Morphological and functional characterization of hemocytes in the giant clam, Tridacna crocea

Eighth JADCI abstracts

67

did not affect wound repair. Histological observation of cut surfaces by HE staining wound healing occurred revealed that completely 3 hrs after cutting. Then, using planaria with healed surfaces, the effect of antibodies on regeneration was studied. Results revealed that regeneration occurred in the presence of anti-HSP, but not in the autolysis was of anti-lectin; presence observed after 48 hr-exposure. These results strongly suggest that HSP60 molecule is required in wound healing and that the body surface mucus lectin is also necessary in regeneration.

chromatography and ultrafiltration of cut off 10,000. The antifungal material is a small peptide and stable after treatment at 100°C for 10 minutes, thus it differs from other dolabellanins. MORPHOLOGICAL B3. FUNCTIONAL CHARACTERIZATION HEMOCYTES IN THE CLAM, crocea. Tridacna

NOVEL FROM

Ryosuke Iijima, Jun Kisugi and Masatoshi Faculty of Pharmaceutical Yamazaki. Sciences, kimagawa

Teikyo University,

Sagamiko-cho,

199-01, Japan. Broad range antimicrobial activities have been exhibited by each group of humoral self-defense factors of invertebrates such as sarcotoxins, cecropins and insect defensins. It can be expected that the combination of these factors contributes to effective immunodefense systems against infectious microorganisms. Homologues of these small peptide factors have been observed not only in insects but also in mammals. Thus, these factors may have evolved before separation of the protostomes and the deuterostomes. We previously purified four cytotoxic proteins named dolabellanins from the sea hare Dolabella auricuralia, the shell-less opisthobranch mollusk. However, the dolabellanins are not small heat-labile proteins. Therefore, we performed experiments designed to find the antimicrobial peptides from D. auricuralia. An antifungal activity, that killed Saccharomyces cerevisiae after two hours coincubation, was extracted by 60% acetonitrile- 1% triofluoroacetate/water from skin and body wall. Further purification involved reverse-phase and cation exchange

OF GIANT

Koji Nakayama, Ann M. Nomoto, Miyuki Nishijima and Tadashi Maruyama.

Marine

Biotechnology

Laboratories,

B2. PURIFICATION OF ANTIFUNGAL ACTIVITY SEA HARE BODY WALL.

AND

Shimizu

Institute, 424,

Shimizu

Japan.

To

understand the cellular immunodefense system in the giant clam, Trdacna crocea, which harbors symbiotic microalga zooxanthella, hemocytes were characterized using light and electron microscopy. We observed of hemocytes: three types eosinophilic granulocytes, agranular cells and morula-like cells. Eosinophilic granulocytes contained granules approximately 0.6 pm in diameter. Agranular cells adhered to glass surfaces and contained electron lucent granules and few electron dense granules. Morula-like cells were packed with large (approximately 3 pm in diameter), electron dense granules. Eosinophilic granulocytes were acid phosphatase positive and were phagocytic against latex particles. Agranular cells and morula-like cells lacked phagocytic ability. When the hemolymph was exposed to seawater, hemocytes aggregated to form large clots and agranular cells were the main component found in the core of the clots. Morula-like cells released large granules during aggregation and they contained protein molecules having a molecular weight of 7.4 kDa. (Supported in a part by The Industrial Science and Technology Frontier Program by the New Energy and Industrial Technology Development Organization (Tokyo, Japan)). B4.

ALLO-RECOGNITION

AND

REJECTION OF SKIN GRAFTS IN THE TERRESTRIAL SLUG,