A freeze etching study on the distribution of nuclear pores during spermatogenesis in ticks

In this study the freeze-fracturing and freeze-etching techniques was used to study pore distribution during spermatogenesis in ticks. Three species of Ixodid ticks were studied: Hyalomma dromedarii, H. marginatum and Amblyomma hebraeum. In all three species of the ticks examined, the nuclei of the early stages of male germ cells showed varying degrees of aggregation into pore-rich and pore-poor areas. Spermatocytes demonstrated significant pore clustering in pore-rich areas, leaving areas almost devoid of pores. Spermatids on the other hand displayed a random distribution of nuclear pores. This random distribution was soon modified in the course of nuclear differentiation. Nuclear pores disappeared in the nuclei of mature spermatozoa of the ticks examined.