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Titolo:
Testes-specific transgene expression in insulin-like growth factor-I transgenic mice
Autore:
Dyck, MK; Ouellet, M; Gagne, M; Petitclerc, D; Sirard, MA; Pothier, F;
Indirizzi:
Univ Laval, Dept Anim Sci, Ctr Rech Biol Reprod, St Foy, PQ G1K 7P4, Canada Univ Laval St Foy PQ Canada G1K 7P4 ol Reprod, St Foy, PQ G1K 7P4, Canada Agr & Agroalimentaire Canada, Lennoxville, PQ, Canada Agr & Agroalimentaire Canada Lennoxville PQ Canada nnoxville, PQ, Canada
Titolo Testata:
MOLECULAR REPRODUCTION AND DEVELOPMENT
fascicolo: 1, volume: 54, anno: 1999,
pagine: 32 - 42
SICI:
1040-452X(199909)54:1<32:TTEIIG>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
FOLLICLE-STIMULATING-HORMONE; MESSENGER-RIBONUCLEIC-ACID; CULTURED SERTOLI CELLS; IGF-BINDING-PROTEINS; DNA METHYLATION; RAT TESTIS; ENHANCER-PROMOTER; GENE-EXPRESSION; LEYDIG; SERUM;
Keywords:
IGF-I; IGFBP; DNA methylation; CMV promoter; testes specific expression;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
49
Recensione:
Indirizzi per estratti:
Indirizzo: Pothier, F Univ Laval, Dept Anim Sci, Ctr Rech Biol Reprod, Pavillon Paul Comtois, StFoy, PQ G1K 7P4, Canada Univ Laval Pavillon Paul Comtois St Foy PQ Canada G1K 7P4 anada
Citazione:
M.K. Dyck et al., "Testes-specific transgene expression in insulin-like growth factor-I transgenic mice", MOL REPROD, 54(1), 1999, pp. 32-42

Abstract

Insulin-like growth factor-1 [IGF-1] is a low molecular weight peptide that mediates the cell proliferating actions of growth hormone. Evidence exists indicating that IGF-1 is produced by various cell types and this growth factor has been implicated in a variety of reproductive processes. To investigate the effect of IGF-1 over-expression on reproductive systems, we generated three independent lines of transgenic mice harbouring a human IGF-1 cDNA (hIGF-1) under the control of a Cytomegalovirus immediate early (CMV) promoter. The CMV promoter was used in an attempt to direct expression of IGF-1 into a variety of tissues both reproductive and non-reproductive. Yet expression of the foreign hIGF-1 gene, determined by Northern blot, was foundto occur only in the testicular tissues of the male mice, apparently due to methylation of the transgene in all the tissues tested except the testes,which demonstrate transgene hypomethylation. Evaluation of the transgene expression during testicular development revealed that expression begins between 10 and 15 days of development, coinciding with the appearance of the zygotene and pachytene primary spermatocytes during early spermatogenesis, therefore indicating germ line expression of the transgene. Extensive study of the CMV-hIGF-1 transgenic lines of mice has revealed that the effects ofthe transgene expression do not extend beyond the testicular tissues. No significant differences (P > 0.05) in the IGF-1 serum levels, growth rates, or testicular histology have been observed between transgenic and non-transgenic male siblings. The ability of transgenic males to produce offspring also appears unaffected. Evaluation of the IGF binding protein (IGFBP) levels in the testicular tissues of CMV-hIGF-1 transgenic mice by Western ligandblot revealed an increase in the concentration of testicular proteins withmolecular weights corresponding to IGFBP-2 and IGFBP-3. These results suggest that the testicular over-expression of IGF-1 induces increased IGFBP localization in this tissue. Inhibition of IGF activity by the IGFBPs would explain the lack of a dramatic physiological effect in the CMV-hIGF-1 transgenic mice, despite the presence of elevated testicular IGF-1. The observation that testis specific IGF-1 overexpression induces localization of IGFBPsin this tissue confirms the existence of a well regulated testicular IGF system and supports the convention that this growth factor plays an important role in testicular function. (C) 1999 Wiley-Liss, Inc.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 24/09/20 alle ore 08:25:05