PDF(Pubmed)
Abstract：
Elasmobranchs have an ancestral reproductive system, which offers insights into vertebrate reproductive evolution. Despite their unchanged design over 400 million years, they evolved complex mechanisms ensuring reproductive success. However, human activities induced a significant decline in elasmobranch populations worldwide. In the Mediterranean basin, the smooth-hound shark (Mustelus mustelus) is one of the species that are considered vulnerable to human activities. Conservation efforts necessitate a thorough understanding of its reproductive strategy. This study focused on mature male specimens of smooth-hound sharks that were captured in the Adriatic area and successively analyzed to provide, for the first time, a histologically detailed description of testicular development in the species. Seven phases of the spermatogenesis process were identified, along with the macromolecular characterization of cells obtained using Fourier-transform infrared imaging. Histological analysis showed structural and cellular features similar to those documented in the spermatocysts of other elasmobranchs. The examination of the evolution and migration of both germinative and Sertoli cells at each phase revealed their close connection. Furthermore, different expression levels of lipids, proteins, and phosphates (DNA) at each spermatogenesis stage were observed. This research provided new information on spermatogenesis in the common smooth-hound shark, which is crucial for conservation efforts against population decline and anthropogenic pressures.
摘要：
弹性神经有祖先的生殖系统，提供了对脊椎动物生殖进化的见解。尽管他们的设计在4亿年前没有改变，他们进化出了确保生殖成功的复杂机制。然而,人类活动导致全球弹性分支种群显着下降。在地中海盆地，光滑猎犬鲨（Mustelusmustelus）是被认为容易受到人类活动影响的物种之一。保护工作需要对其生殖策略有透彻的了解。这项研究的重点是在亚得里亚海地区捕获并连续分析的成熟雄性鲨鱼标本，第一次,该物种睾丸发育的组织学详细描述。确定了精子发生过程的七个阶段，以及使用傅里叶变换红外成像获得的细胞的大分子表征。组织学分析显示，结构和细胞特征与其他弹性肌精囊中记录的相似。在每个阶段检查发芽细胞和支持细胞的进化和迁移，揭示了它们的紧密联系。此外，不同的脂质表达水平，蛋白质，在每个精子发生阶段观察到磷酸盐（DNA）。这项研究为普通光滑猎犬鲨的精子发生提供了新的信息，这对于应对人口减少和人为压力的保护工作至关重要。
