Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 26, 2001
Publication Date: May 20, 2001
Citation: Ford, J.J., Wise, T.H., Lunstra, D.D., Rohrer, G.A. 2001. Interrelationships of porcine X and Y chromosomes with testicular size [abstract]. Proceedings Sixth International Conference on Pig Reproduction, Columbia, Missouri, p. 44. (Abstract No. 14) Technical Abstract: The primary objective of this study was to investigate the effect of breed of origin of a X chromosome QTL and the Y chromosome on testicular traits. A secondary objective was to evaluate the influence of age at unilateral castration on testicular traits. Boars (n=132) were assigned to intact controls or unilateral castration on d 1, 10, 56 or 112. At 220 d, the left testis was removed, trimmed, weighed, cut longitudinally, assigned a color score and a portion frozen for subsequent evaluation of sperm production. Origin of the Y chromosome had no effect (p>0.10) on testicular or epididymal traits. Boars that inherited their X chromosome alleles from the MS breed had smaller testicles (p<0.01) than boars that received this region from the WC breed. Similarly, boars with MS alleles had reduced (p<0.01) total sperm production, smaller epididymal wt, and darker parenchymal color than boars with the WC alleles. At 220 d, weights of the testicle and epididymis decreased (p<0.01) with increasing age at unilateral castration. Parenchymal color was not influenced by unilateral castration. Total sperm production was greater in boars that were unilaterally castrated on 1 or 10 d of age (p<0.01). The current study clearly documents that testicular traits of this population of boars depended substantially upon alleles that map to a QTL of X chromosome. Whereas, the Y chromosome had no significant contribution on the traits that were examined.