• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.979-985
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• 2020

A wide range of techniques have been developed to separate X or Y- chromosome-bearing sperm. In particular, bovine semen sex-sorted by using flow cytometry based on differences in the amount of DNA between X and Y chromosome bearing sperm is used in dairy farms. The first piglets were produced using sex-sorted sperm 30 years ago. However, sexed sperm have not been commercially available in pigs because the flow cytometry technique is not capable of sorting the high number of sperm required for porcine artificial insemination (AI), and the prolonged exposure to an electrical filed might damage to the DNA in sperm. The purpose of this study was to evaluate a boar sperm sorting method based on magnetic nanoparticles. A flow cytometer assay verified the efficacy of the magnetic nanoparticles (> 90% of sex-sorted sperm). In addition, a duplex polymerase chain reaction (PCR) assay using sex chromosome specific genes including SRY (sex-determining region Y; male), ZFY (zinc finger protein Y-linked; male), and ZFX (zinc finger protein X-linked; female) showed that in vitro fertilized porcine embryos by X and Y-chromosome bearing sperm were 100% female (40/40) and 72% female (35/48), respectively, at 8-cell or morula stages, suggesting that the sex-sorted sperm were fertile. In conclusion, our findings suggest that the sex-sorted method based on magnetic nanoparticles can be utilized for porcine sex-sorted AI.

• Biomolecules & Therapeutics
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• v.31 no.3
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• pp.264-275
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• 2023

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by tremors, bradykinesia, and rigidity. PD is caused by loss of dopaminergic (DA) neurons in the midbrain substantia nigra (SN) and therefore, replenishment of DA neurons via stem cell-based therapy is a potential treatment option. Astrocytes are the most abundant non-neuronal cells in the central nervous system and are promising candidates for reprogramming into neuronal cells because they share a common origin with neurons. The ability of neural progenitor cells (NPCs) to proliferate and differentiate may overcome the limitations of the reduced viability and function of transplanted cells after cell replacement therapy. Achaete-scute complex homolog-like 1 (Ascl1) is a well-known neuronal-specific factor that induces various cell types such as human and mouse astrocytes and fibroblasts to differentiate into neurons. Nurr1 is involved in the differentiation and maintenance of DA neurons, and decreased Nurr1 expression is known to be a major risk factor for PD. Previous studies have shown that direct conversion of astrocytes into DA neurons and NPCs can be induced by overexpression of Ascl1 and Nurr1 and additional transcription factors genes such as superoxide dismutase 1 and SRY-box 2. Here, we demonstrate that astrocytes isolated from the ventral midbrain, the origin of SN DA neurons, can be effectively converted into DA neurons and NPCs with enhanced viability. In addition, when these NPCs are inducted to differentiate, they exhibit key characteristics of DA neurons. Thus, direct conversion of midbrain astrocytes is a possible cell therapy strategy to treat neurodegenerative diseases.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.1
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• pp.57-65
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• 1997

Cytogenetic observations of loss of the distal portion of the Y chromosome long arm were found to be associated with disrupted spermatogenesis. The existence of a gene involved in the regulation of spermatogenesis, the azoospermia factor (AZF), was postulated. In this study, we screened the AZF region including DAZ and DAZH genes and observed the expression pattern of DAZ and DAZH transcript in infertile men with azoospermia and oligospermia by using a sequence-tagged site (STS)-based PCR method. PCR primers were synthesized for 11 STSs that span Yq interval 6, SRY, DAZ, and DAZH, functional DAZ homologue on chromosome 3. Microdeletions were detected in 4/32 (12.5%) azoospermic men and 1/11 (9%) severe oligospermic men. Only 2 of 5 patients had microdeletions of Yq that contained the DAZ gene, whereas the other 3 patients had deletions extending from intervals 5L-6F proximal to the DAZ gene on Yq. Testis biopsies of the azoospermic patients revealed a variety from Sertoli cell-only syndrome to testicular maturation arrest. Of 4 men with clinical data available, average testis size was R: 13.8 cc, L: 13.8 cc, serum T was $4.0{\pm}1.25$ ng/ml, LH was $3.63{\pm}1.90$ mIU/ml, and FSH was $8.85{\pm}5.13$ mIU/ml. These values did not differ significantly from the remainder of the patients tested. We could not observed the DAZ transcript in 2 patients, who have no mature spermatozoa. In 11.6% of patients microdeletions of the AZF could be detected. These deletions in the AZF region seem to be involved causing spermatogenic failure. But the frequency of microdeletions proximal to DAZ suggests that DAZ is not the only gene associated with spermatogenic failure.

• Clinical and Experimental Reproductive Medicine
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• v.23 no.3
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• pp.367-377
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• 1996

Genes on the long arm of Y chromosome, particularly interval 6, are believed to playa critical role in human spermatogenesis. The objective of this study was to validate a sequenced-tagged site(STS)-mapping strategy for the detection of Yq microdeletion and to use this method to determine the proportion of men with Yq microdeletions in idiopathic, obstructive, nonobstructive azoospermia, severe OATS and in normal males. We analyzed three STS markers mapped to interval 6 within long arm of the Y chromosome from 106 nonobstructive, 30 obstructive azoospermia, 15 severe OATS patients, and normal 42 males in Korean men. By PCR, we tested leukocyte DNA, for the presences of STS markers(DAZ, sY129 and sY134) and SRY gene as internal control. And PCR results were confirmed by Southern hybridization, and were investigated by SSCP analysis for DAZ gene mutation. None of 42 normal males and 30 obstructive azoospermia had microdeletions, Of the 15 severe OATS typed with DAZ, sY129 and sY134, 3(20.0%) patients failed to amplify 1 or more STS markers, and of the 106 nonobstructive azoospermia typed with DAZ, sY129 and sY134, 12(11.3%) patients failed to amplify 1 or more STS markers. From these results, high prevalence(12.4%) of Yq deletion(DAZ, sY129, sY134) in men with nonobstructive idopathic azoospermia and severe OATS were observed in Korean infertility patients. To avoid the infertile offspring by assisted reproductive technique using ICSI or ROSI, genetic diagnosis will be needed in IVF-ET program.

• Journal of Genetic Medicine
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• v.5 no.2
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• pp.139-144
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• 2008

We report on two cases of pericentric inversion of X chromosome. The cases were found in a 40-year-old man with azoospermia and in a family of a 38-year-old pregnant woman. The first case with 46,Y,inv(X)(p22.1q27) had concentrations of LH, prolactin, estradiol, and testosterone that were within normal ranges; however, FSH levels were elevated. Testis biopsy revealed maturation arrest at the primary and secondary spermatocytes without spermatozoa. There were no microdeletions in the 6 loci of chromosome Y. For the second case, the cytogenetic study of thepregnant woman referring for advanced maternal age and a family history of inversion X chromosome was 46,X,inv(X)(p22.11q27.2). The karyotype of her fetus was 46,X,inv(X)(p22.1q27). Among other family members, the karyotypes of an older sister in pregnancy and her fetus were 46,X,inv(X)(p22.11q27.2), and 46,Y,?inv(X), respectively. The proband's father was 46,Y,inv(X)(p22.11q27.2). All carriers in the family discussed above were fertile and phenotypically normal. In addition, the ratio of inactivation of inv(X) by RBG-banding was discordant between the two sisters, with the older sister having only 4.1% of cells carrying inactivated inv(X) while the proband had a 69.5% incidence of late replicating inv(X). Therefore, we suggest that the cause of azoospermia in the first case might be related to inversion X chromosome with positional effect. Also, the family of the second case showing normal phenotype of the balanced inv(X) might be not affected any positional effect of genes.