- Genetics Selection Evolution

NOTE
Chromosome constitution of a hybrid between East African
Buffalo (Syncerus caffer caffer) and Dwarf Forest Buffalo
(Syncerus caffer nanus)
E. P. CRIBIU
C. P. POPESCU
Jeanine
BOSCHER
Laboratoire de Cytogénétique UNGEIA-LN.R.A.,
Centre national de Recherches zootechniques, LN.R.A.,
.,
F 7835
0 Jouy-en-Josas (Prance)
Summary
The chromosome constitution of a male hybrid of first backcross between a female Fi
X Dwarf African Buffalo (Syncerus cafler cagey X Syncerus catfer nanus) and a
male Dwarf Forest Buffalo (Syncerus cagey nanus) had a chromosome number of 53
: zi acrocentric pairs, 2 unpaired acrocentrics, 3 meta-submetacentric pairs, I unpaired submetacentric
and I acrocentric XY sex chromosome pair. The R-banding pattern shows that the chromosomic difference between the subspecies catfer (
) and nanus (2n ! 52
n 54
2
) is due to a centric
fusion between two acrocentric pairs.
East African
=
Karyotypes of the two subspecies of African Buffalo, East African (Syncerus
cage y
7
ca f e and Dwarf Forest (Syncevus caffer nanus), have already been described
)
K
et
BRICH and HER
r
HKE 7
C
NIRS
BE
SO 1967 and HEC
I
F
,
g6 Ur
I
;
R and ,
’
F
T
URS
(W
al., 19
68).
The Dwarf Forest type had 5
4 chromosomes, among which 3 autosomal
were meta-submetacentric and 23 were acrocentric, with the X and Y
acrocentric. When compared to the karyotype of Dwarf Forest Buffalo,
the East African Buffalo demonstrated 52 chromosomes with one submetacentric
pair instead of two acrocentric pairs.
The present report describes the chromosome constitution of a male hybrid
I and a male Dwarf Forest Buffalo. The
of first backcross between a female F
animal (N! 1
) born in 19
9
5
6
9 and kept in Pare Zoologique de Paris, was slaugh6
pairs
being
tered in
It has recently been included in a study for heredity of
by l,auv!xGN! and R!ErrvoisE (ig8o).
For chromosome observations, a blood sample was obtained from the jugular
vein and cultivated according to the method of D
E GROUCHY et al. (ig6
); R¢
UTRILLAUX
et al. (z
banding was achieved by the technique of D
).
973
The number of chromosomes in the hybrid is 53
, among which a submetacentric and two acrocentrics are not paired.
All other chromosome pairs are
homomorphic except the XY sex chromosome pair. Two acrocentric pairs exhibit
April 19
.
0
8
coat colour variation
large small
arms
(fig.
i,
a).
By using R-banding technique, all chromosome pairs could be identified.
R-banding pattern of ! and q arms of the unpaired submetacentric chromosome
is characteristic of the two unpaired acrocentric autosomes (fig. I
, b).
It is obvious that the unpaired submetacentric chromosome originated from
the East African type whereas the two unpaired acrocentric autosomes were
derived from the Dwarf Forest type.
In regard to the karyotype evolution of the two subspecies of African Buffalo,
it could be suggested that the Dwarf type with 2
n
54 occured first and during
evolution, the East African type should have developed by Robertsonian fusion
of two acrocentric pairs.
Received for publication in novembe
y ig8o.
=
Résumé
Le
caryotype
d’un
hybride entre le Buffle Africain (Syncerus
Bu!e nain (Syncerus caffer nanus)
caffer
caffer)
et le
Le caryotype d’un mâle, produit de croisement de retour d’une femelle hybride Fi Buffle
Africain X Buffle nain (Syncevus ca
fer caffer X Syncevus caffer nanus) et d’un Buffle nain mâle
f
(Syncerus ca
fer nanus) est composé de 53 chromosomes : zrpaires acrocentriques, 2 chromosomes
f
non appariés, 3 paires méta-submétacentriques, i chromosome submétacentrique
chromosomes sexuels X et Y acrocentriques. Le marquage R a montré que la différence
de caryotype de ces deux sous-espèce est due à une fusion centrique entre deux paires de chro-
acrocentriques
et
2
mosomes
acrocentriques.
References
J., Rouairr M., PASSAGE ?;., 19
. Microtechnique pour 1’6tude des chromo4
6
humains à partir d’une culture de leucocytes sanguins. Ann. Genet., 7, q
.
5
O
C
U
T
R
RI
U J., ZaEJ!uN! J., 1973
RILL
T
U
D
U
A
X B., E
AUR M., E
L
T
N
. Coloration pour 1’acridi!le
orange de chromosome préalablement trait6s par le 5 bromodeoxyuridine (B.U.D.R.). C. R.
Acad. Sci. (Paris), 276, 8
31
3179
.
1
HECK H. D., WuRS2!x D. H., E
CHK K., 19
S
NIR
BE
68. Chromosome study of numbers of the
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Saiigetievk, 33, 172
-179.
E J. J., RBNVOISB C., 19
N
G
R
LnuvE
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0
8
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7
CH M., 19
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Ur.sxicx F., E
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7
6
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UR D. H., E
W
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STE
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6DE GROUCHY
somes