Agglutination of "Normal" Germ Cells

Abstract

It is widely believed that freshly shed germ cells are relatively constant. In previous studies, , , an extremely wide variation in many characters and characteristics was noted. In the present study agglutination of sperm by egg water, which agglutination lends itself to fairly exact quantitative determination, was studied under very precise experimental conditions. The sea urchin (Arbacia punctulata) was used. These were freshly collected, opened immediately upon arrival at the laboratory, the “best” egg lots selected and immediately tested for the duration of agglutination. Duplicate tests and tests of aliquot divisions of the eggs gave a difference of 0 to 4 seconds, averaging 1 second or 4.5%. This was considered the experimental error. Thirty series of 3 to 4 females each were studied. When eggs from each female in a series were tested separately, under strictly comparable conditions (including the same sperm suspension), the agglutination time varied very extensively, namely, from 2 to 55 seconds, or 9 to 1300%, with an average of 12 seconds or 142%. Eggs that gave high agglutination values with sperm from one individual gave consistently high, though not the same values, with sperm from other individuals. Similarly eggs that gave intermediate or low values with one male, gave intermediate or low values with other males. This wide variation and increase in agglutination time parallels corresponding wide changes in size, color, shape of eggs, loss of jelly, membrane formation, cleavage, etc., , , The degree of change in any one of these traits measures the extent of overripening of the eggs prior to shedding. It was also noted that severe storms that delay natural shedding, also higher temperature of the sea water, give rise to overripening of the eggs within the body of the sea urchin, with all the symptoms above enumerated.