Abstract INTRODUCTION WHILE many cytological studies of the chicken have been conducted, disagreement concerning the karyotype remains. Differences as to which are true chromosomes have contributed to the disagreement regarding the total number of chromosomes in Gallus domesticus. Newcomer (1957) proposed that only those he considered as the macrochromosomes, 11 for the female and 12 for the male, be the accepted number for the chicken. Other investigators (Ford and Wollam, 1964; Krishan, 1962; Ohno, 1961; Owen, 1965; Van Brink and Ubbels, 1956; Yamashina, 1944) considered all the chromatin elements as true chromosomes. A diploid number of 78 was reported as early as 1944 by Yamashina, but Ford and Wollam (1964) found 40 bivalents in male gonadal tissue, suggesting the possibility of a diploid number of 80. It appears that solutions to many of the problems encountered in cytological investigations will be found by using improved techniques and equipment. In this investigation …
[1]
R. Borland.
THE CHROMOSOMES OF DOMESTIC SHEEP.
,
1964,
Journal of Heredity.
[2]
E. H. Newcomer.
THE MITOTIC CHROMOSOMES OF THE DOMESTIC FOWL
,
1957
.
[3]
E. Newcomer.
A new cytological and nistological fixing fluid.
,
1953,
Science.
[4]
E. H. Newcomer.
Handling avian chromosomes.
,
1952,
Stain technology.
[5]
M. Yamashina.
Karyotype Studies in Birds
,
1944
.
[6]
C. D. Darlington,et al.
The Handling of Chromosomes
,
1942
.
[7]
A. Krishan,et al.
Sex chromosomes in the domestic fowl (Gallus domesticus), turkey (Meleagris gallopavo) and the Chinese pheasant (Phasianus colchicus).
,
1966,
Cytogenetics.
[8]
W. Schmid.
DNA replication patterns of the heterochromosomes in Gallus domesticus.
,
1962,
Cytogenetics.