The effects of 234 X-chromosomes, found in males from a natural population of Drosophila melanogaster, were studied in homozygous females obtained by means of suitable crosses in the laboratory. Males carrying these chromosomes in hemizygous condition are fertile and at least fairly normally viable. One of these chromosomes was nevertheless completely lethal in homozygous females, three were semilethal, ten were clearly subvital, and six made the homozygous females sterile. The frequency of X-chromosomes with major deleterious sex-limited effects is, thus, about 8.5 per cent. There is evidence that some additional chromosomes produce less extreme subvital sex-limited effects. The natural population studied obviously carries a not inconsiderable genetic load in its X-chromosomes.
No takes yet. Share an insight, caveat, or question.
W. Drescher (1964) studied this question.
Synapse has enriched 4 closely related papers on similar clinical questions. Consider them for comparative context: