Karyotyping

Publication Title: 
Proceedings of the National Academy of Sciences of the United States of America

Inclusion of vitamin E (DL-alpha-tocopherol) in the culture medium for human diploid cells greatly prolongs their in vitro lifespan. The addition of 100 mug of DL-alpha-tocopherol per ml of medium has allowed us to culture WI-38 cells for more than 100 population doublings to date. (These cells normally have an in vitro lifespan of 50 +/- 10 population doublings.) Cells at the 100th population doubling have a normal diploid karyotype, appear to behave in all other respects like young WI-38 cells, and are still actively dividing.

Author(s): 
Packer, L.
Smith, J. R.
Publication Title: 
Experimental Cell Research

SV40 T-antigen-expressing human cells generally have an extension of lifespan until a period called "crisis" begins. On rare occasions a clone of cells emerges from the population in crisis and gives rise to an immortalized cell line. The present study compares the frequency of immortalization of cells from two different human lineages, lung fibroblasts and mammary epithelial cells.

Author(s): 
Shay, J. W.
Van Der Haegen, B. A.
Ying, Y.
Wright, W. E.
Publication Title: 
Cancer Biology & Therapy

Studies were conducted to directly test whether the introduction of telomerase protects cancer-prone human mammary epithelial cells from chromosomal instability and spontaneous immortalization. Using a model for Li Fraumeni Syndrome (LFS), infection of human telomerase resulted in maintenance of telomere lengths, extension of in vitro lifespan, and prevention of spontaneous immortalization.

Author(s): 
Elmore, Lynne W.
Turner, Kristi C.
Gollahon, Lauren S.
Landon, Melissa R.
Jackson-Cook, Colleen K.
Holt, Shawn E.
Publication Title: 
Molecular and Cellular Biochemistry

Hexavalent chromium (Cr(VI)) is a metal of increasing public health concern, as exposure to it is widespread and it is a well-established cause of human bronchial carcinomas and fibrosarcomas. The water-insoluble Cr(VI) salts are potent carcinogens compared to the water soluble salts; yet the genotoxic mechanisms of both may be mediated by soluble Cr(VI) ions. Currently, these mechanisms are poorly understood.

Author(s): 
Wise, Sandra S.
Elmore, Lynne W.
Holt, Shawn E.
Little, Jennifer E.
Antonucci, Peter G.
Bryant, Bronwyn H.
Wise, John Pierce
Publication Title: 
Blood

To obtain the large amount of T cells required for adoptive immunotherapy in a clinical setting, T-cell lifespan extension by human telomerase reverse transcriptase (hTERT) transduction is of particular interest. However, constitutive expression of hTERT is associated with malignant transformation and thus warrants a detailed evaluation of the safety of hTERT-transduced T cells before clinical application.

Author(s): 
Schreurs, Marco W. J.
Hermsen, Mario A. J. A.
Geltink, Ramon I. Klein
Scholten, Kirsten B. J.
Brink, Antoinette A. T. P.
Kueter, Esther W. M.
Tijssen, Marianne
Meijer, Chris J. L. M.
Ylstra, Bauke
Meijer, Gerrit A.
Hooijberg, Erik
Publication Title: 
Journal of Molecular Evolution

Drosophila nasuta nasuta (2n = 8) and D. n. albomicans (2n = 6) are morphologically identical, cross fertile and karyotypically dissimilar pair of chromosomal races belonging to nasuta subgroup of immigrans group of Drosophila. Interracial hybridization between these two races yielded karyotypically stabilized newly evolved Cytoraces with new combinations of chromosomes and DNA content, and are called nasuta-albomicans complex of Drosophila.

Author(s): 
Ranjini, Mysore S.
Ramachandra, Nallur B.
Publication Title: 
Proceedings of the National Academy of Sciences of the United States of America

Human fibroblasts whose lifespan in culture has been extended by expression of a viral oncogene eventually undergo a growth crisis marked by failure to proliferate. It has been proposed that telomere shortening in these cells is the property that limits their proliferation. Here we report that ectopic expression of the wild-type reverse transcriptase protein (hTERT) of human telomerase averts crisis, at the same time reducing the frequency of dicentric and abnormal chromosomes.

Author(s): 
Zhu, J.
Wang, H.
Bishop, J. M.
Blackburn, E. H.
Publication Title: 
International Journal of Molecular Sciences

Rubinstein-Taybi syndrome (RSTS) is a rare condition with a prevalence of 1 in 125,000-720,000 births and characterized by clinical features that include facial, dental, and limb dysmorphology and growth retardation. Most cases of RSTS occur sporadically and are caused by de novo mutations. Cytogenetic or molecular abnormalities are detected in only 55% of RSTS cases. Previous genetic studies have yielded inconsistent results due to the variety of methods used for genetic analysis.

Author(s): 
Yoo, Hee Jeong
Kim, Kyung
Kim, In Hyang
Rho, Seong-Hwan
Park, Jong-Eun
Lee, Ki Young
Kim, Soon Ae
Choi, Byung Yoon
Kim, Namshin
Publication Title: 
Rivista Di Biologia

An analysis is made of the kin-selection/group-selection debate on the issue of the biological basis of morals. The kin-selection view sees altruism, and morals in the case of humans, as resting solely on genetic factors; in fact, on this view, evolution itself is to take place only through genetic change -- a position which cannot be reconciled with our knowledge that species evolution involves karyotypic change. Morality is thought to stem from a particular gene which at one time was completely absent from the human population but which later entered and spread through it.

Author(s): 
Dilworth, Craig
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