scholarly journals Biochemical Systematics of Geomys breviceps and Two Chromosomal Races of Geomys attwateri in Eastern Texas

1999 ◽  
Vol 80 (3) ◽  
pp. 799-809 ◽  
Author(s):  
M. S. Burt ◽  
R. C. Dowler
Keyword(s):  
Chromosomal Races ◽  
Geomys Breviceps

Gene Flow Between Chromosomal Races and Species

2019 ◽  
pp. 313-335
Author(s):  
Glenn Yannic ◽  
Patrick Basset ◽  
Agnès Horn ◽  
Jacques Hausser
Keyword(s):  
Gene Flow ◽  
Chromosomal Races

Geomys breviceps

1991 ◽  
pp. 1 ◽  
Author(s):  
James M. Sulentich ◽  
Lawrence R. Williams ◽  
Guy N. Cameron
Keyword(s):  
Geomys Breviceps

scholarly journals Genic differentiation and origin of Robertsonian populations of the house mouse (Mus musculus domesticus Rutty)

1989 ◽  
Vol 53 (1) ◽  
pp. 29-44 ◽  
Author(s):  
Janice Britton-Davidian ◽  
Joseph H. Nadeau ◽  
Henri Croset ◽  
Louis Thaler
Keyword(s):  
Gene Flow ◽  
House Mouse ◽  
Mus Musculus ◽  
Western Europe ◽  
Chromosomal Rearrangements ◽  
Nuclear Gene ◽  
Electrophoretic Analysis ◽  
Mus Musculus Domesticus ◽  
Effective Population ◽  
Chromosomal Races

SummaryThis paper examines the relation between chromosomal and nuclear-gene divergence in 28 wild populations of the house mouse semi-species, Mus musculus domesticus, in Western Europe and North Africa. Besides describing the karyotypes of 15 of these populations and comparing them to those of 13 populations for which such information was already known, it reports the results of an electrophoretic survey of proteins encoded by 34 nuclear loci in all 28 populations. Karyotypic variation in this taxon involves only centric (or Robertsonian) fusions which often differ in arm combination and number between chromosomal races. The electrophoretic analysis showed that the amount of genic variation within Robertsonian (Rb) populations was similar to that for all-acrocentric populations, i.e. bearing the standard karyotype. Moreover, divergence between the two types of populations was extremely low. These results imply that centric fusions in mice have not modified either the level or the nature of genic variability. The genetic similarity between Rb and all-acrocentric populations is not attributed to the persistence of gene flow, since multiple fusions cause marked reproductive isolation. Rather, we attribute this extreme similarity to the very recent origin of chromosomal races in Europe. Furthermore, genic diversity measures suggest that geographically separated Rb populations have in situ and independent origins. Thus, Rb translocations are probably not unique events, but originated repeatedly. Two models are presented to explain how the rapid fixation of a series of chromosomal rearrangements can occur in a population without lowering variability in the nuclear genes. The first model assumes that chromosomal mutation rates are between 10−3 and 10−4 and that populations underwent a series of transient bottlenecks in which the effective population size did not fall below 35. In the second model, genic variability is restored following severe bottlenecks, through gene flow and recombination.

scholarly journals Spatial and Temporal Dynamics of Contact Zones Between Chromosomal Races of House Mice, Mus musculus domesticus, on Madeira Island

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 748 ◽  
Author(s):  
Joaquim T. Tapisso ◽  
Sofia I. Gabriel ◽  
Ana Mota Cerveira ◽  
Janice Britton-Davidian ◽  
Guila Ganem ◽  
...  
Keyword(s):  
Contact Zone ◽  
Temporal Dynamics ◽  
Significant Shift ◽  
Mus Musculus Domesticus ◽  
Landscape Resistance ◽  
Sampling Area ◽  
Contact Zones ◽  
Madeira Island ◽  
The North ◽  
Chromosomal Races

Analysis of contact zones between parapatric chromosomal races can help our understanding of chromosomal divergence and its influence on the speciation process. Monitoring the position and any movement of contact zones can allow particular insights. This study investigates the present (2012–2014) and past (1998–2002) distribution of two parapatric house mouse chromosomal races—PEDC (Estreito da Calheta) and PADC (Achadas da Cruz)—on Madeira Island, aiming to identify changes in the location and width of their contact. We also extended the 1998–2002 sampling area into the range of another chromosomal race—PLDB (Lugar de Baixo). Clinal analysis indicates no major geographic alterations in the distribution and chromosomal characteristics of the PEDC and PADC races but exhibited a significant shift in position of the Rb (7.15) fusion, resulting in the narrowing of the contact zone over a 10+ year period. We discuss how this long-lasting contact zone highlights the role of landscape on mouse movements, in turn influencing the chromosomal characteristics of populations. The expansion of the sampling area revealed new chromosomal features in the north and a new contact zone in the southern range involving the PEDC and PLDB races. We discuss how different interacting mechanisms (landscape resistance, behaviour, chromosomal incompatibilities, meiotic drive) may help to explain the pattern of chromosomal variation at these contacts between chromosomal races.

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