Ultrastructural differentiation of sperm tail region in Diplometopon zarudnyi (an amphisbaenian reptile)

Journal Article
Al-Dokhi, O. . 2015
Magazine \ Newspaper: 
Saudi Journal of Biological Sciences
Volume Number: 
22
Pages: 
448–452
Publication Abstract: 

Diplometopon zarudnyi, a worm lizard belongs to amphisbaenia under trogonophidae

family. This species exists in limited areas of the Arabian Peninsula and is an oscillating digger

found in sub-surface soils. The present study aimed to investigate the sperm tail differentiation

in D. zarudnyi. Ten male adults of D. zarudnyi were collected from Riyadh during April–May

2011. To study the sperm tail at the ultrastructural level the testes were fixed in 3% glutaraldehyde,

than post fixed in 1% osmium tetaroxide followed by dehydration in ethanol grades; samples were

cleared in propylene oxide and embedded in resin. Tail formation begins by the moving of centrioles

and mitochondria towards the posterior pole of sperm head. Simultaneously many microtubules of

the midpiece axoneme were enclosed by a thick layer of granular material. Mitochondria of midpiece

lie alongside the proximal centriole which forms a very short neck region and possess tubular

cristae internally and concentric layers of cristae superficially. During this course a fibrous sheath

surrounds the axoneme of mid and principal piece. At the end dissolution of longitudinal manchette

takes place. The mitochondria then rearrange themselves around the proximal and distal centrioles

to form a neck region. Later, the fibrous sheath surrounds the proximal portion of the flagella. This

part along with sperm head of D. zarudnyi provides a classical model that could be used in future

for evolutionary and phylogenetic purposes of class reptilia.