Ultrastructural differentiation of sperm tail region in Diplometopon zarudnyi (an amphisbaenian reptile)
, O. Al-Dokhi , Ahmed Mukhtar ,A. Al-Dosary , M.K. Al-Sadoon . 2015
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.
