Giardia sp.: comparison of electrophoretic karyotypes

Species in the genus Giardia have been named on the basis of host specificity, cell dimensions, and median body morphology. Despite these criteria, the species taxonomy of Giardia is still in question. To investigate Giardia taxonomy on a molecular level, Giardia chromosomal DNA was analyzed by orthogonal-field-alternation gel electrophoresis (OFAGE) and transverse alternating field electrophoresis (TAFE). Chromosomal DNA of G. duodenalis isolates (human, muskrat, sheep, dog, beaver), G. muris (mouse), and G. ardeae (great blue heron) were subjected to OFAGE and TAFE analyses. Comparable DNA patterns were obtained by both electrophoretic methods, but OFAGE required 8 days while TAFE required only 3 days. DNA patterns among all G. duodenalis isolates, although quite similar to each other, were distinctly different from those of G. muris and G. ardeae; G. muris and G. ardeae DNA patterns were distinctly different from each other. A G. duodenalis (Portland 1) total DNA probe hybridized to the DNA of all G. duodenalis isolates on Southern blots, but not detectably to G. muris and G. ardeae DNA. Similarly, G. muris and G. ardeae total DNA probes only hybridized detectably to their respective DNA. One probe that appears to hybridize to the DNA of all G. duodenalis and to G. ardeae DNA rather than G. muris DNA has been developed. Another probe that hybridizes only to G. muris and G. ardeae DNA has been developed. These data suggest that the differentiation of Giardia isolated from host and environmental samples may eventually be accomplished by DNA probes. Additionally, these techniques perhaps combined with other criteria may lead to the establishment of a sound taxonomic scheme for this genus.     

Colobus type C virus: molecular cloning of unintegrated viral DNA and characterization of the endogenous viral genomes of Colobus.

The unintegrated viral DNA intermediates of colobus type C virus (CPC-1) were isolated from infected human cells that were permissive for viral growth. There were two major species of DNA, linear molecules with two copies of the long terminal repeat and relaxed circles containing only a single long terminal repeat. In addition, there was a minor species (approximately 10%) composed of relaxed circles with two copies of the long terminal repeat. A restriction endonuclease map of the unintegrated DNA was constructed. The three EcoRI fragments of circular CPC-1 DNA were cloned in the EcoRI site of lambda gtWES . lambda B and then subcloned in the EcoRI site of pBR322. Using these subgenomic fragments as probes, we have characterized the endogenous viral sequences found in colobus cellular DNA. They are not organized in tandem arrays, as is the case in some other gene families. The majority of sequences detected in cellular DNA have the same map as the CPC-1 unintegrated DNA at 17 of 18 restriction endonuclease sites. There are, however, other sequences that are present in multiple copies and do not correspond to the CPC-1 map. They do not contain CPC-1 sequences either in an altered form or fused to common nonviral sequences. Instead, they appear to be derived from a distinct family of sequences that is substantially diverged from the CPC-1 family. This second family of sequences, CPC-2, is also different from the sequences related to baboon endogenous type C virus that forms a third family of virus-related sequences in the colobus genome.     

A comparison of the fluorescent karyotypes of the chimpanzee (Pan troglodytes) and man

Individual chimpanzee chromosomes have been identified by their characteristic banding revealed by quinacrine fluorescent staining. A fluorescent karyotype of this species was set up to be compared with the standard human fluorescent karyotype. It was found that chromosomes 1, 3, 11, 12, 14 and X-chromosome of the chimpanzee appear to have banding patterns similar to the equivalent human chromosomes. Chromosomes 6, 7, 8, 10 and 13 also had a fluorescent pattern corresponding to the human chromosomes of the same number, particularly in the long arm. Remarkable variation in intensity and/or size of fluorescent regions was frequently found in the short arm of satellited acrocentric chromosomes 13, 14, 15, 22 and 23. Variations occurred between homologues and between individuals. Such variable fluorescence in a specific chromosomal region of an individual animal is a reproducible characteristic. Unlike its human counterpart, the distal segment in the long arm of the chimp's Y-chromosome is not brightly fluorescent. An earlier report is thus confirmed.     

Electrophoretic karyotypes of clinically isolated yeasts of Candida albicans and C. glabrata.

One-hundred-and-four isolates of yeast were collected from the vaginas of 97 outpatients. The isolates were identified by their characteristics in a carbohydrate assimilation test, a serological test and from their morphology. Candida albicans and Candida glabrata were the major isolates (75% and 20%, respectively). The karyotypes of the isolates were analysed by pulsed-field gel electrophoresis and almost all the karyotypes were distinguishable from one another when the band mobilities were carefully compared. Characteristics and karyotypes were not directly correlated, but seven C. albicans isolates (from six patients) had a common atypical karyotype and shared the same phenotype. These isolates are inferred to be generated by a wide genomic reorganization and mutation and the phenotypic changes may be advantageous for survival. The karyotypes of the isolates recovered from individual patients after intervals of 1-6 months were all identical except for one or two highly variable bands which were identified with an rDNA probe. This suggests that the variable bands are too variable to be useful for distinguishing strains, but from the patterns of the identical bands (i.e. except for the variable bands) we concluded that strains from individual patients do not change, at least over short periods. This, coupled with the extensive inter-isolate variability in karyotype, will be useful for Candida source determination and epidemiological studies.     

黑松,马尾松及其杂种的核型比较

分析了黑松、马尾松及其杂种的核型。其核型公式：黑松为Ｋ（２ｎ）＝２４－２０ｍ（６＿（ＳＡＴ）））＋４ｓｍ;杂种为Ｋ（２ｎ）＝２４＝２３ｍ＋１ｓｍ;马尾松为Ｋ（２ｎ）＝２４－２４ｍ（４＿（ＳＡＴ））。相对长度和臂比方差分析表明,两亲本和杂种差异显著。杂种在相对长度、全组染色体总长、最长与最短染色体比、臂比平均值以及染色体类型上均处于双亲之间。这些研究结果为进一步研究该天然杂种提供必要的细胞学资料。     

The evolution of molar occlusion in the Cercopithecidae and early catarrhines

Those Eocene prosimians which are possible catarrhine ancestors have four blade-like crests on each lower molar. Each crest shears in sequence across two upper molar crests. Occluding crests are concavely curved to hold the foods being sheared. Each of two medial lower molar crests bordering the principal crushing surface shear past single upper molar crests at about the same time the lateral lower molar crests contact the second rank of upper molar crests. Grinding and crushing areas are restricted to hypoconid, trigonid, and protocone surfaces. Oligocene catarrhine molars have increased crushing-grinding capacities and maintained but modify their shearing. As the crushing surface of the protocone expands and a crushing hypocone is added, the “second rank” upper molar shearing crests are functionally reduced. At the same time medial crests are increasingly emphasized so that the total shearing capacity remains virtually unchanged. Marginal shearing blades are straight edged; leading edges of occluding blades are set at different angles to the occlusal plane so that blades contact at only one point at any given time. Early Primates have separate crushing basins surrounded by shearing blades. Catarrhines tend to link expanding crushing surfaces anteroposteriorly into a continuous surface between all molars. A cladistic analysis based on both new and previously recognized characters indicates that: 1, Apidium may be more closely related to Aegyptopithecus than to Parapithecus; 2, cercopithecids are derived from a Parapithecus-related stock; 3, Oreopithecus could equally well have come from an Apidium or Aegyptopithecus stock.     

The karyotypes of Triaenophorus nodulosus and T. crassus (Cestoda: Pseudophyllidea)

Two species of the genus Triaenophorus were found to have widely different chromosome sets. The karyotype of T. nodulosus consists of 26 biarmed chromosomes ranging from 1.45 to 6.75 microns long. The diploid set of T. crassus contains 18 chromosomes with a well-distinguished first pair of large metacentric homologues. All the chromosomes with the exception of the last pair of acrocentric elements are biarmed. Their absolute length ranges from 1.50 to 8.50 microns. The possible pathways of karyotype differentiation and the evolution of these species are discussed.     

The chromosomes of Lepturinae (Coleoptera: Cerambycidae) II. A study of eight more species,with focus on Desmocerus palliatus

Following the study of 28 species of Lepturinae (Coleoptera: Cerambycidae) the karyotypes of seven additional Palaearctic and one Nearctic species are established. The 19,X male karyotypes found in genera Stictoleptura (four species), Vadonia and Judolia (one species each) confirm the loss of Y chromosome in Lepturini. The 22,XY male karyotype of Cortodera humeralis is very close to that of some species of Rhagiini (genera Gaurotes, Acmaeops, Dinoptera, all 22,XY) and Grammoptera ruficornis (24,XY) recently reported. We propose that these taxa could form a monophyletic group within Rhagiini. The karyotype of the Nearctic species Desmocerus palliates (23,neoXneoXneoY) is quite different and characterized by the presence of many acrocentric chromosomes and a complex autosome–gonosome translocation. Its particular karyotype is compatible with its present classification within a separate tribe, the Desmocerini.     

Spectrophotometry of hemoglobin: a comparison of dog and man

1. The absorptivity at 540 nm of hemiglobincyanide (epsilon 540HiCN) from dog blood was determined on the basis of iron and found to be within the range formerly obtained for human hemoglobin. 2. Consequently, epsilon 540HiCN = 11.0, the established value for human hemoglobin, may be used for dog hemoglobin. 3. On this basis the absorption spectra of oxyhemoglobin, de-oxygenated hemoglobin, carboxyhemoglobin, hemiglobin (methemoglobin) and hemiglobincyanide were determined for dog hemoglobin. 4. No significant differences were found between dog and human hemoglobin, except that dog hemiglobin binds less OH- as reflected in a difference between the absorption spectra of dog and human hemiglobin at the same pH.     

Mapping the testis determinants by an analysis of Y-specific sequences in males with apparent XX and XO karyotypes and females with XY karyotypes.

A number of patients with paradoxical sex chromosome complements (so-called XY females, XX and XO males) have been investigated with a series of 19 Yp and 4 Yq DNA probes to establish which region of the Y is essential for male sexual differentiation. Of the 23 XX males, 18 possessed one or more Yp probe sequences with only 5 lacking such sequences. Of 9 XY females examined, only one showed evidence of a deletion in Yp occurring either as a result of X-Y interchange or interstitial deletion. This suggests that the majority of XY females are not commonly deleted for those Y sequences which are found to be transferred to the X in XX males. The DNA of two XO males both contained different portions of the Y. From a comparison of the patterns of Yp sequences in these patients, it has been possible to elaborate a model of Yp in terms of the order of probe sequences and to suggest a location for the testis determining region in distal Yp.