Table 1.
Primers used in this study.
Fig 1.
Multiple sequence alignment of Lhx8 proteins.
Sequence alignment was performed using Clustal Omega (http://www.ebi.ac.uk/Tools/msa/clustalo/). The functional domains were determined by searching the Pfam database (http://pfam.xfam.org/search). The LIM and Homeobox domains are indicated by green and red boxes, respectively. mLhx8: mouse Lhx8 (NP_034843.2), hLhx8: human Lhx8 (NP_001001933.1), zLhx8: zebrafish Lhx8 (NP_001003980.1), rtLhx8: rainbow trout Lhx8 (unpublished data). bLhx8: bovine Lhx8 (KX898027).
Fig 2.
Structure of bovine Lhx8 gene and its transcripts, Lhx8 and Lhx8_v1.
The bovine Lhx8 gene contains 9 exons and spans about 28 kb. Lhx8 encodes a protein of 377 amino acids. The splice variant, Lhx8_v1 which results from alternative splicing of exon 2 and 3, codes for a protein of 293 amino acids. One of the LIM domains in the splice variant is incomplete due to deletion of 83 amino acids near the N terminus. LIM: LIM domain. HB: Homeobox domain.
Fig 3.
RT-PCR analysis of bovine Lhx8 and Lhx8-v1 mRNA expression.
A: Expression of Lhx8 and Lhx8-v1 mRNA in bovine tissues. Tissues tested include spleen, stomach, brain, muscle, kidney, liver, heart, intestine, adult ovary, adult testis, fetal testis and fetal ovary. B: Expression of Lhx8 and Lhx8-v1 mRNA in bovine fetal ovaries from different gestation stages. Fetal ovaries from 90, 95, 100, 150, 160, 200, 210, 230 and 250 day fetuses were analyzed. The ages of fetuses were estimated based on crown-rump length. C: Expression of Lhx8 and Lhx8-v1 mRNA in oocytes and early embryos. Oocytes and embryos samples used in the analysis include GV- and MII-stage oocytes and 2-cell, 4-cell, 8-cell, 16-cell, and morula- and blastocyst-stage embryos. Bovine RPL19 gene was used as a control for RNA quality.
Fig 4.
Cellular localization of bovine Lhx8 protein analyzed by a GFP reporter assay.
HEK293 cells were transfected with GFP reporter constructs expressing either an EGFP-tagged wild type Lhx8 (Lhx8-wt) or Lhx8 mutants with either the monopartite NLS (Lhx8-ΔM-NLS) or the bipartite NLS deleted (Lhx8-ΔB-NLS). Empty pcDNA3-EGFP vector was used as a control. Nuclear DNA was stained with DAPI and cells were analyzed with a fluorescence microscope.
Fig 5.
Interaction of Lhx8 with Figla.
A: Yeast two-hybrid analysis of protein interactions between Lhx8 and Figla or Sohlh1. Right plate: Growth of yeast cells on DDO plate (medium lacking Leucine and tryptophan) showing successful co-transformations. Left plate: growth of yeast cells on selective QDO/X/A plate (Quadruple drop-out medium lacking leucine, tryptophan, adenine and histidine and containing X-gal) indicating protein-protein interactions. B: Co-IP analysis of interaction between Lhx8 and Figla. HEK293 cells were co-transfected with the expression constructs, pcDNA3.1-Lhx8-FLAG and pcDNA3.1-Figla-HA. Cell lysates were immunoprecipitated with anti-Flag antibody followed by Western blot analysis with anti-HA antibody. C: Direct yeast two-hybrid analysis showing LIM domains of Lhx8 are required for interaction with Figla. Right plate: Growth of yeast cells on DDO plate showing successful co-transformations. Left plate: growth of yeast cells on selective QDO/X/A plate indicating protein-protein interactions.