close

Вход

Забыли?

вход по аккаунту

?

Comparative studies with six extenders for sperm cryopreservation in the cynomolgus monkey (Macaca fascicularis) and rhesus monkey (Macaca mulatta).

код для вставкиСкачать
American Journal of Primatology 68:39–49 (2006)
RESEARCH ARTICLE
Comparative Studies With Six Extenders
for Sperm Cryopreservation in the Cynomolgus
Monkey (Macaca fascicularis) and Rhesus Monkey
(Macaca mulatta)
YAHUI LI1–3, KEJUN CAI1, JIAN LI1, ANDRAS DINNYES4, and WEIZHI JI1n
1
Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
2
Graduate School, Chinese Academy of Sciences, Beijing, China
3
College of Food Science and Technology, Yunnan Agricultural University,
Kunming, China
4
Research Group on Applied Animal Genetics and Biotechnology, Hungarian Academy of
Sciences and Szent Istvan University, Godollo, Hungary
Ejaculated spermatozoa from cynomolgus monkeys and rhesus monkeys
were frozen in straws with six different extenders (TTE, DM, mDM,
LG-DM, G-DM, and TCG) containing glycerol. Sperm motility and head
membrane and acrosomal integrity were evaluated after freezing and
thawing, and the cryoprotective effects were compared among the
extenders and the two species studied. The results showed that sperm
motility and motility recovery with the six extenders were comparable for
the cynomolgus and rhesus monkeys. There was no significant difference
in sperm motility and head membrane integrity among the six extenders
in either the cynomolgus or rhesus monkeys (P40.05). However, a
slightly but statistically lower percentage of acrosomal integrity was found
with TCG in both species compared to the other extenders (Po0.05).
These findings demonstrate that TTE, DM, mDM, LG-DM, G-DM, and
TCG are equally suitable extenders for the cryopreservation of
spermatozoa from cynomolgus and rhesus monkeys. Am. J. Primatol.
68:39–49, 2006.
r 2006 Wiley-Liss, Inc.
Key words: extender; cryopreservation; Macaca fascicularis; Macaca
mulatta
Contract grant sponsor: Ministry of Science and Technology of China; Contract grant number:
2001 DEA10009-09; Contract grant sponsor: Major State Research Development Program; Contract
grant number: G200016108; Contract grant sponsor: Chinese Academy of Sciences; Contract grant
number: KSCX1-05; Contract grant sponsor: China National Science Foundation; Contract
grant number: 30370166; Contract grant sponsor: Chinese-Hungarian Bilateral Scientific and
Technological Collaboration; Contract grant number: TET-CHN10/03.
Yahui Li and Kejun Cai contributed equally to this work.
n
Correspondence to: Weizhi Ji, Kunming Institute of Zoology, Chinese Academy of Sciences, 32
Jiaochang Donglu, Kunming, Yunnan 650223, China. E-mail: wji@mail.kiz.ac.cn
Received 27 January 2005; revised 6, April 2005; revision accepted 7 April 2005
DOI 10.1002/ajp.20205
Published online in Wiley InterScience (www.interscience.wiley.com).
r 2006 Wiley-Liss, Inc.
40 / Li et al.
INTRODUCTION
The first attempt to cryopreserve the spermatozoa of nonhuman primates
can be traced back to 1966 [Sadleir, 1966], and to date the spermatozoa of 15
primate species [Morrell & Hodges, 1998; Roussel & Austin, 1967; Si et al., 2000]
have been frozen. However, cryopreservation efficacy varies tremendously among
laboratories. In addition to the different species used, the extender type and
freezing method also differ among previous studies, which may be the major
reasons for the variable results reported in those studies. In general, three
freezing methods (i.e., straw freezing, pellet freezing, and programmed freezing)
are commonly used for sperm cryopreservation [Morrell & Hodges, 1998].
Because it offers easy handling and relatively lower expenses, straw freezing has
been widely used for sperm cryopreservation in many nonhuman primate species
[Conradie et al., 1994; Morrell, 1997; Sankai et al., 1994; Tollner et al., 1990]. In
our laboratory, this method has been used for sperm freezing in rhesus and
cynomolgus monkeys [Li et al., 2003, 2005; Si et al., 2000, 2004], with satisfactory
and reproducible results.
The cryoprotective extender used is another important factor that affects
sperm cryosurvival. According to published results, at least 21 types of extenders
have been used for sperm freezing in nonhuman primates [Chen et al., 1994;
Feradis et al., 2001; Gould & Styperek, 1989; Morrell & Hodges, 1998]; however,
very few results have been published comparing at least two different extenders
[Chen et al., 1994; Leverage et al., 1972; Sadleir, 1966; Si et al., 2000; Tollner
et al., 1990], and only one study has compared four extenders [Chen et al., 1994].
To date, a comparison of the efficiency of sperm freezing between different
primate species with the same extender has not been published.
In the present comparative study, the effects of six extenders (TTE, DM,
mDM, LG-DM, G-DM, and TCG) on sperm cryopreservation in cynomolgus and
rhesus monkeys were studied with straw freezing and glycerol used as the
cryoprotectant.
MATERIALS AND METHODS
All chemicals were obtained from Sigma Chemical Co. (St. Louis, MO) unless
indicated otherwise.
Media Preparation
The composition of the extenders and the concentrations of glycerol used are
presented in Table I.
The extender was prepared as follows: Fresh chicken eggs that had been laid
within 8 hr were purchased from a hennery. The egg yolks were obtained
according to the procedure of Si et al. [2000]. For TCG preparation, the egg yolks
were first mixed with portion of Milli-Q water, and then the mixture was
centrifuged at 7,000g for 1 hr at 41C to sediment the yolk granules. The
supernatants were extracted and the remaining components were dissolved in
water complemented accordingly and mixed with the extracted egg yolk. For the
other extenders, after all of the ingredients were dissolved in Milli-Q water, the
egg yolk was added and mixed thoroughly. The solutions were then separated
from the yolk granules through centrifugation at 7,000g for 1 hr. The
supernatants were adjusted to pH 7.0–7.2 with 1 N NaOH or HCl when needed,
and the extenders were divided into 4-ml aliquots and stored at 301C for no
more than 2 weeks. Before the experiments were conducted, the extenders were
Am. J. Primatol. DOI 10.1002/ajp
Six Extenders for Cryopreservation / 41
TABLE I. Extender Composition (g/100 ml) and the Corresponding Glycerol Concentration
(v/v for Glycerol and Egg Yolk)
Component
Tes
Tris
Lactose
Glucose
Raffinose
Pencillin G
Streptomycin (sulfate)
Egg Yolk
Citric Acid-H2O
pH
Glycerol (v/v, %)*
TTE
DM
mDM
LG-DM
G-DM
TCG
1.2
0.2
2.0
2.0
0.2
6.32 mg
5.0 mg
20 ml
–
7.0–7.2
5%
–
–
11.0
–
–
6.32 mg
5.0 mg
20 ml
–
7.0–7.2
4%
–
–
10.0
1.0
–
6.32 mg
5.0 mg
10 ml
–
7.0–7.2
4%
–
–
5.5
2.75
–
6.32 mg
5.0 mg
10 ml
–
7.0–7.2
4%
–
–
–
5.5
–
6.32 mg
5.0 mg
10 ml
–
7.0–7.2
4%
–
3.63
–
0.5
–
6.32 mg
5.0 mg
20 ml
2.0
7.0–7.2
5%
*Final concentration.
thawed in a 371C water bath. The freezing extenders were prepared by the
addition of glycerol to the extenders.
Semen Collection
Four sexually mature male cynomolgus monkeys and four rhesus monkeys
(5–11 years old) were provided by the Laboratory Animal Center of the Kunming
Institute of Zoology. The animals were individually caged with lights on from 0600
to 1800 hr at a temperature of 20–251C. Each animal was anesthetized with 5 mg
ketamine hydrochloride (Xingang Co. Shanghai, China) per kg body weight i.m.,
and stimulated by means of a penile electro-ejaculation procedure developed in our
laboratory [Yang et al., 1994]. The semen was collected into a disposable plastic test
tube containing 2 ml of prewarmed TALP-Hepes [Bavister et al., 1983]. The diluted
semen was kept in a 371C water bath for 30 min to allow the clot to liquefy. After
liquefaction was completed, the semen was transferred into a 15-ml disposable
plastic tube. A small sample was taken to examine sperm motility and head
membrane and acrosomal integrity (see below). The rest of the samples were
washed twice with 9 volumes of TALP-Hepes and centrifuged at 200g for 10 min.
The supernatant was aspirated and the sperm pellet was dispersed and mixed with
a Pasteur pipette before it was frozen. The volume and concentration of the sperm
were determined, and only ejaculates with a concentration of 2.0–4.0 109 sperm/
ml and containing Z70% motile spermatozoa were used for freezing.
Sperm Freezing and Thawing
The washed spermatozoa were divided into six portions before they were
frozen. The procedure for sperm freezing followed that described by Sankai et al.
[1994]. Briefly, each portion of spermatozoa was diluted with one of the six
extenders without glycerol and kept at 41C (in a water bath) for 2 hr. An equal
volume of precooled (41C) corresponding extender containing glycerol was added
stepwise (five times) at intervals of 6–7 min within 30 min. The spermatozoa were
equilibrated in extender containing glycerol at 41C for another 30 min. Just before
the end of equilibration, the spermatozoa were drawn into 0.25-ml plastic straws
(IMV, L’Aigle, France), sealed with a straw heater (Tew Impulse Sealer, Tish-200;
Tew Electric Heating Equipment Co. Ltd., Taiwan, R.O.C.). After that, the straws
were placed horizontally on a rack 5 cm above the surface of liquid nitrogen and
Am. J. Primatol. DOI 10.1002/ajp
42 / Li et al.
frozen. Ten minutes later they were submerged directly into liquid nitrogen (LN2)
for storage. After they were stored in LN2 for more than 7 days, the straws
containing frozen spermatozoa were put into a 371C water bath for 2 min to thaw.
Examination of Sperm Motility and Motility Recovery
Sperm motility
Using a prewarmed hemocytometer counting chamber, we assessed the
sperm samples for percentage of progressive forward motility by counting 200
spermatozoa, in duplicate. This evaluation was conducted by an operator who did
not know the identity of the sperm samples offered.
Sperm motility recovery rate
We calculated the sperm motility recovery rate by comparing the motility of
pre-freeze (Mpr) and post-thaw (Mps) spermatozoa. If Mpr and Mps are the sperm
motility percentages before and after freezing, then the recovery rate would be
Mps/Mpr 100%.
Examination of Sperm Head Membrane and Acrosomal Integrity
Sperm head membrane integrity
We measured sperm head membrane integrity by means of a dual DNA
staining technique using Hoechst 33342 (H342) and propidium iodide (PI), with
flow cytometry and simultaneous excitation by a single UV laser. Briefly, a 6-ml
volume of H342 (1 mg/ml) and an 8-ml volume of PI (1 mg/ml) were added to each
sperm sample (1 ml). Each sperm suspension was mixed three times by gentle
pipetting, and was then incubated in a 371C water bath for 15 min. After
incubation, all samples were processed for flow cytometric analysis.
Sperm acrosomal integrity
Acrosome status was determined by means of fluorescein isothiocyanateconjugated peanut agglutinin (FITC-PNA) and the acrosome staining process
described by Esteves et al. [2000]. Under a fluorescence microscope, spermatozoa
with intact acrosome showed uniform apple-green fluorescence in the acrosomal
region of the sperm head, while acrosome-reacted spermatozoa showed little or no
green fluorescence in the equatorial segment of the acrosome. A minimum of 200
spermatozoa were counted for each sample.
Statistical Analysis
Ten ejaculates (two to three ejaculates per male) for cynomolgus and rhesus
monkeys, respectively, were studied, and the experiments were conducted with
n = 10 replicates for one species.
All data are expressed as the mean7SD. Data regarding sperm motility and
head membrane/acrosomal integrity were subjected to arcsine square root
transformation and analyzed by analysis of variance (ANOVA) and Fisher’s
protected least significant difference (LSD) test. Values of Po0.05 were
considered statistically significant. Data regarding the recovery rate for sperm
motility and head membrane/acrosomal integrity in the cynomolgus and rhesus
monkeys were subjected to arcsine square root transformation and analyzed by
means of a paired samples test (t-test). Values of Po0.05 were considered
statistically significant.
Am. J. Primatol. DOI 10.1002/ajp
Six Extenders for Cryopreservation / 43
RESULTS
Sperm Cryopreservation in Cynomolgus Monkeys
Post-thaw sperm motility and motility recovery rate for cynomolgus monkey
spermatozoa
As shown in Table II, the sperm motility and motility recovery rate with six
extenders for cynomolgus monkey sperm were 47.79–50.03% and 61.22–63.94%,
respectively. However, there was no significant difference for sperm motility and
motility recovery among all groups (P40.05).
Sperm head membrane integrity of cynomolgus monkey spermatozoa
As shown in Fig. 1, each extender provided a similar level of protection for
sperm head membrane integrity in the cynomolgus monkeys (P40.05).
Acrosomal integrity of cynomolgus monkey spermatozoa
As shown in Fig. 2, the percentages of acrosomal integrity for cynomolgus
monkey sperm were similar for TTE, DM, mDM, LG-DM, and G-DM (P40.05).
TABLE II. Post-thaw Sperm Motility and Motility Recovery Rate for Cynomolgus Monkey
Spermatozoa Cryopreserved in Six Extenders
Cryoprotective
extender
Pre-freeze sperm
motility (%)
TTE
DM
mDM
LG-DM
G-DM
TCG
Motility recovery
rate (%)a
48.7476.90
49.0075.53
49.1477.99
48.8476.48
47.7976.10
50.0376.78
62.3676.28
62.8275.19
62.7476.72
62.5676.31
61.2275.57
63.9475.15
78.0977.37
Values within a column are not significantly different (P40.05).
head membrane integrity (%)
a
Post-thaw sperm
motility (%)a
60
40
20
0
TTE
DM
mDM
LG-DM
G-DM
TCG
extender type
Fig. 1. Proportion of sperm head membrane integrity of cynomolgus monkey spermatozoa after
cryopreservation in six different extenders (P40.05).
Am. J. Primatol. DOI 10.1002/ajp
44 / Li et al.
100
*
acrosomal integrity
80
60
40
20
0
TTE
DM
mDM
LG-DM
G-DM
TCG
extender type
Fig. 2. Proportion of acrosomal integrity of cynomolgus monkey spermatozoa after cryopreservation
in six different extenders. nIndicates significant difference (Po0.05) compared to other values.
TABLE III. Post-thaw Sperm Motility and Motility Recovery Rate for Rhesus Monkey
Spermatozoa Cryopreserved in Six Extenders
Cryoprotective
extender
TTE
DM
mDM
LG-DM
G-DM
TCG
a
Pre-freeze sperm
motility (%)
74.4173.35
Post-thaw sperm
motility (%)a
Motility recovery
rate (%)a
44.8572.97
44.4274.08
44.0472.76
45.0172.90
43.8673.64
44.6973.23
60.2471.76
59.6173.13
59.1571.66
60.4672.03
58.8872.85
60.0272.54
Values within a column are not significantly different (P40.05).
TCG gave a slightly but significantly lower acrosomal integrity than other groups
(Po0.05).
Sperm Cryopreservation in Rhesus Monkeys
Post-thaw sperm motility and motility recovery rate for rhesus monkey
spermatozoa
As shown in Table III, the sperm motility and motility recovery rates for the
rhesus monkeys were 43.86–45.01% and 58.88–60.46%, respectively. There was
no statistical difference in sperm motility and motility recovery among all groups
(P40.05).
Sperm head membrane integrity of rhesus monkey spermatozoa
As shown in Fig. 3, no significant differences were found for sperm head
membrane integrity among all of the groups (P40.05).
Am. J. Primatol. DOI 10.1002/ajp
head membrane integrity (%)
Six Extenders for Cryopreservation / 45
60
40
20
0
TTE
DM
mDM
LG-DM
G-DM
TCG
extender type
acrosomal integrity (%)
Fig. 3. Proportion of sperm head membrane integrity of rhesus monkey spermatozoa after
cryopreservation in six different extenders (P40.05).
*
TTE
DM
mDM
LG-DM
G-DM
TCG
extender type
Fig. 4. Proportion of acrosomal integrity of rhesus monkey spermatozoa after cryopreservation in
six different extenders. nIndicates significant difference (Po0.05) compared to other values.
Acrosomal integrity of rhesus monkey spermatozoa
As shown in Fig. 4, similarly to the results for the cynomolgus monkeys, the
acrosomal integrity values for rhesus monkey sperm with TTE, DM, mDM, LGDM, and G-DM were similar (P40.05). TCG exhibited a lower percentage of
acrosomal integrity than the other treatments (Po0.05).
Comparison of Effects of Extenders on Sperm Motility Following
Cryopreservation in Cynomolgus and Rhesus Monkeys
Sperm motility recovery rates for cynomolgus and rhesus monkeys
As shown in Fig. 5, no significant difference was found in sperm motility
recovery for each extender between the cynomolgus and rhesus monkeys
(P40.05).
Am. J. Primatol. DOI 10.1002/ajp
46 / Li et al.
sperm motility recovery (%)
cynomolgus monkey
rhesus monkey
80
60
40
20
0
TTE
DM
mDM
LG-DM
G-DM
TCG
extender type
Fig. 5. Proportion of sperm motility recovery rates of cynomolgus and rhesus monkey spermatozoa
with six different extenders (P40.05).
head membrane integrity
recovery (%)
cynomolgus monkey
rhesus monkey
80
60
40
20
0
TTE
DM
mDM
LG–DM
G–DM
TCG
extender type
Fig. 6. Proportion of sperm head membrane integrity recovery of cynomolgus and rhesus monkey
spermatozoa with six different extenders (P40.05).
Sperm head membrane integrity recovery for cynomolgus and rhesus monkeys
As shown in Fig. 6, each extender exhibited similar cryoprotection values for
the head membrane between the cynomolgus and rhesus monkeys (P40.05).
Sperm acrosome integrity recovery for cynomolgus and rhesus monkeys
As shown in Fig. 7, the acrosomal cryoprotection values for each extender
were similar in both species, and the acrosomal integrity with TCG was
significantly lower (Po0.05) compared to other extenders in both the cynomolgus
and rhesus monkeys.
Am. J. Primatol. DOI 10.1002/ajp
Six Extenders for Cryopreservation / 47
acrosomal integrity recovery (%)
cynomolgus monkey
rhesus monkey
100
* *
80
60
40
20
0
TTE
DM
mDM
LG-DM
G-DM
TCG
extender type
Fig. 7. Proportion of sperm acrosomal integrity recovery of cynomolgus and rhesus monkey
spermatozoa with six different extenders. nIndicates significant difference (Po0.05) compared to
other values.
DISCUSSION
The composition of the extender plays a key role in sperm cryopreservation.
The six extenders studied in our experiments have been employed, separately or
in combination, in earlier research on nonhuman primates. Previous studies
obtained satisfactory results for TTE in cynomolgus [Li et al., 2003, 2005; Sankai
et al., 1994] and rhesus [Si et al., 2000] monkeys, DM in cynomolgus monkeys
[Mahone & Dukelow, 1978] and Tibetan macaques [Chen et al., 1994], mDM in
Tibetan macaques [Chen et al., 1994], TCG in rhesus monkeys [Sanchez-Partida
et al., 2000], and LG-DM and G-DM in cynomolgus monkeys (our laboratory,
unpublished results). In a recent study, Li et al. [2005] compared the
cryoprotective efficiencies of 11 extenders for sperm cryopreservation in
cynomolgus monkeys and discovered that TTE, DM, mDM LG-DM, G-DM, and
TCG were the best of the extenders studied. Frozen-thawed sperm motility was
around Z45% for the six extenders in these previous studies; however, there were
differences among the studies in the species and freezing methods used. However,
no direct intra- and interspecies comparison for sperm freezing with most of these
six extenders has been made. In the present study, the results show that the six
extenders (TTE, DM, mDM, LG-DM, G-DM, and TCG) provided good cryoprotection during sperm freezing in the cynomolgus and rhesus monkeys, and no
significant differences in efficacy were found for each of the extenders between
the cynomolgus and rhesus monkeys.
The component in DM, mDM, LG-DM, or G-DM is simpler than that of TCG
or TTE, and it is easier to prepare these four extenders. However, unlike TCG
and TTE, no pH buffer is used in DM, mDM, LG-DM, or G-DM, and one should be
very careful to adjust the pH when preparing the latter four extenders.
Sanchez-Partida et al. [2000] reported that four progeny of rhesus monkeys
had been produced with spermatozoa cryopreserved in TCG-glycerol. In that
study, the post-thaw sperm acrosomal integrity and the corresponding recovery
Am. J. Primatol. DOI 10.1002/ajp
48 / Li et al.
rate were 75% vs. 79.94%, respectively. Those findings are consistent with our
results for frozen-thawed sperm acrosomal integrity and its recovery, since the
corresponding values for TCG are 75.56% vs. 82.16% for cynomolgus monkey, and
75.61% vs. 82.05% for rhesus monkey. However, the post-thaw sperm motility in
the present study with TCG for cynomolgus and rhesus monkeys were 50.03%
and 44.69%, respectively, which are much lower than the 85.0% reported by
Sanchez-Partida et al. [2000]. They also found a higher sperm motility compared
to that observed by Leverage et al. [1972], which they ascribed to the different
freezing rates (1001C/min by pellet freezing vs. 1701C/min by straw freezing) used
in rhesus monkeys. According to Morrell & Hodges [1998], the freezing rates for
pellet freezing and straw freezing are 8–271C/min and 10–251C/min, respectively.
In a comparison of the effects of three freezing rates (i.e., pellet freezing, straw
freezing, and programmed freezing) on the cryopreservation of marmoset sperm,
Morrell [1997] found that there was no difference among the methods. The cause
of the major difference in sperm motility reported by Morrell [1997] and SanchezPartida et al. [2000] needs to be investigated further.
An interesting finding of the present study is that spermatozoa cryopreserved
with TCG, whether for the cynomolgus or rhesus monkeys, moved much faster
than that of other extenders, and this rapid sperm movement is similar to that of
spermatozoa being capacitated. Additionally, the percentage of acrosomal
integrity for TCG was lower than that of other extenders (Po0.05), while the
rates of sperm motility and membrane integrity for spermatozoa cryopreserved
with all of the extenders did not differ from each other (P40.05). This result
suggests that spermatozoa cryopreserved with TCG are more easily capacitated
and reacted acrosomally compared to other extenders.
The mechanism behind the sperm cryoprotection offered by the six extenders
remains unclear. These extenders have some characteristics in common: Each
extender contains sugar(s), mainly glucose and/or lactose. These sugars are
believed to be beneficial for sperm cryopreservation because of their ability to
stabilize membrane structures, adjust osmolality, assist in dehydration to avoid
ice crystal formation, and act as metabolites to provide energy for spermatozoa
[Yildiz et al., 2000]. The cryosolutions also contain 4–5% glycerol, which has been
reported as optimal for the spermatozoa of cynomolgus [Sankai et al., 1994] and
rhesus [Si et al., 2004] monkeys. The osmolalities for all of the six extenders are
344–425 mOsm, which are well tolerated by monkey spermatozoa. In addition, the
extenders contain no salt ions, which can be deleterious to sperm cells when these
cells are frozen in concentrated ion extenders [An et al., 2000].
In conclusion, when straw freezing is used, TTE, DM, mDM, LG-DM, G-DM,
and TCG are all suitable extenders with similar efficacy for sperm cryopreservation in both cynomolgus and rhesus monkeys. These results raise the hope that a
single suitable extender can be developed as part of a universal protocol for
freezing nonhuman primate sperm.
REFERENCES
An TZ, Iwakiri M, Edashige K, Sakurai T,
Kasai M. 2000. Factors affecting the
survival of frozen-thawed mouse spermatozoa. Cryobiology 40:237–249.
Bavister BD, Leibfried ML, Lieberman G.
1983. Development of preimplantation
embryos of the golden hamster in a
Am. J. Primatol. DOI 10.1002/ajp
defined culture medium. Biol Reprod 28:
235–247.
Chen JC, Ji WZ, Yang SC, Shi LM. 1994.
Semen cryopreservation in the Tibetan
macaque (Macaca thibetana)–comparison
of different cooling programs and freezing
media. Acta Zool Sin 40:174–181.
Six Extenders for Cryopreservation / 49
Conradie E, Oettle EE, Seier JV. 1994.
Assessment of acrosomal integrity of vervet monkey spermatozoa after cryopreservation. J Med Primatol 23:315–316.
Esteves SC, Sharma RK, Thomas Jr AJ,
Agarwal A. 2000. Improvement in motion
characteristics and acrosome status in
cryopreserved human spermatozoa by
swim-up processing before freezing. Hum
Reprod 15:2173–2179.
Feradis AH, Pawitri D, Suatha IK, Amin
MR, Yusuf TL, Sajuthi D, Budiarsa IN,
Hayes ES. 2001. Cryopreservation of epididymal spermatozoa collected by needle
biopsy from cynomolgus monkeys (Macaca
fascicularis). J Med Primatol 30:100–106.
Gould KG, Styperek RP. 1989. Improved
methods for freeze preservation of chimpanzee sperm. Am J Primatol 18:275–284.
Leverage WE, Valerio DA, Schultz AP,
Kingsbury E, Dorey C. 1972. Comparative
study on the freeze preservation of spermatozoa. Primate, bovine, and human.
Lab Anim Sci 22:882–889.
Li Y, Si W, Zhang X, Dinnyes A, Ji W.
2003. Effect of amino acids on cryopreservation of cynomolgus monkey (Macaca
fascicularis) sperm. Am J Primatol
59:159–165.
Li Y, Cai K, Kovacs A, Ji W. 2005. Effects of
various extenders and permeating cryoprotectants on cryopreservation of cynomolgus monkey (Macaca fascicularis)
spermatozoa. J Androl 26:387–395.
Mahone JP, Dukelow WR. 1978. Semen
preservation in Macaca fascicularis. Lab
Anim Sci 28:556–561.
Morrell JM. 1997. Cryopreservation of marmoset sperm (Callithrix jacchus). Cryo
Lett 18:45–54.
Morrell JM, Hodges JK. 1998. Cryopreservation of non-human primate sperm: priorities for future research. Anim Reprod Sci
53:43–63.
Roussel JD, Austin CR. 1967. Preservation
of primate spermatozoa by freezing.
J Reprod Fertil 13:333–335.
Sadleir RM. 1966. The preservation of
mammalian spermatozoa by freezing.
Lab Pract 15:413–417.
Sanchez-Partida LG, Maginnis G, Dominko
T, Martinovich C, McVay B, Fanton J,
Schatten G. 2000. Live rhesus offspring by
artificial insemination using fresh sperm
and cryopreserved sperm. Biol Reprod 63:
1092–1097.
Sankai T, Terao K, Yanagimachi R, Cho F,
Yoshikawa Y. 1994. Cryopreservation of
spermatozoa from cynomolgus monkeys
(Macaca fascicularis). J Reprod Fertil 101:
273–278.
Si W, Zheng P, Tang X, He X, Wang H,
Bavister BD, Ji W. 2000. Cryopreservation
of rhesus macaque (Macaca mulatta)
spermatozoa and their functional assessment by in vitro fertilization. Cryobiology
41:232–240.
Si W, Zheng P, Li Y, Dinnyes A, Ji W. 2004.
Effect of glycerol and dimethyl sulfoxide
on cryopreservation of rhesus monkey
(Macaca mulatta) sperm. Am J Primatol
62:301–306.
Tollner TL, VandeVoort CA, Overstreet JW,
Drobnis EZ. 1990. Cryopreservation of
spermatozoa from cynomolgus monkeys
(Macaca fascicularis). J Reprod Fertil 90:
347–352.
Yang Sh, Ji W, Chen J, Shang E, Zou R.
1994. The use of improved penile electroejaculation in Rhesus, Tibetan and Assamese macaques and study on the
parameters of their semen. Zool Res 15:
77–83.
Yildiz C, Kaya A, Aksoy M, Tekeli T. 2000.
Influence of sugar supplementation of the
extender on motility, viability, and acrosomal integrity of dog spermatozoa during
freezing. Theriogenology 54:579–585.
Am. J. Primatol. DOI 10.1002/ajp
Документ
Категория
Без категории
Просмотров
8
Размер файла
168 Кб
Теги
extenders, cynomolgus, fascicularis, monkey, rhesus, mulatta, comparative, macaca, six, sperm, studies, cryopreservation
1/--страниц
Пожаловаться на содержимое документа