Heming B S
Department of Entomology, University of Alberta, Edmonton, Alberta, Canada T6G 2E3.
J Morphol. 1979 Jun;160(3):323-343. doi: 10.1002/jmor.1051600305.
Comparison of germ cells in male and female embryos of the arrhenotokous thrips, Haplothrips verbasci, yields the following observations: A mean of 11 cleavage energids enter the posterior pole plasm of the egg after the sixth cleavage division and apparently become pole cells when they take up polar granules in their cytoplasm. The cells proliferate asynchronously prior to and during anatrepsis to yield a mean of 36 germ cells in male embryos and 31 in females. Visible sexual differentiation of germ cells begins during germ band elongation and is completed shortly after the appearance of appendages. Female germ cells are larger than those of the males and may contain two nucleoli. The germ cells separate into two groups just before katatrepsis and mesodermal cells collect about these to form the primary epithelial sheaths of the gonads and the primordia of the gonoducts shortly after revolution is completed. Each gonad contains a mean of 13 germ cells in male embryos and 7 in females - a number that persists until mitosis resumes after hatching. During ketatrepsis, a mean of 11 germ cells in male embryos and 2.6 in females fail to be enclosed within the gonads, become dispersed in the yolk and perhaps transform into vitellophages. Germ cell development in H. verbasci embryos resembles similar events taking place in psocid embryos, providing additional evidence for a close phylogenetic relationship between Thysanoptera and Psocoptera.
对产雄孤雌生殖蓟马——黄胸蓟马（Haplothrips verbasci）的雄性和雌性胚胎中的生殖细胞进行比较，得出以下观察结果：在第六次卵裂后，平均有11个卵裂子进入卵的后极质，当它们在细胞质中摄取极粒时，显然会变成极细胞。这些细胞在胚胎反转前和反转过程中异步增殖，雄性胚胎中平均产生36个生殖细胞，雌性胚胎中平均产生31个生殖细胞。生殖细胞的明显性别分化在胚带伸长期间开始，并在附肢出现后不久完成。雌性生殖细胞比雄性生殖细胞大，可能含有两个核仁。在胚胎反转前，生殖细胞分成两组，反转完成后不久，中胚层细胞围绕这些细胞聚集，形成性腺的初级上皮鞘和生殖导管原基。雄性胚胎的每个性腺平均含有13个生殖细胞，雌性胚胎中平均含有7个生殖细胞——这个数量一直持续到孵化后有丝分裂恢复。在胚胎反转后期，雄性胚胎平均有11个生殖细胞，雌性胚胎有2.6个生殖细胞未能被包裹在性腺内，而是分散在卵黄中，可能会转变为卵黄吞噬细胞。黄胸蓟马胚胎中的生殖细胞发育类似于啮虫胚胎中发生的类似事件，为缨翅目和啮虫目之间密切的系统发育关系提供了额外证据。
