B chromosome


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B chromosome

Genetics A supernumerary–'extra' segment of DNA present in many species, which may be driven to self-duplicate, as BCs are transmitted at higher rates than otherwise expected from classic mendelian genetics
References in periodicals archive ?
It is not know whether Bs in Lolium perenne drive, but several studies have shown that the more densely plants with B chromosome are planted, the better they survive.
Thus, the objective of this study was the assessment and comparison of the number and behaviour of B chromosome during the meiosis and mitosis of an accession of Lolium multiflorum.
Only one accession (ETBAZ 055--from Capao do Leao, Rio Grande do Sul State, Brazil) showed B chromosome.
Such variations in the number of B chromosome between cells have been reported already for Lolium by HOVIN & HILL (1966) and for other species by POWELL & BURTON (1966); JONES (1975); RAO & PANTULU (978) and RICCI et al.
In meiocytes with one B chromosome, they (chromosomes) appear as univalent in diakinesis and metaphases I; when in number of two, they form bivalents.
The B chromosome of maize has a complex genetic organization with at least four different regions that influence the nondisjunction process, which happens on the male side only.
Studies on B chromosome stability during development.
Is maize B chromosome preferential fertilization controlled by a single gene?
Selection of B chromosome in Secale cereale and Lolium perenne.
B chromosome in plants: escapees from the A chromosome genome?
On the mechanism of chromatin loss induced by the B chromosome of maize.
In the mealy bug, for example, the B chromosome hitches a ride on those chromosomes that remain active whether offspring become male or female.