Biology Reference
In-Depth Information
Table 3.1 Presence of centrosome (centriole pairs detected by centrin immunostaining) and
assessment of centrosomal functions (sperm aster formation after sperm injection and success of
embryo development) for different types of fresh spermatozoa or after various preservation
approaches
Centrin
labeling
Proportion
of large
sperm aster
Embryo
development
Source
Epididymal spermatozoa
(from cauda or ductus
deferens)
+
[75 %
*35 % blastocysts
Pers. obs.
Ejaculated spermatozoa
+
[75 %
*35 % blastocysts
Comizzoli et al.
(
2006
)
Testicular spermatozoa
+
0 %
Arrest at the 16-cell
stage
Comizzoli et al.
(
2006
)
Abnormal spermatozoa from
teratospermic ejaculate
+
0 %
Arrest at the 16-cell
stage
Pers. obs.
Normal spermatozoa from
teratospermic ejaculate
+
[75 %
*35 % blastocysts
Pers. obs.
Epididymal or ejaculated
spermatozoa post-freezing
+
[75 %
*35 % blastocysts
Comizzoli et al.
(
2006
)
Epididymal or ejaculated
spermatozoa post-drying
+
0 %
Arrest at the 16-cell
stage
Pers. obs.;
Ringleb
et al. (
2011
)
Epididymal or ejaculated
spermatozoa preserved
in liquid
+
[75 %
Arrest at the 16-cell
stage
Pers. obs.;
Murakami
et al. (
2005
)
teratospermic ejaculate can undergo normal fertilization and early embryo
developmental events when microinjected into a conspecific oocyte. We confirmed
these results by detecting the presence of normal sperm aster formations after
injecting structurally normal spermatozoa from teratospermic ejaculates into cat
oocytes (Table
3.1
). Simultaneously, we observed that malformed spermatozoa
from the same teratospermic semen had dysfunctional centrosomes based on the
formation of small sperm asters and arrested early embryonic development
(Table
3.1
). This malfunction occurred even though a normally appearing cen-
triole pair was detected in these pleiomorphic cells (Table
3.1
). These observations
in the cat are analogous to what occurs in some cases of human teratospermia
where poor centrosomal function is due, for instance, to abnormal alignment of the
head-flagellum junction (Manandhar et al.
2005
; Nakamura et al.
2005
). However,
human centrosomal aberrations in teratospermic human ejaculate have been
associated with lower expression of pericentriolar proteins, including centrin
(Manandhar et al.
2005
; Nakamura et al.
2005
). This finding has not been apparent
in the cat, although a search for alternative centrosomal proteins that might be
involved in cat teratospermia is a worthy target for future study.
