Two new karyotypes in the Peruvian owl monkey (Aotus trivirgatus)

The observation of remarkable karyotypic variation in owl monkeys (Aotus trivirgatus) stimulated us to study the chromosomal evolution of this New World genus. As an extension of this project, we examined the chromosome complement of a “phenotype-B” Aotus population from Peru. In addition to karyotype V(2n = 46), two new karyotypes with diploid numbers of 47 and 48 were identified. A G-band comparison of these karyotypes indicated that the chromosome number polymorphism in these Peruvian owl monkeys resulted from a single fusion or fission event involving a single metacentric and two acrocentric chromosome pairs. This mechanism is also known to be responsible for the chromosome number polymorphism in at least two other populations of phenotype B Aotus, one from Colombia and the other from Panama.     

Possible assignment of the glyoxalase I (GLO) gene to chromosome 6 using man-mouse somatic cell hybrids

Summary A correlation between the expression or absence of human glyoxalase I and chromosome 6 (as well its markers ME₁, IPO-B, and PGM₃) was observed in man-mouse somatic cell hybrids. This segregation pattern indicates that the GLO gene is situated on chromosome 6.

---

Zusammenfassung In Hybriden somatischer Zellen zwischen Maus und Mensch wurde eine Korrelation zwischen Vorhandensein bzw. Abwesenheit der menschlichen Glyoxalase I und von Chromosom 6 (sowie seinen Markern ME₁, IPO-B und PGM₃) ermittelt. Diese Korrelation spricht dafür, daß das GLO-Gen auf Chromosome 6 liegt.

---

---

Supported by the Deutsche Forschungsgemeinschaft BE 352/8 and GR 373/6.     

MHC class I genes in the owl monkey: mosaic organisation, convergence and loci diversity

The MHC class I molecule plays an important role in immune response, pathogen recognition and response against vaccines and self- versus non-self-recognition. Studying MHC class I characteristics thus became a priority when dealing with Aotus to ensure its use as an animal model for biomedical research. Isolation, cloning and sequencing of exons 1–8 from 27 MHC class I alleles obtained from 13 individuals classified as belonging to three owl monkey species (A. nancymaae, A. nigriceps and A. vociferans) were carried out to establish similarities between Aotus MHC class I genes and those expressed by other New and Old World primates. Six Aotus MHC class I sequence groups (Ao-g1, Ao-g2, Ao-g3, Ao-g4, Ao-g5 and Ao-g6) weakly related to non-classical Catarrhini MHC were identified. An allelic lineage was also identified in one A. nancymaae and two A. vociferans monkeys, exhibiting a high degree of conservation, negative selection along the molecule and premature termination of the open reading frame at exon 5 (Ao-g5). These sequences high conservation suggests that they more likely correspond to a soluble form of Aotus MHC class I molecules than to a new group of processed pseudogenes. Another group, named Ao-g6, exhibited a strong relationship with Catarrhinis classical MHC-B-C loci. Sequence evolution and variability analysis indicated that Aotus MHC class I molecules experience inter-locus gene conversion phenomena, contributing towards their high variability.     

Stability of a multiple X chromosome system and associated B chromosomes in birch aphids (Euceraphis spp.; Homoptera: Aphididae)

Autosomal dissociations are a common feature of aphid karyotype evolution, but multiple X chromosome systems are rare. Birch-feeding aphids of the genus Euceraphis, however, have X₁X₂O males as a general rule, X₁ being always much larger than X₂. Only one species has XO males, and this condition appears to be secondary. Most Euceraphis karyotypes also have one or more, usually heterochromatic, elements that occur in the same numbers in both males and females, yet behave like X chromosomes at male and female meiosis I. They appear to be supernumerary, non-functional X chromosomes, although showing greater within-species stability in size and number than typical B chromosomes. Euceraphis gillettei forms a separate group within the genus and feeds on alders (Alnus species), yet has a similar system, and the two most closely related genera, Symydobius and Clethrobius, also have additional chromosomal elements possibly representing non-functional X chromosomes. Thus the multiple X chromosome system in these aphids seems to be a primitive condition.     

Comparative chromosomal studies on two minnow fish, Phoxinus phoxinus (Linnaeus, 1758) and Eupallasella perenurus (Pallas, 1814); an associated cytogenetic-taxonomic considerations

The present work provides new data on the banding pattern of two cyprinid fish species Phoxinus phoxinus and Eupallasella perenurus from Poland. C-banding, silver-staining (Ag), and fluorescent staining with chromomycin A₃ techniques were used to describe the karyotypes. Both of the species karyotypes of 2n=50 were characterised by one pair of acrocentric chromosomes, the largest in the set, and by two pairs of NOR-bearing chromosomes. In the chromosome set of Ph. phoxinus Ag-stained NORs were located on telomeres of two metacentric and two submetacentric chromosomes, but in most metaphases only one of the two homologous was observed. The karyotype of E. perenurus was characterised by Ag-NOR regions at a telomeric position on the shorter arm of two submetacentric chromosome pairs. In most metaphases only three NOR-bearing chromosomes were observed. In both investigated species the location of the A₃ positive signals corresponded with the location of Ag-stained NORs and these sites were associated with heterochromatin shown as C-bands. The results of cytogenetical studies on other related, mainly the North American phoxinins, species are compared and discussed.     

Multi-directional chromosome painting maps homologies between species belonging to three genera of New World monkeys and humans

We mapped chromosomal homologies in two species of Chiropotes (Pitheciini, Saki Monkeys) and one species of Aotus (Aotinae, Owl Monkey) by multi-directional chromosome painting. Human chromosome probes were hybridized to Chiropotes utahicki, C. israelita and Aotus nancymae metaphases. Wooly Monkey chromosome paints were also hybridized to Owl Monkey metaphases. We established Owl Monkey chromosome paint probes by flow sorting and reciprocally hybridized them to human chromosomes. The karyotypes of the Bearded Saki Monkeys studied here are close to the hypothesized ancestral platyrrhine karytoype, while that of the Owl Monkey appears to be highly derived. The A. nancymae karyotype is highly shuffled and only three human syntenic groups were found conserved coexisting with 17 derived human homologous associations. A minimum of 14 fissions and 13 fusions would be required to derive the A. nancymae karyotype from that of the ancestral New World primate karyotype. An inversion between homologs to segments of human 10 and 16 suggests a link between Callicebus and Chiropotes, while the syntenic association of 10/11 found in Aotus and Callicebus suggests a link between these two genera. Future molecular cytogenetic work will be needed to determine whether these rearrangements represent synapomorphic chromosomal traits.     

High-resolution flow karyotyping and chromosome sorting in Vicia faba lines with standard and reconstructed karyotypes

Flow cytometric analysis has been performed on chromosomes isolated from formaldehyde-fixed root tips in a Vicia faba (2n = 12) line with a standard (wild-type) karyotype and in six V. faba translocation lines with reconstructed karyotypes. The resolution of individual chromosome types on histograms of chromosome fluorescence intensity (flow karyotypes) depended on the type of fluorochrome used for chromosome staining. The highest degree of resolution was achieved with 4,6-diamidino-2-phenylindole (DAPI). The lower resolution obtained after staining with mithramycin A (MIT) and propidium iodide (PI) was probably due to the sensitivity of these stains to changes in chromatin structure induced by formaldehyde fixation. After the staining with DAPI, only 1 chromosome type could be discriminated in the line with a standard karyotype. In the translocation lines, the number of chromosome types resolved on flow karyotypes ranged from 2 in the G and the ACB lines to all (6) chromosome types in the EFK and EF lines. Refined flow karyotyping permitted the sorting of a total of 15 different chromosome types from five of the translocation lines. It is expected that flow sorting of chromosomes from reconstructed karyotypes will become a powerful tool in the study of nuclear genome organisation in V. faba.     

Reproduction of the owl monkey (Aotus spp.) in captivity

Abstract: The reproduction performance of captive owl monkeys, a breed used extensively in biomedical research, was observed at the Battelle Primate Facility (BPF). The colony grew through captive breeding, imports from the Peruvian Primatological Project, and others to a peak size of 730. It included seven karyotypes of Aotus sp. Results showed that owl monkeys can breed successfully in a laboratory in numbers sufficient to sustain modest research programs. Reproductive success increases when pairs are compatible, of the same karyotype, and stabilized; however, mated pairs of different karyotype are also productive. Under conditions of controlled lighting and heating, owl monkeys at BPF showed no birth peak nor birth season.     

Chromosome assignment of the gene loci ETS1 and THY1 in the owl monkey

Our previous assignment of the gene loci HBB, HRAS1, INS, PTH, LDHA, and CAT to owl monkey chromosome 19 of karyotype VI (K-VI) indicated a putative homology of this owl monkey chromosome with the short arm of human chromosome 11 (HSA 11p). To investigate further the extent of shared homology, we localized in the owl monkey complement two genes known to be on HSA 11q. Segregation analysis of ETS1 and THY1 homologous DNA in three karyotypically different panels of rodent x owl monkey somatic cell hybrids provided evidence for the syntenic assignment of these loci to homologous chromosomes of three owl monkey karyotypes, namely, chromosomes 4 (K-VI), 3 (K-II), and 5 (K-V). The results indicate a disruption of syntenic gene loci on the distal portion of HSA 11q from 11p during primate evolution.     

Localization of genes on human chromosomes by studies of human-Chinese hamster somatic cell hybrids

Summary About 75 man-Chinese hamster hybrid clones were analysed for their human chromosome complement and simultaneously tested for human enzyme markers. Correlation of the presence of chromosomes and enzyme activity revealed assignments of the PGD linkage group to chromosome 1, ME₁, PGM₃ and IPO-B to 6, LDH-A to 11, LDH-B to 12 and IPO-A to 21.The assignment of PGM₃ puts the HL-A loci on chromosome 6. Segregation of the enzymes of the PGD linkage group was demonstrated in a clone which had retained a deleted chromosome 1. Subclones of this line indicate that the loci for PGD and PGM₁ are situated on the short arm or proximal part of the long arm of 1 and the locus for Pep-C on the long arm.

---

Zusammenfassung Etwa 75 Hybrid-Zellklone Mensch/Chinesischer Hamster wurden in bezug auf den menschlichen Anteil ihres Chromosomensatzes analysiert und gleichzeitig auf menschliche Enzym-Marker untersucht. Die Korrelation zwischen Anwesenheit von Chromosomen und Enzym-Markern ließ die Folgerung zu, daß die PGD-Koppelungsgruppe auf Chromosom 1, ME₁, PGM₃ und IPO-B auf Nr. 6, LDH-A auf 11, LDH-B auf 12 und IPO-A auf Chromosom 21 gelegen ist.Die Lokalisation von PGM₃ läßt die Folgerung zu, daß auch die HL-A-loci auf Chromosom 6 lokalisiert sind. Aufspaltung der Enzyme der PGD-Koppelungsgruppe konnte an einem Klon dargestellt werden, der ein deletiertes Chromosom 1 enthielt. Die Subklone dieser Linie zeigen, daß die loci für PGD und PGM₁ auf dem kurzen Arm oder dem proximalen Teil des langen Arms von Chromosom Nr. 1 liegen, während der locus für Pep-C auf dem langen Arm gelegen ist.

     

Cytogenetics of the parthenogenetic grasshopper Moraba virgo and its bisexual relatives

An undescribed bisexual grasshopper species closely related to the all-female parthenogenetic Moraba virgo has an X₁X₂Y sex chromosome mechanism which incorporates 7 chromosomes of the ancestral karyotype (the original X and three pairs of autosomes). Apparently three separate chromosomal fusions have occurred, one of these being a tandem fusion followed by a crossover which stabilized it in the sex chromosome system. M. virgo probably arose from an ancestor which had X₁X₂Y males but lacked the tandem fusion present in the new species, the females of virgo having the constitution X₁X₁X₂O.Supported by Public Health Service Grant GM-07212 from the Division of General Medical Sciences, U.S. National Institutes of Health, and by a grant from the Australian Research Grants Committee.     

Heteromorphic sex chromosomes of lizardfish (Synodontidae): focus on the ZZ-ZW1W2 system in Trachinocephalus myops

The karyotype and DNA content of four lizardfish species (family Synodontidae), that is, Saurida elongata, Synodus ulae, Synodus hoshinonis and Trachinocephalus myops, were analyzed. The karyotype of T. myops significantly differed from that of the other three species having diploid chromosome number of 48 with mainly acrocentric chromosomes and the ZZ-ZW sex chromosome system. The chromosome number of male T. myops was 2n=26, while that of female T. myops was 2n=27. The karyotype consisted of 11 pairs of metacentrics, one pair of acrocentrics and, in addition, two large metacentrics in the male and a single large metacentric, a distinctly small subtelocentric and a microchromosome in the female. C-banding demonstrated that in the female the subtelocentric chromosome and the microchromosome were heterochromatic. The karyotype of T. myops was thought to be derived from a 48 chromosome type synodontid fish through the involvement of Robertsonian rearrangement; the rearrangement of the sex chromosomes proceeded during karyotype evolution. Among the chromosomes, the large metacentrics were determined to be neo-Z (a fusion of the original Z and an autosome), the microchromosomes the W₁ (originally W), and the subtelocentric chromosomes the W₂ (derived from an autosome pair). The miniaturization of W₁ and W₂ chromosomes and their heterochromatinization suggested that sex chromosomes in this species have been already highly differentiated. The findings on DNA content implied that the karyotype of T. myops evolved by centric fusion events without loss in DNA amount.     

Karyotype studies in seven species of cyprinidae

The present report embodies karyotype studies of seven Indian cyprinids. Of these, the karyotypes of five species possess chromosomes all of which are acrocentric. These areLabeo calbasu (Ham.) 2n=54,Puntius sophore (Ham.),P. conchonius Ham.,P. stigma (Ham.) 2n=50 andChela bacaila (Ham.) 2n=52. The karyotype ofCrossocheilus latius punjabensis Mukerji has 48 chromosomes, 12 of which are metacentric (2n=12m+36r's). InAmblypharyngodon mola (Ham.), 52 chromosomes form the diploid set which include 8 metacentrics. In none of the seven species morphologically distinguishable sex chromosomes were found.Literature on cyprinid karyotypes has been reviewed in order to understand in how far the cytological characters are in agreement with the classification based on morphological studies. The validity ofMatthey's notion of nombre fondamental to establish kinship between cytologically known cyprinid species has also been discussed.     

Mapping of five human chromosome 19 DNA markers to owl monkey chromosomes.

Hybridization of DNA from three panels of karyotypically distinct owl monkey x rodent somatic cell hybrids with human DNA probes resulted in the syntenic assignments of INSR-LDLR-TGFB1-APOE-D19S8 to owl monkey chromosome 25 of karyotype VI (2n = 49/50), INSR-LDLR-TGFB1-D19S8 to chromosome 2 of karyotype II (2n = 54), and INSR-APOE to chromosome 2 of karyotype V (2n = 46). The APOE and D19S8 loci are on adjacent regions proximal to the centromere of chromosomes 25q (K-VI) and 2p (K-II), as determined by in situ chromosomal hybridization analysis. These findings support our previous proposals on (1) the homology of these chromosomes of three owl monkey karyotypes, (2) the evolutionary derivation of chromosome 2 of karyotypes II and V as the result of two separate centric fusion events, and (3) the likelihood that owl monkey chromosome 25 (K-VI) (and its homologs) is a conserved genetic homoeolog of human chromosome 19.     

The physical map ofMus musculus chromosome 11 reveals evolutionary relationship with different syntenic groups of genes inHomo sapiens

Summary The physical localization of sequences homologous to three cloned genes was determined by in situ hybridization to metaphase chromosomes. Previous work had assigned the skeletal myosin heavy chain gene cluster (Myh), the functional locus for the cellular tumor antigen p53 (Trp53-1), and the cellular homologue of the viral erb-B oncogene (Erbb) toMus musculus chromosome 11 (MMU11). Our results provide regional assignments ofMyh andTrp53-1 to chromosome bands B2C, and ofErbb to bands A1A4. Taken together with in situ mapping of three other loci on MMU 11 (Hox-2 homeobox-containing gene cluster, theSparc protein, and theColla-1 collagen gene), which have been reported elsewhere, these data allowed us to construct a physical map of MMU11 and to compare it with the linkage map of this chromosome. The map positions of the homologous genes on human chromosomes suggest evolutionary relationships of distinct regions of MMU11 with six different human chromosome arms: 1p, 5q, 7p, 16p, 17p, and 17q. The delineation of conserved chromosome regions has important implications for the understanding of karyotype evolution in mammalian species and for the development of animal models of human genetic diseases.     

Comparative chromosomal mapping of the owl monkey serum albumin gene

We have mapped the albumin locus (ALB) in the owl monkey, Aotus trivirgatus, using a cloned human albumin gene probe, pcHSA 33-1. Rodent-owl monkey somatic cell hybrids were used to map the owl monkey albumin locus in three subgroups of Aotus, karyotypes II, V, and VI. Segregation analysis of the molecular hybridization pattern of pcHSA 33-1 in the somatic cell hybrids indicated that the albumin locus maps to chromosome 9 of owl monkey karyotype II, chromosome 12 of karyotype V, and chromosome 1 of karyotype VI. This assignment provides evidence for the homology of these three chromosomes and supports the hypothesis of Ma on the formation of chromosome 1 in karyotype VI.     

Cytotaxonomy of antarctic teleosts of the Pagothenia/Trematomus complex (Nototheniidae,Perciformes)

Summary The interspecific relationships and taxonomy of 12 antarctic coastal Nototheniids (the Pagothenia/ Trematomus complex) are still under discussion. Here we present karyological data on eight species in hope that further cytogenetic data can help to clarify phylogenetic problems. Pagothenia bernacchii (2n = 48) has a generalized karyotype which has not developed heterochromosomes. P. hansoni, P. borchgrevinki and Trematomus newnesi share very similar karyotypes with 2n = 46 for females and 2n = 45 for males. The difference between sexes is probably due to the development of a multiple sex-chromosome system with a neo-Y, typical of males, which originated from a centric fusion of an autosome (now X₂) with an undifferentiated Y. The chromosome morphology of the three species seems to be related to that of P. bernacchii. T. nicolai (2n = 58, 57) has a karyotype numerically and morphologically divergent from that of the above species; T. nicolai males may have developed a neo-Y through a tandem translocation. T. pennellii (2n = 32), T. loennbergii (2n = 28; 2n = 30 in a single female) and T. eulepidotus (2n = 24) show karyotypes with progressively fewer chromosomes but with an increasing number of large, bi-armed chromosomes. Such a symmetrization process is generally found in advanced poikilothermic Vertebrates and the three species of Trematomus could therefore be considered as karyologically derived. However, parallelism in the karyotype differentiation producing convergence in the chromosome morphology of distantly related species cannot yet be excluded.     

Red cell enzymes of the Pongidae

Summary The red cell enzymes acid phosphatase, adenylate kinase, adenosine deaminase and phosphoglucomutase were analyzed by horizontal starch gel electrophoresis in 43 members of the family Pongidae: Pongo pygmaeus (n=10), Gorilla g. gorilla (n=8), Pan troglodytes (n=22) and Pan paniscus (n=3).In all the Pongidae a red cell acid phosphatase zymogram corresponding to the phenotype B in man was found. The adenylate kinase corresponded to the human phenotype AK 1. All the Pongidae showed the same homozygous adenosine deaminase phenotype which was different from the zymograms in man and was designated ADA ape. In all Pongidae the allele PGM ₁ ¹ was present, in addition in Gorilla g. gorilla a second allele was demonstrated, PGM ₁ ^Go . In Pan troglodytes a second allele, PGM ₁ ^Pan was recognized. In Pongo pygmaeus and Gorilla g. gorilla the PGM₂ patterns differed in their migration rates from PGM₂ 1 in man. In one individual of the species Pan troglodytes a PGM₂ zymogram was found resembling the heterozygous phenotype PGM₂ 3–1, PGM ₂ ¹ PGM ₂ ³, (type Palmer) in man. In all the other individuals of the species Pan troglodytes and in those of the species Pan paniscus the PGM₂ zymogram corresponded to the phenotype PGM₂ 1 in man.

---

Zusammenfassung Bei 43 Vertretern der Familie Pongidae, Pongo pygmaeus (n=10), Gorilla g. gorilla (n=8), Pan troglodytes (n=22) und Pan paniscus (n=3), wurden die Erythrocytenenzyme saure Phosphatase, Adenylatkinase, Adenosindeaminase und Phosphoglucomutase mit der horizontalen Stärkegelelektrophorese analysiert. Bei allen Pongiden fanden wir eine saure Phosphatase, die dem Phänotyp B des Menschen entsprach, und eine Adenylatkinase, die dem Phänotyp AK 1 des Menschen glich. Alle Pongiden besaßen das gleiche, einem homozygoten Phänotyp entsprechende Adenosindeaminase-Zymogramm, das sich von den Zymogrammen des Menschen unterschied; wir bezeichnen diesen Phänotyp mit ADA ape. Bei allen Pongiden kommt das Allel PGM ₁ ¹ vor, bei Gorilla g. gorilla zusätzlich ein zweites Allel, PGM ₁ ^Go , und bei Pan troglodytes ein zweites Allel, PGM ₁ ^Pan . Die PGM₂-Zymogramme von Pongo pygmaeus und Gorilla g. gorilla unterschieden sich in ihrer elektrophoretischen Wandergeschwindigkeit vom Phänotyp PGM₂ 1 des Menschen. Bei einem Individuum der Species Pan troglodytes fanden wir ein heterozygotes PGM₂-Zymogramm, das an den heterozygoten Phänotyp PGM₂ 3–1, PGM ₂ ¹ PGM ₂ ³ (Typ Palmer) des Menschen erinnerte, bei allen übrigen Individuen der Species Pan troglodytes und bei denen der Species Pan paniscus ein homozygotes PGM₂-Zymogramm, das dem Phänotyp PGM₂ 1 des Menschen entsprach.

---

---

Supported by the Deutsche Forschungsgemeinschaft.     

Notes on chromosomes of ten species of the genus chrysolina mots. (Coleoptera:Chrysomelidae)

SixChrysolina species from Catalonia and the Canary Islands (Spain), viz.americana, gemina, femoralis, cerealis, menthastri andpolita, have similar diploid karyotypes of 24 (sub)metacentric chromosomes, and show Xy sex-determining system.C. banksi andobsoleta have 2n ()=23; their karyotype is presumably derived from that of the former group by loss of the y chromosomes. InC. haemoptera andC. carnifex 40 elements appear in the diploid set. It seems that 2n=24 is the most frequent number in theChrysolina. Higher chromosome numbers have possibly originated through centric fissions, as the acrocentric shape ofC. carnifex chromosomes seems to suggest. The 2n=23 and 24 species feed onLabiatae, while the two higher chromosome number species are associated with plants belonging to other families.