Nucleolar organiser region (NOR) location in karyotypes of Australian ground frogs (family Myobatrachidae)

Mahony, Michael; Robinson, E. S.

doi:10.1007/bf02424409

Cited by 28 publications

(26 citation statements)

References 17 publications

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“…In agreement with earlier investigations (Morescalchi and Ingram, 1974;King et al, 1979;Mahony and Robinson, 1986), both species have a diploid chromosome number of 2n = 24. All chromosomes are biarmed and can be arranged in 12 pairs (Fig.…”

Section: Constitutive Heterochromatin and Nucleolus Organizer Regionssupporting

confidence: 79%

“…A small number of studies on the chromosomes of the genus Mixophyes have been performed using conventional staining and silver labeling of the nucleolus organizer regions (Morescalchi and Ingram, 1974;King et al, 1979;Mahony and Robinson, 1986). All four species possess 2n = 24 very similar biarmed chromosomes and one pair of nucleolus organizers.…”

confidence: 99%

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Chromosome banding in Amphibia

Schmid

Haaf

Steinlein

et al. 2002

Cytogenet Genome Res

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The mitotic chromosomes of the Australian ground frogs Mixophyes fasciolatus and M. schevilli were analyzed by means of banding techniques and restriction endonuclease digestions. Chromosomal differentiation in these two species occurred exclusively by considerable changes in the amount of telomeric and centromeric heterochromatin, whereas the sizes and locations of interstitial heterochromatic regions, the sizes of all euchromatic segments as well as the positions of centromeres remained nearly identical during karyotype evolution. The major heterochromatic regions in the karyotypes of M. fasciolatus and M. schevilli amount to 30.2% and 20.7%, respectively. They consist of AT base pair-rich repetitive DNA sequences that are brightly labeled by AT-specific fluorochromes and display quenched fluorescence after staining with GC-specific fluorochromes. The heterochromatic regions can be differentiated by treatment of metaphase chromosomes and interphase cell nuclei with various restriction enzymes which either disclose the complete set of C-band patterns in the karyotypes of both species, or else reveal several subsets of these C-bands.

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Section: Constitutive Heterochromatin and Nucleolus Organizer Regionssupporting

confidence: 79%

confidence: 99%

Chromosome banding in Amphibia

Schmid

Haaf

Steinlein

et al. 2002

Cytogenet Genome Res

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“…Multiple NOR-bearing chromosome pairs have been considered a derived state in Anurd , and have been found in species from different families (SCHMID 1978b;MAHONY and ROBINSON 1986;WILEY et al 1989;SCHMID et al 1995;LOURENGO et al 1998a). The evolutionary origin of multiple NORs in anurans probably includes events such as inversions, translocations, transposition by mobile genetic elements, amplification of "orphan" rDNA cistrons, and reinsertion errors during extrachromosomal amplification of ribosomal cistrons, as have been discussed by several authors (WILEY et al 1989;KING et al 1990;FOOTE et al 1991;SCHMID et al 1995;LOURENGO et al 1998a).…”

Section: Discussionmentioning

confidence: 99%

Cytogenetics of two Species of Paratelmatobius (Anura: Leptodactylidae), with Phylogenetic Comments

2004

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In this paper we provide a cytogenetic analysis of Paratelmatobius cardosoi and Paratelmatobius poecilogaster. The karyotypes of both species showed a diploid number of 24 chromosomes and shared some similarity in the morphology of some pairs. On the other hand, pairs 4 and 6 widely differed between these complements. These karyotypes also differed in their NOR number and location. Size heteromorphism was seen in all NOR-bearing chromosomes of the two karyotypes. In addition, both karyotypes showed small centromeric C-bands and a conspicuous heterochromatic band in the short arm of chromosome 1, although with a different size in each species. The P. curdosoi complement also showed other strongly stained non-centromeric C-bands, with no counterparts in the P. curdosoi karyotype. Chromosome staining with fluorochromes revealed heterogeneity in the base composition of two of the non-centromeric C-bands of P . curdosoi.Comparison of the chromosomal morphology of these Parutelmatohius karyotypes with that of P. Iutzii showed that the P . poeciloguster karyotype is more similar to that of P . lutzii than P. cardosoi. These cytogenetic results agree with the proposed species arrangements in the P. curdosoi and P. lutzii groups based on morphological and ecological data. SP, The genus Paratelmatobius Lutz and Carvalho is endemic to Brazil and comprises the species P. lutzii, P. gaigeae, P. poecilogaster, P. cardosoi and P. mantiqueira (see review by POMBAL JR. and HADDAD 1999). Paratelmatobius species are usually rare, and P. gaigeae, P. lutzii and P. mantiqueira may be considered as missing species (POMBAL JR. and HADDAD 1999). Based on morphological and ecological data, POMBAL JR. and HADDAD (1999) recognized two species groups, the P. cardosoi group and the P. lutzii group, in this genus. The former group contains P. cardosoi and P. mantiqueira and the P. lutzii group encompasses P. lutzii, P. poecilogaster, and probably P. gaigeae. Shirlei Muriu Recco-Pimentel, Departamenin de Biologia Cellular, IB Universidude Esradual de Cumpinas (UNICAMP)The intergeneric phylogenetic relationships of this group are not yet clear. LYNCH (1971) considered Paratelmatobius a member of the subfamily Leptodactylinae and pointed out some morphological similarities among Paratelmatobius, Scythrophrys, Physalaemus and, to a lesser extent, Zachaenus. This classification was followed by FROST (1999). HEYER (1975) Paratelmatobius grouped together with the genera Scythrophrys, Zuchaenus, Thoropa, Megaelosia, Hylodes, Cycloramphus, Crossodactylus, Crossodactylodes and Craspedoglossa. The proximity between the genera Paratelmatobius and Scythrophrys, suggested by LYNCH (1971) andHEYER (1975), was also indicated by GARCIA (1996). Based on ecological and morphological characters, GARCIA (1 996) suggested a closer relationship between Scythrophrys and P. gaigeae ( = P. cardosoi sensu POMBAL JR. and HAD-DAD 1999) than between this species of Paratelmatobius and P. lutzii, and suggested a revision of both of these genera.The cytogenetic informatio...

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“…During the spring and summer of 1991-1992 the area was visited routinely once again. During the first nine years the reasons for trips were primarily for the purpose of genetic and systematic studies (Mahony and Robinson 1988), and there was no thought that measures of abundance were necessary because there had been no alarm bells on the subject. However, field notes were compiled for distribution, and at times notes were added about the abundance of particular species.…”

Section: Methodsmentioning

confidence: 99%

The status of frogs in the Watagan Mountains area the Central Coast of New South Wales

Mahony¹

1993

Herpetology in Australia

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The composition of frog communities and the numbers of the various species present have been studied for over 15 years in several habitats in the Watagan l\/lountains area of New South Wales, making it possible to document changes in these features over this period. The habitats studied include two ponds, three streams, one site with both ponds and a stream, and several ephemeral situations. Fifteen myobatrachid and 15 hylid species occur in the area. During the period of the study five species have disappeared -three myobatrachids and two hylids. These are two species of Great Barred River frog (Mixophyes balbus and M. iteratus) that breed in streams; one pond species -the Green and Golden Bell Frog {Utoria aurea), and two species that breed in ephemeral situations, Bibron's Toadlet {Pseudophryne bibroni) and an as yet undescribed species of tree frog. Although quantitative measures of abundance were not recorded over the entire period of the study, there was an apparent decline in the number of stream frogs, while the numbers of most species that breed in ponds and ephemeral situations appear to have remained unchanged. To understand the causes of the disappearances and declines there is a need to establish an active research programme involving experimental manipulations to eludicate the causes combined with the establishment of long-term monitoring sites and survey programmes.

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Nucleolar organiser region (NOR) location in karyotypes of Australian ground frogs (family Myobatrachidae)

Cited by 28 publications

References 17 publications

Chromosome banding in Amphibia

Chromosome banding in Amphibia

Cytogenetics of two Species of Paratelmatobius (Anura: Leptodactylidae), with Phylogenetic Comments

The status of frogs in the Watagan Mountains area the Central Coast of New South Wales

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