750 



SPERM, OVA, AND PREGNANCY 



antigens, seem to be transported across the 

 genital epithelium, or to migrate by way of 

 the peritoneal cavity. Parsons and Hyde 

 (1940), for example, fomid circulating anti- 

 bodies after introducing antisperm serum 

 into the vaginas of rabbits, and McCartney 

 (1923) claimed that circulating antibodies, 

 actively produced in rats against sperm, 

 could be detected in the uterine and vagmal 

 fluids. Antibodies are known, of course, to 

 pass into the uterine lumen of rabbits dur- 

 ing pregnancy (Brambell, Hemmings and 

 Henderson, 1951). 



Very little has been attempted in altering 

 the fertility of female animals by means of 

 passive immunization with spermatozoa, 

 perhaps because the outstanding investiga- 

 tion of Henle, Henle, Church and Foster 

 (1940) was so conclusive. Repeated injec- 

 tion of mice with antisperm serum, pro- 

 duced in rabbits, failed to modify reproduc- 

 tive capacity in any significant way. 



The treatment of fresh sperm with spe- 

 cific antisperm serum has profound effects 

 on the gametes, the basis, in fact, of the 

 sperm-agglutination and sperm-immobiliza- 

 tion test methods. The treatment generally 

 renders sperm, both invertebrate and verte- 

 brate, incapable of fertilizing eggs (God- 

 lewski, 1926; Tyler, 1948; Kiddy, Stone and 

 Casida, 1959). A significant contribution, 

 moreover, has been the recent demonstra- 

 tion that if the exposure to antiserum is 

 carefully controlled, surprising and subtle 

 effects may occur when these sperm are used 

 for artificial insemination. Rabbit sperm, 

 treated for 15 minutes with high concentra- 

 tions of bovine antirabbit antiserum be- 

 fore insemination, were incapable of effect- 

 ing fertilization, as judged from the recovery 

 of unfertilized ova. However, a 15-minute 

 exposure of sperm to the same, but diluted, 

 immune serum permitted fertilization, but 

 resulted in a high percentage of embryonic 

 deaths (Kiddy, Stone and Casida, 1959). 

 No such fetal wastage occurred when rabbit 

 sperm were similarly exposed to normal 

 bovine serum. The antisera employed in 

 these experiments were prepared against 

 whole semen, rather than against washed 

 sperm, but any additional antigenic com- 

 ponents in plasma would not be expected 

 to have altered the results. Various inter- 



pretations can be placed on these findings, 

 including the possibility that the fertilizing 

 sperm might have carried antibodies into 

 the egg which impaired development, or, an 

 alternative possibility, that the antibodies 

 had a mutagenic action on the spermatozoa 

 leading to abnormal development after fer- 

 tilization (Kiddy, Stone and Casida, 1959). 

 There seemed to be no injurious effect on 

 the sperm that resulted in delayed fertiliza- 

 tion; thus the effects cannot be attributed to 

 aging of the ova. 



An immunologic mechanism has been im- 

 plicated by Gershowitz, Behrman and Neel 

 (1958) to account for the variations from 

 the expected ratio of offspring of couples 

 with incompatible ABO-blood groups. These 

 investigators found hemagglutinins in the 

 cervical mucus of 17 out of 77 cases so dis- 

 tributed that they might be regarded as con- 

 stituting a preconceptive selection mecha- 

 nism by blood group antibodies of the 

 uterine secretions acting on the sperm. 



In conclusion, a brief survey of the im- 

 munologic literature relating to fertility 

 indicates that spermatozoa may be deeply 

 involved in both experimentally and natu- 

 rally induced modifications in reproductive 

 performance and capacity. Other immune- 

 like interrcactions between specific sub- 

 stances, fertilizin and antifertilizin, ex- 

 tracted from invertebrate eggs and sperm, 

 also have been demonstrated; the possible 

 role of these reactions in the fertilization 

 process is discussed in the following chapter. 



VII. Morphology and Composition 

 of Spermatozoa 



A. STRUCTURAL FEATURES 



As one of the first objects to be viewed 

 microscopically (van Leeuwenhoek, 1678) , 

 the spermatozoon has had a long morpho- 

 logic history,- and still enjoys great popu- 

 larity, particularly among cytochemists and 

 electron microscopists. No exhaustive item- 



^Reimer Kohnz (1958) calls attention to a re- 

 cent "find" in the library of the Cologne Cathedral 

 which, if genuine, would shed revolutionary light 

 on the history of microscopic science. A manu- 

 script, purported to have been illuminated by 

 monks of the Reichenau Monastery ca. 1000 A.D., 

 is interpreted as showing an egg with eight sperma- 

 tozoa attached ! 



