Identification and expression of XRTN2 and XRTN3 duringXenopus development

Abstract

The reticulon (RTN) family of proteins has been described as a new eukaryotic protein family. We have isolated Xenopus cDNA homologues of RTN2 and RTN3 and examined their expression patterns during Xenopus development. XRTN2 has two transcripts, XRTN2-B and XRTN2-C, which encode 321 and 191 amino acids, respectively. XRTN3 has only one transcript that encodes 214 amino acids. We detected the XRTN2-B transcript in the neural tissues and brain from the early neurula stage. XRTN2-C is strongly expressed in the myotome, future skeletal muscle. The XRTN3 mRNA is localized in the animal hemisphere of the egg and blastula stage embryos and then subsequently restricted, mainly in the neural tissues. At the subcellular level, The XRTN proteins are expressed in the endoplasmic reticulum network structure of the animal cap cells as well as COS-7 cells. Our results suggest the potential roles of XRTN2s and XRTN3 during Xenopus embryogenesis. Developmental Dynamics 233:240 -247, 2005.

Identification of germ plasm‐associated transcripts by microarray analysis of Xenopus vegetal cortex RNA

“…We used a full-length rtn3.1 clone as a probe and analyzed its expression at different stages by whole-mount in situ hybridization, focusing on oocyte and early embryo stages. Our in situ results generally agreed with the Park et al (2005) study, including evidence of expression in the animal pole of the blastula, neural plate, branchial arches, and epidermis (Fig. 3).…”

“…Proteins of the reticulon family are thought to associate with the endoplasmic reticulum and may have roles in regulating apoptosis in neurons (Park et al, 2005). rtn3.1 is the only family member to be maternally expressed in Xenopus , and the embryonic expression and sequence analysis of rtn3.1 has been previously reported (Park et al, 2005), although its expression in the germ plasm was not noted. We used a full-length rtn3.1 clone as a probe and analyzed its expression at different stages by whole-mount in situ hybridization, focusing on oocyte and early embryo stages.…”

“…We identified a sequence representing reticulon 3.1 (rtn3.1) in the set of vegetal cortex-enriched transcripts, which was increased $8.6-fold compared with the whole oocyte (data not shown). Proteins of the reticulon family are thought to associate with the endoplasmic reticulum and may have roles in regulating apoptosis in neurons (Park et al, 2005). rtn3.1 is the only family member to be maternally expressed in Xenopus, and the embryonic expression and sequence analysis of rtn3.1 has been previously reported (Park et al, 2005), although its expression in the germ plasm was not noted.…”

The Drosophila reticulon, Rtnl-1, has multiple differentially expressed isoforms that are associated with a sub-compartment of the endoplasmic reticulum

“…Lastly, the shortest transcripts with promoters closest to the RHD-encoding exons are often enriched in muscle. This has been shown to be the case for mammalian Nogo/RTN4 [8], RTN1 [41] and RTN3 [6] as well as Xenopus reticulons [42,51]. It is clear that in Drosophila the largest transcripts whose promoters lie closest to the 5′ start of the gene are also predominantly expressed in the nervous system.…”

Germ‐Cell Specification inXenopus

“…(Kloc et al , 2002a Fingers Zinc finger, unknown function (Kloc et al 2002,b) XFACS/ACSL Long-chain acyl-CoA synthetase, meiotic arrest acsl1b (Wang et al 2012) Mitochondrially encoded large rRNA Unknown function mtlrRNA (Kloc et al 2002a,b) Mitochondrially encoded small rRNA Unknown function mtsrRNA (Kloc et al 2002a,b) One expectation, then, is that the germ plasm will contain gene pathway(s) that regulate apoptosis. The ER component reticulon (rtn3.1), the multipass membrane protein, is highly enriched as a germ plasm RNA and may be involved in regulating apoptosis (Cuykendall and Houston 2010;Park et al 2005). Finally, the cell-signaling factor Wnt11, essential in dorsal specification, is found within the germ plasm.…”