title: Testicular Characteristics and the Block to Spermatogenesis in Mature Hinny.
abstract: Most hinnies (female donkey×male horse) and mules (female horse×male donkey) are sterile with few reports of equine fertile hybrids. The main cause of this sterility is thought to be a meiotic block to spermatogenesis and oogenesis. This study compared the developmental features of the testes and a histological analyses of spermatogenesis in a male hinny with those of a normal, fertile stallion and Jack donkey. Hinny testes showed a thicker tunica albuginea, fewer blood vessels and more connective tissue in the testis parenchyma than those of the stallion and Jack donkey. Although the mean number of seminiferous tubules was significantly higher in stallion and hinny than Jack donkey (p<0.01), the mean proportion of seminiferous tubules was lower in the hinny (p<0.01) which resulted in a smaller diameter of seminiferous tubules. The mean number of spermatogonia and spermatocytes per unit area were significantly lower in hinny testis (p<0.01) and no spermatids or mature spermatozoa cells were found during immunofluorescent analyses. These results indicated that defects in seminiferous tubule development and structure occur in the testis of hinnies. Furthermore, most spermatogonia and spermatocytes cease development in synapsis during mid-meiosis of spermatocytes, which results in a block to spermatogenesis that prevents the formation of spermatids and matured spermatozoa during meiosis in male hinnies.
authors.affiliation: Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Huhhot 010021, China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Han
authors.affiliation: Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Huhhot 010021, China.
authors.forename: Aihong
authors.initials: A
authors.lastname: Wang
authors.affiliation: Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Huhhot 010021, China.|Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Huhhot 011517, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Liu
authors.affiliation: Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Huhhot 011517, China.
authors.forename: Gaoping
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Huhhot 011517, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Su
authors.affiliation: Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Huhhot 010021, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Wang
authors.affiliation: Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Huhhot 010021, China.|Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Huhhot 011517, China.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Li
authors.affiliation: Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Huhhot 010021, China.
authors.forename: Jindun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Huhhot 011517, China.
authors.forename: Baojiang
authors.initials: B
authors.lastname: Wu
authors.affiliation: Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Huhhot 010021, China.|Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Huhhot 011517, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Huhhot 010021, China.|Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Huhhot 011517, China.
authors.forename: Shuxiang
authors.initials: S
authors.lastname: Hu
authors.affiliation: Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Huhhot 011517, China.
authors.forename: Shuyu
authors.initials: S
authors.lastname: Li
authors.affiliation: Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Huhhot 010021, China.|Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Huhhot 011517, China.
authors.forename: Lixia
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Research Center for Animal Genetic Resources of Mongolian Plateau, Inner Mongolia University, Huhhot 010021, China.|Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Huhhot 011517, China.
authors.forename: Xihe
authors.initials: X
authors.lastname: Li
keywords: Defect; Hinny; Seminiferous Tubule; Spermatogenesis; Sterility; Testis