Xenopus as a Model System for the Study of GOLPH2/GP73 Function: Xenopus golph2 Is Required for Pronephros Development

Abstract

GOLPH2 is a highly conserved protein. It is upregulated in a number of tumors and is being considered as an emerging biomarker for related diseases. However, the function of GOLPH2 remains unknown. The Xenopus model is used to study the function of human proteins. We describe the isolation and characterization of Xenopus golph2, which dimerizes and localizes to the Golgi in a manner similar to human GOLPH2. Xenopus golph2 is expressed in the pronephros during early development. The morpholino-mediated knockdown of golph2 results in edema formation. Additionally, Nephrin expression is enhanced in the glomus, and the expression of pronephric marker genes, such as atp1b1, ClC-K, NKCC2, and NBC1, is diminished in the tubules and duct. Expression patterns of the transcription factors WT1, Pax2, Pax8, Lim1, GATA3, and HNF1β are also examined in the golph2 knockdown embryos, the expression of WT1 is increased in the glomus and expanded laterally in the pronephric region. We conclude that the deletion of golph2 causes an increase in the expression of WT1, which may promote glomus formation and inhibit pronephric tubule differentiation.

The Divergence, Actions, Roles, and Relatives of Sodium-Coupled Bicarbonate Transporters

“…Low abundance of Xenopus NBCe1 ("XNBC1") mRNA occurs in the early and late PTs at developmental stage NF29, 21 but a greater abundance of XNBC1 is present in the late distal segment by stage NF33 (1102), where its distribution overlaps with that of Ca2 (1103). A more recent model of the Xenopus pronephros, based on a large-scale in situ hybridization mapping of transcripts, localizes a significant population of NBCe1 transcripts to an early distal tubule region "DT(1)" that is homologous to the mammalian thick ascending limb (581,779). Aside from the pronephric presence, NBCe1 transcripts are detected in the cranial ganglia, nasal pit, otic vesicle, somites, hatching gland, and cement gland of Xenopus embryos as well as in the bladder, brain, and small intestine of Ambystoma (809).…”

Gulo Acts as a <b><i>de novo</i></b> Marker for Pronephric Tubules in <b><i>Xenopus laevis</i></b>

“…To identify which organ is the main location for Gulo expression during embryonic development, we selected two positive markers, ATP1B1 and BIP [13,14], which are mainly expressed in the pronephric region (Fig. 4J-L).…”

“…RNA probe was synthesized with T3 RNA polymerase (Thermo Scientific). The probe for whole-mount in situ hybridization reactions was generated by amplifying a partial sequence of ATP1B1 and BIP using the reference PCR primers [13,14]. The resulting fragment was sub-cloned into a pBST-II vector.…”

Sirtuin inhibitor Ex‐527 causes neural tube defects, ventral edema formations, and gastrointestinal malformations in Xenopus laevis embryos

“…Interestingly, major pronephros markers are diminished by antisense morpholino oligomers for golph2 , and the edema formations are frequently observed in these morphants (Li et al . ). In our study even though pronephros formed in Ex‐527‐treated embryos, the size of pronephros was certainly reduced (Fig.…”