The Role of Fertilizin in the Fertilization of Eggs of the Sea-Urchin and Other Animals

Fertilization Selection on Egg and Jelly-Coat Size in the Sand Dollar Dendraster Excentricus

“…This notion has been illustrated in sea urchins, where egg traits appear to be under such selection (Levitan 1993(Levitan , 1996a(Levitan ,b, 1998b. Laboratory and field studies have documented that the percentage of eggs fertilized is correlated with egg size within (Levitan 1996a) and among (Levitan 1993(Levitan , 1998b closely related sea-urchin species and that egg traits may be adapted to particular spawning conditions in ways that optimize fertilization success (Levitan 1993(Levitan , 1996a(Levitan ,b, 1998b Thomas 1994a,b;Podolsky 1995;Podolsky and Strathmann 1996;Styan 1998).What has remained unclear is what attribute of the egg or which component of egg size is actually responsible for increases in fertilization efficiency and what role the jelly coat plays in this interaction (Lillie 1915;Tyler 1941;Hagstrom 1956;Hagstrom and Markman 1957;Levitan 1995;Podolsky 1995;Podolsky and Strathmann 1996;Farley and Levitan 2001). The two factors that determine the fertilization rate of eggs are the rate at which sperm and eggs collide (collision rate) and the rate at which these collisions result in fertilization (fertility rate).…”

“…What has remained unclear is what attribute of the egg or which component of egg size is actually responsible for increases in fertilization efficiency and what role the jelly coat plays in this interaction (Lillie 1915;Tyler 1941;Hagstrom 1956;Hagstrom and Markman 1957;Levitan 1995;Podolsky 1995;Podolsky and Strathmann 1996;Farley and Levitan 2001). The two factors that determine the fertilization rate of eggs are the rate at which sperm and eggs collide (collision rate) and the rate at which these collisions result in fertilization (fertility rate).…”

Gamete surface molecular components and their functional roles in sperm-egg interactions of the horseshoe crab, Limulus polyphemus L. (Merostomata): an immunological and biochemical approach

“…It also attacks saturated fatty acids to form keto acids (Mead, Howton, and Nevenzel, 1965). Tyler (1941) demonstrated that hydro gen peroxide destroys the agglutinability of fertilizin but does not affect the integrity of the active site which combines with sperm antifertilizin.…”

“…These authors suggest that this fragment is analogous to the Fc portion of the antibody molecule which holds the combining entities together, further demonstrating the antigen-âtîtibcdy nature of the fertilizin-antifsrtllizin system. Univalent fertilizin can also be prepared artificially by treat ment with hydrogen peroxide, ultraviolet light, or proteolytic enzymes (Tyler, 1941;Metz, 1942). Univalent fertilizin prepared in this manner yields four bands upon electrophoresis versus one band for the multivalent form (Stern and Metz, 1967).…”

“…Also reduction with sodium dithionite (Nag^SgO^) had no affect. However, oxidation with periodate (Runnstrom, 1935) and hydrogen peroxide (Metz, 1967;Tyler, 1941) does destroy the sperm agglutinating action of fertilizin. In the case of hydrogen peroxide, the oxidation does not block the fertilizin active site but only cleaves the molecule to the univalent form.…”