Active immunization with recombinant GnRH fusion protein in boars reduces both testicular development and mRNA expression levels of GnRH receptor in pituitary.
Immunization using recombinant maltose binding protein-gonadotropin releasing hormone (MBP-GnRH6) altered both testicular development and transcription of the pituitary GnRH receptor (GnRHR) gene in boars. Scrotal measurement and blood samples were taken at 4-week interval after immunization at 9 weeks of age. The concentrations of testosterone and anti-GnRH antibodies in serum were determined by radioimmunoassay and enzyme-linked immunosorbent assay, respectively. The results showed that active immunization with MBP-GnRH6 increased the serum concentration of anti-GnRH antibodies (P<0.05) and reduced the serum concentration of testosterone (P<0.05) as compared with MBP controls. At 25 weeks of age, boars were sacrificed and testes were evaluated histologically. Testicular development was suppressed in the MBP-GnRH6 immunized animals as compared with MBP immunized boars. MBP-GnRH6 immunized pigs exhibited mounting behavior 4 weeks later than MBP immunized boars. No mature spermatozoa were observed from MBP-GnRH6 immunized animals. By real-time quantitative PCR analysis, the amount of GnRHR mRNA in the pituitary tissue was found to be significantly lower in MBP-GnRH6 immunized animals than in controls (P<0.05). These data demonstrate that recombinant MBP-GnRH6 was effective in immunological castration in boars.
Fang
Fugui
F
Department of Animal Medicine, College of Animal Science and Technology, Anhui Agricultural University, No. 130 Changjiang West Road, Hefei, Anhui, PR China.
Li
Haidong
H
Liu
Ya
Y
Zhang
Yunhai
Y
Tao
Yong
Y
Li
Yunsheng
Y
Cao
Hongguo
H
Wang
Suolu
S
Wang
Lin
L
Zhang
Xiaorong
X
D000818:Animals; D000906:Antibodies / Q000097:blood; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D008297:Male; D058619:Maltose-Binding Proteins; D033902:Periplasmic Binding Proteins / Q000235:genetics / Q000276:immunology; D010902:Pituitary Gland / Q000737:chemistry*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D011966:Receptors, LHRH / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D012726:Sexual Behavior, Animal; D013094:Spermatozoa / Q000502:physiology; D013245:Sterilization, Reproductive / Q000379:methods / Q000662:veterinary*; D013552:Swine / Q000254:growth & development* / Q000378:metabolism; D013737:Testis / Q000033:anatomy & histology / Q000254:growth & development*; D013739:Testosterone / Q000097:blood; D014611:Vaccination / Q000662:veterinary
D000906:Antibodies; D058619:Maltose-Binding Proteins; D033902:Periplasmic Binding Proteins; D012333:RNA, Messenger; D011966:Receptors, LHRH; D011993:Recombinant Fusion Proteins; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone