Figure 2

Ubiquitous occurrence of SiaS in mouse. (a) Immunohistochemistry of mouse adult tissue sections with the anti-SiaS antibody 3G9. The sections were treated with 3G9 and its isotype control (2G9), followed by the Alexa-488-conjugated anti-mouse IgM treatment to visualize the SiaS epitopes (Alexa, green). Nuclei are stained with DAPI (Dapi, blue); (b) Western blotting of the mouse brains with 3G9 and GAPDH (loading control). Lane P.C: sea urchin sperm as positive control; lane E14.5: 14.5 days post-fertilization; lanes P1, P15, P30, and P45: 1, 15, 30, and 45 days after birth. The arrows denote the 3G9-epitope-containing components, and their molecular masses are indicated; (c) Chemical detection of SiaS in the mouse brain at E14.5. The brain homogenate was subjected to SDS-PAGE, followed by the transfer to a PVDF membrane. The left edge of the membrane was removed and used for immunostaining with 3G9 (left panel). The rest of the membrane was cut into nine pieces according to the molecular size, and analyzed by fluorometric HPLC (right panel).