Based on the majority of freemartins in cattle are infertile and their karyotyping is XX/XY sex chromosome chimaerism, a new polymerase chain reaction (PCR) diagnostic method was developed to detect the infertile freemartins: bovine 1.

Cross experiments between the artificial pigmentation mutants and the wild type in Porphyra haitanensis Chang et Zheng, were carried out to examine the occurrence of meiosis in its life history, according to the appearance of color segregation and color-sectored blades in the F_1 gametophytic blades developed from the conchospors of the heterozygous conchocelis.

Cloning and sequencing of two molecular markers located on the sex chromosomes of the cotton bollworm, Helicoverpa armigera;

Studies of Karyotypes and Sex Chromosomes in Pseudotaxus chienii;

Sex chromosome abnormalities and analysis of the relationship between male infertility

Results Abnormal chromosome karyotype(ACK) was detected in 23 patients, sex chromosomes were involved in all these cases, the most were 47,XXY, 17 cases, which accounted for 29.

From the cytogenetic perspective, only a small proportion of fish species have heteromorphic sex chromosomes.

Molecular evolution processes of sex chromosomes and sex determination provide a clue to tendency of sex-determining genes to appear on heterotypic sex chromosome.