Difference in Chromosome Lengths between Male and Female Sheep

Abstract

A STUDY of the lengths of the chromosomes in sheep and goats¹ suggested incidentally that there are small differences between the sexes in the lengths of some chromosome pairs. Here I report the measurement of thirty chromosome spreads from thirteen genetically normal male sheep and thirty-one spreads from thirteen normal ewes, showing differences between the sexes in two pairs of large autosomes which were longer in the males than in the females. Nine spreads were examined from an intersex sheep, a genetic female which had well-developed testes and masculinized genitalia. The lengths of some of the chromosomes in her karyotype resembled those of normal males. The observations may indicate some autosomal control of the differentiation of sex.