Thanks.
Ploidy has to do with the number of complete sets of chromosomes. Diploid cells contain two complete sets. Octoploid cells have eight.
What grif said.
As Grif said, diploid is two sets of chromosomes - one set from the male and one from the female. A few species of frogs are considered polyploidy or having more than one pair. It is likely the diploid represents the most ancient of the species within the genus. Among frogs, the genus Xenopus (African clawed frogs) has the most diverse of chromosome numbers - there are species that are diploid (2 sets); tetraploid (4 sets); octoploid (8 sets) and dodecaploid (12 sets).
Often times, identification of a particular species can be extremely difficult due to "cryptic species" - a group of species which satisfy the biological definition of species—that is, they are reproductively isolated from each other—but whose body characteristics are very similar (in some cases virtually identical). The only way to tell them apart is by advertisement call and analyzing the DNA. A great example concerns the two species of gray treefrogs of North America - they are physically identical, their call and DNA are different. Hyla chrysoscelis is diploid (call is of higher pitch) and H. versicolor is tetraploid (lower pitch).
Another detailed study of cryptic species is on the sand frogs of Southern Africa (genus Tomopterna, also known as "pyxie frogs" and a relative to the African bullfrog).
Terry Gampper
Nebraska Herpetological Society
“If we can discover the meaning in the trilling of a frog, perhaps we may understand why it is for us not merely noise but a song of poetry and emotion.”
--- Adrian Forsyth
Chromosome banding in Amphibia. IX. The polyploid karyotypes of Odontophrynus americanus and Ceratophrys ornata (Anura, Leptodactylidae).
Abstract
Schmid M, Haaf T, Schempp W.
The somatic and meiotic chromosomes of the South American leptodactylid toads Odontophrynus americanus, Ceratophyrys ornata, and C. cranwelli were analysed both with conventional staining and differential banding techniques. The karyotypes of O. americanus were tetraploid; those of C. ornata octaploid. Ceratophrys cranwelli is a diploid species whose karyotype displays great similarities with that of C. ornata. The high frequency of multivalent pairing configurations in the meioses of O. americanus and C. ornata indicate that these animals were of autopolyploid origin. The conventionally stained somatic chromosomes of O. americanus can be arranged into sets of four similar chromosomes (quartets); those of C. ornata, into sets of eight similar chromosomes (octets). The banding patterns revealed heterogeneity within some quartets of O. americanus, dividing each of them into two pairs of homologous chromosomes. In analogy, some octets of C. ornata can be subdivided into two quartets of chromosomes with homologous bands. These structural heterogeneities within the quartets and octets are interpreted as a "diploidization" of the polyploid karyotypes. Diploidization leads to genomes that are polyploid with respect to the amount of genetic material and diploid with respect to chromosomal characteristics and the level of gene expression. In tetraploid O. americanus, the number of nucleolus organizer regions (NORs) and their DNA content is proportional to the degree of ploidy. In contrast, up to eight NORs have been deleted in the octoploid C. ornata. These NOR losses are discussed as a possible reason for the reduction of genetic activity in polyploid genomes.
A recent journal article detailing the diploid and octoploid relationships between Pacman Frogs (Horned Frogs), particularly the Chacoan Horned Frog (Ceratophrys cranwelli) and Ornate Horned Frog (Ceratophrys ornata).
http://www.bioone.org/doi/abs/10.2994/SAJH-D-14-00032.1
You can get the full article from the authors here:
https://www.researchgate.net/profile...tophryidae.pdf
Founder of Frogforum.net (2008) and Caudata.org (2001)
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