ancestral aquatic and terrestrial organisms. Two positively selected sites were found in the ancestral lineages of teleost fish, but none in the ancestral lineages of mammals. One positively selected site was located on the α-helices of the 3D structure, the other on the random coil. Our results are of value for further study of the function of wnt4 and the mechanism of selection.

Characteristics of the Completed Chloroplast Genome Sequence of Xanthium Spinosum: Comparative Analyses, Identification of Mutational Hotspots and Phylogenetic Implications

“…The 2ΔLnL value of the accD gene is 25.91159 with a p-value of LRT is 0.0000024. The positively selected sites detected in the present study may drive the accD protein-coding gene allowing the occupation of diverse habitats [34,35].…”

Expression of wnt4/5 during reproductive cycle of catfish and wnt5 promoter analysis

“…Tissue distribution pattern of wnt5 and wnt4 showed their abundance in the ovary indicating a potential influence of these correlates as observed in other species (Vainio et al 1991, Oreal et al 2002, Pailhoux et al 2002, Jaaskelainen et al 2010, and in contrast to these, ovarypredominant function was not observed in rainbow trout (Nicol et al 2012). The levels of wnt4, which seems to be homologous to its paralog, wnt4a observed in other species shows contradictory expression pattern by being predominant in ovary unlike Cynoglossus semilaevis wnt4a (Hu et al 2014). Although the levels of expression are comparatively less in tissues other than ovary and kidney, the presence of wnt transcripts suggests their role in development as that of other teleosts (Matsui et al 2005).…”

“…In humans, it is required for oocyte selection, follicle formation and maturation (Boyer et al 2010b, Jaaskelainen et al 2010, Prunskaite-Hyyryläinen et al 2014. The precise functions of this gene in teleosts are not well explored in reproduction although it is identified in several teleosts such as zebrafish (Ungar et al 1995), rainbow trout (Nicol et al 2012), medaka (Yokoi et al 2003), half-smooth tongue sole (Hu et al 2014), black porgy (Wu & Chang 2009) and hermaphrodite and orange-spotted grouper (Chen et al 2015). Two paralogs of this gene were reported in zebrafish, medaka and half-smooth tongue sole with variant functions during development.…”

Sexually Dimorphic Expression of Foxl2 and Ftz‐F1 in Chinese Giant Salamander Andrias Davidianus

“…Reverse transcription (RT) was performed at 30°C for 10 min followed by 42°C for 60 min in a total volume of 20 μL consisting of 1 μg total RNA, 1×M‐MLV buffer, 0.5 mM each dNTP, 1.25 μM random primers, and 200 UM‐MLV Reverse Transcriptase (Takara, Dalian, People's Republic of China). The PCR reaction mixture and conditions were performed as described (Hu et al., ). PCR was performed as follows: five cycles of 94°C for 30 sec and 72°C for 3 min; five cycles of 94°C for 30 sec, 70°C for 30 sec, and 72°C for 3 min; then 27 cycles of 94°C for 30 sec, 68°C for 30 sec, and 72°C for 3 min.…”