Figure 2.

Phylogenetic relations between mouse Saa3 and human SAA1 and SAA2. A) Mouse (m) as well as human (h) SAA1/SAA2 sequences show high homology with each other, and mouse Saa3 shows a high similarity to mouse and human SAA1/SAA2 after amino acid 30. In humans, the SAA3 gene is reported to be a pseudogene (SAA3P); a mutation/insertion at base 147 causes a frameshift generating a stop codon at position 61. B) Gene homology tree between human and mouse A-SAA proteins. C) In differentiating primary human osteoblasts, SAA1 and SAA2 mRNA expressions increase drastically after 26–30 d of culture. D) In contrast, SAAL1 expression remains unaffected during the whole differentiation process. E) The differentiation to mature osteoblasts is demonstrated by BGLAP and RUNX2 expressions reaching the maximum at d 12. The drop in BGLAP and RUNX2 expression is accompanied by increased levels of osteocyte markers DMP1, SOST, and MEPE (F). 18S rRNA is a reference gene for RT-qPCR analysis; d 1 is set to 1, and later time points are referred to as fold change relative to d 1. Values are represented as the mean ± sd; for all experiments n = 3.