The karyology of birds is less developed in comparison, for example with
mammalian karyology. From 17 existing penguin species only 3 species were
karyotyped (humbolt's, ostrich and jackass penguins).
Low number of studied karyotypes of penguin species dependents on the one hand
with problems of samples collecting, and to another - with common features of
karyotypes of birds.
Birds karyotypes have conservative structure: thay have similar high diploid
numbers and two conditional classes of chromosomes: macrochromosomes and
microchromosome. The presence of microchromosomes complicates detailed analysis
of karyotypes, ascertainment exact diploid numbers. Therefore, investigators
frequently are limited to analysis macrochromosomes, which have similar
morphology (especially first three couples) for the majority of the
representatives of the class. Diploid number of chromosome of studyed species of
penguins varies in range 70-80, first three couples of macrochromosomes have
typical morphology for the majority of birds species.
It is not present sufficient data about a structural of macrochromosomes and
quantitative polymorphism of microchromosomes. For study of polymorphism it is
necessary to analyze karyotypes enough plenty individuals, but majority of the
explorers are limited to one or two animals. Meanwhile, it is possible to
explain some discrepancy between the authors at the description of karyotypes of
the representatives of one species (discrepancy in diploid numbers, description
of morphology of macrochromosomes) not only methodical or different
interpretation of morphological types of chromosomes, but also interpopulation
distinctions. It is not known, whether have different subspecies of penguins
karyologycal differences (for example by quantityof microchromosomes).
In addition to karyologycal analysis for obtaining of the information about
interpopulation differences it is possible to apply analysis of cytogenetic
manifestations of genome instability. In this case we can obtain the data about
fastness of a genome of representatives of various birds populations to
conditions of habitation.
The cytogenetic approaches can allow to obtain highly informative data
concerning differences between various systematical groups of birds. However,
significant elaboration of the approaches is required, especial for penguins.
An authors express one's thanks to the INTAS for support of this research (INTAS project 01-0517).
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