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Y C Yan

Publications and source records attributed to Y C Yan.

At least 37 records · Page 2Linked to original sources
PubMed1990

Expression of a sperm protein gene during spermatogenesis in mammalian testis: an in situ hybridization study.

In previous work a specific membrane protein with an estimated Mr of 20.1 kDa was purified from rabbit sperm tails and designated as rSMP-B protein. Antibodies were raised against rSMP-B protein and used to isolate and identify the cDNA coding the rSMP-B protein from a rat testis lambda gt11 expression library. The nucleotide sequence of the cDNA was determined in a previous study. Single-stranded 35S-labeled RNA probes were prepared. With the techniques of in situ hybridization, rSMP-B mRNA was detected in spermatids of rat and rabbit testis. The present results support our previous observation that immunization of male rabbits with the rSMP-B protein results in the arrest of spermatogenesis at the spermatid stage. Overall, rSMP-B protein appears to be involved in spermiogenesis, and the synthesis of the mRNA encoding the protein occurs in germ cells during the postmeiotic haploid phase of spermatogenesis.

Animals↗
PubMed1990

Characterization of cDNA encoding a human sperm membrane protein related to A4 amyloid protein.

A rat testis lambda gt11 cDNA library was screened with a monoclonal antibody raised against a human sperm membrane protein designated YWK-II. A clone was found with a cDNA insert composed of 1837 base pairs that contained an open reading frame coding for 191 amino acid residues. The deduced polypeptide contained a segment with high homology to the transmembrane-cytoplasmic domains of the A4 amyloid protein found in brain plaques of Alzheimer disease patients. A sequence of basic amino acid residues, Arg-Lys-Arg, was found instead of Lys-Lys-Lys at the probable membrane-cytoplasmic junction that may be a unique property of sperm membrane proteins.

Amino Acid Sequence↗
PubMed1987

Properties of a monoclonal antibody interacting with human sperm.

A monoclonal antibody (MAB) interacting with human sperm was purified by ammonium sulfate fractionation and gel filtration on Sephadex G-200. The MAB designated as YWK-II belongs to the IgM class and is composed of mu heavy chains and kappa light chains. The MAB localized to the equatorial region of the sperm head, midpiece, and tail. The sperm antigen interacting with the YWK-II MAB was purified by immunoaffinity chromatography on Sepharose 4B conjugated with YWK-II antibodies. Two interacting proteins, estimated Mr of 60 and 72 kD, were identified.

Animals↗
PubMed1984

Immunolocalization of a sperm membrane protein in human male reproductive organs.

A monoclonal antibody that induces agglutination of human sperm was used to localize the interacting antigen in various tissues by indirect immunofluorescence. The antibody localized to the immature sperm and Sertoli cells of the seminiferous tubules, simple cuboidal epithelial cells of the rete testis, and the columnar epithelial cells of the ductuli efferentes. The present results show that the interacting protein is found associated with germ cells undergoing spermatogenesis.

Animals↗
PubMed1981

Effect of heterospecific DNA on the development of Rana nigromaculata.

Both the DNA of a balancer-bearing species (Cynops orientalis) and that of a non-balancer-bearing species (Rana nigromaculata), when injected into the fertilized eggs of R. nigromaculata, cause some tadpoles derived from the injected eggs to bear a single balancer-like process on the left operculum. Based upon these results, it may be so concluded that the occurrence of the balancer-like process in the tadpole is neither due to genetic transformation, nor due to balancer induction, but rather due to a non-specific developmental effect of DNA.

Animals↗
PubMedDate not supplied

Immune responses in rats following oral immunization with attenuated Salmonella typhimurium expressing human sperm antigen.

The HSD-I gene codes a human sperm membrane protein (hSMP-1) and has been assigned the accession number U12978. The gene is located on human chromosome 9, region p12-p13. When the 1.7-kb cDNA of HSD-I was digested sequentially with EcoRI, BamHI, and HindIII, a 550-bp cDNA fragment was formed, which codes for the extracellular domain. This fragment was cloned into the asd+ vector pYA3149 to construct pYA3149R. The recombinant plasmid was used to transform an avirulent deltacva, deltacrp, deltaasd vaccine strain of Salmonella typhimurium chi4550. The hSMP-1 component was localized on the surface of the head of mature rat spermatozoa by an immunofluorescence technique using polyclonal anti-hSMP-1 antibodies. Since rat sperm contain hSMP-1, this rodent can be used to assay the immunogenicity of pYA3149R. Female Wistar rats were immunized by oral administration of the recombinant Salmonella. Anti-hSMP-1 antibodies in blood and vaginal washes of immunized animals were determined. Both body fluids contained significant amounts of the antibodies, showing that the recombinant Salmonella is an effective oral immunogen in rats.

Administration, Oral↗
PubMedDate not supplied

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.

Animals↗
PubMedDate not supplied

Monoclonal antibody inducing human sperm agglutination.

A mouse fused splenic cell line producing antibody that induces agglutination of human sperm was cultivated. The antibody was localized to the midpiece and tail of human spermatozoa by an indirect immunofluorescence method. The interacting antigen was identified in a sperm membrane protein preparation by SDS gel/protein blot immunofluorescence method. The molecular weight of the antigen was in the vicinity of 84 Kdaltons.

Animals↗
PubMedDate not supplied

Gene expression of human sperm component related to A4 amyloid precursor protein.

Monoclonal antibodies were raised against a specific human sperm protein and designated as the YWK-II mAb. The partial cDNA encoding the protein was isolated from a rat testis lambda gt11 expression library and the amino acid sequence of the protein was deduced. The cytoplasmic-transmembrane domains of the deduced protein had high homology with the A4 amyloid precursor protein of Alzheimer's disease. To evaluate the stage of spermatogenesis when the gene was expressed, single-stranded 35S-labeled RNA probes were prepared from the cDNA. By an in situ hybridization technique the mRNA for the antigen was detected in germ cells at all stages of spermatogenesis. The finding that the gene is expressed in spermatogonia suggests possible involvement in the initiation of germ cell differentiation or in the detachment of spermatogonia from the basement membrane.

Amyloid beta-Peptides↗
PubMedDate not supplied

Expression of a gene encoding a specific human sperm protein in Chinese hamster ovarian cells.

The cDNA (RSD-2) encoding a human sperm protein (YWK-II) was isolated from a rat testis lambda gt11 expression library. Its nucleotide sequence was determined. The deduced polypeptide showed high identity with the transmembrane-cytoplasmic domains of A4 amyloid precursor protein of Alzheimer's disease. The RSD-2 was inserted into the EcoRI site of the pSV2-EP vector to construct the pSVRS-2 vector. Chinese hamster ovarian (CHO-dhfr) cells were cotransformed with pSV2-neo and pSVRS-2. mRNA and chromosomal DNA prepared from the transformed cells interacted with [32P]RSD-2 as probe by dot hybridization. The production of the YWK-II protein was determined by staining with the YWK-II mAb by an indirect immunofluorescence technique. There was marked staining of the cytoplasm. The RSD-2 cDNA encoding the YWK-II sperm was expressed in the transformed CHO cells. The pSV2-EP vector and the CHO cell expression system can be utilized to produce sperm proteins for antifertility studies.

Amyloid beta-Protein Precursor↗
PubMedDate not supplied

Testis epidermal growth factor and spermatogenesis.

Epidermal growth factor (EGF) is a cytokine that promotes cell proliferation, regulates tissue differentiation, and modulates organogenesis. Although a rich source of EGF is the submaxillary gland, many tissues produce this cytokine, including the testis. Leydig cells are the principal source of EGF in the testis. On attainment of sexual maturation the germ cells, primarily spermatocytes and round spermatids, form EGF with the onset of spermatogenesis. EGF appears to be involved in the development of the testis and in spermatogenesis. The expression of the EGF gene in rat testis was determined by the application of the RT-PCR method and testis RNA as substrate. The results suggest that EGF produced by Leydig cells and germ cells may modulate spermatogenesis as an autocrine and/or paracrine factor.

Animals↗