Testicular development in Brahman bulls
Testicular development in Brahman bulls
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DOI：
10.1016/j.theriogenology.2005.03.016
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发表时间：
2005-10-01
期刊：
影响因子：
2.8
通讯作者：
Bastidas, P
中科院分区：
文献类型：
--
作者：
Aponte, PM;de Rooij, DG;Bastidas, P
婆罗门品种公牛（Bos indicus）被广泛用于向产肉牛群引入环境抗性特征。然而，它们的生殖发育比欧洲品种（Bos taurus）慢。本研究的目的是评估婆罗门公牛生精上皮的发育。对二十三头青春期前的公牛进行阉割并采集睾丸样本进行组织学处理。将光学显微图像数字化并评估生精上皮细胞。未成熟的支持细胞数量逐渐减少，约 14 个月大后不再检测到；同时，成熟支持细胞的数量从 10 个月增加到 14 个月。精子发生在第九个月开始；在此之前，仅观察到生殖细胞和未成熟的支持细胞。 A型精原细胞、精母细胞、圆形精子细胞、细长精子细胞和精子分别在9.5、11、11、13和16月龄时首次检测到。婆罗门公牛的青春期开始时间相对于金牛座公牛而言延迟是由于青春期前时期（从精子发生开始到青春期的间隔）较长且精子发生开始较晚。 (c) 2005 Elsevier Inc. 保留所有权利。
Brahman breed bulls (Bos indicus) are widely used to introduce environmental resistance traits into meat-producing herds. However, their reproductive development is slower than European breeds (Bos taurus). The objective of this study was to assess the development of the seminiferous epithelium in Brahman bulls. Twenty-three prepubertal bulls were castrated and testicular samples taken for histological processing. Light microscopic images were digitized and cells of the seminiferous epithelium were assessed. Immature Sertoli cells gradually decreased in numbers and were no longer detected after approximately 14 months of age; concurrently, the numbers of mature Sertoli cells increased from 10 to 14 months. Spermatogenesis started during the ninth month; prior to that, only gonocytes and immature Sertoli cells were observed. Type A spermatogonia, spermatocytes, round spermatids, elongated spermatids and spermatozoa were first detected at 9.5, 11, 11, 13 and 16 months of age, respectively. The delay in the onset of puberty in Brahman bulls with respect to B. taurus was attributed to a longer duration of the prepubertal period (interval from start of spermatogenesis to puberty) and a later start of spermatogenesis. (c) 2005 Elsevier Inc. All rights reserved.