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CHANGES OF CHROMOSOMES DURING THE EARLY NEURAL DEVELOPMENT OF A JAPANESE NEWT, CYNOPS PYRRHOGASTER
Author(s) -
YAMAMOTO KIYOKO YAMAZAKI,
YAMAZAKI KIMIE,
KATO YOSHIHIRO
Publication year - 1980
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1980.00079.x
Subject(s) - biology , chromosome , ploidy , gastrulation , karyotype , mitosis , anatomy , embryo , genetics , embryogenesis , gene
The karyotype of Cynops pyrrhogaster was determined on the mitotic chromosomes in the presumptive neural area of an early gastrula. 24 chromosomes of a diploid set consisted of 8 metacentric and 4 submetacentric pairs. Individual chromosomes were identified on the basis of their morphology and characteristic C‐binding patterns. Sex chromosomes were not identified. Total length of the haploid chromosome set in the presumptive neural area decreased remarkably from morulae to gastrulae, further continued to decrease up to neurulae and thereafter remained unchanged till tail‐buds. Chromosome shortening occurring from morulae to gastrulae was accompanied with a prominent decrease in chromosome volume, keeping chromosome width constant. Shortening took place evenly along the longitudinal axis of a chromosome. When gastrulae and neurulae were compared concerning their positions of the appearance of the C‐bands, the basic pattern remained unchanged. In certain chromosomes, the number of C‐bands decreased as the result of their fusion, as gastrulae proceeded to neurulae.