We described the clinical, cytogenetic and molecular findings of 17 clinical equine cases presented for abnormal sexual development and infertility. Six horses with an enlarged clitoris had an XX, SRY-negative genotype, which displayed male-like behavior (adult individuals). Bilateral ovotestes were noted in 2 of those cases, while another case showed increased levels of circulating testosterone. Six horses with a female phenotype, including normal external genitalia, had an XY, SRY-negative genotype. These individuals had small gonads and an underdeveloped internal reproductive tract. Four horses with normal appearing external genitalia had an XY, SRY-positive genotype, 3 of them had hypoplastic testes and male-like behavior. In addition, one young filly with enlarged clitoris and hypoplastic testes had the same genotype but did not show male-like behavior due to her age. Three of these horses were related with 2 being siblings. These findings demonstrate the diversity of disorders of sexual development seen in the horse. Furthermore, they emphasize the need for further research to identify genes involved in abnormal sex determination and differentiation in the horse.

No abstract

Genetic sex in mammals is determined by the sex chromosomal composition of the zygote. The X and Y chromosomes are responsible for numerous factors that must work in close concert for the proper development of a healthy sexual phenotype. The role of androgens in case of XY chromosomal constitution is crucial for normal male sex differentiation. The intracellular androgenic action is mediated by the androgen receptor (AR), and its impaired function leads to a myriad of syndromes with severe clinical consequences, most notably androgen insensitivity syndrome and prostate cancer. In this paper, we investigated the possibility that an alteration of the equine AR gene explains a recently described familial XY, SRY ⁺ disorder of sex development. We uncovered a transition in the first nucleotide of the AR start codon (c.1A>G). To our knowledge, this represents the first causative AR mutation described in domestic animals. It is also a rarely observed mutation in eukaryotes and is unique among the >750 entries of the human androgen receptor mutation database. In addition, we found another quiet missense mutation in exon 1 (c.322C>T). Transcription of AR was confirmed by RT-PCR amplification of several exons. Translation of the full-length AR protein from the initiating GTG start codon was confirmed by Western blot using N- and C-terminal-specific antibodies. Two smaller peptides (25 and 14 amino acids long) were identified from the middle of exon 1 and across exons 5 and 6 by mass spectrometry. Based upon our experimental data and the supporting literature, it appears that the AR is expressed as a full-length protein and in a functional form, and the observed phenotype is the result of reduced AR protein expression levels.

No abstract

CASE DESCRIPTION 5 mares were evaluated because of reproductive complications following long-term (> 1 year) use of intrauterine glass marbles for estrus suppression. CLINICAL FINDINGS 3 mares had 1 intrauterine glass marble, and 2 mares had 2 intrauterine glass marbles. On examination, 2 mares had signs of chronic endometritis, and 3 had signs of pyometra. Marbles or glass shards adhered to the endometrium were identified by means of hysteroscopy in 3 of 5 mares. Five of 7 marbles had surface imperfections or were broken. TREATMENT AND OUTCOME All patients were treated with uterine lavage and intrauterine and systemic administration of antimicrobials chosen on the basis of results of bacterial culture and susceptibility testing. Two of 5 mares were treated with intrauterine Tris-EDTA. One mare underwent 3 unsuccessful embryo transfer procedures and was subsequently lost to follow-up. One mare was euthanized because of severe vaginal and cervical adhesions and chronic vaginal discharge. Three mares had no apparent signs of reproductive disease at the time of follow-up but were not rebred. CLINICAL RELEVANCE Results of the present small case series suggested that use of intrauterine glass marbles should be discouraged because of the potential for severe reproductive consequences.

Postpartum uterine disease due to poor uterine involution continues to be a significant factor that contributes to poor reproductive efficiency in dairy cattle. Therapy that increases the frequency, duration and strength of uterine contractions in the postpartum period might enhance uterine involution, resulting in improved reproductive performance. The objective of this clinical trial was to study the effect of two uterine ecbolic therapies, oxytocin and prostaglandinF2α on uterine involution, postpartum endometritis, and reproductive performance. A randomized double-blinded clinical trial was conducted in 118 dairy cows from two research herds that had normal parturition and expulsion of the fetal membranes. Within 24 hr after calving, cows were randomly assigned to receive intramuscular injections twice a day of 50 IU of oxytocin, or 25 mg of dinoprost (PGF2α) or saline (control) for 7 days. Cows were monitored from day 3 to day 63 ± 3 days postpartum by transrectal palpation of the uterus, vaginoscopy, Metricheck® examination and by endometrial cytology. Blood samples were collected for measurement of progesterone in weeks 3 (21 ± 3 days), 5 (35 ± 3 days), 7 (49 ± 3 days), and 9 (63 ± 3 days) postpartum. Herd breeding records were obtained to determine reproductive performance in all cows. Neither oxytocin nor prostaglandin F2α therapy during the first week postpartum had any significant effect on the rate of uterine involution, prevalence of endometritis or reproductive performance, compared to untreated controls. Ecbolic drugs, as used here, are not recommended for use in clinical practice to improve involution or reproductive tract health in normal cows.

No abstract

The objective of this study was to evaluate the differences in the uterine flush fluid proteome between healthy mares and mares with endometritis or fibrotic endometrial degeneration (FED). Uterine flush fluid samples were collected from healthy mares (n=8; oestrus n=5 and dioestrus n=3) and mares with endometritis (n=23; oestrus n=14 and dioestrus n=9) or FED (n=7; oestrus n=6 and dioestrus n=1). Proteomic analysis was performed using label-free liquid chromatography–tandem mass spectrometry. Of 216 proteins identified during oestrus, 127 were common to all three groups, one protein was exclusively detected in healthy mares, 47 proteins were exclusively detected in mares with endometritis and four proteins were exclusively detected in mares with FED. Of 188 proteins identified during dioestrus, 113 proteins were common between healthy mares and mares with endometritis, eight proteins were exclusively detected in healthy mares and 67 proteins were exclusively detected in mares with endometritis. Quantitative analysis revealed a subset of proteins differing in abundance between the three groups during oestrus and between healthy mares and mares with endometritis during dioestrus. These results provide a springboard for evaluation of specific proteins as biomarkers of uterine health and disease and for investigation of their roles in the establishment and maintenance of pregnancy.