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R Toder

Publications and source records attributed to R Toder.

31 records · Page 2Linked to original sources
PubMed1997

Genes located in and near the human pseudoautosomal region are located in the X-Y pairing region in dog and sheep.

We cloned and mapped the dog and/or sheep homologues of two human pseudoautosomal genes CSF2RA and ANT3. We also cloned and mapped dog and/or sheep homologues of STS and PRKX, which are located nearby on the differential region of the human X and have related genes or pseudogenes on the Y. STS, as well as CSF2RA, mapped to the tips of the short arm of the sheep X and Y (Xp and Yp), and STS and PRKX, as well as ANT3, mapped to the tips of the dog Xp and Y long arm (Yq). These locations within the X-Y pairing regions suggest that the regions containing all these human Xp22.3-Xpter genes are pseudoautosomal in dog and sheep. This supports the hypothesis that a larger pseudoautosomal region (PAR) shared by eutherian groups was disrupted by chromosomal rearrangements during primate evolution. The absence of STS and ANT3 from the sex chromosomes in two prosimian lemur species must therefore represent a recent translocation from their ancestral PAR, rather than retention of a smaller ancestral PAR shared by mouse.

Animals↗
PubMed1997

A human candidate spermatogenesis gene, RBM1, is conserved and amplified on the marsupial Y chromosome.

Three genes, RBM1, DAZ and TSPY, map to a small region of the long arm of the human Y chromosome which is deleted in azoospermic men. RBM1, but not DAZ or TSPY, has a Y-linked homologue in marsupials which is transcribed in the testis. This suggests that RBM1 has been retained on the Y chromosome because of a critical male-specific function. Marsupial RBM1 is closely related to human RBM1, but, like the related autosomal gene hnRNPG, lacks the amplification of an exon. This suggests that RBM1 evolved from hnRNPG at least 130 million years ago and has undergone internal amplification in primates, as well as independent amplification in several therian [corrected] lineages.

Amino Acid Sequence↗
PubMed1997

Shared synteny between human chromosome 10 and chromosome 1 of the marsupial tammar wallaby, Macropus eugenii.

Marsupial homologs of the human chromosome 10 loci IL2RA, HK1, and PLAU have been cloned and mapped by fluorescence in situ hybridization to chromosome 1q of the tammar wallaby, Macropus eugenii. Relative distance measurements of the hybridization signals on M. eugenii chromosome 1 show that marsupial homologs of human (HSA) 10p IL2RA and 10q HK1/PLAU flank the marsupial homologs of the human 5q gene IL5 and the human 15q imprinted genes SNRPN and ZNF127. The shared synteny, therefore, does not necessarily mean that HSA 10 represents an ancestral grouping; rather, it suggests that HSA 10p and HSA 10q represent two different ancestral mammalian units which fused directly in primates and were incorporated independently into two different regions of the same chromosome in marsupials.

Animals↗
PubMed1996

The human/mouse imprinted genes IGF2, H19, SNRPN and ZNF127 map to two conserved autosomal clusters in a marsupial.

The four genes IGF2, H19, SNRPN and ZNF127 are imprinted in mouse and human. IGF2 and H19 form one conserved cluster on the distal part of mouse chromosome 7 and human chromosome 11p15.5, whereas SNRPN and ZNF127 form another on the middle of mouse chromosome 7 and on human chromosome 15q11-13. We have explored the evolution of these imprinted regions by cloning and mapping IGF2, H19, SNRPN and ZNF127 homeologues in marsupials. Specifically, we wished to determine whether the arrangements were shared in eutherian and marsupial mammals, and to determine whether they lay on autosomes, or on the X, as might be predicted by the hypothesis that imprinting evolved from X inactivation. Using fluorescence in situ hybridization, we localized the marsupial homeologues of IGF2 and H19 to the distal part of tammar wallaby chromosome 2p and the marsupial homeologues of SNRPN and ZNF127 to the middle of chromosome 1q. Thus, these genes were originally organized in two separate autosomal clusters in the therian ancestor 180 million years ago, the conservation of which may suggest a functional relationship. The autosomal location of these clusters does not suggest a recent evolutionary relationship between imprinting and X chromosome inactivation.

Animals↗
PubMed1995

ANT3 and STS are autosomal in prosimian lemurs: implications for the evolution of the pseudoautosomal region.

Comparative in situ hybridization in various primate species has revealed a pseudoautosomal location for the human ANT3 gene and an X-specific location for the steroid sulfatase (STS) gene throughout the higher primate species up to the New World monkeys. However, ANT3 and STS map together on an autosome of two prosimian species of the genus Lemur and Eulemur. These results suggest an autosome-to-X/Y translocation after the simians radiated from the prosimians, resulting in a pseudoautosomal location of genes such as ANT3 and STS. In simian primates, STS then became X-specific by a pericentric inversion in the Y chromosome followed by mutational inactivation of the Y allele.

Animals↗
PubMed1995

Comparative mapping of YRRM- and TSPY-related cosmids in man and hominoid apes.

Using chromosomal in situ hybridization it has been demonstrated that specific members of the YRRM and the TSPY families are multicopy and Y chromosome specific in hominoids. After hybridization with the YRRM-related cosmid A5F and the TSPY-related cosmids cos36 and cY91, a reverse and complementary pattern of main and secondary signals is detected on the Y chromosomes of the human, the pygmy chimpanzee and the gorilla, while the location of signals coincides on the Y chromosomes of the chimpanzee, both orang-utan subspecies and the white hand gibbon. This complementary distribution of YRRM and TSPY sequences on the hominoid Y chromosomes possibly originates from a similar sequence motif that is shared by and evolutionarily conserved between certain members of both gene families and/or repeated elements flanking those genes. Otherwise this complementary distribution could go back to a common organization of these genes next to each other on an ancient Y chromosome which was disrupted by chromosomal rearrangements and amplification of one or other of the genes at each of the locations.

Animals↗
PubMed1994

De novo isochromosome 18p in two patients: cytogenetic diagnosis and confirmation by chromosome painting.

This report concerns two patients with clinical features typical for tetrasomy 18p syndrome. Chromosomal analysis revealed a male karyotype in both cases, with an additional small metacentric marker chromosome, putatively an i(18p). Fluorescent in situ hybridization with a chromosome 18-specific paint confirmed that the marker chromosome consisted of chromosome 18 material in both cases.

Abnormalities, Multiple↗
PubMed1993

Comparative mapping of SRY in the great apes.

Cytogenetic studies of the primate Y chromosomes have suggested that extensive rearrangements have occurred during evolution of the great apes. We have used in situ hybridization to define these rearrangements at the molecular level. pHU-14, a probe including sequences from the sex determining gene SRY, hybridizes close to the early replicating pseudoautosomal segment in a telomeric or subtelomeric position of the Y chromosomes of all great apes. The low copy repeat detected by the probe Fr35-II is obviously included in Y chromosomal rearrangements during hominid evolution. These results, combined with previous studies, suggest that the Y chromosome in great apes has a conserved region including the pseudoautosomal region and the testis-determining region. The rest of the Y chromosome has undergone several rearrangements in the different great apes.

Animals↗
PubMed1993

Inverted and satellited Y chromosome in the orangutan (Pongo pygmaeus).

An inverted and satellited Y chromosome of almost acrocentric appearance was detected in seven of 14 male orangutans. In the remaining seven animals a submetacentric Y chromosome without NORs occurred. The high frequency with which the satellited Y chromosomes were associated with acrocentric autosomes and the positive AgNO3-staining of their satellite stalks clearly indicate the active state of the NOR on the Y chromosomes. DNA fingerprinting in two orangutan families showed that the inverted and satellited Y chromosomes in carrier orangutan males do not interfere with normal fertility. Within our sample of male orangutans studied, the inverted and satellited Y chromosome is restricted to Sumatran animals; all Bornean specimens possessed the submetacentric Y chromosome. The question arises whether these two kinds of Y chromosome differ constitutively between the Pongo pygmaeus subpopulations.

Animals↗
PubMed1993

A retrospective CISS hybridization analysis of a case with de novo translocation t(18;22) resulting in an 18p- syndrome.

An unbalanced de novo translocation t(18;22) leading to a severely malformed liveborn girl with 18p- syndrome is described. Using the chromosomal in situ suppression (CISS) hybridization technique on 4-year-old G-banded chromosome preparations, it could be demonstrated that the translocation chromosome is composed of the long arm including the centromere of a chromosome 22 and the long arm of a chromosome 18. Consequently, the patient described here has lost the short arm including the centromere of chromosome 18. The possibility of restudying cytogenetically unsolved cases in clinical cytogenetics using older G-banded chromosome preparations with the fluorescence in situ hybridization techniques is pointed out.

Adult↗
PubMed1993

An X-Y homologous pairing segment in tree shrews (Tupaia).

High-resolution early replication banding of tupaia metaphase chromosomes revealed a synchronous early replicating segment in the short-arm telomeric regions of the active and inactive X chromosomes and in the long-arm telomeric region of the Y chromosome. Hybridization with the human-derived pseudoautosomal probe 113F (STIR) showed that this repeat is conserved and specifically localized within these synchronously early replicating segments of the X short arm and the Y long arm of all three tupaia species (Tupaia belangeri, T. chinensis, and T. glis) investigated. Moreover, meiotic studies demonstrated that a synaptonemal complex is formed at one telomeric end of the XY bivalent during the pachytene stage of meiosis in a male T. glis specimen. Thus, apart from the mouse, the tupaias are the first nonprimate mammals for which cytogenetic and molecular evidence is provided that their highly heteromorphic X and Y chromosomes share a conserved homologous segment in the telomeric position, a location that is compatible with pairing and crossing-over in male meiosis. Taken together, these observations strongly, albeit indirectly, suggest that this chromosome segment at the tip of a sex-chromosome arm might behave pseudoautosomally.

Animals↗
PubMed1992

Comparative cytogenetic studies in tree shrews (Tupaia).

Through use of BrdU replication, RBA-banded karyotypes of Tupaia belangeri, T. chinensis, and T. glis were obtained. A chromosome number of 2n = 62 for T. belangeri is described here for the first time and is confirmed for T. chinensis. All chromosomes between these two phenotypically different species appear to have identical RBA banding patterns; in addition, there is no difference between T. belangeri and T. chinensis in the number and position of nucleolus organizer regions (NORs). The reduced chromosome number of 2n = 60 in T. glis can be explained by a Robertsonian translocation between two acrocentric chromosome pairs, Nos. 10 and 13, of T. belangeri and/or T. chinensis, resulting in the metacentric chromosome pair 1 of T. glis. Furthermore, two chromosome pairs each of T. glis and T. belangeri and/or T. chinensis are not homoeologous, as judged by their RBA patterns. Differences were also found in the number and position of NORs; whereas T. glis displays eight positively stained NORs after AgNO3 staining, there are only four silver-stained NORs in both T. belangeri and T. chinensis. The possibility of geographical isolation as an explanation for the lack of chromosomal differentiation between T. belangeri and T. chinensis is discussed.

Animals↗