Potential paralogous contigs located on either chromosome 18 or chromosome 21 (target chromosomes) and alternative autosomes
(reference chromosomes) were identified by sampling each target chromosome at 10-bp intervals in 100-bp segments.
The genus Spalax includes larger species, possessing karyotypes with higher diploid chromosome numbers (2n = 60 or 62) and usually no acrocentric autosomes
. The species of the genus Nannospalax are smaller, their karyotypes are extremely variable (2n = 36-62) and include acrocentric autosomes
(Topachevskii 1969, Lyapunova et al.
The nonhomology could involve different autosomes
involved in the fusion events giving rise to neo-Y chromosomes in each species.
But the deeper branches since discovered are entirely African, the same pattern which the mtDNA and autosomes
For instance, CC2D1A, TRAPPC9 (on autosome
) and AGTR2, GDI1 ( on X chromosome) are involved in signal transduction and in some case they share the common pathway (Table -2).
The evolution of neo-xY1Y2 sex chromosome system by autosome
sex chromosome fusion in Dundocoris nodulicarius Jacobs
Did the platypus XY evolve independently of the bird ZW, and is it a coincidence that parts of them came from the same autosome
? The platypus XY probably evolved independently of the eutherian XY.
destructor from the USA populations was karyotyped (Stuart and Hatchett 1988) and the authors found that female somatic cells have two pairs of autosomes
and two pairs of sex chromosomes (2n = 8), while male somatic cells have two pairs of autosomes
and two monosomic sex chromosomes (2n - 2 = 6).
Sexually reproducing organisms have two major types of chromosomes; that is, sex chromosomes and autosomes
. Sex chromosomes contain genes that are particularly important in determining whether an individual will develop ovaries or testes.
The clones are assayed for autosomal meiotic nondisjunction by crossing clone-bearing females to males that carry a compound autosome
(C(3)EN to screen 2L and C(2)EN to screen 3R).
No cryptic differences were revealed by G-bands among the first 25 pairs of autosomes
. The only variable autosome
is pair 26 that is acrocentric in the European snow voles examined in this study, but metacentric in the other three species.
A number of reports have claimed familial occurrence, supporting single-gene inheritance for HI, but none has been proved.[2,3,8] Miscellaneous chromosomal abnormalities have been demonstrated in some but not all affected individuals and are currently classified into 2 groups[3,9]: (1) various mosaicism for almost any autosome
or sex chromosomes and (2) nonmosaic balanced X;autosome translocations with breakpoints in the juxtacentromeric region of the X Chromosome at Xp11 found so far in a limited group of girls with HI. Such mosaicism is generally not transmissible from one generation to the next, and this could explain the sporadic occurrence of the disorder.