Alberti G, Meyer-Rochow V B
Zoologisches Institut und Museum, Universität Greifswald, Bachstr. 11/12, D-17489 Greifswald, Germany.
Arthropod Struct Dev. 2002 Jun;30(4):315-28. doi: 10.1016/s1467-8039(02)00008-7.
Testes and sperm cells of two species of halacarid mites, Thalassarachna basteri from the Baltic Sea and Halacarellus thomasi from McMurdo Sound (Antarctica), were investigated. Testes are paired structures, composed of a glandular and a germinal part. The testicular lumen is filled with a very complex secretion that contributes to sperm cell aggregates. Early spermatids of T. basteri display unusual chromatin condensation within the nucleus, but the formation of an acrosomal complex with a small acrosomal vesicle and a long acrosomal filament can be regarded as typical for the group. Tubular invaginations of the plasmalemma occur at the cell periphery. A deep, ring-like infold divides the cell into one part containing the chromatin body and another containing mainly the invaginations and the acrosomal complex. The mature sperm cell is ovoid, aflagellate and surrounded by a distinct secretion sheath. In H. thomasi only a limited number of spermiogenesis stages were observable. Chromatin condensation was rather similar and peripheral invaginations also occurred. However, no acrosomal complex was observed in the early stages. The division of the mature sperm cells into two halves was even more pronounced in H. thomasi, since one half of the cell contained masses of convoluted structures. The same half also contained a structure that remotely resembled an acrosomal complex. The observed differences between T. basteri and H. thomasi sperms support the placing of the two halacarids in separate genera.
对两种海螨的睾丸和精子细胞进行了研究，这两种海螨分别是来自波罗的海的巴氏深海螨（Thalassarachna basteri）和来自麦克默多湾（南极洲）的托氏拟海螨（Halacarellus thomasi）。睾丸是成对的结构，由腺体部分和生殖部分组成。睾丸腔充满了一种非常复杂的分泌物，这种分泌物有助于形成精子细胞聚集体。巴氏深海螨的早期精子细胞在细胞核内显示出异常的染色质浓缩，但顶体复合体的形成，包括一个小顶体泡和一条长顶体丝，可以被视为该类群的典型特征。质膜的管状内陷出现在细胞周边。一个深的环状褶皱将细胞分为一部分，其中包含染色质体，另一部分主要包含内陷和顶体复合体。成熟的精子细胞呈卵形，无鞭毛，并被一个明显的分泌鞘包围。在托氏拟海螨中，仅观察到有限数量的精子发生阶段。染色质浓缩相当相似，周边内陷也会出现。然而，在早期阶段未观察到顶体复合体。在托氏拟海螨中，成熟精子细胞分为两半的情况更为明显，因为细胞的一半包含大量盘绕的结构。同一半还包含一个与顶体复合体有一定相似之处的结构。巴氏深海螨和托氏拟海螨精子之间观察到的差异支持将这两种海螨置于不同的属中。
