PARENT SESSION
TESTIS

Wednesday, August 4, 2004
10:30 AM–12:30 PM
Buchanan Courtyard

(740) TRANSCRIPT OF BOULE GENE IN THE TESTIS OF AZOOSPERMIC MEN AND ITS ROLE IN PREDICTING THE PRESENCE OF MATURE SPERM IN MEN UNDERGOING SPERM RETRIEVAL.

Lin, Yung Ming^{1, 4}, Lin, Ying Hung², Kuo, Pao Lin³, Leung, Peter C.K.⁴, ¹ Department of Urology, School of Medicine, National Cheng Kung University, Tainan, Taiwan⁴ Department of Obstetrics & Gynecology, University of British Columbia, Vancouver, Canada² Institute of Basic Medical Science, School of Medicine, National Cheng Kung University, Tainan, Taiwan³ Department of Obstetrics and Gynaecology, School of Medicine, National Cheng Kung University, Tainan, Taiwan

ABSTRACT- Human BOULE gene, a germ cell specific cell cycle regulator, was recently identified and was mapped to chromosome 2. It is believed that BOULE gene is highly conserved from flies to human. In fly, boule is required for completion of meiosis in male germ cells. Mutation of boule resulted in male fly sterility, and human BOULE could rescue the meiotic defects in infertile fly. In human, BOULE is expressed exclusively in the male germline. Therefore, human BOULE, a meiotic regulatory gene, is a candidate gene of sterility. In this study, we aimed to assess whether the BOULE transcripts is correlated with testicular phenotypes as well as the results of sperm retrieval. A total of 31 men with spermatogenic failure and 10 men with irreparable obstructive azoospermia and normal spermatogenesis were recruited into this study. The BOULE transcript was measured by QC-RT-PCR. The BOULE transcripts ranged from 12.5 to 60 × 10³ copy/ng RNA for men with normal spermatogenesis and ranged from 1.6 to 35.2 × 10³ copy/ng RNA for men with spermatogenic failure. A significant difference was noted between the 2 groups (p=0.002, unpaired student t test). If our patients were divided into 4 groups according to the severity of testicular failure (normal, hypospermatogenesis, maturation arrest, Sertoli cell-only syndrome), a progressive decrease in the BOULE transcripts was noted (p=0.0007, Kruskal-Wallis test). We divided the 31 men into 2 groups according to the presence or absence of mature sperm at TESE. The BOULE transcripts ranged from 11.8 to 55.2 × 10³ copy/ng RNA for 19 men with successful sperm retrieval, and 1.6 to 4.5 ×10³ copy/ng RNA for 12 men with failed sperm retrieval, respectively. A significant difference between the 2 groups was noted (p < 0.0001, unpaired student t test). If we used a cut-off value of 10 × 10³ copy/ng RNA to predict the presence of sperm, the sensitivity, specificity, positive predictive value, and negative predictive value were all 100%. We then concluded that BOULE transcript was well correlated with testicular phenotypes and revealed prognostic significance for the presence of testicular sperm.

KEY WORDS: Meiosis, BOULE, Spermatogenesis, Azoospermia