Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1987-10-7
pubmed:abstractText
Vertical starch gel electrophoresis and trefoil immunodiffusion were used to study the systematics of some ascaridoid nematodes. Within the Ascarididae, the time scale of divergence was too great for intergeneric electrophoretic comparisons. Congeneric electrophoretic comparisons of Baylisascaris procyonis (host--raccoon) versus Baylisascaris transfuga (host--black bear), and Toxocara canis (host--domestic dog) versus Toxocara cati (host--domestic cat) yielded Nei genetic distance coefficients of 1.21 and 1.55, respectively. Estimates of times of divergence made from 1 electrophoretic clock calibration suggest that the Baylisascaris species have not shared a common ancestor for 25 million years (Myr), and that the Toxocara species diverged 33 Myr ago. The Baylisascaris divergence estimate corresponds to host-family divergence estimates based on immunological and paleontological evidence, which suggests that cospeciation has occurred. In contrast to this, Ascaris suum (host--pig) and Ascaris lumbricoides (host--human) have a distance coefficient of 0.09. This indicates that these species diverged comparatively recently and may represent a case of host range expansion. Trefoil immunodiffusion comparisons of ascaridoid albumins yielded reactions of identity for A. suum, A. lumbricoides, Parascaris equorum, B. procyonis, B. transfuga, T. canis, and T. cati. This confirms that these taxa are members of a monophyletic group.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-3395
pubmed:author
pubmed:issnType
Print
pubmed:volume
73
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
811-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Biochemical and immunological systematics of some ascaridoid nematodes: genetic divergence between congeners.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't