Differential Segment

2001 ◽  
pp. 533
Author(s):  
L. Silver
Keyword(s):  
1974 ◽  
Vol 16 (3) ◽  
pp. 539-548 ◽  
Author(s):  
N. A. Tuleen ◽  
J. H. Gardenhire

Five T1-5 and 10 T1-6 barley translocations were crossed with the translocation T1-7f. Plants in which the T1-5 and T1-6 translocations had been combined with T1-7f due to crossing over in the differential segment were selected in the F2 generation. One of the chromosomes present in plants carrying the translocations in the combined form is made up of parts of the three chromosomes involved in the two translocations, and the segmental arrangement of this tripartite chromosome is determined by the position of the breakpoints in chromosome 1. The karyotypes of these stocks were analyzed and the breakpoints in seven of the translocations were assigned to the same arm and eight to the opposite arm of chromosome 1 relative to the position of the breakpoint in T1-7f.


1982 ◽  
Vol 16 (4) ◽  
pp. 319-328 ◽  
Author(s):  
Dagmar Klein ◽  
Sneh Tewarson ◽  
Felipe Figueroa ◽  
Jan Klein

1972 ◽  
Vol 14 (1) ◽  
pp. 129-137 ◽  
Author(s):  
A. S. Robinson ◽  
C. F. Curtis

The production and fertility of a double translocation heterozygote in Drosophila melanogaster are reported. A difference in the fertility of male and female double heterozygotes was recorded and explained on the basis of crossing over, occurring in the differential segments of female double heterozygotes, producing extra unbalanced gametes. It was shown that crossing over was absent from one differential segment but the amount of crossing over occurring in the other differential segment was measured. The possible use of multiple translocation systems for pest control is discussed with particular reference to the use of double translocation heterozygotes.


2011 ◽  
Vol 250-253 ◽  
pp. 1329-1333
Author(s):  
Yu Min Song ◽  
Ding Jun Wu

In this paper, a differential segment of curved beam in the vibration state is analyzed, and the internal force equilibrium equations are established, then the vibration differential equations of curved beam are derived by considering Timoshenko’s geometric equations and physical equations. The vibration differential equations derived are similar to the Vlasov’s static differential equation of curved beam. By analyzing the vibration differential equations, some characteristics of vibration are obtained, and ideas of solving the vibration differential equations are also proposed. The vibration differential equations of curved beam can be reduced to those of corresponding straight beams, validating the derived vibration differential equation of curved beam.


1946 ◽  
Vol 133 (872) ◽  
pp. 313-326 ◽  

The differential segment of the X -chromosome of Cricetus auratus when its nucleic acid charge is reduced appears as a thin, unspiralized and understained thread. This happens under all conditions which lower the frequency of spermatogenesis and in proportion to their effect in doing so, viz. winter conditions (anoestrus), undernourishment, disease and old age. The frequency of the effect is variable, ranging from nil to 90% of cells in a given testis. In up to 3% of cells, the starvation of the differential segment is recognizable but incomplete. In 10 % the sex bivalent could not be recognized and its differential segment was assumed to be fully charged. When conditions lead to extreme nucleic acid depletion there is some failure of chiasma formation and metaphase pairing of both autosomes and sex chromosomes. This indirect deprivation of nucleic acid, like that directly induced by cold, suppresses spiralization and hinders division or separation of the chromosome threads. Extreme food starvation, combined with senility, stops spermatogenesis at the pachytene stage, presumably owing to protein as well as nucleic acid starvation. The variability of nucleic acid charge in a warm-blooded animal as opposed to its regularity when reduced by cold in plants and Amphibia seems to be due to its dependence on the supply of ribose nucleic acid and not on the simpler chemical process of conversion of this supply into the desoxyribose form. The sensitivity of heterochromatin to variation in nucleic acid supply makes it possible to use its behaviour as an indicator of nucleic acid metabolism.


1997 ◽  
Vol 29 (3) ◽  
pp. 1769 ◽  
Author(s):  
D. Křenová ◽  
T.W. Kurtz ◽  
J.M. Wang ◽  
M. Pravenec ◽  
V. Křen

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