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The chromosomes in the maturation of the germ cells of two species of triclad Turbellarians
Author(s) -
Pennypacker Miriam I.
Publication year - 1938
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.1050630302
Subject(s) - biology , chromatid , ploidy , chromosome , karyotype , genetics , b chromosome , germ , meiosis , mitosis , chromatin , prophase , haematoxylin , chromosome number , zoology , staining , microbiology and biotechnology , dna , gene
The maturation of the germ cells of the two hermaphroditic species, Curtisia foremanii (Girard) and Bdelloura candida (Girard) has supplied the material for this chromosome study. Both species of flatworms are believed by the author to possess a diploid number of twelve chromosomes and a haploid number of six, although Curtisia foremanii has previously been reported as having a smaller and variable number of chromosomes. A tendency of the chromatids comprising individual chromosomes to separate from one another at certain times was noted in both species. This action results in giving the appearance of a larger number of chromosomes than the germ cells actually possess. A further source of apparent increase in chromosome number in the Curtisia oocytes, after treatment with the usual Allen's B 3 and B 15 and Heidenhain's iron haematoxylin, is the presence of some deeply staining, non‐chromatin material. No significant differences in number, form and behavior of chromosomes of male and female complexes were noted, with the possible exception of the tendency of the chromatids to separate from one another, to be greater in the female than in male germ cells.