scholarly journals Introduced Swedish Canada geese (Branta canadensis) have low levels of genetic variation as revealed by DNA fingerprinting

1995 ◽  
Vol 8 (2) ◽  
pp. 195-207 ◽  
Author(s):  
H>>kan Tegelstrom ◽  
Goran Sjoberg
1997 ◽  
Vol 6 (3) ◽  
pp. 241-245
Author(s):  
Kristiina Antonius ◽  
Gun Werlemark ◽  
Hilde Nybom

Most blackberry plants cultivated in Finland closely resemble the American species Rubus allegheniensis. Thirty nine such blackberry accessions in the University of Helsinki clone collection were studied by hybridization-based DNA fingerprinting and compared with some known cultivars of R. allegheniensis derivation. ‘lmperial’ appears to be identical to the old cultivar ‘Majestät’, but ‘Earliest of All’ differs considerably. In addition, 37 of the accessions analysed also have DNA fingerprints that appear to be completely identical to that of ‘Majestät’! The remaining two accessions, although identical to each other, exhibit one band not found in ‘Majestät’ that is probably caused by a somatic mutation.


Genetics ◽  
2003 ◽  
Vol 163 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Arjun Sivasundar ◽  
Jody Hey

AbstractCaenorhabditis elegans has become one of the most widely used model research organisms, yet we have little information on evolutionary processes and recent evolutionary history of this widespread species. We examined patterns of variation at 20 microsatellite loci in a sample of 23 natural isolates of C. elegans from various parts of the world. One-half of the loci were monomorphic among all strains, and overall genetic variation at microsatellite loci was low, relative to most other species. Some population structure was detected, but there was no association between the genetic and geographic distances among different natural isolates. Thus, despite the nearly worldwide occurrence of C. elegans, little evidence was found for local adaptation in strains derived from different parts of the world. The low levels of genetic variation within and among populations suggest that recent colonization and population expansion might have occurred. However, the patterns of variation are not consistent with population expansion. A possible explanation for the observed patterns is the action of background selection to reduce polymorphism, coupled with ongoing gene flow among populations worldwide.


The Auk ◽  
2000 ◽  
Vol 117 (3) ◽  
pp. 651-662 ◽  
Author(s):  
Corinne Rabouam ◽  
Vincent Bretagnolle ◽  
Yves Bigot ◽  
Georges Periquet

Abstract We used DNA fingerprinting to assess genetic structure of populations in Cory's Shearwater (Calonectris diomedea). We analyzed mates and parent-offspring relationships, as well as the amount and distribution of genetic variation within and among populations, from the level of subcolony to subspecies. We found no evidence of extrapair fertilization, confirming that the genetic breeding system matches the social system that has been observed in the species. Mates were closely related, and the level of genetic relatedness within populations was within the range usually found in inbred populations. In contrast to previous studies based on allozymes and mtDNA polymorphism, DNA fingerprinting using microsatellites revealed consistent levels of genetic differentiation among populations. However, analyzing the two subspecies separately revealed that the pattern of genetic variation among populations did not support the model of isolation by distance. Natal dispersal, as well as historic and/or demographic events, probably contributed to shape the genetic structure of populations in the species.


2018 ◽  
Vol 56 (11) ◽  
pp. 813-821
Author(s):  
Daisy Pérez-Brito ◽  
Alberto Cortes-Velázquez ◽  
Teresita Valencia-Yah ◽  
Anuar Magaña-Álvarez ◽  
Cuauhtémoc Navarro ◽  
...  

1981 ◽  
Vol 59 (3) ◽  
pp. 493-497 ◽  
Author(s):  
Robert C. Skene ◽  
O. Remmler ◽  
M. A. Fernando

A survey of adult Canada geese, Branta canadensis, at Kortright Waterfowl Park in Guelph, Ontario, Canada, showed that 20% of the geese sampled passed small numbers of coccidial oocysts throughout the winter months (October 1975 to February 1976). Four species of coccidia, Eimeria hermani Farr, 1953, E. magnalabia Levine, 1951, E. truncata (Raillet and Lucet, 1891) Wasielewski, 1904, and Tyzzeria parvula (Kotlan, 1933) Klimes, 1963, were identified from the samples examined. A hitherto undescribed Isospora sp. was found in 5% of the fecal samples. It is named Isospora anseris and described as a new species. In the spring goslings were found to be passing E. hermani oocysts between the 8th and 13th day of hatching.


1996 ◽  
Vol 199 (1-2) ◽  
pp. 1-15 ◽  
Author(s):  
Cheryl S. Roesel ◽  
W. John Kress ◽  
Brunella Martire Bowditch
Keyword(s):  

2002 ◽  
Vol 62 (3) ◽  
pp. 503-508 ◽  
Author(s):  
N. MORAES ◽  
J. S. MORGANTE ◽  
C. Y. MIYAKI

In this study we analyzed a population of Bradypus torquatus with individuals originally distributed in different localities of Bahia, and two populations of B. variegatus with individuals from Bahia and São Paulo States. Using the DNA fingerprinting method, we assessed the genetic variability within and between populations. Analysis of the DNA profiles revealed genetic similarity indices ranging from 0.34 ± 0.07 to 0.87 ± 0.04. Similar low levels of genetic variability were found only in isolated mammalian populations or among related individuals. This study presents the first analyses of genetic diversity in sloth populations.


The Auk ◽  
1988 ◽  
Vol 105 (4) ◽  
pp. 749-755 ◽  
Author(s):  
John P. Badgerow

Abstract I analyzed formations of Canada Geese (Branta canadensis) with a single, direct method of testing predictions from multiple hypotheses. The results support both energetic (aerodynamic) advantage and orientation communication through visual contact as functions of this complex behavior. Comparison of observed positioning patterns with criteria for optimal function suggests priority may be given to the maximization of energy savings within limits imposed by environmental and other constraints.


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