Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1990-11-21
pubmed:abstractText
The pachytene behavior of chromosomes participating in quadrivalent formation in male mice heterozygous for T(X;4)7Rl or T(X;4)8Rl was analyzed in electron micrographs of microspread spermatocytes. In each population of nuclei from the translocation heterozygotes, the longest 4X axes were approximately the proportional length expected from the respective contributions of the 4 and the X estimated from breakpoint positions in mitotic chromosomes. However, the 4X axis of these translocation quadrivalents undergoes extensive shortening. In both R7 and R8 the shortest 4X axis observed in the population of nuclei was approximately the length of the normal 4 axis. This equalization of axial lengths suggests that there may be an interchromosomal interaction between synapsed chromosomes. In R8, axial shortening of the 4X occurs as pachynema progresses. In both translocations, shortening is accompanied by twisting of the 4X around the 4. Both axial shortening and twists are characteristics exhibited by chromosomal axes of unequal length as part of the meiotic phenomenon described as "synaptic adjustment" (Moses, 1977). Synaptic adjustment involves, in addition, nonhomologous synapsis, which is delayed until the latter part of pachynema. However, axial shortening in R7 and R8 is not accompanied by nonhomologous synapsis. In R7, nonhomologous synapsis does not occur; in R8, it is confined to quadrivalents in which the 4X axis is near its maximum length (i.e., early). This behavior suggests that axial shortening and nonhomologous synapsis during the progression of pachynema (previously considered collectively under the term "synaptic adjustment") are not necessarily coupled events.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0301-0171
pubmed:author
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
185-90
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Axial shortening during pachynema unrelated to nonhomologous synapsis.
pubmed:affiliation
Department of Zoology, University of Tennessee, Knoxville 37996.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.