On the Chromosomes of Four Species of Indian Snakes

Sharma, O. P.; Kour, Gurpreet

doi:10.1508/cytologia.70.65

Cited by 1 publication

(1 citation statement)

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“…In accordance with previous studies [ 11 , 45 , 46 ], we conclude that all species of sand boas so far examined share a diploid chromosome number of 2n = 34, which is possibly an apomorphy of Erycidae, as species from closely related groups have mostly 2n = 36 chromosomes [ 7 , 13 , 23 , 47 , 48 ]. However, while all other sand boas have 16 macrochromosomes and 18 microchromosomes and share chromosome morphology, E. colubrinus has 20 macrochromosomes and 14 microchromosomes.…”

Section: Discussionsupporting

confidence: 92%

Cytogenetic Analysis of the Members of the Snake Genera Cylindrophis, Eryx, Python, and Tropidophis

Charvát

Augstenová

Frynta

et al. 2022

Genes

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The recent discovery of two independently evolved XX/XY sex determination systems in the snake genera Python and Boa sparked a new drive to study the evolution of sex chromosomes in poorly studied lineages of snakes, where female heterogamety was previously assumed. Therefore, we examined seven species from the genera Eryx, Cylindrophis, Python, and Tropidophis by conventional and molecular cytogenetic methods. Despite the fact that these species have similar karyotypes in terms of chromosome number and morphology, we detected variability in the distribution of heterochromatin, telomeric repeats, and rDNA loci. Heterochromatic blocks were mainly detected in the centromeric regions in all species, although accumulations were detected in pericentromeric and telomeric regions in a few macrochromosomes in several of the studied species. All species show the expected topology of telomeric repeats at the edge of all chromosomes, with the exception of Eryx muelleri, where additional accumulations were detected in the centromeres of three pairs of macrochromosomes. The rDNA loci accumulate in one pair of microchromosomes in all Eryx species and in Cylindrophis ruffus, in one macrochromosome pair in Tropidophis melanurus and in two pairs of microchromosomes in Python regius. Sex-specific differences were not detected, suggesting that these species likely have homomorphic, poorly differentiated sex chromosomes.

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