GROWTH AND FUNCTION OF THE BURSA OF FABRICIUS IN THE DOMESTIC FOWL DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University by Bruce Glick, B. S., M. S. THE OHIO STATE UNIVERSITY 1 Approved by: Department of Poultry/Science ACKNOWLEDGEMENT Sincere appreciation is expressed to Dr. R. George Jaap, for his patience, counsel, and guidance in the fulfillment of the objectives of this research, I am also indebted to the staff of the Poultry Department for their cooperation and assistance, B. G. ii TABLE OF CONTENTS Page INTRODUCTION .... X , ....................... 1 NORMAL GROWTH OF THE BURSA ^OF FA B R I C I U S .......... 2 I Review of L i t e r a t u r e ..................... 2 II Materials and M ethods..................... 11 III Results ..... ......................... 12 A Initial Trial ......... 12 B Bursa Growth ........... 18 1 White Leghorns... ................... 18 2 Rhode Islaijd R e d s ................... 21 C Influence of Inheritance on Bursa Weight . 23 D Bursa - Booty- Relationship. ........ 32 E Bursa - Testes Relationship ........... 33 IV Discussion............................... 36 V Summary ........... U5 EXPERIMENTAL MODIFICATION OF BURSA GROWTH ........ hi I Review of Literature . hi II Materials and Methods..................... 50 III Re s u l t s.................................. 51 IV Discussion ............... 57 V Summary ......... 61 STUDIES IN BURSECTOMY............................. 62 I Review of Literature .................... 62 II Materials and Methods . ........ ...... 65 III Results .......... ........ 67 IV Discussion ........... 76 V Su m m a r y ......... 81 THE ROLE OF THE BURSA OF FABRICIUS IN ANTIBODY PRODUCTION ........................ 82 I Introduction ............. 82 II Review of L i t e r a t u r e ........ 83 III Materials and M ethods.......! ............. 85 IV R e s u l t s ........... 87 V D i s c u s s i o n .................... 8 8 VI Summary......... 91 GENERAL SUMMARY ................................ 93 BIBLIOGRAPHY........................ 96 AUTOBIOGRAPHY.................................... 102 iii LIST OF TABLES Tables Page 1 Growth of the Bursa in Barred Plymouth Rock X Dominant White Rock C rosses.............................. 13 2 Correlation Coefficients between Bursa and Booty and Bursa and Testes in the Barred Plymouth Rock X Dominant White Rock Crosses............... 1$ 3 Growth of the Bursa in White Leghorns ................. 19 1* Growth of the Bursa in Rhode Island R e d s ............... 22 5 Comparison of the Bursae of White Leghorns and Rhode Island Reds .................................... 21* 6 Heritability Estimate of Bursa Size in 1* Week Old White Leghorns.................................. 26 7 Heritability Estimates of Bursa Size in 1* Week Old Rhode Island Reds ................... 27 8 Analysis of Covariance of Bursa Size in White Leghorns and Rhode Island Reds by Families ................... 28 9 Average Bursa Size of 2 Week Old White Leghorns, Rhode Island Reds, and Reciprocal Crosses between the Two Breeds 30 10 Analysis of Covariance of Bursa Size between Progeny of White Leghorns, Rhode Island Reds, and Reciprocal Crosses of the Two Breeds .................................. 31 11 Correlation Coefficients between Bursa and Body in White Leghorns and Rhode Island R e d s ......................... 3k 12 Regression Coefficients of Bursa on Body in White Leghorns and Rhode Island' R e d s ................................ 35 13 The Bursa and Testes of White Leghorns and Rhode Island Reds Expressed in Percent of Body W e ight............... 39 ill Correlation Coefficients between Bursa and Testes in White Leghorns and Rhode Island Reds . ............. 1*0 iv Tables Page 1$ A Comparison of Varying Levels of Cortone on the Body and Bursa of k Week Old Rhode Island R e d s ................. 52 16 The Effect of Oreton, Qreton Plus Cortone, and Caponiza- tion on 8 Week Old Rhode Island Red M a l e s ............. 5U 17 The Effect of Oreton and Cortone on the Bursa and Body of U Week Old Male White Leghorns......................... 56 18 The Effect of Oreton and Cortone on the Bursa and Body of ij. Week Old Female White Leghorns....................... 56 19 The Effect of Oreton and Cortone on the Bursa and Body of U Week Old Male Rhode Island R e d s ..................... 58 20 The Effect of Bursectony at 12, 19., and 26 Days on the Testes of White Leghorns . ............................. 6 8 21 The Effect of Bursectomy at 2 Days on the Weight of the Testes, Comb and Oviduct of 3 Week Old White Leghorns . 70 22 Comb Area in lUi Bursectomized and Control Rhode Island Reds ............................ 71 23 Comb Area in 1*0 Bursectomized and Control White Leghorns . 72 2k The Effect of Bursectony at 12 Days on the Testes of White Leghorns and Rhode Island R e d s ................... 7k 25 The Effect of Bursectony at 12 Days on the Ovaries of White Leghorns and Rhode Island Reds . ................. 7b 26 The Effect of Bursectony at 12 Days on the Weight of the Testes, Comb, and Ovary of Ij. Week Old White Leghorns . 75 27 Body Weight Gains in Male and Female White Leghorns Bursectomized and "Sham" Operated at 12, 19, and 26 Days of A g e ........... 77 28 Body Weight Gains in I4O Bursectomized and Control Male and Female White Leghorns ............. * .......... 78 29 Body Weight Gains in Uli Bursectomized and Control Male and Female Rhode Island Reds ...... ......... .... 79 30 Number of Birds and Antibodies Produced by 7 Week Old Male and Female White Leghorns......................... 89 v Tables Page 31 Number of Birds and Antibodies Produced by 17 Week Old White Leghorns and Rhode Island Reds ...................... 89 vi LIST OF FIGURES Number Page 1 The relationship between the bursa and testes of Barred Plymouth Rock x Dominant TKhite Rock crosses. 17 2 The relationship between the bursa and testes of llihite L e g h o r n s ................................ 37 3 The relationship between the bursa and testes of Rhode Island R e d s ............................ 38 vii INTRODUCTION The bursa of Fabricius was first observed by Hieronymus Fabri- cius (1 5 3 3 -1 6 1 9 ) in his treatise on the embryology of the chick, (Adelman, 19ii2). There are sufficient histological data to demon­ strate that the bursa consists of lymph follicles and epithelial tissue. Available data concerning the growth and function of the bursa are few in number and in respect to function fail to reveal the role of the bursa in Avian physiology* The bursa of Fabricius is found exclusively within the class Aves. It has no known homologue in any other class of vertebrates. The objectives of this research were to characterize the growth of the bursa, study the factors involved in its regression, and to investigate the function of the bursa in the domestic fowl. 1 NORMAL GROWTH OF THE BURSA OF FABRICIUS I. Review of Literature The man who first discovered the bursa was Hieronymus Fabricius (1533-1619)t (Adelman, 19U2). His treatise on the embryology of the chick, in which the bursa was discussed, is reported to have been the most extensive study of its kind for that period. Fabricius erred in his description of the bursa which he called a double sac situated near the cloaca and connected with the uterus. He also believed erroneous]y that the bursa was to be found only in the female where it acted as a storage place for the cock's semen. Since the time of Fabricius the histology of the bursa has been extensively studied. Lillie's development of the chick (Hamilton, 1952), Bradley (1950) and Biester and Schwarte (191$) are the three most recent textbooks which include a discussion of the histology of the bursa. Calhoun (1933) has reviewed the early literature pertain­ ing to this subject. The bursa is a round or pear shaped dorsal diverticulum of the cloaca. In general, it consists of a serosa, a muscular tunic of smooth fibers, and a mucous membrane of longitudinal folds made up of a mass of lymphoid and epithelial tissue, Calhoun (1933)• According to Boyden (1922), the bursa was considered to be pri­ marily a lymph organ by Leydwig (1857) and primarily a glandular organ by Stieda (1880). On the Inside wall of the bursa are folds which contain many follicles. The follicles when stained show two cellular zones, a darkly staining cortex and a lighter medulla, Bradley (1950). Jolly (l911t) reported 12 - II4. folds per bursa in the chicken. Retterer (1885) found lj.0 - 50 follicles per fold. Wenckebach (1896) stated that the follicles consisted of two parts; epithelial and connective tissue. He believed, unlike Retterer (1885), that the connective tissue and blood vessels did not penetrate the medullary section of the follicle. Calhoun (1933) compared the medullary division to a germ center of a lymph node. A reticular network of cells separated the cortical and medullary portion. Blood vessels were not observed in the medullary division of the follicle, but they were present in the cortical part. The epithelium was found by Calhoun (1933) to be pseudostratified columnar on, and near, the tips of the folds, but simple columnar be­ tween the folds. A valve covering the opening of the duct from the cloaca to the bursa was not observed by Forbes (1877), but was present in the birds examined by Calhoun (1933)* Ectodermal and entodermal. origins have been theorized for the bursa. Jolly (1910) concludes that the bursa develops at the expense of the epithelium of the cloaca. And, therefore, it is of entodermal origin. This was confirmed by Boyden (1922). The follicles arise from epithelial buds and connective tissue. According to Bqyden (1922), epithelial buds of the folds grow into the surrounding mesenchyme and become enveloped in a cortical layer of connective tissue. The epithelial bud then becomes the medulla of the follicle. The increasing size of the follicles result in a polyhedral shape and a thickening of the bursal wall.