Incorporation of Arsenic into Cock Sperm.

Arsenicals have been shown to stimulate growth and improve feed efficiency in broilers and to improve laying hen performance. Although Pope and Schaible (1) reported that arsanilic acid exerts a sparing action on the protein requirement of breeding hens and layers when egg production was the criterion, small amounts did not improve hatchability or fertility in breeding chickens. Excess arsenic has been shown to be toxic to chickens. The position of arsenic in the periodic table would suggest that it has some chemical properties which are similar to phosphorus, and therefore, could replace phosphorus in some compounds. Since P32I4 or phosphate-P32 is readily incorporated into the deoxyribonucleic acid (DNA) of cock sperm in amounts allowing its detection (2) it was decided to use radioactive Arsenic (As76) and also stable arsenic in mineralization studies with cock sperm to determine if arsenic was incorporated into the DNA of sperm. Experimental. Ten sexually active New Hampshire cocks selected from a group maintained for artificial insemination were each given 200 μC of radioactive Arsenic 76 as As2O3 subcutaneously. The semen was collected 26 hours after radionuclide administration and each 26 hours thereafter for 4 collections. Twenty-six hours was used as the collection time because it was estimated that this period plus the time required to fractionate the semen would be equivlent to one half-life of Arsenic76 (about 26.8 hours). The radioactivity of the semen, sperm, seminal fluid, protein (TCA precipitate) and DNA fraction was determined. The DNA fraction was prepared as outlined by Borenfreund, Fitt and Bendich (3). The results are shown in Table I and demonstrate that Arsenic 76 was readily incorporated into cock sperm. Most of the Arsenic76 was found in the diluent (seminal fluid) and fractionation of the sperm showed that on the 52 hour period the sperm contained the greatest concentration of Arsenic76. The DNA fraction had its greatest concentration on the 78 hour period and protein fraction on the 52 hour period. Since these data indicated that Arsenic76 was in the DNA fraction of sperm, a further study was designed to study the incorporation of stable arsenic into the DNA of sperm.