Vol. 179, No. 4, Supplement, Wednesday, May 21, 2008 THE JOURNAL OF UROLOGY® 617

tend to be smaller, less multiple, less invasive, and more favorable in tumor grade at initial presentation. Differences in genetic and molecular aberrations in bladder tumors and accumulation of these aberrations in older patients may relate to age. Further investigation is needed to

Source of Funding: None

Infertility: Physiology, Pathophysiology and Basic Research (I)

Podium Session 41

Wednesday, May 21, 2008 8:00 - 10:00 am

1798IDENTIFICATION OF CANDIDATE GENES FOR INDIVIDUAL STEPS IN SPERMATOGENESISPeter J Stahl*, Anna Mielnik, Michael B Marean, Peter N Schlegel, Darius A Paduch. New York, NY.

INTRODUCTION AND OBJECTIVE: Male fertility depends upon migration of germ cells, gonocyte differentiation, meiotic progression, and spermiogenesis. Inferences about the genetic regulation of these processes have been drawn from studies of infertile men with Y chromosome microdeletions (YCM). We precisely

of interest (ROI) within the Y chromosome essential for individual steps in spermatogenesis.

METHODS: YCMs were detected in 246 men by PCRusing 31 sequence tagged sites (STS). 26 patients for whom semen

underwent microtesticular sperm extraction (microTESE) were excluded.

failed microTESE, including 6 with postmeiotic maturation arrest, 14 with spermatocytic arrest, and 13 with germ cell absence. Patients were grouped by phenotype and a deletion map was constructed, in which grey indicates STS absence (Figure). The ROI for a spermatogenic

cases of spermatogenesis step completion, and, when completely or partially absent, universally precluded step completion. The protein coding genes within each ROI were determined by query of the NCBI GenBank database.

RESULTS: 5 candidate genes for presence of germ cells

genes for progression from spermatocytes to spermatids (NLGN4Y,XKRY1, CDY2B) were found within a 3.8 Mb ROI at the proximal end

CYorf15A, CYorf15B, SMCY, EIF1AY, RPS4Y2, RBMY1B, RBMY1A1)

CONCLUSIONS: We linked candidate genes on the Ychromosome with individual steps in spermatogenesis through precise phenotype-genotype correlative analysis. Our data will allow us and others to focus our research on a limited set of protein coding genes,

and ultimately enhance our ability to diagnose and treat genetic causes of infertility.

Source of Funding: Generous support from Mr. Paul Ostling.

1799CHROMA-SORT SELECT™: A NOVEL SORTING TECHNOLOGY THAT ALLOWS FOR HIGHLY EFFICIENT SELECTION OF SPERM WITHOUT CHROMATIN DAMAGEHoward H Kim*, Peter N Schlegel, Darius A Paduch. New York, NY.

INTRODUCTION AND OBJECTIVE: Sperm chromatin damage may be a negative predictor for IVF outcomes in couples with recurrent spontaneous abortions and poor embryo development. Unfortunately, available methods for detecting chromatin damage such as SCSA, TUNEL, Halosperm and Comet assays require permanent

apoptotic events resulting in chromatin damage are associated with increased permeability of the cell membrane to large ions. We propose

activated cell sorting to select sperm without chromatin damage.

sperm are permeable to PI, and apoptotic cells are permeable to PF-1. Intact cells are impermeable to both. Hoechst 33342 was used

staining (Figure). Percoll density gradient was used to remove debris prior to sorting. To verify selection of intact sperm, the stained and unstained populations were examined microscopically for motility and

two populations were compared using the chi-square test for difference in the percentage of TUNEL-positive cells.

RESULTS: In the group positive for PF-1 and PI, 431 of 2,167 sperm (19.5 %) were TUNEL positive. In the non-staining group only

motility and normal morphology. CONCLUSIONS: This technology allows for sperm chromatin

damage analysis as well as quick and reliable sorting, separating normal sperm from those with chromatin damage. Because the test employs large molecules that require activation of sodium channels to