1. Expression pattern of germ cell–specific genes in the testis of patients with nonobstructive azoospermia: usefulness as a molecular marker to predict the presence of testicular sperm 
Gyun Jee Song, M.S., Hyoung-Song Lee, M.S., Yong-Seog Park, Ph.D., Ho Joon Lee, Ph.D., You Sik Lee, M.D., Joo Tae Seo, M.D., Inn Soo Kang, M.D. 
Fertility and Sterility 
Volume 73, Issue 6, Pages (June 2000)
DOI: /S (00)

2. Figure 1
Nuclear status and gene expression during spermatogenesis. Several types of spermatogenic cells are represented. The DAZ gene is transcribed from the stage of spermatogonia. The PGK2 gene is transcribed in pachytene spermatocytes. The protamine-2 gene is transcribed in the round spermatid, postmeiotic stage. Bottom shows three types of testicular histopathology in patients with nonobstructive azoospermia. SCO = Sertoli cell–only syndrome.
Song. Molecular diagnosis of sperm. Fertil Steril 2000.
Fertility and Sterility  , DOI: ( /S (00) )

3. Figure 2
(A), RT-PCR products of DAZ, PGK2, and protamine-2 genes in testicular tissues. β-actin is used as a positive control. N = patient with normal spermatogenesis; P1 = patient with maturation arrest; P2 and P3 = patients with Sertoli cell–only syndrome; NR = the PCR product with no RT product as a negative control. (B), PCR products were digested by restriction enzymes. The 380-bp DAZ product is digested into 217-bp and 163-bp fragments. The PGK2 product is digested into 194-, 126-, and 37-bp fragments. The protamine-2 product is digested into 109- and 38-bp fragments. M = 100-bp ladder; lanes 1, 3, and 5 are PCR products of DAZ, PGK2, and protamine-2, respectively. Lanes 2, 4, and 6 are the products of restriction enzyme cutting, respectively.
Song. Molecular diagnosis of sperm. Fertil Steril 2000.
Fertility and Sterility  , DOI: ( /S (00) )