PSI-4 Investigation of a Naturally Occurring XX Male Bull

Abstract The Y chromosome–linked gene sex-determining region (SRY) is believed to be the master initiator of male sex determination in almost all eutherian mammals, functioning upregulate expression its direct target SRY-related HMG box–containing 9 (SOX9). XX maleness humans a rare syndrome with frequency 1 20,000–25,000 males. Approximately 90% these cases carry some amount chromosome sequences due an illegitimate recombination between X and chromosomes, where most have normal genitalia. A more severe manifestation, remaining 10% do not any Y-chromosome sequences, typically ambiguous In this study, we report case infertile bull. Physical examination purebred Holstein bull showed phenotypically androgynous animal penis, cryptorchidism (2 diminutive testicles, only one descended), skeletal conformation stance usually associated female individuals. Lymphocytes from heparin sodium anticoagulated blood were cultured, harvested, prepared according conventional cell culture methods revealed 60, karyotype no numerical or structural chromosomal aberrations. PCR analyses negative for SRY gene, positive androgen receptor on chromosome. No sperm found seminal fluid collected routine breeding soundness exam at 17 months age. was slaughtered 18 age, reproductive tract collected. testicle weighed 18.9 g (descended), 42.4 (abdominal). Neither testicle/epididymal unit appropriate size fully developed. Two very enlarged vesicular glands (43.36 52.52 g, normally each ~ 20 g) observed alongside what appeared uterine tissue. Histology tubular grooves ampulla epididymis devoid sperm. development phenotype SRY-negative individuals suggests that addition SRY, there are autosomal X-linked genes involved pathway. humans, dose change SOX9 loss function mutations WNT4, FoxL2, RSPO1 testicular suppressing genes, genomic rearrangements within regulatory SRY-box transcription factor 3 (SOX3) been reversal. To investigate whether mutation rearrangement responsible bull, DNA his sire dam long-read trio sequencing. These data may provide evidence either inhibiting testes formation individuals, gain downstream determining