Biology Reference
In-Depth Information
Fig. 2.4 Ultrastructure of neck attachment misalignments and acephalic spermatozoa. a At an
early stage of spermiogenesis this spermatid still shows a normally positioned basal body (Bb)
anchored to the cell membrane. Acrosomic vesicle (AV). b This elongating spermatid lacks a
nuclear implantation fossa (**), and the flagellar anlage is not attached to the nucleus. c Another
spermatid showing centrioles (Ce) with abnormal implantation into the nucleus. d An acephalic
spermatozoon. There is no head. Centrioles, mitochondrial sheath, and flagellum are normal.
e Spermatid with abnormal angle between head and midpiece. Flagellar attachment is similar to
that depicted in panel c. Bars represent 1 lm (Figure 4 was originally published by Chemes et al.
(
1999
)
and
Chemes
and
Rawe
(
2010
)
and
reproduced,
modified
from
the
original,
with
permission from the publishers)
Various earlier publications had reported single patients with similar sperm
phenotypes and identified them as ''microcephalic'', ''pin-head'', or ''decapitated''
spermatozoa (Zaneveld and Polakoski
1977
; Nistal et al.
1978
; LeLannou
1979
;
Perotti and Gioria
1981
; Perotti et al.
1981
; Baccetti et al.
1984
). We introduced the
