The spermatozoa of Gymnophiona show the following autapomorphies: 1) penetration of the distal centriole by the axial fiber; 2) presence of an acrosomal baseplate; 3) presence of an acrosome seat (flattened apical end of nucleus); and 4) absence of juxta-axonemal fibers. The wide separation of the plasma membrane bounding the undulating membrane is here also considered to be apomorphic. Three plesiomorphic spermatozoal characters are recognized that are not seen in other Amphibia but occur in basal amniotes: 1) presence of mitochondria with a delicate array of concentric cristae (concentric cristae of salamander spermatozoa differ in lacking the delicate array); 2) presence of peripheral dense fibers associated with the triplets of the distal centriole; and 3) presence of a simple annulus (a highly modified, elongate annulus is present in salamander sperm). The presence of an endonuclear canal containing a perforatorium is a plesiomorphic feature of caecilian spermatozoa that is shared with urodeles, some basal anurans, sarcopterygian fish, and some amniotes. Spermatozoal synapomorphies are identified for 1) the Uraeotyphlidae and Ichthyophiidae, and 2) the Caeciliidae and Typhlonectidae, suggesting that the members of each pair of families are more closely related to each other than to other caecilians. Although caecilian spermatozoa exhibit the clear amphibian synapomorphy of the unilateral location of the undulating membrane and its axial fiber, they have no apomorphic characters that suggest a closer relationship to either the Urodela or Anura.

译文

:裸子藻的精子表现出以下自发性:1)轴向纤维穿透远端中心细胞; 2)顶体底板的存在; 3)存在顶体位(核顶端扁平);和4)没有近轴纤维。结合起伏膜的质膜的宽分离在这里也被认为是无定形的。识别出三个两栖类的精子动物特征,这些特征在其他两栖动物中均未见,但在基底羊膜动物中出现:1)线粒体的存在与同心的ista细小排列(sal精子的同心cr不同,缺少细细的排列); 2)存在与远端中心三胞胎相关的周围致密纤维; 3)存在简单的环(sal精子中存在高度修饰的细长环)。含有小孔的核内管的存在是凯撒精子的多形性特征,与乌德勒犬,一些基底无尾类动物,翼翅目鱼类和一些羊膜动物共有。精子的同形亚型被鉴定为1)伞形科和鱼鳞科,以及2)ec科和鼓虫科,这表明每对家庭的成员彼此之间的亲缘关系比其他盲目者更为紧密。尽管凯撒精子在起伏的膜及其轴向纤维的单侧位置上表现出明显的两栖类突触,但它们却没有与阿罗德拉或阿努拉的亲密关系。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录