centric fusion

ro·bert·so·ni·an trans·lo·ca·tion

translocation in which the centromeres of two acrocentric chromosomes appear to have fused, forming an abnormal chromosome consisting of the long arms of two different chromosomes with loss of the short arms. A carrier of a balanced robertsonian translocation has only 45 chromosomes but near normal chromosomal complement and a clinically normal phenotype; however, he or she is at risk of having a child with unbalanced chromosomal complement. A person with an unbalanced robertsonian translocation is trisomic for the long arm of the chromosome.
Synonym(s): centric fusion
[W.R.B. Robertson, U.S. geneticist.]

ro·bert·so·ni·an trans·lo·ca·tion

(rob'ĕrt-sō'nē-ăn tranz'lō-kā'shŭn)
Translocation in which the centromeres of two acrocentric chromosomes appear to have fused, forming an abnormal chromosome consisting of the long arms of two different chromosomes; if the translocation is balanced, the individual is clinically normal but a carrier of the translocation; if the translocation is unbalanced, the individual is trisomic for the long arm of a chromosome.
Synonym(s): centric fusion.
[W.R.B. Robertson, U.S. geneticist.]

centric fusion

the joining together of two ACENTRIC CHROMOSOMES to produce one METACENTRIC CHROMOSOME.

Robertson,

W.R.B., U.S. geneticist, 1881–.
robertsonian translocation - translocation in which the centromeres of two acrocentric chromosomes appear to have fused, forming an abnormal chromosome. Synonym(s): centric fusion
References in periodicals archive ?
The large Y chromosome in both species likely represents centric fusion between an autosome and a morphologically cryptic Y chromosome, giving rise to a situation of multiple sex chromosomes: [X.
The independent origins of multiple sex chromosomes via centric fusion involving a cryptic Y chromosome in the widely divergent Megupsilon and Garmanella suggests that cryptic male heterogamety (XY) might have characterized the most-recent common ancestor of the Cyprinodontina.
Chromosome polymorphisms and natural selection in Leptysma argentina (Orthoptera): external phenotype affected by a centric fusion predicts adult survival.
2004) failed to detect the centric fusions in a population from Sao Lourenco da Mata, Pernambuco, Brazil (latitude 8[degrees]S), so at the moment the only described chromosome rearrangements are those found in Argentina.
aquaticum sited in the middle and lower course of the Parana River were polymorphic for 3 centric fusions (1/6, 2/5, and 3/4).
Once a neo-XY system has arisen by centric fusion, it may undergo a further conversion into an X1X2Y system through a Y-autosome fusion, if a second pair of teleo/acrocentric autosomes is available to become incorporated into the sex-chromosome mechanism (White 1973, Hewitt 1979, Castillo et al.
2]Y mechanisms derive from previous XY systems through centric fusion of the neo-Y with a second autosome (the unfused element becoming X2, see above), it is probable that all known cases have originated from advanced XY systems.
The Y chromosome originated by the centric fusion of a large neo-Y and a medium-size autosome.
The neo-X and neo-Y are the result of a centric fusion involving the former X acrocentric chromosome with an A1 chromosome of the acrocentric autosome pair A1A2 of the standard karyotype.
There was a centric fusion involving a long acrocentric X chromosome, the biggest one ofthe set, which is totally heteropicnotic during the first prophase; the biggest of the second group was formed by acrocentric autosomes, giving rise to the biggest element of the set that becomes submetacentric and is now recognized as neo-X.
The same karyotypic particularities are observed in specimens from Boraceia Reserve (Sao Paulo) and Mantiqueira Mts (Minas Gerais); the presence of a relatively recent centric fusion involving the X chromosome and a medium-sized autosome, giving origin to a sex mechanism of neo-XY type, together with an autosome-autosome fusion and a process of chromatin integration, all are excellent characters for species identification.
Causes of chiasma repatterning due to centric fusions.