Behavior of Hemocytes in the Allorejection Reaction in Two Compound Ascidians, Botryllus scalaris and Symplegma reptans.

In botryllid ascidians, the type of allorejection reaction differs among species. Comparative studies of these different reactions contribute to our understanding of the allorecognition and nonself-rejection system. We studied the morphology of hemocyte behavior during allorejection reactions in two species, Botryllus scalaris and Symplegma reptans, which stand at important points in botryllid phylogeny. In B. scalaris, phagocytes mediated hemocyte aggregation, resulting in interruption of blood flow just after vascular fusion of incompatible colonies. Although previous studies indicate that morula cells (MCs) play a central role in the rejection reaction, the MCs of B. scalaris did not participate in the rejection reaction. Colonies of S. reptans showed two types of allorejection reaction that started at different points in the process of vascular fusion between two colonies. In both types of rejection reaction, the MCs played a central role and behaved similarly to those of all botryllids except B. scalaris and a botryllid from Israel. These observations suggest that the differences in hemocyte behavior and allorecognition site observed in this study reflect the variation in allorejection reactions among botryllids.

[1]  L. Ballarin,et al.  Phenoloxidase and cytotoxicity in the compound ascidian Botryllus schlosseri. , 1998, Developmental and comparative immunology.

[2]  I. Weissman,et al.  EVOLUTION OF ALLORECOGNITION IN BOTRYLLID ASCIDIANS INFERRED FROM A MOLECULAR PHYLOGENY , 1998, Evolution; international journal of organic evolution.

[3]  B. Rinkevich,et al.  Contribution of morula cells to allogeneic responses in the colonial urochordate Botryllus schlosseri , 1998 .

[4]  C. Caruso,et al.  Phenoloxidase-dependent cytotoxic mechanism in ascidian (Styela plicata) hemocytes active against erythrocytes and K562 tumor cells. , 1997, European journal of cell biology.

[5]  E. Hirose,et al.  Subcuticular Rejection: an Advanced Mode of the Allogeneic Rejection in the Compound Ascidians Botrylloides simodensis and B. fuscus. , 1997, The Biological bulletin.

[6]  L. Ballarin,et al.  Morula Cells and Histocompatibility in the Colonial Ascidian Botryllus schlosseri , 1995 .

[7]  B. Rinkevich,et al.  Allorecognition/xenorecognition responses in Botrylloides (ascidiacea) subpopulations from the mediterranean coast of Israel , 1994 .

[8]  L. Ballarin,et al.  Phagocytosis in the colonial ascidian Botryllus schlosseri. , 1994, Developmental and comparative immunology.

[9]  E. Hirose,et al.  Surgical fusion between incompatible colonies of the compound ascidian, Botrylloides fuscus. , 1994, Developmental and comparative immunology.

[10]  E. Hirose,et al.  Allorecognition in compound ascidians. , 1994, The International journal of developmental biology.

[11]  I. Weissman,et al.  Morphologic and Genetic Verification That Monterey Botryllus and Woods Hole Botryllus are the Same Species. , 1990, The Biological bulletin.

[12]  Yasunori Saito,et al.  A New Type of the Manifestation of Colony Specificity in the Compound Ascidian, Botrylloides violaceus Oka , 1988 .

[13]  H. Mukai,et al.  Viviparous development in Botrylloides (Compound Ascidians) , 1987, Journal of morphology.

[14]  Yasunori Saito,et al.  Studies on Japanese Compound Styelid Ascidians -IV. Three New Species of the Genus Botrylloides from the Vicinity of Shimoda- , 1985 .

[15]  Yasunori Saito,et al.  Self or Non-self Discrimination in Ascidians , 1985 .

[16]  H. Watanabe,et al.  Studies on colony specificity in the compound ascidian, Botryllus primigenus Oka. I. Initiation of "nonfusion" reaction with special reference to blood cells infiltration. , 1982, Developmental and comparative immunology.

[17]  H. Watanabe,et al.  Studies on colony specificity in the compound ascidian, Botryllus primigenus Oka. II. In vivo bioassay for analyzing the mechanism of "nonfusion" reaction. , 1982, Developmental and comparative immunology.

[18]  H. Mukai,et al.  STUDIES OF JAPANESE COMPOUND STYELID ASCIDIANS -I. TWO NEW SPECIES OF BOTRYLLUS FROM THE VICINITY OF SHIMODA- , 1981 .

[19]  H. Mukai,et al.  STUDIES ON JAPANESE COMPOUND STYELID ASCIDIANS -II. A NEW SPECIES OF THE GENUS BOTRYLLOIDES AND REDESCRIPTION OF B. VIOLACEUS OKA- , 1981 .

[20]  H. Watanabe,et al.  Fine structure of fusion reaction in compound ascidian Botryllus primigenus OKA. , 1980, Developmental biology.

[21]  H. Mukai.  Comparative studies on the structure of reproductive organs of four botryllid ascidians , 1977, Journal of morphology.

[22]  H. Mukai,et al.  On the occurrence of colony specificity in some compound ascidians. , 1974, The Biological bulletin.

[23]  H. Watanabe,et al.  Allogeneic inhibition in a compound ascidian, Batryllus primigenus Oka. I. Processes and features of "Nonfusion" reaction. , 1973, Cellular immunology.

[24]  K. Tanaka.  Allogeneic inhibition in a compound ascidian, Botryllus primigenus Oka. II. cellular and humoral responses in "nonfusion"reaction. , 1973, Cellular immunology.

[25]  Hiroshi Watanabe,et al.  Colony-Specificity in Compound Ascidians as Tested by Fusion Experiments , 1957 .

[26]  N. Berrill.  Studies in Tunicate Development. Part V. The Evolution and Classification of Ascidians , 1936 .