THE SPERMATOPHORE OF THE CARRION BEETLE THANATOPHILUS-SINUATUS - BIOCHEMICAL-CHARACTERIZATION OF PROTEINS AND INCORPORATION OF RADIOACTIVELY LABELED AMINO-ACIDS

Male Thanatophilus sinuatus (Coleoptera, Silphidae) transfer a spermat ophore to females at mating, consisting on average of 40% protein base d on dry mass. One-dimensional gel electrophoresis revealed several st ainable proteins in the range of 14 kDa-70 kDa. The protein pattern wa s found constant for spermatophores of different individuals. One lipo protein, two glycoproteins and one glyco-lipoprotein were detected by staining methods. Several isoforms of all proteins were detected after two-dimensional gel electrophoresis, varying in the isoelectric point s. The majority of the proteins were slightly acidic. By immunodetecti on of chromosomal proteins, histone H2A/H2B and high mobility group pr otein HMGI could be selectively demonstrated as compounds of the sperm atophore. Autoradiographic studies showed, that radioactively labelled amino acids (H-3 or C-14), injected into the male, were incorporated into proteins of the male accessory glands. Comparing the labelled pro tein pattern, the predominant proteins of the spermatophore seemed to derive mostly from the long accessory glands. In relation to whole bod y, labelled amino acids were preferentially incorporated into reproduc tive tissues. The highest accumulation of radioactivity was found for spermatophores. For the vasa deferentia, the place of sperm storage, a nd the long accessory glands, a high accumulation was detected. Based on incorporated radioactivity, about half of the proteinous accessory gland secretions were used in spermatophore production.