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Chromosome replication has been analysed in four species of Chilocorus. In C. ORBUS Csy., C. tricyclus Smith, and C. hexacyclus Smith, centric regions of all chromosomes are last to replicate, preceded in order by heterochromatic arms and euchromatic arms. In C. stigma Say, very late replication of centric regions can be detected only in otherwise wholly euchromatic chromosomes (= monophasics); in chromosomes with one arm heterochromatic ( = disphasics), these arms are last to replicate. Based on pachytene bivalent morphology and chromosome banding patterns, and supported by autoradiographic data, models are presented for the general organisation of Chilocorus chromosomes. All chromosomes in the first three species are subdivided into euchromatic arm, centric heterochromatin, and either a second euchromatic are (monophasics) or a heterochromatic arm (diphasics). Chilocorus stigma diphasics apparently lack distinct centric organisation, and are therefore divided into euchromatic and heterochromatic arms only. 相似文献
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AM Bertini-Oliveira MM Keppler A Luisi S Tarico VL Delascio Lopes D Delascio L Camano 《Canadian Metallurgical Quarterly》1982,26(5):636-644
The results of a two-and-a half-year study on cytodetection of preclinical cervical malignancy during pregnancy are presented. Of 3,534 pregnant women, 125 (3.5%) had cytologic diagnoses of dysplasia, carcinoma in situ or microinvasive carcinoma of the uterine cervix. These results are compared with those obtained from colposcopy and from tissue diagnosis following biopsy, cervical conization and hysterectomy. They are also analyzed in relation to the patients' age, parity and age at first sexual intercourse. The management of these patients during pregnancy is discussed, especially with regard to the authors' experience in dealing with patients from very poor socioeconomic and cultural backgrounds. 相似文献
138.
On 68 families with 134 children and on 115 mother-child pairs the serum albumin levels were examined by means of the single radial immundiffusion test after MANCINI et al. (1965). Neither age nor sex dependences were seen. Against that our materials indicate the existence of genetic factors controlling at least to some degree the concentration of this serum protein. Nevertheless, the serum albumin level is also influenced by non-genetic factors. At the present stage of research, however, it is not yet possible to separate exactly genetic and non-genetic variation from another. 相似文献
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LM O''Rourke R Tooze M Turner DM Sandoval RH Carter VL Tybulewicz DT Fearon 《Canadian Metallurgical Quarterly》1998,8(5):635-645
Germ cells are distinct from somatic cells in their immortality, totipotency, and ability to undergo meiosis. Candidates for components that guide the unique germline program are the distinctive granules observed in germ cells of many species. We show that a component of germ granules is essential for fertility in C. elegans and that its primary function is in germline proliferation. This role has been revealed by molecular and genetic analyses of pgl-1. PGL-1 is a predicted RNA-binding protein that is present on germ granules at all stages of development. Elimination of PGL-1 results in defective germ granules and sterility. Interestingly, PGL-1 function is required for fertility only at elevated temperatures, suggesting that germline development is inherently sensitive to temperature. 相似文献