Molecular basis of albinism in the rhesus monkey

Sequence analysis of the tyrosinase (TYR) coding region from one albino rhesus monkey (Macaca mulatta) family revealed that the two monkeys with phenotype similar to human TYR-negative oculocutaneous albinism (OCA) were homozygous for a missense mutation (S184TER) in exon 1 at codon 184. The offspring of one of the albino monkey (''Kangkang'') are all heterozygous for the S184TER mutation, but the S184TER mutation was not observed in 93 control individuals. We conclude that the point mutation is responsible and sufficient to generate the albino rhesus monkey phenotype. The rough age of the S184TER nonsense mutation may be about 0.8 million years using a rate of 0.16% per million years. (C) 2000 Elsevier Science B.V. All rights reserved.

Digestion of selected foods by Yunnan snub-nosed monkey Rhinopithecus bieti (Colobinae)

Three digestion trials were conducted to quantify aspects of digestive physiology in the Yunnan snub-nosed monkey Rhinopithecus bieti, a foregut fermenter that feeds primarily on lichens. Mean retention time (MRT, the average time plastic markers spent in

Adaptive evolution of a duplicated pancreatic ribonuclease gene in a leaf-eating monkey

Although the complete genome sequences of over 50 representative species have revealed the many duplicated genes in all three domains of life(1-4), the roles of gene duplication in organismal adaptation and biodiversity are poorly understood. In addition,

Pseudogenization of the tumor-growth promoter angiogenin in a leaf-eating monkey

Physiological functions of human genes may be studied by gene-knockout experiments in model organisms such as the mouse. This strategy relies on the existence of one-to-one gene orthology between the human and mouse. When lineage-specific gene duplication occurs and paralogous genes share a certain degree of functional redundancy, knockout mice may not provide accurate functional information on human genes. Angiogenin is a small protein that stimulates blood-vessel growth and promotes tumor development. Humans and related primates only have one angiogenin gene, while mice have three paralogous genes. This makes it difficult to generate angiogenin-knockout mice and even more difficult to interpret the genotype-phenotype relation from such animals should they be generated. We here show that in the douc langur (Pygathrix nemaeus), an Asian leaf-eating colobine monkey, the single-copy angiogenin gene has a one-nucleotide deletion in the sixth codon of the mature peptide, generating a premature stop codon. This nucleotide deletion is found in five unrelated individuals sequenced, and therefore is likely to have been fixed in the species. Five colobine species that are closely related to the douc langur have intact angiogenin genes, suggesting that the pseudogenization event was recent and unique to the douc langur lineage. This natural knockout experiment suggests that primate angiogenin is dispensable even in the wild. Further physiological studies of douc largurs may offer additional information on the role of this cancer-related gene in normal physiology of primates, including humans. Our findings also provide a strong case for the importance of evolutionary analysis in biomedical studies of gene functions. (C) 2003 Elsevier Science B.V. All rights reserved.

Single UV excitation of Hoechst 33342 and propidium iodide for viability assessment of rhesus monkey spermatozoa using flow cytometry

Many fluorescent probes excited by visible light have been used to assess sperm quality by flow cytometry. Developing a viability evaluation method using UV excited stains would be useful for multiparameter analysis of sperm function. This investigation was conducted to determine the efficacy of Hoechst 33342 (H342) and propidium iodide (PI) dual staining for evaluating rhesus monkey sperm viability through use of flow cytometry and excited by a single UV laser. The results showed that the live cells stained only with H342 strongly correlated with expected sperm viability, and flow cytometric analyses were highly correlated with fluorescence microscopic observation. Using H342/PI/SYBR-14 triple staining method, it was found that the live/dead sperm distributions were completely concordant in both H342/PI and SYBR-14/PI assays. In addition, this dual staining was extended with fluorescein isothiocyanate-conjugated peanut agglutinin (FITC-PNA) to simultaneously analyze viability and acrosome integrity of sperm cryopreserved using two different extenders, TTE and TEST, and indicated that TTE offered better Preservation of plasma and acrosome integrity than TEST Therefore, the H342/PI dual staining provides an accurate technique for evaluating viability of rhesus monkey sperm and should be valuable for multiparameter flow cytometric analysis of sperm function.

Transplantable neural progenitor populations derived from Rhesus monkey embryonic stem cells

Cell-based therapies using embryonic stem cells (ESCs) in the treatment of neural disease will require the generation of homogenous donor neural progenitor (NP) populations. Here we describe an efficient culture system containing hepatocyte growth factor (HGF) and G5 supplement for the production of highly enriched (88.3% +/- 8.1%)populations of NPs from rhesus monkey ESCs. Additional purification resulted in NP preparations that were 98% nestin positive. Moreover, NPs, as monolayers or neurospheres, could be maintained for prolonged periods of time in media containing HGF+G5 or G5 alone. In vitro differentiation and in vivo transplantation assays showed that NPs could differentiate into neurons, astrocytes, and oligodendrocytes. The kinds and quantities of differentiated cells derived from NPs were closely correlated with their niches in vivo. Glial differentiation was predominant in periventricular areas, whereas cells migrating into the cortex were mostly neurons. Cell counts showed that 2 months after transplantation, approximately 25% of transplanted NPs survived and 65% - 80% of the surviving transplanted cells migrated along the ventricular wall or in a radial fashion. Subcloning demonstrated that several clonal lines derived from NPs expressed nestin and differentiated into three neural lineages in vitro and in rat brains in vivo. In contrast, some subcloned lines showed restricted differentiation both in vitro and in vivo in rat brains. These observations set the stage for obtaining highly enriched NPs and evaluating the efficacy of NP-based transplantation therapy in the nonhuman primate and will provide a platform for probing the molecular mechanisms that control neural induction.

Homologous feeder cells support undifferentiated growth and pluripotency in monkey embryonic stem cells

In the present study, five homologous feeder cell lines were developed for the culture and maintenance of rhesus monkey embryonic stem cells (rESCs). Monkey ear skin fibroblasts (MESFs), monkey oviductal fibroblasts (MOFs), monkey follicular granulosa fibroblast-like (MFG) cells, monkey follicular granulosa epithelium-like (MFGE) cells, and clonally derived fibroblasts from MESF (CMESFs) were established and compared with the ability of mouse embryonic fibroblasts (MEFs) to support rESC growth. MESF, MOF, MFG, and CMESF cells, but not MFGE cells, were as good as or better than MEFs in supporting undifferentiated growth while maintaining the differentiation potential of the rESCs. In an effort to understand the unique properties of supportive feeder cells, expression levels for a number of candidate genes were examined. MOF, MESF, and MEF cells highly expressed leukemia inhibitory factor, ciliary neurotrophic factor, basic fibroblast growth factor, stem cell factor, transforming growth factor PI, bone morphogenetic protein 4, and WNT3A, whereas WNT2, WNT4, and WNT5A were downregulated, compared with MFGE cells. Additionally, all monkey feeder cell lines expressed Dkk1 and LRP6, antagonists of the WNT signaling pathway, but not WNT1, WNT8B, or Dkk2. rESCs grown on homologous feeders maintained normal karyotypes, displayed the characteristics of ESCs, including morphology, alkaline phosphatase, Oct4, the cell surface markers stage-specific embryonic antigen (SSEA)-3, SSEA-4, tumor-related antigen (TRA)-1-60, and TRA-1-81, and formed cystic embryoid bodies in vitro that included differentiated cells representing the three major germ layers. These results indicate that the four homologous feeder cell lines can be used to support the undifferentiated growth and maintenance of pluripotency in rESCs.

A comparative approach to somatic cell nuclear transfer in the rhesus monkey

BACKGROUND: Despite the potential utility of primate somatic cell nuclear transfer (SCNT) to biomedical research and to the production of autologous embryonic stem (ES) cells for cell- or tissue-based therapy, a reliable method for SCNT is not yet availab

Epigenetic marks in cloned rhesus monkey embryos: Comparison with counterparts produced in vitro

Until now, no primate animals have been successfully cloned to birth with somatic cell nuclear transfer (SCNT) procedures, and little is known about the molecular events that occurred in the reconstructed embryos during preimplantation development. In man

Impairments in embryonic genome activation in rhesus monkey somatic cell nuclear transfer embryos

Somatic cell nuclear transfer (SCNT) is a remarkable process in which a somatic cell nucleus is acted upon by the ooplasm via mechanisms that today remain unknown. Here we show the developmental competence (% blastocyst) of embryos derived from SCNT (21%)

Neural progenitors derived from monkey embryonic stem cells in a simple monoculture system

A simple monoculture system. combined with a chemically defined medium containing hepatocyte growth factor (HGF) and G5 supplement, was used to induce rhesus monkey embryonic stem cells (rESC) directly into neuroepithelial (NE) cells. Under these conditio