Chromosomal identification and meiotic behavior of reciprocal translocations in a rye polymorphic population. Evolutionary implications

1990 ◽  
Vol 79 (5) ◽  
pp. 686-692 ◽  
Author(s):  
A. M. Figueiras ◽  
M. T. González-Jaén ◽  
M. Candela
1976 ◽  
Vol 17 (2) ◽  
pp. 98-111 ◽  
Author(s):  
A.C. Chandley ◽  
H. Seuánez ◽  
J.M. Fletcher

2008 ◽  
Vol 10 (10) ◽  
pp. 730-738 ◽  
Author(s):  
Ester Anton ◽  
Francesca Vidal ◽  
Joan Blanco

Crop Science ◽  
1966 ◽  
Vol 6 (2) ◽  
pp. 127-131 ◽  
Author(s):  
Hugh W. Bennett ◽  
Norman C. Merwine
Keyword(s):  

Crop Science ◽  
1964 ◽  
Vol 4 (5) ◽  
pp. 483-486 ◽  
Author(s):  
E. A. Wernsman ◽  
W. F. Keim ◽  
R. L. Davis
Keyword(s):  

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 250
Author(s):  
Rebecca E O’Connor ◽  
Lucas G Kiazim ◽  
Claudia C Rathje ◽  
Rebecca L Jennings ◽  
Darren K Griffin

With demand rising, pigs are the world’s leading source of meat protein; however significant economic loss and environmental damage can be incurred if boars used for artificial insemination (AI) are hypoprolific (sub-fertile). Growing evidence suggests that semen analysis is an unreliable tool for diagnosing hypoprolificacy, with litter size and farrowing rate being more applicable. Once such data are available, however, any affected boar will have been in service for some time, with significant financial and environmental losses incurred. Reciprocal translocations (RTs) are the leading cause of porcine hypoprolificacy, reportedly present in 0.47% of AI boars. Traditional standard karyotyping, however, relies on animal specific expertise and does not detect more subtle (cryptic) translocations. Previously, we reported development of a multiple hybridisation fluorescence in situ hybridisation (FISH) strategy; here, we report on its use in 1641 AI boars. A total of 15 different RTs were identified in 69 boars, with four further animals XX/XY chimeric. Therefore, 4.5% had a chromosome abnormality (4.2% with an RT), a 0.88% incidence. Revisiting cases with both karyotype and FISH information, we reanalysed captured images, asking whether the translocation was detectable by karyotyping alone. The results suggest that chromosome translocations in boars may be significantly under-reported, thereby highlighting the need for pre-emptive screening by this method before a boar enters a breeding programme.


Genetics ◽  
1997 ◽  
Vol 147 (1) ◽  
pp. 289-296 ◽  
Author(s):  
Jason Ehrlich ◽  
David Sankoff ◽  
Joseph H Nadeau

Abstract An important problem in comparative genome analysis has been defining reliable measures of synteny conservation. The published analytical measures of synteny conservation have limitations. Nonindependence of comparisons, conserved and disrupted syntenies that are as yet unidentified, and redundant rearrangements lead to systematic errors that tend to overestimate the degree of conservation. We recently derived methods to estimate the total number of conserved syntenies within the genome, counting both those that have already been described and those that remain to be discovered. With this method, we show that ~65% of the conserved syntenies have already been identified for humans and mice, that rates of synteny disruption vary ~25-fold among mammalian lineages, and that despite strong selection against reciprocal translocations, inter-chromosome rearrangements occurred approximately fourfold more often than inversions and other intra-chromosome rearrangements, at least for lineages leading to humans and mice.


Genetics ◽  
1976 ◽  
Vol 82 (4) ◽  
pp. 605-627
Author(s):  
Etta Käfer

ABSTRACT To analyze mitotic recombination in translocation heterozygotes of A. nidulans two sets of well-marked diploids were constructed, homo- or heterozygous for the reciprocal translocations T1(IL;VIIR) or T2(IL;VIIIR) and heterozygous for selective markers on IL. It was found that from all translocation heterozygotes some of the expected mitotic crossover types could be selected. Such crossovers are monosomic for one translocated segment and trisomic for the other and recovery depends on the relative viabilities of these unbalanced types. The obtained segregants show characteristically reduced growth rates and conidiation dependent on sizes and types of mono- and trisomic segments, and all spontaneously produce normal diploid sectors. Such secondary diploid types either arose in one step of compensating crossing over in the other involved arm, or—more conspicuously—in two steps of nondisjunction via a trisomic intermediate.—In both of the analyzed translocations the segments translocated to IL were extremely long, while those translocated from IL were relatively short. The break in I for T1(I;VII) was located distal to the main selective marker in IL, while that of T2(I;VIII) had been mapped proximal but closely linked to it. Therefore, as expected, the selected primary crossover from the two diploids with T2(I;VIII) in coupling or in repulsion to the selective marker, showed the same chromosomal imbalance and poor growth. These could however be distinguished visually because they spontaneously produced different trisomic intermediates in the next step, in accordance with the different arrangement of the aneuploid segments. On the other hand, from diploids heterozygous for T1(I;VII) mitotic crossovers could only be selected when the selective markers were in coupling with the translocation; these crossovers were relatively well-growing and produced frequent secondary segregants of the expected trisomic, 2n+VII, type. For both translocations it was impossible to recover the reciprocal crossover types (which would be trisomic for the distal segments of I and monosomic for most of groups VII or VIII) presumably because these were too inviable to form conidia.—In addition to the selected segregants of expected types a variety of unexpected ones were isolated. The conditions of selection used favour visual detection of aneuploid types, even if these produce only a few conidial heads and are not at a selective advantage. For T2(I;VIII) these "non-selected" unbalanced segregants were mainly "reciprocal" crossovers of the same phenotype and imbalance as the selected ones. For T1(I;VII) two quite different types were obtained, both possibly originating with loss of the small VII-Itranslocation chromosome. One was isolated when the selective marker in repulsion to T1(I;VII) was used and, without being homo- or hemizygous for the selective marker, it produced stable sectors homozygous for this marker. The other was obtained from both coupling and repulsion diploids and showed a near-diploid genotype; it produced practically only haploid stable sectors of the type expected from monosomics, 2n-1 for the short translocation chromosome.


2019 ◽  
Vol 13 (2) ◽  
pp. 68-70
Author(s):  
K. H. Venkatesh ◽  
G. S. Pragathi ◽  
M. Shivashankar

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