Concerning morphological parameters

Concerning morphological parameters, only the
percentage of abnormal spermatozoa was statistically
different between male A and males N (33.60  4.12%
vs. 18.48  1.52%, for A and N respectively, Table 3).
Male A produced semen of lower sperm concentration
than the males N (66.55  22.75  106 sperm/ml vs.
171.65  9.90  106 sperm/ml, for A and N males
respectively, Table 3). Kinematic parameters, VAP,
VCL, VSL, LIN, ALH, STR, and WOB did not show
any differences between males (least square means and
contrasts are not shown in tables).
4. Discussion
To date in the rabbit species, no trials have been
reported where the level of chromosomal aneuploidy
detected from peripheral blood of adult males has been
investigated with reference to fertility or sperm
characteristics.
In this study a significant difference was found in the
incidence of aneuploidies between males and it was also
found that aneuploidy had a deleterious effect on male
reproductive performance. Semen from male A showed
reduced fertility (around 30% in fertility at birth and an
increase of 17% in pregnancy loss) compared with the
contemporary males. These results are in agreement
with those observed previously in boars where more
than 50% of all boars with reproductive problems
carried a chromosome abnormality [17]. The sperm
abnormalities from male A were higher than from the
contemporary males but while the sperm concentration
was lower in male A the other parameters did not show
any differences.
When rabbit peripheral blood lymphoid cells of
donor males were cultured for 72 h and then harvested,
differences in chromosome number between cells as
well as between males could be observed. These
intercellular differences of chromosomal content in the
same individual are defined as chromosomal mosaicism,
and some authors have reported that chromosomal
mosaicism is more likely to manifest as aneuploidy.
Studies performed specifically to reveal the real rate of
cell-to-cell chromosomal number variability have
shown that almost all tissues exhibit aneuploid cells.
However, association between chromosomal mosaicism
and a physiological alteration requires a thorough
control study of unaffected individuals [18].
Aneuploidy is generated by numerous factors
including interference with mitotic spindle dynamics,
abnormal centrosomes, duplication, altered chromosome
condensation and cohesion, defective centromeres,
and the loss of mitotic checkpoints [1]. An
important advance in the study of aneuploidy was the
discovery that many cancer cell lines exhibit chromosomal
instability, a phenotype in which cell division is
accompanied by an abnormally high rate of chromosome
loss and gain [19].
The cytogenetic analysis performed in the present
study indicates a frequency of around 5% of males
showing 16% of cultured cells with chromosomal
108 R. Lavara et al. / Theriogenology 74 (2010) 105–110
Table 2
Fertility and prolificacy.
Male type AI Fertility 12th Fertility at birth1 Pregnancy losses NT
A 54 (44%)b (31%)b (29%)a 8.11  3.10
24/54 17/54 (7/24) (17)
N 583 (66%)a (59%)a (12%)b 7.81  2.80
388/583 343/583 (45/388) (343)
Male type: altered male (A); contemporary males (N); AI: number of artificial inseminations; NT: total kids born at birth. a,b Values in the same
column with different superscripts are statistically different (P < 0.05).
Table 3
Least square means  standard error of variables in a classic spermiogram.
Male type VOL CON MOT NAR ANR
A 0.54  0.11 66.55  22.75a 63.51  8.4 72.05  8.79 33.60  4.12a
(n) (11) (11) (11) (11) (11)
N 0.59  0.04 171.65  9.90b 70.85  3.09 75.68  3.13 18.48  1.52b
(n) (80) (77) (79) (80) (80)
Male type: altered male (A); contemporary males (N); VOL: volume (ml); CON: sperm concentration (106/ml);MOT (%): percentage of total motile
sperm; NAR (%): percentage of sperm with normal apical ridge; ANR (%): percentage of abnormal sperm; a,b Values in the same column with
different superscripts are statistically different (P < 0.05). (n): number of ejaculates

ผลลัพธ์ (อังกฤษ) 1:

Concerning morphological parameters, only thepercentage of abnormal spermatozoa was statisticallydifferent between male A and males N (33.60 4.12%vs. 18.48 1.52%, for A and N respectively, Table 3).Male A produced semen of lower sperm concentrationthan the males N (66.55 22.75 106 sperm/ml vs.171.65 9.90 106 sperm/ml, for A and N malesrespectively, Table 3). Kinematic parameters, VAP,VCL, VSL, LIN, ALH, STR, and WOB did not showany differences between males (least square means andcontrasts are not shown in tables).4. DiscussionTo date in the rabbit species, no trials have beenreported where the level of chromosomal aneuploidydetected from peripheral blood of adult males has beeninvestigated with reference to fertility or spermcharacteristics.In this study a significant difference was found in theincidence of aneuploidies between males and it was alsofound that aneuploidy had a deleterious effect on malereproductive performance. Semen from male A showedreduced fertility (around 30% in fertility at birth and anincrease of 17% in pregnancy loss) compared with thecontemporary males. These results are in agreementwith those observed previously in boars where morethan 50% of all boars with reproductive problemscarried a chromosome abnormality [17]. The spermabnormalities from male A were higher than from thecontemporary males but while the sperm concentrationwas lower in male A the other parameters did not showany differences.When rabbit peripheral blood lymphoid cells ofdonor males were cultured for 72 h and then harvested,differences in chromosome number between cells aswell as between males could be observed. Theseintercellular differences of chromosomal content in thesame individual are defined as chromosomal mosaicism,and some authors have reported that chromosomalmosaicism is more likely to manifest as aneuploidy.Studies performed specifically to reveal the real rate ofcell-to-cell chromosomal number variability haveshown that almost all tissues exhibit aneuploid cells.However, association between chromosomal mosaicismand a physiological alteration requires a thoroughcontrol study of unaffected individuals [18].Aneuploidy is generated by numerous factorsincluding interference with mitotic spindle dynamics,abnormal centrosomes, duplication, altered chromosomecondensation and cohesion, defective centromeres,and the loss of mitotic checkpoints [1]. Animportant advance in the study of aneuploidy was thediscovery that many cancer cell lines exhibit chromosomalinstability, a phenotype in which cell division isaccompanied by an abnormally high rate of chromosomeloss and gain [19].The cytogenetic analysis performed in the presentstudy indicates a frequency of around 5% of malesshowing 16% of cultured cells with chromosomal108 R. Lavara et al. / Theriogenology 74 (2010) 105–110Table 2Fertility and prolificacy.Male type AI Fertility 12th Fertility at birth1 Pregnancy losses NTA 54 (44%)b (31%)b (29%)a 8.11 3.1024/17/54 54 (7/24) (17)N 583 (66%)a (59%)a (12%)b 7.81 2.80343/388/583 583 (45/388) (343)Male type: altered male (A); contemporary males (N); AI: number of artificial inseminations; NT: total kids born at birth. a,b Values in the samecolumn with different superscripts are statistically different (P < 0.05).Table 3Least square means standard error of variables in a classic spermiogram.Male type VOL CON MOT NAR ANRA 0.54 0.11 66.55 22.75a 63.51 8.4 72.05 8.79 33.60 4.12a(n) (11) (11) (11) (11) (11)N 0.59 0.04 171.65 9.90b 70.85 3.09 75.68 3.13 18.48 1.52b(n) (80) (77) (79) (80) (80)Male type: altered male (A); contemporary males (N); VOL: volume (ml); CON: sperm concentration (106/ml);MOT (%): percentage of total motilesperm; NAR (%): percentage of sperm with normal apical ridge; ANR (%): percentage of abnormal sperm; a,b Values in the same column withdifferent superscripts are statistically different (P < 0.05). (n): number of ejaculates