Expression of genes encoding antimicrobial peptides in the Harderian gland of the bullfrog Lithobates catesbeianus.
The Harderian gland is an orbital gland found in many tetrapod species that possess a nictitating membrane. While the main role of the Harderian gland is lubrication of the eyeballs, numerous other functions are attributed to this gland. In amphibians, mast cells have been detected in the Harderian gland, suggesting that the gland is involved in the host's system of innate immunity defending against microbial invasions. Using reverse-transcription polymerase chain reaction, we cloned from the bullfrog Harderian gland total RNA preparations, cDNAs encoding biosynthetic precursors for the antimicrobial peptides temporin-CBa (FLPIASLLGKYL-NH2), previously isolated from an extract of bullfrog skin, and chensirin-2CBa (IIPLPLGYFAKKP) that contained the amino acid substitution Thr13-->Pro compared with chensirin-2 from the Chinese brown frog, Rana chensinensis. By means of in situ hybridization using digoxigenin-labeled cRNA probes for preprotemporin-CBa and preprochensirin-2CBa, we have demonstrated for the first time in an amphibian the presence of mRNAs encoding these two precursors in the cytoplasm of the glandular cells in the bullfrog Harderian gland.
Department of Biology, Faculty of Education and Integrated Arts and Sciences, Center for Advanced Biomedical Sciences, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
Itaru
I
Hasunuma
Shawichi
S
Iwamuro
Tetsuya
T
Kobayashi
Kazuhiko
K
Shirama
J Michael
JM
Conlon
Sakae
S
Kikuyama
D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D015870:Gene Expression; D006243:Harderian Gland / Q000378:metabolism*; D008969:Molecular Sequence Data; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D011898:Ranidae / Q000235:genetics* / Q000378:metabolism
D023181:Antimicrobial Cationic Peptides; D011506:Proteins; C104501:temporin