Microtubule and microfilament distribution and tubulin content in the cell cycle of Indian muntjac cells

Using DAPI, rabbit antitubulin antibody, FITC-labeled goat anti-rabbit IgG, and TRITC-phalloidin to stain individual cells, the microspectrophotometric analysis showed that three markers that represent the nucleus, microtubules (MT), and microfilaments (MF), respectively, could be recognized in individual cells without interference. The phase of the cell cycle was determined by DNA content. We found that in Indian muntjac (IM) cells, the amount of tubulin in G2 and M phases was about twice as much as that in G1 phase. In G2 cells, the cytoplasmic microtubule complex (CMTC) became denser than in G1 cells. The cytoplasmic MT extent in basically the same orientation as MF bundles in interphase. The regions where the MT is denser also have a denser MF distribution.     

Compound kinetochores of the Indian muntjac

The chromosomes of the Indian muntjac (Muntiacus muntjak vaginalis) are unique among mammals due to their low diploid number (2N=6, 7) and large size. It has been proposed that the karyotype of this small Asiatic deer evolved from a related deer the Chinese muntjac (Muntiacus reevesi) with a diploid chromosome number of 2n= 46 consisting of small telocentric chromosomes. In this study we utilized a kinetochore-specific antiserum derived from human patients with the autoimmune disease scleroderma CREST as an immunofluorescent probe to examine kinetochores of the two muntjac species. Since CREST antiserum binds to kinetochores of mitotic chromosomes as well as prekinetochores in interphase nuclei, it was possible to identify and compare kinetochore morphology throughout the cell cycle. Our observations indicated that the kinetochores of the Indian muntjac are composed of a linear beadlike array of smaller subunits that become revealed during interphase. The kinetochores of the Chinese muntjac consisted of minute fluorescent dots located at the tips of the 46 telocentric chromosomes. During interphase, however, the kinetochores of the Chinese muntjac clustered into small aggregates reminiscent of the beadlike arrays seen in the Indian muntjac. Morphometric measurements of fluorescence indicated an equivalent amount of stained material in the two species. Our observations indicate that the kinetochores of the Indian muntjac are compound structures composed of linear arrays of smaller units the size of the individual kinetochores seen on metaphase chromosomes of the Chinese muntjac. Our study supports the notion that the kinetochores of the Indian muntjac evolved by linear fusion of unit kinetochores of the Chinese muntjac. Moreover, it is concluded that the evolution of compound kinetochores may have been facilitated by the nonrandom aggregation of interphase kinetochores in the nuclei of the ancestral species.     

Structural organization of chromosomes of the Indian muntjac (Muntiacus muntjak)

The identification, morphology, and banding pattern of the chromosomes of the Indian muntjac (Muntiacus muntjak) are described. A diagrammatic representation of the banding pattern as revealed by various techniques is presented following the nomenclature suggested by Paris Conference (1971) for human chromosomes. The Y2 chromosome and the neck of the X chromosome are late replicating based on observations made with the use of a bromodeoxuridine plus Giemsa technique. Most of the G-bands are early replicating, contrary to earlier findings based on autoradiography.     

A simple and rapid in situ staining method for granulocyte-macrophage colonies in agar culture

This report describes a very simple, quick and effective method for in situ staining of granulocyte-macrophage colonies in agar cultures and for classifying various colony types. The procedure takes only one minute to fix and a few minutes to stain; a few additional minutes are required for preparation of the permanent whole plate. In this process the Riu stain, a modified Romanowsky stain, is used. Besides the ease and rapidity of this procedure, the identification of colony types appears to be enhanced. Thus, the method seems to be very beneficial in routine observations of colony types.     

Concerning the axial rotational flexibility of the Fab regions of immunoglobulin G

By electron microscopy, we have observed immunocomplexes with both negative stain and in amorphous ice using monoclonal antibodies directed against one of the 24 subunits of scorpion haemocyanin. A copy of this subunit occurs at each of the corners of the square-shaped haemocyanin molecule. Three distinct orientations of adjacent haemocyanin molecules may be observed in immunocomplex pairs or chains using both the above-mentioned methods. These observations, coupled with low-resolution computer simulations of immunocomplex formation, argue strongly in favour of the existence of a considerable degree of rotational flexibility within the IgG molecule and around the long axis of the Fab arms, as was suggested by previous observations with negative stain. We find that the arms can rotate by up to 180 degrees with respect to the Fc region.     

Chimpanzee tool technology in the Goualougo Triangle, Republic of Congo

With the exception of humans, chimpanzees show the most diverse and complex tool-using repertoires of all extant species. Specific tool repertoires differ between wild chimpanzee populations, but no apparent genetic or environmental factors have emerged as definitive forces shaping variation between populations. However, identification of such patterns has likely been hindered by a lack of information from chimpanzee taxa residing in central Africa. We report our observations of the technological system of chimpanzees in the Goualougo Triangle, located in the Republic of Congo, which is the first study to compile a complete tool repertoire from the Lower Guinean subspecies of chimpanzee (Pan troglodytes troglodytes). Between 1999 and 2006, we documented the tool use of chimpanzees by direct observations, remote video monitoring, and collections of tool assemblages. We observed 22 different types of tool behavior, almost half of which were habitual (shown repeatedly by several individuals) or customary (shown by most members of at least one age-sex class). Several behaviors considered universals among chimpanzees were confirmed in this population, but we also report the first observations of known individuals using tools to perforate termite nests, puncture termite nests, pound for honey, and use leafy twigs for rain cover. Tool behavior in this chimpanzee population ranged from simple tasks to hierarchical sequences. We report three different tool sets and a high degree of tool-material selectivity for particular tasks, which are otherwise rare in wild chimpanzees. Chimpanzees in the Goualougo Triangle are shown to have one of the largest and most complex tool repertoires reported in wild chimpanzee populations. We highlight new insights from this chimpanzee population to our understanding of ape technological systems and evolutionary models of tool-using behavior.     

Synapsis and meiotic recombination in male Chinese muntjac (Muntiacus reevesi)

The muntjacs (Muntiacus, Cervidae) have been extensively studied in terms of chromosomal and karyotypic evolution. However, little is known about their meiotic chromosomes particularly the recombination patterns of homologous chromosomes. We used immunostained surface spreads to visualise synaptonemal complexes (SCs), recombination foci and kinetochores with antibodies against marker proteins. As in other mammals pachytene was the longest stage of meiotic prophase. 39.4% of XY bivalents lacked MLH1 foci compared to less than 0.5% of autosomes. The average number of MLH1 foci per pachytene cell in M. reevesi was 29.8. The distribution of MLH1 foci differed from other mammals. On SCs with one focus, the distribution was more even in M. reevesi than in other mammals; for SCs that have two or more MLH1 foci, usually there was a larger peak in the sub-centromere region than other regions on SC in M. reevesi. Additionally, there was a lower level of interference between foci in M. reevesi than in mouse or human. These observations may suggest that the regulation of homologous recombination in M. reevesi is slightly different from other mammals and will improve our understanding of the regulation of meiotic recombination, with respect to recombination frequency and position.     

A method for rapid and sensitive negative staining of proteins in SDS‐PAGE using 2′,7′‐dichlorofluorescein

We report here a rapid and sensitive technique for negative visualization of protein in 1D and 2D SDS‐PAGE by using 2′, 7′‐dichlorofluorescein (DCF), which appeared as transparent and colorless bands in an opaque gel matrix background. For DCF stain, down to 0.1–0.2 ng protein could be easily visualized within 7 min by only two steps, and the staining is fourfold more sensitive than that of Eosin Y (EY) negative stain and glutaraldehyde (GA) silver stain, and eightfold more sensitive than that of the commonly used imidazole‐zinc (IZ) negative stain. Furthermore, DCF stain provided good reproducibility, linearity, and MS compatibility compared with those of IZ stain. In addition, the potential staining mechanism was investigated by colorimetric experiment and molecular docking, and the results demonstrated that the interaction between DCF and protein occurs mainly via van der waals force, electrostatic interaction, and hydrogen bonding.     

Comparative gene mapping in cattle,Indian muntjac,and Chinese muntjac by fluorescence in situ hybridization

The Indian muntjac (Muntiacus muntjak vaginalis) has a karyotype of 2n = 6 in the female and 2n = 7 in the male. The karyotypic evolution of Indian muntjac via extensive tandem fusions and several centric fusions are well documented by molecular cytogenetic studies mainly utilizing chromosome paints. To achieve higher resolution mapping, a set of 42 different genomic clones coding for 37 genes and the nucleolar organizer region were used to examine homologies between the cattle (2n = 60), human (2n = 46), Indian muntjac (2n = 6/7) and Chinese muntjac (2n = 46) karyotypes. These genomic clones were mapped by fluorescence in situ hybridization (FISH). Localization of genes on all three pairs of M. m. vaginalis chromosomes and on the acrocentric chromosomes of M. reevesi allowed not only the analysis of the evolution of syntenic regions within the muntjac genus but also allowed a broader comparison of synteny with more distantly related species, such as cattle and human, to shed more light onto the evolving genome organization. For convenience and to avoid confusion we added for each species a three letter abbreviation prior to the chromosomal band location discussed in this paper: BTA, Cattle chromosome; HSA, Human chromosome; MMV, M. m. vaginalis chromosome; MRE, M. reevesi chromosome.     

Three-dimensional electron microscopy of ribosomal chromatin in two higher plants: a cytochemical, immunocytochemical, and in situ hybridization approach

We report the 3-D arrangement of DNA within the nucleolar subcomponents from two evolutionary distant higher plants, Zea mays and Sinapis alba. These species are particularly convenient to study the spatial organization of plant intranucleolar DNA, since their nucleoli have been previously reconstructed in 3-D from serial ultra-thin sections. We used the osmium ammine-B complex (a specific DNA stain) on thick sections of Lowicryl-embedded root fragments. Immunocytochemical techniques using anti-DNA antibodies and rDNA/rDNA in situ hybridization were also applied on ultra-thin sections. We showed on tilted images that the OA-B stains DNA throughout the whole thickness of the section. In addition, very low quantities of cytoplasmic DNA were stained by this complex, which is now the best DNA stain used in electron microscopy. Within the nucleoli the DNA was localized in the fibrillar centers, where large clumps of dense chromatin were also visible. In the two plant species intranucleolar chromatin forms a complex network with strands partially linked to chromosomal nucleolar-organizing regions identified by in situ hybridization. This study describes for the first time the spatial arrangement of the intranucleolar chromatin in nucleoli of higher plants using high-resolution techniques.     

Two-dimensional electrophoresis of cerebrospinal fluid proteins in normal and pathological conditions

The two-dimensional polyacrylamide gel electrophoresis technique has been adapted for the analysis of human cerebrospinal fluid proteins. Proteins were detected by Coomassie brilliant blue stain and/or by silver stain. Highly reproducible protein patterns were obtained. We analyzed ten normal CSF specimens, thirty pathological CSF specimens and the corresponding sera. We mapped the protein patterns observed by examination of serum/CSF differences and by immunofixation. Preliminary observations on the changes in protein patterns in CSF specimens from patients with neurological disorders are reported.     

Allomaternal care: helper-assisted birth in the Rodrigues fruit bat, Pteropus rodricensis (Chiroptera: Pteropodidae)

We report observations of allomaternal care, or epimeletic (care-giving) behaviour, exhibited by one female toward another, before, during, and after giving birth, in the Rodrigues fruit bat, Pteropus rodricensis (Chiroptera: Pteropodidae). Interactions between the expectant mother and other roost mates, from the onset to completion of birth, were observed continuously over a period of approximately three hours. The attending female assisted the mother when she: (I) intermittently groomed her anovaginal region; (2) grasped her with partially outstretched wings; (3) 'tutored' her in a feet-down birthing posture; (4) groomed the emerging pup; and (5) physically assisted the mother by manoeuvring the pup into a suckling position. This is the first report of extensive assistance given by a female bat to another during parturition. We suggest that epimeletic behaviour may be common in the highly social Chiroptera, especially among primiparous or inexperienced females and/or when an expectant mother experiences difficulty during labour and parturition. Our observations support the hypothesis that roosting associations in bats may be as important as relatedness in explaining the occurrence of apparently altruistic acts.     

New ways to look at the architecture of plant cell walls : localization of polygalacturonate blocks in plant tissues

We report the use of Ni²⁺ and Co²⁺ on free-hand sections of soybean (Glycine max L.) and Bidens sp to localize polygalacturonates. In soybean only the hourglass cells of the seedcoat stain intensely. In the pod the epidermis of the outer pod wall and a few layers of subepidermal cells stain lightly, while that part of the funiculus adjacent to the seedcoat palisade epidermal cells stains heavily and the neck of the funiculus close to the pod also stains. In Bidens stem sections, the walls of the collenchyma stain most intensely.     

舟山群岛春秋季黄麂的栖息地特征及其利用的初步研究

栖息地选择是野生动物与其环境之间的基本关系,野生动物的栖息地特征研究对野生动物的保护和利用具有重要意义(骆颖等,2009).动物的食物资源具有季节性变化(蒋志刚,2004),在舟山群岛,春季有蹄类动物的可利用资源相对较为缺乏而到秋季相对丰富,有蹄类动物的栖息地特征由于不同季节间的环境可利用资源不同而产生差异(Sehmitz,1991).研究不同季节动物的柄息地特征及利用机制,可以深入了解动物是如何适应环境的(蒋志刚,2004).     

Co-existence of immunoreactivity to anti-dopamine,anti-serotonin and anti-vasotocin in the cerebral giant neuron of the pond snail Lymnaea stagnalis

Summary Consecutive sections of certain neurons in the central ganglia of the pond snail Lymnaea stagnalis appear to be immunoreactive to anti-dopamine and anti-serotonin. The Cerebral Giant Neurons stain in addition with antivasotocin. The observations indicate the presence of two biogenic amines within the same neuron and in addition their co-existence with a biologically active peptide.     

Visualization of early embryos of the butterfly Bicyclus anynana

We report on the first attempts, using both light and fluorescence microscopy, to visualize the developing embryo of the butterfly Bicyclus anynana. We developed a new protocol that enabled the clear visualization of the internal egg structures in early embryogenesis (1-24 h after egg laying). Dechorionation was followed by fixation and physical dissection of the external egg structures. Observations of embryonic and extra-embryonic cells were made using a Hoechst nuclear stain that fluoresces in the blue spectrum when bound to DNA and excited with ultraviolet (UV) light under a fluorescence microscope. Preliminary data on the developmental rate of the early embryo are also presented.     

Multivariate statistical analysis of ribosome electron micrographs. L and R lateral views of the 40 S subunit from HeLa cells

The morphology of the small (40 S) subunit of the eukaryotic ribosome from HeLa cells has been examined by single-particle averaging and multivariate image analysis applied to electron micrographs of negatively stained specimens. The use of multivariate image analysis allows different, independent components of the structural variation within the particles to be identified and separately studied. The largest component of variance for both lateral views (termed L and R) was the variation in the peripheral stain intensity. The second largest component of interparticle variation is due to changes in the particle appearance most likely associated with a change of orientation on the specimen film.Averages formed from particles falling within a small range of peripheral stain intensity allowed the changes in the projected structure to be studied as a function of local stain level. Visual observations of stain variation could be confirmed quantitatively.Significant differences were found between averages of particles in the L view and those in the R view. Multivariate image analysis of a mixed population of L and mirrored R particles showed that the differences consistently affect all particles. However, the R view increasingly resembles the L view as the overall level of stain is increased, in agreement with a model of partial stain immersion.     

5-Azacytidine- and Hoechst-induced aneuploidy in Indian muntjac

Hoechst 33258 (bis-benzimidazole) and 5-azacytidine (5-AC) cause decondensation of the pericentric heterochromatin in mouse and aberrations in the sequence of centromere separation apparently by different mechanisms. We treated the male Indian muntjac cells (2n=7), which do not undergo decondensation of the pericentric heterochromatin, to study if these chemicals would result in induction of aneuploidy limited to the Y(2) chromosome. This paper reports that both agents result in aneuploidy primarily limited to one chromosome, the Y(2). It is likely that other chromosomes are not tolerated in aneuploid condition because every chromosome carries some household genes including those essential for mitotic progression. The loss/gain of the Y(2) chromosome is tolerated because it is the smallest chromosome and is almost entirely composed of constitutive heterochromatin. Since Indian muntjac has only three pairs of large chromosomes comprising its basic genome, which can be clearly viewed under high dry objective, these cells are very suitable for the preliminary analysis of aneuploidy-inducing ability of various chemicals.     

Cholesterol-free phospholipid domains may be the membrane feature selected by N epsilon-dansyl-L-lysine and merocyanine 540

We have used N epsilon-dansyl-L-lysine as a fluorescent membrane probe, to study cells taken from tissues concerned with immune function. There is a striking similarity between the staining selectivity of this compound and that reported by others for merocyanine 540. Both compounds stain leukemic, human, peripheral leukocytes, an erythroleukemia line, and some mouse bone marrow cells, suggesting common selectivity for a membrane feature of hemopoietic cells. Both compounds fail to stain red blood cells, normal human leukocytes, mouse spleen and thymus cells. We have recently reported that dansyl-lysine apparently selects for cholesterol-free phospholipid domains in liposomes and now report similar selectivity for merocyanine 540 staining of liposomes.