Screening the stage-specific expression gene from different germ cells of rat

<正> Objective:To screen the stage-specific expression genes from rat spermatogonia,pachytene spermatocytes and round spermatids.Methods:Highly purified spermatogonia were isolated from 9-day-old rats,pachytene spermatocytes and round spermatids from adult rats by sedimentation velocityat unit gravity,using 2%-4% BSA gradient in DMEM/F12 medium.A mRNA differen-tial display method was used for screening the stage-specific expression gene.Results:Nineteen differentially/ expressed cDNA fragments were obtained.Afterexcluding the false positive cDNA fragments by dot blot,13 cDNAs were selected toclone and sequence.To obtain longer cDNAs,six ESTs were used to screen the rattestis λ-zap Ⅱ cDNA library.Two longer cDNA fragments,designated as LY21 andLM66,were obtained.The analysis with DNAMAN software indicated that LY21 had along open reading frame coding 372 amino acids while LM66 had no long open readingframe.LY21 were highly homologous with hnRNP H1.To observe the expression pat-terns of LY21 gene in the testicular cells,we performed in situ hybridization on testissections from adult rats.The LY21 gene expression was found in the spermatogonia andprimary spermatocytes.Conclusion:This study indicated that LY21 gene was associated with spermatogen-esis.Further studies will be needed to explore the function of LY21.     

从大鼠不同生精细胞筛选精子发生过程中阶段特异表达基因

目的 :从大鼠精原细胞、粗线期精母细胞和圆形精子细胞筛选精子发生过程中阶段特异表达基因。　方法 :用牛血清白蛋白梯度沉降法 (STAPUT法 ) ,分别从 9d龄和成年大鼠睾丸中 ,分离出处于减数分裂前、中、后的 3种生精细胞 ,即精原细胞、粗线期精母细胞和圆形精子细胞。运用RNA差异显示方法筛选差示cDNA。　结果 :本实验获得 19个cDNA差示片段 ,并克隆和测序出其中 6个cDNA序列 ,通过非重复序列 (nr)和EST序列同源比较 ,发现 5条cDNA分别与小鼠睾丸、附睾、乳腺、早期胚胎和大鼠卵巢基因高度同源 (88%～ 98% ) ,有一条未知新EST。结论 :差异显示技术是分离与精子发生有关基因的强有力工具。     

Age-dependent expression of the cystatin-related epididymal spermatogenic （Cres） gene in mouse testis and epididymis

Aim： To investigate the spatial and temporal expression of the cystatin-related epididymal spermatogenic （Cres） gene in mouse testis and epididymis during postnatal development. Methods： The QuantiGene assay and indirect immunofluorescence technique were used to examine the Cres mRNA and Cres protein level in mouse testis and epididymis on postnatal days 14, 20, 22, 28, 35, 49, 70 and 420. Results： （1） In both the testis and epididymis, Cres mRNA was fast detected on day 20, then it increased gradually from day 20 to day 70, and the high expression level maintained till day 420. （2） In the testis, the Cres protein was exclusively localized to the elongating spermatids and was first detected on day 22. The number of Cres-positive spermatids increased progressively till day 49. From day 49 to day 420, the number of Cres-positive cells was almost stable. （3） The Cres protein was first detected on day 20 in the proximal caput epididymal epithelium. By day 35, the expression level of the Cres protein increased dramatically and the high level was maintained till day 420. Moreover, the luminal fluid of the midcaput epididymis was also stained Cres-positive from day 35 on. No Cres-positive staining was observed in distal caput, corpus and cauda epididymis throughout. Conclusion： The Cres gene displays a specific age-dependent expression pattern in mouse testis and epididymis on both the mRNA and protein level.     

Human sperm membrane protein (hSMP-1): a developmental testis-specific component during germ cell differentiation

Serum was obtained from an infertile woman having antibodies with sperm agglutinating activity. The antibodies interacted with a human sperm membrane protein (hSMP-1) with an estimated Mr of 55 kD. The gene (HSD-1) coding hSMP-1 was isolated from a human testis cDNA expression library and assigned the accession number U12978. The cDNA was conjugated to a prokaryotic expression vector to construct the recombinant vector, pRSET-HSD-I, which was expressed in Escherichia coli. The recombinant hSMP-1 was isolated and used to immunize rabbits to raise polyclonal antibodies. Usingan immunocytochemical technique, hSMP-1 protein was immunolocalized in germ cells of human testis at all stages of spermatogenesis. mRNAs were prepared from 16 different human tissues and analyzed by Northern blot using HSD-1 as probe. A positive reaction was elicited only with testis mRNA. The present findings suggest that the expression of hSMP-1 gene is testis-specific and occurs during the early stages of germ cell differentiation. In a comparative study, the location of the hSMP-I protein in sperm and in germ cells of the seminiferous tubules of rats was determined. The target antigen was immunolocated on the head and tail of rat sperm and in late spermatids and spermatozoa of rat testis. These results suggest that, in the rat, the HSD-1 gene is expressed during spermiogenesis.     

Ultrastructural and immunocytochemical study of P1, protamine localization in human testis

Summary. Two monoclonal antibodies (MAbs) directed against human protamine P ₁ were realized. Anti- P ₁ specificity was assessed by western-blot and confirmed by elisa. Monoclonal antibody 97-3 was selected. Protamine P ₁, was specifically demonstrated in human testis by immunoelectron microscopy, using 97-3 MAb and an indirect post-embedding immunogold technique. Our results clearly demonstrated the precise time of appearance of P ₁ protamine in the nuclei of human spermatids. P ₁, first appeared in the nucleus of step 5 spermatids and its concentration was increased in steps 6–8 spermatids, cytoplasm was not labelled.     

大鼠睾丸发育过程基因表达的研究

本研究选取１、３ 和８（成年）周龄等不同发育阶段大鼠,应用睾丸组织树脂包埋形态学观察与ｍ ＲＮＡ 差异显示逆转录－聚合酶链反应技术（ｄｉｆｆｅｒｅｎｔｉａｌｄｉｓｐｌａｙ ＲＴ－ＰＣＲ,ＤＤＲＴ－ＰＣＲ）相结合,探讨大鼠睾丸发育过程中,精子发生过程睾丸特异基因的表达。结果：对不同周龄大鼠睾丸ｍ ＲＮＡ 进行差异比较,共得到 ８２ 个ｃＤＮＡ 差异片段。又分别标记不同周龄大鼠睾丸全部 ｍ ＲＮＡ 为探针,对其中 ４０ 个ｃＤＮＡ差异片段进行斑点杂交,得到１２ 个初步鉴定的特异或表达增加的ｃＤＮＡ 差异片段,片段范围２５０～５００ ｂｐ,其中２ 个在１ 周龄睾丸组获得,４ 个在３ 周龄睾丸组获得,在８ 周龄组获得 ５ 个,一个为１ 周和３ 周龄共有而８ 周龄大鼠缺乏的ｃＤＮＡ 片段。通过形态学观察与ｍ ＲＮＡ 差异显示的结果对应分析,初步认为２ 个１ 周龄的特异基因片段属于睾丸二倍染色体生精细胞表达基因,４ 个３ 周龄睾丸特异基因片段也属二倍或四倍体生精细胞表达基因,其中Ｂ型精原细胞和初级精母细胞的表达基因占主要成分;而成年动物的５ 个特异基因片段是属单倍体的精子细胞以及减数分裂过程的精母细胞表达基因片段     

Analyis of Protamine mRNA in sperm of men,rats and mice

Aim: To investigate the existence of the protamine mRNA insperm of men, rats and mice. Methods: By means of RT-PCRtechniques, protamine cDNA fragments were obtained from totalRNA of the mature sperm of men, rats and mice. Results:mRNA of protamine gene was present in the mature sperm of men,rats and mice. The protamine cDNA obtained by RT-PCR in ratsperm with an abnormal head was much less in number than that inthe normal rat sperm. Conclusion: mRNA in the sperm mightrepresent the condition of corresponding gene expression duringspermatogenesis. (Reprod Contracep 2001; 21: 200 - 5)     

Human glyceraldehyde 3-phosphate dehydrogenase-2 gene is expressed specifically in spermatogenic cells

Although the process of glycolysis is highly conserved in eukaryotes, several glycolytic enzymes have unique structural or functional features in spermatogenic cells. We previously identified and characterized the mouse complementary DNA (cDNA) and a gene for 1 of these enzymes, glyceraldehyde 3-phosphate dehydrogenase-s (Gapds). This gene is expressed only in spermatids. The enzyme appears to have an essential role in energy production required for fertilization, and it is reported to be susceptible to inhibition by certain environmental chemicals. We have now cloned and sequenced the cDNA for the human homologue of glyceraldehyde 3-phosphate dehydrogenase (GAPD2) and determined the structure of the gene. The messenger RNA (mRNA) was detected in testis, but not in 15 other human tissues analyzed by Northern blot technique. The deduced GAPD2 protein contains 408 amino acids and is 68% identical with somatic cell GAPD. GAPD2 has a 72-amino acid segment at the amino terminal end that is not present in somatic cell GAPD. This segment is proline-rich but contains smaller stretches of polyproline and is 30 amino acids shorter than the comparable segment of mouse GAPDS. The structure of the human GAPD2 gene was determined by polymerase chain reaction (PCR) to identify exon-intron junctions in a genomic clone and in total genomic DNA. The locations of these junctions in the GAPD2 gene corresponded precisely to those of the 11 exon-intron junctions in the mouse Gapds gene. Immunohistochemical studies found that GAPD2 is located in the principal piece of the flagellum of human spermatozoa, as are GAPDS in mouse and rat spermatozoa. GAPD2 extracted from human spermatozoa and analyzed by Western blot technique migrated with an apparent molecular weight of approximately 56,000, although the calculated molecular weight is 44 501. The conserved nature of the mouse, rat, and human enzymes suggests that they serve similar roles in these and other mammalian species.     

Transition protein 1 mRNA expression is not related to pregnancy rate in azoospermic men undergoing TESE-ICSI

Our laboratory has previously reported significantly low levels of protamine (PRM) gene expression in infertile men. This drop was correlated with a low pregnancy rate, suggesting that PRMs may be useful as predictive factors for the outcome of testicular sperm extraction and intracytoplasmic sperm injection (TESE-ICSI) in azoospermic men. Transition nuclear proteins (TPs) are expressed earlier in spermatogenesis than protamines and are required for normal sperm development. In the present study, we examined the expression of the transition nuclear protein 1 gene (TNP1) in azoospermia and its relationship with TESE-ICSI outcomes. The cellular expression of TNP1 mRNA in spermatids was quantified by in situ hybridisation on paraffin sections of testis biopsies from 21 men with obstructive azoospermia and 23 men with non-obstructive azoospermia. Cases of non-obstructive and obstructive azoospermia did not differ significantly in terms of TNP1 expression. Furthermore, TNP1 mRNA expression was similar in non-pregnant and pregnant couples. Hence, the pregnancy rate was not related to TNP1 mRNA expression levels in azoospermia. Our results emphasise the value of TNP1 as a reliable predictive marker for the presence of spermatids/spermatozoa in the testis biopsies used for TESE but also indicate that expression of the TNP1 gene (believed to be a major player in spermiogenesis and required for production of normal sperm) may not be a predictive factor for successful post-ICSI embryonic development.     

Developmental expression of c-kit protooncogene in the rat testis

IntroductionInmammalianembryos,thegermcelllinebeginswithprimordialgermcelIs,andinmales,primordialgermcellsbecomegono-cytes,thece1lprecursorsofthespermatogoni-a.ThedevelopmentofanormaltestisdependsupontheproliferationofprimordialgermcellsandtheiraggregationwithSertolicellprecur-sorsLl:.Theseeventshavebeenshowntobeassociatedwiththeexpressionofthec-kitProtooncogenemappedtothe"whitespottinglocus(W)~ofthemouse[2,3j.Thec-kitPro-tooncogeneencodesatransmembranetyrosinekinasereceptor(4,5).Thestructu…     

Developmental expression of ACRV1 in humans and mice

To identify the developmental expression of the ACRV1 gene in humans and mice, testes cDNA samples were collected at different post-natal days (days 4, 9, 18, 35, 54, and 6 months) from Balb/c mice and were hybridised to the mouse whole genome 430 2.0 Array (Affymetrix Inc.) chip. The characteristics of ACRV1 were analysed using various cellular and molecular biotechnologies. The results showed that the expression of mouse ACRV1 was not detected in mouse testes on days 4, 9, and 18 but was present on days 35, 54, and 6 months. Using RT-PCR analysis of mouse ACRV1, we determined that mouse ACRV1 was expressed specifically in the mouse testis, and its expression began at days 35. Western blot analysis demonstrated that human ACRV1 was primarily expressed in human testes, and immunofluorescent and immunohistochemistry staining showed that human ACRV1 protein was predominantly located in round and elongated spermatids in human testes, indicating that ACRV1 may play an important role in mammalian spermatogenesis and may be a target of a contraceptive vaccine.