INTRATESTICULAR INOCULATION OF AVIAN-LEUKOSIS VIRUS (ALV) IN CHICKENS- PRODUCTION OF NEUTRALIZING ANTIBODIES AND LACK OF VIRUS SHEDDING INTO SEMEN

In order to investigate the possibility of producing transgenic chicke ns by injection of avian leukosis virus-based vectors into testis, we have analyzed the infection rate of testicular cells following inocula tion of Rous-associated virus type 1 (RAV-1) into the gonads of adult and 1-wk-old brown leghorn males. Viroproduction, neutralizing antibod y production, and viral DNA presence in testis, blood, muscle, and sem en were analyzed at various times after infection. Inoculation of RAV- 1 into the gonads of adult males resulted in a low level of viroproduc tion in testis and blood, followed by the appearance of neutralizing a ntibody 2 or 3 wk later. Neither viroproduction in semen nor viral DNA presence in sperm were detected even though the infected chickens wer e found to produce RAV-1 in testis. One week after intratesticular ino culation of 1-wk-old males with RAV-1, a high level of viroproduction was found in blood and testis, and viral DNA was detected in gonadal c ells. Further, by 6 wk after inoculation, the production of virus decr eased in all tissues, viral DNA could not longer be detected in the te stis, and neutralizing antibodies appeared in blood. All together thes e data show that it is possible to infect testicular cells by direct i noculation of RAV-1 in the testis, and that the immune response of bot h adult and young chickens seems to reduce this infection. Moreover, n o evidence of spermatozoa infection was found; this result suggests th at RAV-1 inoculation into testis may not induce genetic transmission o f virus, and consequently would not be useful in the production of tra nsgenic chickens.