Spermatogenesis in Dioon edule

Chamal (Dioon edule Lindl.) in the State of San Luis Potosí, México

INTRODUCTION A 20% of world cycad species are found in Mexico, 80% of which are endemic (Vovides, 2000). At least nine species are present in the state of San Luis Potosí: Dioon edule, Zamia fi scheri, Z. loddigesii, Ceratozamia hildae, C. kuesteriana, C. latifolia, C. mexicana, C. microstrobila, and C. zaragozae (Yáñez-Espinosa, 2006) [Ed’s note: Zamia vazquezii is also found in San Luis Potos...

Chromosomal Abnormality in Men with Impaired Spermatogenesis

AN ULTRASTRUCTURAL STUDY OF PLANT SPERMATOGENESIS Spermatogenesis in Nitella

Spermatogenesis in the charophyte Nitella has been followed in antheridia prepared for light and electron microscopy. The antheridial filament cells contain paired centrioles which are similar in structure and behavior to the centrioles of animal cells. In the early spermatid, the centrioles undergo an initial elongation at their distal ends and become joined by a spindle-shaped fibrous connect...

Drug transporters in spermatogenesis

Drug transporters are integral membrane proteins expressed by a variety of organs, including the liver, kidney, small intestine and testis, and they are generally known to mediate drug or xenobiotic transport into and out of cells. Previous studies have also reported the presence of several drug transporters at blood-tissue barriers where they are thought to protect organs from harmful agents. ...

In vitro spermatogenesis

The generation of functional sperm in vitro has been a goal for almost a century. Until recently, researchers have only succeeded in reproducing the early steps of spermatogenesis. This is not surprising given that spermatogenesis is a complicated process that requires the coordinated efforts of germ cells and several somatic cells within the tubular structure of the testis. Finally-last year-S...