Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh Original cung cấp cho các bạn kiến thức về sinh học đề tài:Phenotypic plasticity of body pigmentation in Drosophila: Expression a of X chromosome fragility in Holstein-Friesian cattle: preliminary study. | 395 Genet Sei Evol 1997 29 395-401 Elsevier Inra Original article Expression of X chromosome fragility in Holstein Friesian cattle a preliminary study G Rincon s Llambf A Postiglioni Laboratorio de Citogenética de Animates Domésticos Area Genética Departamento de Biologia Molecular y Celular Facultad de Veterinaria Lasplaces 1560 Montevideo Uruguay Received 17 December 1996 accepted 25 June 1997 Summary - Twenty Uruguayan Holstein-Friesian cows were cytogenetically examined focusing on Xq fragility manifestation Fra Xq . Comparative culture media studies were carried out by simultaneously culturing blood samples in TC 199 and RPMI 1640 media. Taking into account that X chromosome aberrations may be interfering with fertility the cattle population were also evaluated for their reproductive performance. One thousand metaphase spreads were studied in each culture media and showed normal chromosome constitution in most cells. Frequency of Xq fragility detected in TC 199 was while in RPMI 1640 it was p . According to reproductive performance repeat breeders manifested 92 of all Fra Xq detected. The differences in expression in both tissue culture media and the frequencies of the Xq fragility observed in cattle with reproductive problems are discussed. fragile X I cattle cytogenetics fertility Resume Etude préliminaire sur 1 incidence de la fragilite du chromosome X en race bovine Holstein. Vingt vaches de race Holstein-Friesian Uruguayenne ont été examinees cytogénétiquement pour apprécier lafragilite Xq Fra Xq . Une étude comparative entre les milieux de culture a été menée par culture simultanée des échantillons sanguins dans le smilieux TC 199 et RPMI 1640. En raison de I incidence possible des aberrations du chromosome X sur la fertilite les animaux ont été aussi évalués pour leur performance reproductive. Mille metaphases ont été étudiées dans chaque milieu de culture et la majorite des cellules a montré une constitution chromosomique .
