Marsupial Cytogenetics

Hayman, D. L.

doi:10.1071/zo9890331

Cited by 73 publications

(86 citation statements)

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“…As for D. gliroides, it has been repeatedly claimed that, in spite of its South American distribution, this species is more closely related to Australian marsupials (Kirsch et al 1991;Szalay 1994;Spotorno et al 1997;Palma and Spotorno 1999;Janke et al 2002;Amrine-Madsen et al 2003;Nilsson et al 2003). Taken together, such relationships give support to the idea that the special features that sex chromosomes present during meiosis could have originated very early in the evolution of marsupials [stemming at least from the radiation of the extant marsupial orders 64 million years ago (Nilsson et al 2003)], and they would have been line in some marsupial species (Hayman 1990;Palma 1995), including D. gliroides (Gallardo and Paterson 1987). As mentioned above, the absence of recombinathe recombination machinery (Pelttari et al 2001).…”

Section: Specific Phosphorylation Of Sex Chromosomal Aesmentioning

confidence: 70%

The Program of Sex Chromosome Pairing in Meiosis Is Highly Conserved Across Marsupial Species

et al. 2005

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Marsupials present a series of genetic and chromosomal features that are highly conserved in very distant species. One of these features is the absence of a homologous region between X and Y chromosomes. According to this genetic differentiation, sex chromosomes do not synapse during the first meiotic prophase in males, and a special structure, the dense plate, maintains sex chromosome association. In this report we present results on the process of meiotic sex chromosome pairing obtained from three different species, Thylamys elegans, Dromiciops gliroides, and Rhyncholestes raphanurus, representing the three orders of American marsupials. We have investigated the relationships between the axial structures organized along sex chromosomes and the formation of the dense plate. We found that in the three species the dense plate arises as a modification of sex chromosomal axial elements, but without the involvement of other meiotic axial structures, such as the cohesin axes. Considering the phylogenetic relationships among the marsupials studied here, our data reinforce the idea that the dense plate emerged early in marsupial evolution as an efficient mechanism to ensure the association of the nonhomologous sex chromosomes. This situation could have influenced the further evolution of sex chromosomes in marsupials.

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Section: Specific Phosphorylation Of Sex Chromosomal Aesmentioning

confidence: 70%

The Program of Sex Chromosome Pairing in Meiosis Is Highly Conserved Across Marsupial Species

et al. 2005

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“…Conversely, sex chromosomes in almost all eutherian mammals only preserve a small region of homology. The extreme situation is found in some eutherian and in almost all marsupial mammals, in which sex chromosomes do not share any homologous region (Solari and Ashley 1977;Wolf et al 1988;Carnero et al 1991;Hayman 1990;Graves 1996). Moreover, in the species with XX/X0 sex determining system, many insects for instance, the heterogametic sex only bears a copy of the X chromosome.…”

Section: Introductionmentioning

confidence: 99%

Sex chromosomes, synapsis, and cohesins: a complex affair

et al. 2006

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During first meiotic prophase, homologous chromosomes are held together by the synaptonemal complex, a tripartite proteinaceous structure that extends along the entire length of meiotic bivalents. While this feature is applicable for autosomes, sex chromosomes often escape from this rule. Many species present sex chromosomes that differ between them in their morphology, length, and gene content. Moreover, in some species, sex chromosomes appear in a single dose in one of the sexes. In all of these cases, the behavior of sex chromosomes during meiosis is conspicuously affected, and this includes the assembly and dynamics of the synaptonemal complex. We review in this study the structure of the synaptonemal complex in the sex chromosomes of three groups of organisms, namely: mammals, orthopterans, and hemipterans, which present different patterns of sex chromosome structure and behavior. Of special interest is the analysis of the organization of the axial/lateral elements of the synaptonemal complex in relation to other axial structures organized along meiotic chromosomes, mainly the cohesin axis. The differences found in the behavior of both axial structures reveal that while the organization of a cohesin axis along sex chromosomes is a conserved feature in most organisms and it shows very little morphological variations, the axial/lateral elements of the synaptonemal complex present a wide range of structural modifications on these chromosomes.

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“…Captive-based studies indicate that with no chromosomal differences (Hayman and Martin, 1969;Hayman, 1990), successful hybridization between grey kangaroos may occur despite differences in several reproductive traits such as gestation length and the timing and length of the oestrus cycle (Kirsch and Poole, 1972;Poole and Catling, 1974). However, hybridization appears unidirectional, with the only F1s produced resulting from matings between M. giganteus females and M. fuliginosus males, the reciprocal never occurred (Poole and Catling, 1974).…”

Section: Introductionmentioning

confidence: 99%

Molecular detection of hybridization between sympatric kangaroo species in south-eastern Australia

et al. 2009

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Introgressive hybridization has traditionally been regarded as rare in many vertebrate groups, including mammals. Despite a propensity to hybridize in captivity, introgression has rarely been reported between wild sympatric macropodid marsupials. Here we investigate sympatric populations of western (Macropus fuliginosus) and eastern (Macropus giganteus) grey kangaroos through 12 autosomal microsatellite loci and 626 bp of the hypervariable mitochondrial DNA (mtDNA) control region. M. fuliginosus and M. giganteus within the region of sympatry corresponded, both genetically and morphologically, to their respective species elsewhere in their distributions. Of the 223 grey kangaroos examined, 7.6% displayed evidence of introgression, although no F1 hybrids were detected. In contrast to captive studies, there was no evidence for unidirectional hybridization in sympatric grey kangaroos. However, a higher portion of M. giganteus backcrosses existed within the sample compared with M. fuliginosus. Hybridization in grey kangaroos is reflective of occasional breakdowns in species boundaries, occurring throughout the region and potentially associated with variable conditions and dramatic reductions in densities. Such rare hybridization events allow populations to incorporate novel diversity while still retaining species integrity.

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Marsupial Cytogenetics

Cited by 73 publications

References 0 publications

The Program of Sex Chromosome Pairing in Meiosis Is Highly Conserved Across Marsupial Species

The Program of Sex Chromosome Pairing in Meiosis Is Highly Conserved Across Marsupial Species

Sex chromosomes, synapsis, and cohesins: a complex affair

Molecular detection of hybridization between sympatric kangaroo species in south-eastern Australia

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